tag:theconversation.com,2011:/uk/topics/malaria-control-38058/articlesMalaria control – The Conversation2022-11-04T06:57:52Ztag:theconversation.com,2011:article/1933992022-11-04T06:57:52Z2022-11-04T06:57:52ZMalaria in Africa: why most countries haven’t beaten it yet<figure><img src="https://images.theconversation.com/files/492516/original/file-20221031-21-j9vutx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">80% of malaria deaths are in children younger than five. </span> <span class="attribution"><span class="source">Olympia de Maismont/AFP via Getty Images</span></span></figcaption></figure><p>Malaria remains one of the most devastating parasitic diseases affecting humans. In 2020 there were around 241 million cases and 672,000 malaria-related deaths. This is a sharp <a href="https://www.who.int/publications/i/item/9789240040496">increase</a> from 2019. </p>
<p>One reason it’s so persistent is that the malaria parasite has a very <a href="https://www.cdc.gov/malaria/about/biology/index.html#:%7E:text=The%20malaria%20parasite%20life%20cycle,which%20rupture%20and%20release%20merozoites%20">complex life cycle</a>. It involves many different developmental stages and multiple hosts (mosquitoes and humans). </p>
<p>And in Africa, what adds to the challenge of controlling malaria is that the continent is home to some of the most <a href="https://apps.who.int/iris/bitstream/handle/10665/310862/9789241550499-eng.pdf">efficient malaria vectors</a>. These include <em>Anopheles gambiae</em> and <em>An. funestus</em>. Also, the malaria parasite species <em>Plasmodium falciparum</em>, the <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">dominant species</a> in Africa, is the most lethal. It’s responsible for most malaria cases and deaths – 80% of which occur in children younger than five. </p>
<p>The World Health Organization (WHO) acknowledged these factors when it excluded Africa from its first Global Malaria Eradication Campaign, which ran <a href="https://www.cdc.gov/malaria/about/history/">from 1955 until 1969</a>.</p>
<p>Since then, there have been many advances in malaria control. These include long-lasting insecticide treated nets, malaria rapid diagnostic tests and artemisinin-based combination therapies (ACTs) for malaria treatment. </p>
<p>But malaria elimination is still a challenge. Only <a href="https://www.who.int/teams/global-malaria-programme/elimination/countries-and-territories-certified-malaria-free-by-who">two African countries</a>, Algeria and Morocco, have been certified malaria-free by the WHO. </p>
<p>There are many reasons for the elimination targets remaining out of reach. In this article we highlight four: poverty, human movement, resistance and climate change.</p>
<h2>Poverty</h2>
<p>The limited progress towards malaria elimination is not surprising considering that some of the most malaria-burdened countries in Africa are also some of <a href="https://www.malariaconsortium.org/userfiles/file/Past%20events/factsheet2%20-%20malaria%20and%20poverty.pdf">the poorest countries</a> in the world.</p>
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<a href="https://theconversation.com/ending-malaria-in-africa-needs-to-focus-on-poverty-quick-fixes-wont-cut-it-169205">Ending malaria in Africa needs to focus on poverty: quick fixes won't cut it</a>
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<p>Malaria is both a cause and a consequence of poverty. The disease will therefore remain a significant problem in Africa, if more is not done to improve the socio-economic status of malaria-affected communities. Eliminating poverty to improve the health and well-being of all are part of both the <a href="https://www.un.org/millenniumgoals/">millennium</a> and <a href="https://sdgs.un.org/goals">sustainable</a> development goals. This should be a priority for governments of malaria-endemic countries.</p>
<h2>Mobility</h2>
<p>Africa has one of the fastest growing populations, with a <a href="https://www.migrationpolicy.org/article/africa-intracontinental-free-movement#:%7E:text=The%20African%20continent%20has%20the,region%20is%20growing%20even%20faster">high level of mobility</a>. Marginalised and vulnerable populations are some of most mobile groups within Africa. They travel vast distances across countries with varying malaria transmission intensities. </p>
<p>Human mobility is strongly associated with the global <a href="https://www.gavi.org/vaccineswork/5-reasons-why-pandemics-like-covid-19-are-becoming-more-likely">spread of infectious diseases</a>, as demonstrated by the recent COVID-19, Ebola and monkeypox outbreaks. This presents a challenge to Africa’s malaria elimination aspirations. </p>
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Read more:
<a href="https://theconversation.com/how-africas-porous-borders-make-it-difficult-to-contain-ebola-118719">How Africa's porous borders make it difficult to contain Ebola</a>
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<p>Malaria parasites and mosquitoes do not respect country borders, so malaria services must expand to mobile and marginalised populations. Universal access to effective malaria diagnostics and treatment will reduce the malaria burden by decreasing onward transmission.</p>
<h2>Resistance</h2>
<p>One of the biggest threats to eliminating and eradicating malaria is the <a href="https://www.who.int/news-room/fact-sheets/detail/malaria#:%7E:text=Progress%20in%20global%20malaria%20control,to%20insecticides%20among%20Anopheles%20mosquitoes">emergence and spread</a> of insecticide, diagnostic and drug resistance. </p>
<p>Both the malaria vectors and parasites have proved to be very adaptable. They have rapidly developed mechanisms to survive and multiply in the presence of insecticides and antimalarial drugs, respectively. </p>
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<a href="https://theconversation.com/some-malaria-parasites-are-evading-detection-tests-causing-an-urgent-threat-to-public-health-177258">Some malaria parasites are evading detection tests, causing an urgent threat to public health</a>
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<p>Insecticide resistance is widespread across the <a href="https://www.bdi.ox.ac.uk/news/tracking-the-spread-of-mosquito-insecticide-resistance-across-africa">African region</a>. It reduces the efficacy of strategies based on suppressing vectors, such as long-lasting insecticide treated nets and indoor residual spraying. </p>
<p>To extend the effective lifespan of the available insecticides, the WHO has provided <a href="http://apps.who.int/iris/bitstream/handle/10665/44768/9789241502801_eng.pdf;jsessionid=233E06F6978781E9163F1479ED99F9F7?sequence=1">new guidance</a> in its handbook for integrated vector management. The handbook highlights the importance of routine entomological surveillance to determine the type of vectors present, changes in vector behaviour and the insecticide susceptibility status of the vector. All this information can guide effective vector suppression if available in good time. </p>
<p>Having the correct diagnostic method and treatment in place also hinges on having a robust surveillance system. The system must be capable of generating efficacy data in near real-time to allow for prompt evidence-based decision-making. The need for this type of <a href="https://www.who.int/news/item/28-05-2021-statement-by-the-malaria-policy-advisory-group-on-the-urgent-need-to-address-the-high-prevalence-of-pfhrp2-3-gene-deletions-in-the-horn-of-africa-and-beyond">routine surveillance</a> has become even more urgent as African malaria parasites have developed mutations that allow them to evade detection by the most widely used rapid diagnostic tests on the continent. These undetected cases will go untreated, potentially sustaining onward transmission. The result will be major increases in malaria cases, severe disease, and potentially death.</p>
<p>Besides becoming invisible to rapid diagnostic tests, <em>P. falciparum</em> parasites in many central and west African countries have become <a href="https://www.npr.org/sections/goatsandsoda/2022/02/06/1077953012/drug-resistant-malaria-is-emerging-in-africa-doctors-are-worried-yet-hopeful">resistant</a> to artemisinins. This is a component of the most widely used antimalarials in Africa, ACTs. The spread of artemisinin-resistant parasites will potentially raise case numbers and deaths, repeating the devastating trend observed when drug-resistant parasites previously emerged. The loss of ACTs would severely set back elimination efforts as there are no novel WHO-approved antimalarials currently available. Efforts are needed to prevent the spread of artemisinin-resistant parasites through strong surveillance and containment responses.</p>
<h2>Climate change</h2>
<p>The impact of climate change is complex, but there are <a href="https://www.un.org/en/chronicle/article/climate-change-and-malaria-complex-relationship#:%7E:text=An%20increase%20in%20temperature%2C%20rainfall,it%20was%20not%20reported%20earlier">suggestions</a> that more places will become malaria risk areas. Mosquitoes will now be able to survive and transmit malaria in these warmer areas. This, in turn, will increase malaria cases, severe illness and deaths in the non-immune communities.</p>
<h2>Positive developments</h2>
<p>In spite of these challenges, there is some light at the end of tunnel. </p>
<p>After years of research there are two new malaria vaccines. The first, <a href="https://www.gsk.com/en-gb/media/press-releases/who-grants-prequalification-to-gsk-s-mosquirix-the-first-and-only-approved-malaria-vaccine/">Mosquirix</a>, has been prequalified for use by the WHO. The second, <a href="https://www.medicalnewstoday.com/articles/malaria-new-vaccine-candidate-shows-promise-in-clinical-trials">R21/Matrix M</a>, has shown promising results in phase 2 clinical trials. </p>
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Read more:
<a href="https://theconversation.com/vaccines-could-be-a-game-changer-in-the-fight-against-malaria-in-africa-193233">Vaccines could be a game-changer in the fight against malaria in Africa</a>
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<p>There are new long-lasting insecticide treated nets and insecticide formulations for vector control. There are also novel strategies for parasite suppression. </p>
<p>Adding these tools to the elimination toolbox will assist Africa get closer to malaria elimination.</p><img src="https://counter.theconversation.com/content/193399/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaishree Raman is affiliated with the National Institute for Communicable Diseases, the Wits Research Institute for Malaria and UP Institute for Sustainable Malaria Control. She received funding from the South African Research Trust, South African Medical Research Council, Bill and Melinda Gates Foundation, the Global Fund, Clinton Health Access Initiative, National Research Foundation and the National Institute for Communicable Diseases</span></em></p><p class="fine-print"><em><span>Shüné Oliver s affiliated with the National Institute for Communicable Diseases and the Wits Research Institute for Malaria and receives funding from the National Research Foundation, the National Health Laboratory Services Research Trust and the Female Academic Leadership fund. </span></em></p>There are many reasons that malaria is so persistent in Africa. Four of them are poverty, human movement, resistance and climate change.Jaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesShüné Oliver, Medical scientist, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1888372022-08-18T14:11:42Z2022-08-18T14:11:42ZMosquito species from Asia poses growing risk to Africa’s anti-malaria efforts<figure><img src="https://images.theconversation.com/files/479721/original/file-20220817-13-x71gvq.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Anopheles stephensi is usually found in South-East Asia. </span> <span class="attribution"><span class="source">Jim Gathany </span></span></figcaption></figure><iframe id="noa-web-audio-player" style="border: none" src="https://embed-player.newsoveraudio.com/v4?key=x84olp&id=https://theconversation.com/mosquito-species-from-asia-poses-growing-risk-to-africas-anti-malaria-efforts-188837&bgColor=F5F5F5&color=D8352A&playColor=D8352A" width="100%" height="110px"></iframe>
<p>The spread of the mosquito species <em>Anopheles stephensi</em> across Africa poses a significant problem to a continent already heavily burdened by malaria. Most – <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">90%</a> – of the world’s malaria deaths are on the continent. </p>
<p>Researchers from Djibouti reported the presence of <em>An. stephensi</em> in the Horn of Africa in 2012. Until then it had not been found in Africa although it was known to be widespread in Southeast Asia and parts of the Arabian Peninsula. By <a href="https://ccp.jhu.edu/2022/06/13/malaria-africa-anopheles/">2017</a> it had spread through the Horn of Africa, reaching Ethiopia, Somalia and Sudan. </p>
<p>The spread of <em>An. stephensi</em> is particularly concerning because the mosquito has a number of characteristics that make it <a href="https://www.pnas.org/doi/10.1073/pnas.2006781117?cookieSet=1">difficult to control</a>. This species can thrive in urban areas and likes being near humans. They lay their eggs in any available water source – such as water containers, abandoned tyres and flowerpots – and their eggs can survive being dry for a long period of time. In addition, <em>An. stephensi</em> feeds on its vertebrate host both indoors and outdoors. This reduces the impact of commonly used vector control methods such as insecticide-treated nets and indoor residual spraying.</p>
<p>The invasion of this urban mosquito into Africa threatens the malaria elimination aspirations of the continent, particularly as <a href="https://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS?locations=ZG">42.5%</a> of Africa’s population now live in urban areas. </p>
<p>As a result, national malaria control programmes have increased surveillance efforts in urban areas to enable early detection and control. Countries have also run awareness campaigns to encourage communities to reduce potential breeding sites. </p>
<p>The species has not yet been detected in southern Africa. Nevertheless the South African national malaria control programme, with the support of the National Institute for Communicable Diseases, is increasing surveillance activities in areas where this species may occur. </p>
<h2>Invasive species</h2>
<p>Many <a href="https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.1890/070151">epidemics and pandemics</a> have been driven by pathogens, hosts and vectors invading new areas. These include the Black Death in 14th century Europe, caused by the invasion of rats carrying fleas infected with the plague. </p>
<p>The Asian tiger mosquito (<em>Aedes albopictus</em>) and the yellow fever mosquito (<em>Aedes aegypti</em>) both carry dangerous diseases such as dengue, yellow fever and Zika. The spread of these mosquito species into North America and Europe during the 1970s and 1980s was associated with large increases in these diseases.</p>
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<a href="https://theconversation.com/invasive-mosquito-species-could-bring-more-malaria-to-africas-urban-areas-147530">Invasive mosquito species could bring more malaria to Africa's urban areas</a>
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<p>While <em>Aedes</em> mosquitoes transmit viral diseases, <em>Anopheles</em> mosquitoes transmit malaria. Of the 500 <em>Anopheles</em> species, only 30-40 can spread malaria. Common species that transmit malaria in Africa are <em>Anopheles gambiae</em>, <em>An. arabiensis</em> and <em>An. funestus</em>.</p>
<p><em>Anopheles gambiae</em> is one of the most effective malaria vectors in the world. It invaded South America in the <a href="https://www.nature.com/articles/143890e0">1930s</a>. This species rapidly established itself in Brazil, causing a malaria epidemic with an estimated fatality rate of 13%. <em>Anopheles gambiae</em> was eventually eliminated from Brazil in the 1940s after a highly co-ordinated and resource-intensive effort.</p>
<p><em>Anopheles stephensi</em> is a malaria vector native to South Asia. It transmits both <em>Plasmodium falciparum</em> and <em>P. vivax.</em> It rapidly adapts to changes in the environment and is found in both rural and urban areas. This is different from African malaria vectors, which are typically found in rural areas. </p>
<p>Controlling this invasive mosquito is very challenging. It is difficult to find, particularly in urban areas, and is resistant to a number of insecticides. Although there are no specific programmes to eliminate this species from Africa, the affected countries are <a href="https://www.who.int/publications/i/item/WHO-HTM-GMP-2019.09/">implementing</a> a range of control measures.</p>
<h2>Urgent action</h2>
<p>The presence of <em>An. stephensi</em> in Africa is a call to action to all interested in controlling and eliminating malaria. </p>
<p>It is imperative that entomological surveillance (the search for and biological investigation of insects, including malaria vectors) is strengthened across the continent. New information about the species must be shared promptly to ensure malaria control programmes use the correct methods to prevent it from spreading further into the continent.</p>
<p>And an integrated approach to vector control is urgently required. Vector control measures, adapted to local conditions, are key to preventing the spread of <em>An. stephensi</em>. National malaria control programmes cannot rely solely on insecticides to control this mosquito. They must invest in novel vector control methods that target outdoor-biting mosquitoes.</p>
<p>Governments must also invest in educating communities on the appropriate methods for storing water as well as eliminating potential breeding sources. South America has implemented strong policies to reduce breeding areas for <em>Aedes</em> mosquitoes. Similar approaches in Africa would reduce the presence of <em>An. stephensi</em>, as well as of <em>Aedes</em> mosquitoes, which carry many dreaded diseases including dengue, yellow fever, chikungunya and Zika.</p>
<p>Crucially, a healthy population without circulating parasites is key to a malaria-free future. Integrating clinical care, vector control and community awareness of the disease is the best way to ensure a malaria-free future for the continent.</p><img src="https://counter.theconversation.com/content/188837/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Shüné Oliver receives funding from the National Research Foundation and the Female Academic Leadership Fellowship. </span></em></p><p class="fine-print"><em><span>Jaishree Raman receives funding from the Gates Foundation, the Global Fund, South African Medical Research, Research Trust, National Research Foundation and National Institute for Communicable Diseases</span></em></p>The spread of this urban malaria vector species threatens the gains made against malaria and the achievement of malaria elimination.Shüné Oliver, Medical scientist, National Institute for Communicable DiseasesJaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1836542022-05-25T13:23:53Z2022-05-25T13:23:53ZArtificial light may become a new weapon in the fight to control malaria<figure><img src="https://images.theconversation.com/files/465048/original/file-20220524-26-kpfwwo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Artificial light may trick malaria-transmitting mosquitoes into changing their feeding habits, protecting people against bites.</span> <span class="attribution"><span class="source">Professor Lizette Koekemoer/University of the Witwatersrand</span></span></figcaption></figure><p>The world has not yet won the war against malaria. While the total number of cases has declined from about 81.1 cases per 1,000 population to 59 per 1,000 since 2000, there were still an estimated <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">240 million cases and 600,000 deaths</a> in 2020 globally. </p>
<p>Malaria remains a menace across Africa. The continent carries by far the world’s <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">largest disease burden</a>: 94% of cases and 96% of deaths occur across the continent. Alarmingly, children aged five or younger account for <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">80% of these deaths</a>.</p>
<p>There is no room for complacency. While <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">vaccines look promising</a>, there is still a steady rise of antimalarial drug resistance, especially in East Africa. The <a href="https://theconversation.com/some-malaria-parasites-are-evading-detection-tests-causing-an-urgent-threat-to-public-health-177258">parasites are evolving</a> mutations which allow them to escape routine diagnosis. The mosquitoes are also evolving increased <a href="https://theconversation.com/fresh-signs-of-mosquito-insecticide-resistance-in-south-africa-181618">resistance to insecticides</a>.</p>
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Read more:
<a href="https://theconversation.com/malaria-elimination-in-southern-africa-possibly-but-these-gaps-need-attention-171031">Malaria elimination in southern Africa? Possibly, but these gaps need attention</a>
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<p>This situation underscores the need for sharpening the multiple vector control options, and exploring new strategies. </p>
<p><a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.768090/full">My research</a> explores one such potential strategy: the use of artificial lights to trick malaria-transmitting mosquito species that feed nocturnally into behaving as if it’s daytime. This may deter feeding, helping to keep people safe from malaria-carrying mosquito bites. </p>
<h2>New light</h2>
<p>Light is a fundamental cue in nature. It regulates much of the timing of biological events, like when birds breed, lions hunt – and humans’ sleep patterns. It is also an ancient cue. While species have been exposed to changes in climate cycles over the eons, the timing of day and night has remained relatively constant over evolutionary time, owing to the rotation of the earth. This means that all life on the planet has evolved with such regular day-night cycles. The gene for the <a href="https://www.nccih.nih.gov/health/melatonin-what-you-need-to-know">melatonin hormone</a>, which regulates sleep-awake cycles, is shared between widely different and old taxonomic groups, such as plants and animals.</p>
<p>However, these natural dark cycles are <a href="https://theconversation.com/skyglow-forces-dung-beetles-in-the-city-to-abandon-the-milky-way-as-their-compass-165110">rapidly changing</a> because people are increasingly using artificial light. <a href="https://www.darksky.org/80-of-world-population-lives-under-skyglow-new-study-finds/">Nearly 80%</a> of the world’s people now live under artificially lit skies. </p>
<p>So, what impact might such artificial light use have on malaria? </p>
<h2>Altering mosquito biology</h2>
<p>The <em>Anopheles</em> group of mosquitoes, which is responsible for all of Africa’s malaria cases, is a nocturnal feeder. After mating, the females will seek out a blood meal. In doing so, they transfer the <em>Plasmodium</em> parasite which causes malaria. This is why bed nets are <a href="https://www.thelancet.com/journals/langlo/article/PIIS2214-109X(21)00216-3/fulltext">so effective</a> when used correctly – they block bites when people are sleeping at night.</p>
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Read more:
<a href="https://theconversation.com/curious-kids-what-would-happen-if-all-the-mosquitoes-in-the-world-disappeared-175528">Curious Kids: What would happen if all the mosquitoes in the world disappeared?</a>
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<p><a href="https://parasitesandvectors.biomedcentral.com/articles/10.1186/s13071-017-2196-3">Emerging research</a>, including <a href="https://www.frontiersin.org/articles/10.3389/fevo.2021.768090/full">my own</a>, <a href="https://www.researchgate.net/publication/348313670_Artificial_light_and_biting_flies_the_parallel_development_of_attractive_light_traps_and_unattractive_domestic_lights">argues</a> how artificial light at night can change mosquitoes’ behaviour.</p>
<p>This is because the artificial light used in homes can alter mosquito biology. For example, a short pulse of Light Emitting Diode (LED) light, commonly used lights in homes as “downlights” or reading lamps, can delay the onset of biting by hours in <em>Anopheles</em>, and so reduce biting rates and malaria transfer. The light essentially tricks the mosquitoes into not feeding.</p>
<p>These ideas are promising. But strategies to control vectors don’t always work at a bigger scale, especially if those strategies are not properly applied. For instance, bed nets treated with mosquito repellents are sometimes <a href="https://theconversation.com/mosquito-nets-are-often-used-for-fishing-a-smart-response-is-needed-66283">used as fishing nets</a> in parts of Africa. Demonstrating the effects of artificial light in controlled laboratory settings is one thing, but rolling out their use as an effective vector control strategy is quite another.</p>
<p>Even if governments could easily get LED lights into many homes to guard against malaria-carrying mosquitoes, there might be unintended consequences for human health. A burgeoning <a href="https://www.ama-assn.org/sites/ama-assn.org/files/corp/media-browser/public/about-ama/councils/Council%20Reports/council-on-science-public-health/a16-csaph2.pdf">body of research</a> is examining the effects of artificial light on human health. Early indications are that it can have negative impacts like disrupted sleep.</p>
<h2>A growing body of research</h2>
<p>Overall, it is not yet clear how artificial lights might be used to lessen the risk of malaria infections. But the growing body of work on this issue suggests that it’s a concept which needs more attention from the World Health Organization and other groups.</p>
<p>Once the impacts of artificial light use are more fully understood, developmental planners across Africa might be able to ensure that lights of the correct kinds, used in optimal places and times, become part of the continent’s efforts to control malaria.</p><img src="https://counter.theconversation.com/content/183654/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bernard Coetzee is funded by the Jennifer Ward Oppenheimer Research Grant. It is a US$150 000 grant awarded annually to address pressing environmental issues in Africa. </span></em></p>Artificial lights could trick malaria-transmitting mosquito species that feed nocturnally into behaving as if it’s daytime.Bernard Coetzee, Senior lecturer, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1815392022-04-24T09:05:17Z2022-04-24T09:05:17ZMalaria elimination: South Africa needs to regroup and refocus to get there<figure><img src="https://images.theconversation.com/files/459099/original/file-20220421-22-xfpzmu.jpg?ixlib=rb-1.1.0&rect=72%2C114%2C3736%2C2516&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">South Africa has mobile malaria border surveillance units working with communities and in highly mobile migrant populations.</span> <span class="attribution"><span class="source">Photo: Jaishree Raman</span></span></figcaption></figure><p>In recent years South Africa has made significant progress in its effort to eliminate malaria. The World Health Organization (WHO) <a href="https://www.who.int/teams/global-malaria-programme/elimination/e-2020-initiative-of-malaria-eliminating-countries">lists it</a> as one of the countries that has the potential to eliminate the disease in the near future.</p>
<p>In 2021, the WHO also <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">hailed South Africa</a> for bucking a grim trend. It was one of the few malaria-endemic countries in Africa that did not see a <a href="https://www.who.int/news/item/06-12-2021-more-malaria-cases-and-deaths-in-2020-linked-to-covid-19-disruptions">major upsurge</a> in malaria cases caused by COVID-related disruptions.</p>
<p>But it’s not all good news. For the second time in a decade, South Africa is set to miss its <a href="https://www.nicd.ac.za/wp-content/uploads/2019/10/MALARIA-ELIMINATION-STRATEGIC-PLAN-FOR-SOUTH-AFRICA-2019-2023-MALARIA-ELIMINATION-STRATEGIC-PLAN-2019-2023.pdf">malaria elimination target</a>. The country had committed to <a href="https://www.sanews.gov.za/south-africa/sa-recommits-zero-malaria-2018">ending malaria by 2018</a>, but this did not happen. In 2019, the government set a goal to end malaria <a href="https://www.nicd.ac.za/wp-content/uploads/2019/10/MALARIA-ELIMINATION-STRATEGIC-PLAN-FOR-SOUTH-AFRICA-2019-2023-MALARIA-ELIMINATION-STRATEGIC-PLAN-2019-2023.pdf">by 2023</a>. Despite implementing a number of new interventions which have reduced the country’s malaria burden, South Africa failed to halt the transmission of malaria within its borders.</p>
<p>The country’s malaria case numbers have also <a href="https://www.iol.co.za/capeargus/news/warning-with-malaria-cases-on-the-rise-due-to-increased-border-movement-b7c951d9-9513-43bf-a39b-025c5d830fe6">started rising</a> since travel restrictions were lifted in early 2022. This comes after much lower malaria cases during 2020 and 2021 – a result of reduced cross-border movements because of COVID regulations, as well as proactive, innovative actions by some South African provinces’ malaria control programmes. </p>
<p>It is crucial that South Africa’s malaria control programme regroups and refocuses. This will enable the country to get its malaria elimination efforts back on track.</p>
<h2>A complicated situation</h2>
<p>There are numerous and complex reasons for South Africa missing its elimination target. COVID is one of them and it played a pivotal role in setting the country’s malaria control efforts back.</p>
<p>Before the pandemic South Africa was on track to declare certain malaria-endemic districts free of malaria. That’s one of the major goals of the current elimination strategy. Then resources were diverted to deal with COVID; travel and movement restrictions were put in place and staff absences rose.</p>
<p>The situation was further complicated by people with a fever or flu-like symptoms delaying visits to healthcare facilities. People feared getting infected with COVID or worried that they had COVID and might pass it on to others.</p>
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<img alt="" src="https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/459267/original/file-20220422-24-ppofs2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="attribution"><a class="source" href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">Ozayr Patel / WHO</a></span>
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<p>The delivery of essential elimination interventions, particularly those associated with vector control and surveillance, has also been severely compromised over the past two years. </p>
<p>The test and treat activities of <a href="https://malariaelimination8.org/sites/default/files/publications/raman_et_al_eliminating_malaria_from_the_margins_of_transmission_in_southern_africa_through_the_elimination_8_initiative_trssa_2021.pdf">mobile malaria border surveillance units</a> were especially hamstrung. These units have played a major role in reducing malaria in border communities and in highly mobile migrant populations. It is critical for these units to become fully operational again as soon as possible.</p>
<p>So, what can South Africa do to repair the damage wrought to malaria control efforts by COVID?</p>
<h2>Room for improvement</h2>
<p>Some work is already under way. The national malaria control programme is expanding access to essential services during this current malaria season. This initiative will run until South Africa is declared malaria-free. Certified malaria environmental health practitioners will conduct community testing using rapid diagnostic tests. They will also be able to treat any individuals with uncomplicated malaria with artemisinin-based combination therapies (ACTs). </p>
<p>This is a good plan. But for it to work, it is essential that effective rapid diagnostic tests and ACTs are available. <a href="https://theconversation.com/some-malaria-parasites-are-evading-detection-tests-causing-an-urgent-threat-to-public-health-177258">Reports</a> of African parasites being able to evade detection by these tests or to <a href="https://www.healio.com/news/infectious-disease/20210923/resistant-malaria-has-gained-a-foothold-in-africa">survive ACT treatment</a> are becoming more frequent. </p>
<p>South Africa was one of the first African countries to establish a programme to routinely assess drug and diagnostic efficacy. Unfortunately the programme is under-utilised by the provincial malaria control programmes. Samples from the South African province most affected by malaria, Limpopo, are rarely assessed by this programme. </p>
<p>If South Africa is serious about its elimination goals and wants to prevent a drug-resistant and insecticide-resistant malaria outbreak as experienced during the <a href="http://www.kznhealth.gov.za/malaria/update12.2003.pdf">1999/2000</a> malaria season, the effectiveness of rapid tests, ACTs and insecticides used for vector control must be regularly assessed.</p>
<p>The country has a long history of using insecticide-based indoor residual spraying to successfully control malaria. But in recent years it has struggled to adequately protect communities using this intervention. This is because of delays in procuring or delivery insecticides and spray pumps. People are also increasingly refusing to have their homes exposed to indoor residual spraying as they feel malaria is no longer a problem in South Africa.</p>
<h2>More to do</h2>
<p>Processes and procedures must be urgently put in place to improve procurement and delivery. Community awareness campaigns illustrating the benefits of indoor residual spraying are also crucial. These must be developed and delivered, as a matter of urgency, to improve uptake of this critical intervention. Failing to address these issues will see vector populations rebound – and most likely result in an uptick of malaria cases.</p>
<p>Improved real-time case reporting is an imperative too. This allows health authorities to respond promptly to every confirmed case to prevent any possibility of onward transmission. Connectivity challenges in many of the endemic regions and over-burdened staff with many competing diseases and reports are just two of reasons for the reporting lag. This issue must be addressed by improving connectivity within rural malaria endemic areas and having dedicated staff for the reporting of malaria and other notifiable conditions.</p>
<p>South Africa is edging closer to eliminating malaria. But the country needs to do more. Work as usual is no longer enough – malaria elimination requires an extra effort from all stakeholders. There must be sustainable funding to support the effective implementation of elimination interventions, with all cadres of the malaria work force willing to go above and beyond if South Africa is to achieve malaria elimination.</p><img src="https://counter.theconversation.com/content/181539/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaishree Raman receives funding from the Bill and Melinda Gates Foundation, the Clinton Health Access Initiative, the NHLS Research Trust, the National Institute for Communicable Diseases and the South African Medical Research Council. She is affiliated with the National Institute for Communicable Diseases, the UP Institute for Sustainable Malaria Control and the WITS Research Institute for Malaria Research. </span></em></p>South Africa is one of the few malaria-endemic countries in Africa that did not see a major upsurge in malaria cases caused by COVID-related disruptions.Jaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1733552021-12-08T15:27:14Z2021-12-08T15:27:14ZHalf the world’s people could be at greater risk of malaria if control efforts do not improve<figure><img src="https://images.theconversation.com/files/436309/original/file-20211208-188518-1xg19l8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Indoor residual spraying is one of the main components of malaria control. </span> <span class="attribution"><span class="source">Cristina Aldehuela/AFP via Getty Images</span></span></figcaption></figure><p>The COVID-19 pandemic continues to have a devastating impact on international malaria control and elimination efforts. According to the latest <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2021">World Malaria Report</a>, there were an estimated <a href="https://www.who.int/news/item/06-12-2021-more-malaria-cases-and-deaths-in-2020-linked-to-covid-19-disruptions">14 million</a> more cases of malaria in 2020 compared to 2019. </p>
<p>Even more concerning was the marked increase in malaria-related deaths. These were mainly in children under the age of five living in sub-Saharan Africa. This is a sombre finding. Malaria is a preventable disease. Effective point-of-care diagnostic tools (rapid diagnostic tests) and treatments (artemisinin-based combination therapies) are widely available.</p>
<p>Progress towards achieving a malaria-free world had begun stalling – and in some regions reversing – from 2015. But the COVID-19 pandemic, continual Ebola outbreaks and ongoing humanitarian crises have posed additional challenges for national malaria control programmes. These factors have increased the chances that the 2030 targets set by the World Health Organization (WHO) won’t be met. The <a href="https://www.who.int/docs/default-source/documents/global-technical-strategy-for-malaria-2016-2030.pdf?sfvrsn=c82afcc_0">Global Malaria Strategy</a> goals are to reduce malaria cases and deaths by 90%, and eliminate the disease in 35 countries by 2030. </p>
<p>The WHO warns that without immediate decisive action, all the impressive gains made against malaria since 2000 will be eroded. This will allow malaria to rebound and expose at least <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">half of the world’s population</a> to an increased risk of malaria. </p>
<h2>Responding to the COVID-19 threat</h2>
<p>National malaria control programmes across Africa have been commended for acting against the threat that COVID-19 posed to the delivery of essential malaria services. Disruptions did occur. But prompt innovative actions ensured they <a href="https://www.who.int/news/item/23-04-2020-who-urges-countries-to-move-quickly-to-save-lives-from-malaria-in-sub-saharan-africa">were not at the scale many experts predicted</a> at the start of the pandemic. </p>
<p>Encouragingly, in 2020 many malaria endemic countries achieved their targets for delivering insecticide treated nets and spraying indoors. The number of children receiving seasonal chemoprevention in Africa exceeded the initial target. </p>
<p>However, more needs to be done to get malaria control efforts back on track. There must be improved access to essential malaria services. This is especially important for populations most at risk. Of particular concern are people in sub-Saharan Africa. In this region, six countries – Nigeria, Uganda, Democratic Republic of the Congo, Angola, Mozambique and Burkina Faso – accounted for over 50% of all malaria cases and deaths reported in 2020. </p>
<h2>Threats to effective malaria control</h2>
<p>Both the malaria parasite and the mosquito vector are continually developing mechanisms to evade control interventions. </p>
<p>Malaria parasites resistant to the artemisinin component of the WHO- recommended <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">artemisinin-based combination therapies</a> have now been confirmed in <a href="https://www.healio.com/news/infectious-disease/20210923/resistant-malaria-has-gained-a-foothold-in-africa">Uganda and Rwanda</a>. This raises concerns over whether the therapies will continue to work. </p>
<p>There are currently no effective alternatives to these drugs. The WHO recommends that national malaria control programmes routinely assess whether drugs are still effective and whether parasites are mutating. Countries are also advised to develop feasible, fully costed containment and response plans to use as soon as they detect resistant parasites. </p>
<p>The widespread use of rapid diagnostic tests and artemisinin-based combination therapies enables prompt diagnosis and effective treatment. These actions have made a positive difference to treatment outcomes. </p>
<p>But the current World Malaria Report sounds the alarm over the spread of malaria parasites with genetic changes that make them invisible to the rapid diagnostic tests most widely used in sub-Saharan Africa. </p>
<p>Malaria in pregnancy remains another challenge in Africa. In 2020, about 11.6 million pregnancies were exposed to malaria. As a result, 819,000 infants had low birthweights – which is strongly associated with death in childhood. The WHO recommends making greater efforts to reach pregnant women with interventions. These include insecticide treated nets and <a href="https://www.who.int/elena/titles/iptp-pregnancy/en/">intermittent preventive treatment</a> – where pregnant women are treated for malaria whether they have the disease or not. If 90% of women at risk had been treated, it would have prevented at least 200,000 low-weight births in 2020. </p>
<h2>Improved surveillance and innovation</h2>
<p>Insecticide treated nets and indoor residual spraying are essential to control and eventually eliminate malaria. The WHO applauded all countries that achieved optimal coverage in these efforts, despite the challenges faced in 2020. </p>
<p>Resistance is a threat here too, however. Over 88% of the countries that contributed to the 2020 World Malaria Report reported mosquito resistance to at least one class of insecticide. Nineteen countries reported resistance to all four classes of approved insecticides.</p>
<p>But it’s not all doom and gloom. </p>
<p>Earlier this year the WHO approved the roll-out of the <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">first malaria vaccine</a>, RTS,S, in highly burdened African countries. This vaccine has the potential to significantly improve outcomes in young African children. This group suffers disproportionately from malaria. </p>
<p>There are also new insecticides which could help sustain the efficacy of nets and spraying. And there is increased funding to integrate genomic surveillance into routine malaria surveillance systems. </p>
<p>These and other novel interventions, together with strong political commitment and sustained funding, have the potential to get malaria control efforts back on track and make malaria elimination a reality in our lifetime.</p><img src="https://counter.theconversation.com/content/173355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaishree Raman is affiliated with the Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research at the National Institute for Communicable Diseases, the Wits Research Institute for Malaria and University of Pretoria Institute for Sustainable Malaria Control. She receives funding from the Research Trust, the National Research Foundation, the South African Medical Research Council and the Gates Foundation.</span></em></p>Like the coronavirus causing the current pandemic, both the malaria parasite and mosquito vector are developing ways to avoid control.Jaishree Raman, Principal Medical Scientist and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1686042021-11-15T14:10:58Z2021-11-15T14:10:58ZSome Nigerian plants show potential to treat malaria<figure><img src="https://images.theconversation.com/files/423358/original/file-20210927-21-1w3gaaz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Malaria is endemic in Nigeria.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/children-run-with-advertising-banners-for-the-fight-against-news-photo/161362816?adppopup=true">Alexander Joe/AFP via Getty Images</a></span></figcaption></figure><p>Six countries in Africa accounted for about <a href="https://www.who.int/news-room/fact-sheets/detail/malaria">half</a> of all malaria deaths worldwide in 2019: Nigeria (23%), the Democratic Republic of the Congo (11%), Tanzania (5%), Burkina Faso (4%), Mozambique (4%) and Niger (4%).</p>
<p>The World Health Organization (WHO) has set an <a href="https://www.who.int/publications/i/item/9789240031357">ambitious target</a> of reducing the global malaria burden <a href="https://www.who.int/docs/default-source/documents/global-technical-strategy-for-malaria-2016-2030.pdf?sfvrsn=c82afcc_0">by 90% by 2030</a>. This is important work, given that malaria remains one of the world’s <a href="https://www.weforum.org/agenda/2020/04/covid-19-infectious-diseases-tuberculosis-measles-malaria/">deadliest infectious diseases</a>. The WHO <a href="https://www.who.int/data/gho/data/themes/malaria#:%7E:text=Globally%2C%20an%20estimated%203.4%20billion,getting%20malaria%20in%20a%20year">estimates</a> that 3.4 billion people in 92 countries are at high risk of being infected with malaria and 1.1 billion are at high risk of getting malaria in a year. </p>
<p>There has been some progress towards the 2030 goal, with both cases of and deaths from malaria <a href="https://www.who.int/news-room/feature-stories/detail/world-malaria-report-2019">dropping</a> from about 400,000 in 2010 to about 260,000 in 2018. But efforts are being hampered by the parasites <a href="https://www.nature.com/articles/d41586-021-02592-6?utm_source=Nature+Briefing&utm_campaign=821a738445-briefing-dy-20210924&utm_medium=email&utm_term=0_c9dfd39373-821a738445-45517738">resisting antimalarial drugs</a> that people take and by mosquitoes <a href="https://idpjournal.biomedcentral.com/articles/10.1186/s40249-019-0572-2">resisting insecticides</a>. While the WHO has <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">recommended</a> a vaccine for malaria, it is not yet accessible to all. </p>
<p>Researchers, myself among them, are also exploring alternative strategies to manage and treat malaria. I am studying whether plant-based remedies drawn from traditional medicinal practices may be of use. <a href="https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/210301">Herbs</a> are already used to treat diseases in many cultures. In <a href="http://www.bioline.org.br/pdf?tc07026">Nigeria</a>, as in other African countries and most parts of Asia, medicinal herbs are widely used to treat and prevent various ailments – including malaria.</p>
<p>Some current antimalarial drugs developed in laboratories, including amodiaquine and artemisinin, were either isolated from plants or were developed from chemical compounds found in plants. So it’s logical to investigate more plants and other natural products as potential sources of novel antimalarial agents. </p>
<p>Our <a href="https://pubmed.ncbi.nlm.nih.gov/33961995/">new study</a> examined whether extracts from a variety of plants were able to counter the effects of a malaria-causing parasite in mice – in other words, whether the plants treated malaria symptoms. We made a drink from three plants and gave it to mice infected with the <em>Plasmodium berghei</em> parasite.</p>
<p>We found a mixture of the herbs suppressed and prevented the presence of parasites inside the mice. This was more effective than each herb on its own. </p>
<h2>What we did</h2>
<p>A large number of medicinal plants are <a href="https://guardian.ng/sunday-magazine/living-wellbeing/herbal-cocktail-for-drug-resistant-malaria/">used</a> for treating malaria in Nigeria. This is common in the southern region of the country, where <a href="https://scied.ucar.edu/learning-zone/climate-change-impacts/vector-borne-disease">rainforests and a humid tropical climate</a> create ideal conditions for malaria transmission all year round. </p>
<p>One of the many groups of herbal remedies used in Nigeria is the antimalarial decoction popularly called <em>Agbo iba</em>. The composition, method of preparation and dosage of these antimalarial decoctions vary from vendor to vendor, as earlier <a href="http://gja.unilag.edu.ng/index.php/ujmst/article/view/367">reported</a> by my research group. These decoctions are often polyherbal (containing more than one herb) and prepared in water or alcohol. </p>
<p>For our experiment, we used <em>Mangifera indica</em>, (mango), <em>Azadirachta indica</em> (known in Nigeria as dongoyaro), <em>Nauclea latifolia</em> (African peach) and <em>Morinda lucida</em> (brimstone tree). They are all used traditionally in malaria treatment. </p>
<p>We bought the plants fresh from Mushin herbal market in Lagos and they were identified and authenticated at the herbarium of the Department of Botany, University of Lagos.</p>
<p>Mice are commonly used in preclinical trials because of biological similarities with humans. They can mimic malaria disease in humans and indicate how people might respond to the herbal mixture. </p>
<p>The study was conducted with approval from the Health Research Ethics Committee of the College of Medicine, University of Lagos. We inoculated the mice with chloroquine-sensitive <em>Plasmodium berghei</em>, obtained from the <a href="https://nimr.gov.ng/">Nigerian Institute of Medical Research</a>. </p>
<p>The animals were grouped and dosed to examine for three possible responses: preventing, suppressing and curing effects of the polyherbal mixture. Both prevention and suppression involve destroying the malaria parasite. Cure means the herbal mixtures eliminate the parasites.</p>
<h2>Our findings</h2>
<p>The mixture preparations gave promising antimalarial results in the three investigations. </p>
<p>In the prophylactic (prevention) test, the herbal decoctions demonstrated significant chemosuppression. Chemosuppression is the use of chemicals to defeat parasites in an animal. </p>
<p>All the herbal decoctions showed chemosuppressive activities. They significantly reduced the parasite load 24 hours after administration to the end of the treatment – four to seven days.</p>
<p>All the herbal decoctions were also active in the curative test. They considerably reduced the parasite load from day 2 of treatment. </p>
<p>At the end of treatment, none of the decoctions had completely cleared the parasites, but they all produced substantial clearance. This shows their potential usefulness against established plasmodial infection. </p>
<p>Our findings showed that the combination of all the plants could be useful in suppressing malaria in its early stages. All the decoctions investigated in this study could be considered as active antimalarial candidates. They could help with eradication of malaria parasites.</p>
<h2>Going forward</h2>
<p>Further studies will be needed to evaluate whether the polyherbal mixture we tested on mice is safe and effective in humans.</p>
<p>But this is a good starting point. The study shows that, with the right safety and clinical controls, the use of standardised herbal medicines could be a valid complementary approach for malaria management.</p>
<p>It’s good to find new medicines for malaria treatment because the parasites and microbes get used to the existing ones and become resistant. Medicinal plants are potential sources of new medicines.</p><img src="https://counter.theconversation.com/content/168604/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephanie Alaribe works for/consults to/owns shares in University of Lagos, Nigeria. She is affiliated with so many scientific bodies. </span></em></p>A combination of herbs in Nigeria should be evaluated further as it offers potential to treat malaria, which is endemic in the country.Stephanie Alaribe, Lecturer, University of LagosLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1710312021-11-06T08:08:43Z2021-11-06T08:08:43ZMalaria elimination in southern Africa? Possibly, but these gaps need attention<figure><img src="https://images.theconversation.com/files/430472/original/file-20211105-17-1r1whoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Blood feeding female malaria vector Anopheles arabiensis.</span> <span class="attribution"><span class="source">University of Pretoria Institute for Sustainable Malaria Control </span></span></figcaption></figure><p>Malaria is a risk to <a href="https://www.health.gov.za/wp-content/uploads/2020/11/media-statement-2020-sadc-malaria-day-commemoration.pdf">three quarters</a> of the population in the Southern African Development Community, a 16-member organisation that draws in countries across southern and eastern Africa.</p>
<p>Some countries in the region have set a target to eliminate the disease from as early as 2023 to 2030.</p>
<p>Though this won’t be simple, it can be done. It’s a race between changes in mosquitoes, the malaria parasite, and changes in what people can do when they work together.</p>
<p>This complex disease is still responsible for almost half a million deaths annually worldwide, including more than <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">260,000 African children</a> under five. The World Health Organization (WHO) <a href="https://www.health.gov.za/wp-content/uploads/2020/11/media-statement-2020-sadc-malaria-day-commemoration.pdf">estimates</a> that 35 million children under five and about 8.5 million pregnant women in the region are at risk. </p>
<p>The Southern African Development Community (SADC) renewed its malaria control efforts in 2009 by establishing the <a href="https://malariaelimination8.org/sites/default/files/publications/raman_et_al_eliminating_malaria_from_the_margins_of_transmission_in_southern_africa_through_the_elimination_8_initiative_trssa_2021.pdf">Elimination 8</a> initiative. This is a coalition of eight countries working together to curb the spread of the disease. Four of them – eSwatini, Botswana, Namibia and South Africa – are reporting very <a href="https://malariaelimination8.org/sites/default/files/publications/e8_annual_report_2020.pdf">low transmission</a>. The other four – Angola, Mozambique, Zambia and Zimbabwe – are <a href="https://malariaelimination8.org/sites/default/files/publications/e8_annual_report_2020.pdf">high-burden</a> countries.</p>
<p>Current control strategies mostly target the mosquito vector, which transmits the malaria-causing parasites to humans when feeding. Vector controls include indoor residual spraying and insecticide-treated bed nets. Resistance to insecticides and changes in mosquito biting behaviour are slowing down gains made in malaria control over the past decade. </p>
<p>In the Southern African Development Community region, malaria transmission dynamics remain highly interconnected. This is because countries share related populations, economies, ecologies and epidemiologies. </p>
<p>This interconnectedness is leading to the identification of new gaps and challenges. But it is also allowing innovative alternative and complementary strategies to be developed through research across disciplines – and through collaboration. </p>
<p>Our experience over the <a href="https://www.up.ac.za/media/shared/236/ZP_Resources/up-ismc_2019_case-study_sd-report.zp203457.pdf">past 10 years</a> includes collaborations across the sciences and social sciences. Our work addresses anything from vector and parasite control to capacity building and education. It’s testament that an <a href="https://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-11-431">integrated approach</a> is needed to reach elimination. </p>
<h2>Latest breakthrough</h2>
<p>The most recent advance in the fight against malaria is the first ever vaccine (RTS,S/AS01). The WHO announced in <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">October 2021</a> that it had approved the vaccine for use in children living in moderate to high malaria transmission areas. </p>
<p>The vaccine brings <a href="https://theconversation.com/breakthrough-malaria-vaccine-offers-to-reinvigorate-the-fight-against-the-disease-169500">hope</a> to affected communities. It is a step toward malaria elimination.</p>
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Read more:
<a href="https://theconversation.com/malaria-vaccine-is-a-major-leap-forward-but-innovation-mustnt-stop-here-169639">Malaria vaccine is a major leap forward: but innovation mustn't stop here</a>
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<p>But it’s not a cure. And it has <a href="https://theconversation.com/malaria-vaccine-is-a-major-leap-forward-but-innovation-mustnt-stop-here-169639">limitations</a>: </p>
<ul>
<li><p>it is only effective in very young children (five to 17 months) </p></li>
<li><p>at least four doses (including a booster 18 months after the initial dose) are needed for optimal effect </p></li>
<li><p>it prevents severe disease but not necessarily infection </p></li>
<li><p>it is only effective against <a href="https://www.tandfonline.com/doi/pdf/10.1080/21645515.2019.1669415?needAccess=true"><em>Plasmodium falciparum</em></a> – one of five human malaria parasites.</p></li>
</ul>
<p>In spite of these limitations, the vaccine can contribute to making gains in malaria control again. The danger is that the vaccine announcement may lead to countries taking their eyes off the ball. This can’t happen. </p>
<p>Even with a vaccine in hand, there are some big gaps that need to be filled for the region, and the globe, to reach malaria elimination. </p>
<h2>Some of the gaps</h2>
<p>One such a gap is in human resources. In particular, leadership and management skills in national malaria control programmes. <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-018-2199-3#:%7E:text=Actions%20to%20expand%20training%20for,programs%20at%20the%20national%20level">Adequate training</a> is needed to address these capacity challenges. The Southern African Development Community region has not benefited from routine training offered to national malaria control programmes in west and east Africa. </p>
<p>To address this, the Gates Foundation is providing financial backing for a course to be developed and delivered by a <a href="https://www.up.ac.za/up-institute-for-sustainable-malaria-control/news/post_3029960-up-institute-for-sustainable-malaria-control-secures-a-gates-foundation-grant-to-build-capacity-in-africa">transdisciplinary team</a>. The course aims to provide people with the skills they need as leaders, managers, implementation scientists and facilitators that can develop and apply effective evidence-based elimination strategies. This is an exciting new collaboration that will involve the University of Pretoria’s <a href="https://www.gibs.co.za/Pages/default.aspx">Gordon Institute of Business Science (GIBS)</a> and the <a href="https://www.up.ac.za/albert-luthuli-leadership-institute">Albert Luthuli Leadership Institute</a>.</p>
<p>The course will also aim to get women into more senior positions on national malaria control programmes.</p>
<p>A second worrying gap relates to fighting growing resistance to antimalarial drugs. Malaria treatment is dependent on drugs that either prevent disease onset or treat infected patients and prevent death. But there’s evidence of increasing <a href="https://www.nature.com/articles/s41467-020-20629-8">parasite resistance</a> to antimalarial drugs. </p>
<p>Continuous discovery and development of innovative antimalarial drugs that target all forms of the parasite are needed. We are doing ground-breaking work in this area. For example, a consortium approach has made a <a href="https://www.up.ac.za/up-institute-for-sustainable-malaria-control/news/post_2945911-up-researchers-team-discovers-new-compounds-with-the-potential-to-eliminate-malaria">breakthrough discovery</a> and has led to exciting developments in the areas of <a href="https://www.nature.com/articles/s41467-020-20629-8">parasite transmission blocking</a>, where two potent chemical compounds showed activity against all parasite forms in a laboratory setting. Both compounds show potential as drug candidates for malaria treatment and transmission blocking. </p>
<p>Future antimalarial drugs like this will ultimately mean that the region can move from malaria control to elimination.</p>
<p>In addition, more sustainable vector control methods need to be developed to overcome insecticide resistance. </p>
<p>Our work across disciplines has shown how collaboration can produce tools and strategies to address this. For example, ongoing research have looked at innovative product development, including <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-015-1005-8">polyethylene wall linings</a>, and <a href="https://theconversation.com/scientists-design-a-novel-formula-that-repels-and-kills-mosquitoes-95323">new repellent formulations</a>. </p>
<p>There are also still gaps on the ground in how control strategies are rolled out. Many don’t have enough community buy-in. This is key to success. Communities must be aware of malaria research taking place to understand its purpose and benefits. And people need knowledge about the disease so they have the power to take responsibility for their own health. </p>
<p>A major – and important – gap is funding. The <a href="https://www.unhcr.org/4afac5629.pdf">malaria budget must increase</a> substantially to incorporate the human resources, technology and other resources needed to effectively reduce transmission and to reach elimination.</p><img src="https://counter.theconversation.com/content/171031/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The countries share related populations, economies, ecologies and epidemiologies. This interconnectedness highlights challenges and opportunities for more effective malaria control across the region.Taneshka Kruger, UP ISMC: Project Manager and Coordinator, University of PretoriaTiaan de Jager, Dean: Faculty of Health Sciences and Director: UP Institute for Sustainable Malaria Control, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1710272021-11-04T15:53:15Z2021-11-04T15:53:15ZThe seven steps South Africa is taking to get it closer to eliminating malaria<figure><img src="https://images.theconversation.com/files/430218/original/file-20211104-11504-ubo1nb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">South Africa offers free malaria testing and treatment to anyone entering the country along shared borders.</span> <span class="attribution"><span class="source">Jaishree Raman</span></span></figcaption></figure><p>There were <a href="https://www.isglobal.org/en_GB/-/la-crisis-de-covid-19-podria-duplicar-los-casos-de-malaria-en-el-africa-subsahariana">dire warnings</a> that malaria cases would surge across Africa after the World Health Organisation (WHO) <a href="https://www.who.int/director-general/speeches/detail/who-director-general-s-opening-remarks-at-the-media-briefing-on-covid-19---11-march-2020">declared</a> the COVID-19 outbreak as a global pandemic in early March 2020.</p>
<p>Many felt that the already overburdened healthcare systems would not be able to cope with increased patient loads. There was also concern that the pandemic would disrupt the delivery of essential malaria services. </p>
<p>Fortunately, these predictions have not fully materialised. Most malaria control programmes on the continent took action to keep delivering essential malaria services. </p>
<p>The South African malaria control programme, for one, found ways to keep its efforts at stopping transmission on track despite the threat from COVID-19. For example, it set up systems to <a href="http://www.samj.org.za/index.php/samj/article/view/13111">screen and test for COVID-19 and malaria</a> in malaria-risk areas. It also modified the training for indoor residual spraying to comply with COVID-19 regulations.</p>
<p>South Africa is aiming to eliminate malaria by 2023. The disease only occurs in certain areas of the South Africa. It is currently limited to the low altitude border regions of three provinces – KwaZulu-Natal, Mpumalanga and Limpopo. KwaZulu-Natal is the province closest to eliminating malaria by 2023. And it’s closely followed by Mpumalanga. Unfortunately, Limpopo will most likely miss the 2023 elimination target. It is the province most affected by malaria. </p>
<p>In June 2021 China became the 40th country to be declared <a href="https://www.who.int/teams/global-malaria-programme/elimination/countries-and-territories-certified-malaria-free-by-who">malaria-free</a> by the WHO. Other countries to achieve this recently are El Salvador in 2021 and Algeria and Argentina in 2019. </p>
<p>South Africa has adopted a number of innovations to achieve its elimination goal. Seven stand out. These are: prompt diagnosis; reporting every confirmed case to healthcare authorities; effective treatment; effective vector control measures; monitoring resistance to antimalarials and insecticide; and increased community-based malaria testing and treating. </p>
<p>Most important has been the <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-021-03875-z">uninterrupted domestic funding</a> of the malaria elimination programme. </p>
<h2>One step at a time</h2>
<p>Malaria prevalence is low in South Africa. This is why diagnosis is key. Every malaria infection must be confirmed either by the microscopic examination of a blood smear or by a malaria rapid diagnostic test before treatment can be prescribed.</p>
<p>Treating a patient based only symptoms such as fever, fatigue and headache is not encouraged. Many other disease share these symptoms – including COVID-19. </p>
<p>All malaria-related healthcare professionals are allowed to use a malaria rapid diagnostic test to test for malaria within communities.</p>
<p>Notification after diagnosis is also important. Malaria is classified as a Category 1 medical condition in South Africa. This means that healthcare professionals must report every confirmed malaria case within 24 hours using the National Medical Conditions reporting system. </p>
<p>The prompt reporting of every case allows the malaria control programmes to investigate the case and respond in a timely manner to prevent further transmission or a malaria outbreak.</p>
<p>The next crucial step is treatment. South Africa was one of the first African malaria-endemic countries to use an artemisinin-based combination therapy. This treatment is recommended by the WHO for uncomplicated malaria. The drug used in South Africa (artemether-lumefantrine) is very effective. It has played a significant role in decreasing the country’s malaria burden. To ensure the drug remains effective, it is essential that all six doses of the drug are taken with some fatty food.</p>
<p>But medical interventions only go so far. Effective vector control is essential for malaria control and elimination. </p>
<p>Indoor residual spraying was developed in South Africa in the 1940s. This involves treating the inner walls of homesteads with an insecticide. It remains the primary method used to control the malaria mosquito in South Africa. But additional vector control tools are needed to achieve malaria elimination. </p>
<p>The national control programme is working with research partner organisations to test more tools. These include larviciding (treating mosquito breeding sites with chemicals or biological agents that kill mosquito larvae), and <a href="https://www.dst.gov.za/index.php/media-room/latest-news/2662-sterile-insect-technique-field-trials-to-eliminate-malaria-under-way">the sterile insect technique</a>. </p>
<p>Innovation is key to staying ahead of this disease given the threat of resistance. In 1999-2000 South Africa experienced a malaria outbreak. It was driven by the emergence of drug-resistant parasites and insecticide-resistant mosquito vectors. To prevent this from happening again, antimalarial drug and insecticide efficacy are routinely monitored by the national malaria control programme with support from partners. </p>
<p>Resistance to artemisinin-based combination therapy is emerging in some African countries. But artemether-lumefantrine remains effective in South Africa.</p>
<p>Lastly, the country has remained steadfast in funding its malaria control programme. The South African Malaria Control Programme is one of the few on the continent that is entirely funded by government. This stable source of funding has allowed the programme to carry out uninterrupted malaria control interventions.</p>
<h2>The final push</h2>
<p>These interventions have played a major role in getting South Africa close to eliminating malaria. But more work remains to be done. </p>
<p>The importation of malaria from neighbouring countries poses a significant threat to South Africa’s elimination aspirations. To address this problem South Africa, with support from a non-governmental organisation, <a href="https://www.humana.org/">Humana People to People</a>, has established malaria surveillance units. These are at strategic points along shared borders. The units offer free malaria testing and treatment services to anyone entering South Africa. </p>
<p>All individuals found to be have malaria are treated. They receive artemether-lumefantrine and a single low dose of transmission blocking drug, primaquine. These units have contributed to a significant decrease in malaria cases reported from the border areas.</p>
<p>Communities in malaria-endemic areas need to play an active role in eliminating malaria. They can remove potential breeding sites, ensure they get promptly tested for malaria when they have symptoms, and finish the entire course of antimalarials.</p><img src="https://counter.theconversation.com/content/171027/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jaishree Raman receives funding from the National Research Foundation of South Africa, the National Health Laboratory Services Research Trust and the Bill and Melinda Gates Foundation. She is affiliated with Centre for Emerging Zoonotic Diseases, National Institute for Communicable Diseases, the Wits Research for Malaria, University of Witwatersrand and the UP Institute for Sustainable Malaria Control, University of Pretoria.</span></em></p><p class="fine-print"><em><span>Shüné Oliver receives funding from the National Research Foundation of South Africa and the National Health Laboratory Services Services Research Trust. She is affiliated with Centre for Emerging Zoonotic Diseases, National Institute for Communicable Diseases and the Wits Research for Malaria, University of Witwatersrand</span></em></p>The South African Malaria Control Programme is one of the few on the continent that is entirely funded by government. The stable source of funding has allowed for steady malaria control interventions.Jaishree Raman, Principal Medical Scientis and Head of Laboratory for Antimalarial Resistance Monitoring and Malaria Operational Research, National Institute for Communicable DiseasesShüné Oliver, medical scientist , National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1695012021-10-08T18:22:32Z2021-10-08T18:22:32ZWHO approved a malaria vaccine for children – a global health expert explains why that is a big deal<figure><img src="https://images.theconversation.com/files/425496/original/file-20211008-21-zm7jbr.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C7719%2C5150&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A helping hand in the fight against malaria.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/in-this-photo-illustration-a-person-holds-two-vials-of-the-news-photo/1235759941?adppopup=true">Patrick Meinhardt/Getty Images</a></span></figcaption></figure><p><em>The World Health Organization <a href="https://www.who.int/news/item/06-10-2021-who-recommends-groundbreaking-malaria-vaccine-for-children-at-risk">recommended its first malaria vaccine for children</a> on Oct. 6, 2021 – a breakthrough hailed by the U.N. agency as a “historic moment.”</em></p>
<p><em>Approval of the RTS,S/AS01 vaccine, which goes by the name Mosquirix, provides a “glimmer of hope” for Africa, according to Dr. Matshidiso Moeti, WHO regional director for Africa. It will now be rolled out to protect children against one of the world’s oldest and most deadly diseases.</em></p>
<p><em><a href="https://www.medschool.umaryland.edu/profiles/Laufer-Miriam/">Malaria and global child health expert</a> Dr. Miriam K. Laufer answered The Conversation’s questions about the vaccine and the WHO announcement.</em></p>
<h2>What has the WHO announced?</h2>
<p>The WHO has recommended the use of the RTS,S malaria vaccine, which is produced by GlaxoSmithKline. It is the first malaria vaccine to be recommended by the global health body.</p>
<p>It follows a review of two years of <a href="https://www.who.int/news/item/20-04-2021-rts-s-malaria-vaccine-reaches-more-than-650-000-children-in-ghana-kenya-and-malawi-through-groundbreaking-pilot-programme">piloting studies</a> of the vaccine in three sub-Saharan African countries with a high burden of malaria: Malawi, Kenya and Ghana. </p>
<p>After careful evaluation and extensive discussion, the WHO came to the consensus that the vaccine should be recommended for use in children living in areas of moderate to high malaria burden.</p>
<h2>Why is this seen as a major development?</h2>
<p>Malaria <a href="https://www.unicef.org/press-releases/ten-things-you-didnt-know-about-malaria#:%7E:text=Among%20all%20communicable%20diseases%2C%20malaria,young%20lives%20lost%20each%20day">kills hundred of thousands of children</a>, mostly in sub-Saharan Africa, every year. This is the first time that researchers, vaccine manufacturers, policymakers and advocates have successfully delivered a vaccine that has made it through clinical trials and received not only regulatory approval but also a recommendation from the WHO.</p>
<p>This vaccine prevents about 30% of severe malaria cases that are more likely to lead to death.</p>
<p>Although researchers knew that RTS,S was effective in well-controlled clinical trials, a few questions remained about whether it was feasible for sub-Saharan African countries to safely roll out the four-dose vaccine in a real-world setting. But since 2019, the <a href="https://www.who.int/initiatives/malaria-vaccine-implementation-programme">malaria vaccine implementation program</a> in Malawi, Kenya and Ghana has shown excellent vaccine uptake and a good safety profile. To date, the vaccine has been administered to around 800,000 children in those three countries. </p>
<h2>How big a killer is malaria?</h2>
<p>Malaria, a parasitic disease transmitted by bites from infected mosquitoes, causes nearly <a href="https://www.who.int/teams/global-malaria-programme/reports/world-malaria-report-2020">half a million deaths per year</a>, mostly in children in sub-Saharan Africa.</p>
<p>It is a disease that preys on the poorest of the poor. It causes the most disease and death in places where people lack access to basic health care, where housing conditions allow mosquitoes to enter and where inadequate water management provides breeding ground for mosquitoes. Despite international efforts to control it, the burden of malaria has continued and even increased over the past several years.</p>
<h2>How effective will the vaccine be compared to other treatments?</h2>
<p>We learned through the report of the trials to the WHO that the vaccine will be able to reach all children in areas of moderate to high risk of malaria. This will save lives from the deadly infection, especially among children with limited access to health services.</p>
<p>Prevention is almost always more cost-effective than treating disease, especially with an infection as common as malaria. Drugs are sometimes used to prevent malaria, but they have to be given frequently, which is both expensive and inconvenient.</p>
<p>In addition, the more often a drug is used, the more likely the malaria parasites will <a href="https://www.cdc.gov/malaria/malaria_worldwide/reduction/drug_resistance.html">develop resistance</a> to the drug.</p>
<h2>Why did it take so long to develop a vaccine?</h2>
<p>Lack of political will to develop a malaria vaccine certainly played a role in why it took so long. With no real market for a malaria vaccine in resource-rich countries like the U.S., pharmaceutical companies did not have a strong financial incentive to accelerate vaccine development.</p>
<p>But the malaria parasite is also very complex, and the targets of the immune system are diverse, so developing an effective vaccine wasn’t easy.</p>
<p>A vaccine developed against one malaria strain grown in the laboratory generally does not work against many of the malaria parasites that children encounter when bitten by infected mosquitoes, which is why even though RTS,S is a good vaccine, it protects against only 30% of infections.</p>
<p>If you think about this in terms of the COVID-19 vaccine, researchers developed a vaccine against the strain of the disease that was circulating in early 2020. But now we see that the vaccine does not protect people quite <a href="https://www.cdc.gov/mmwr/volumes/70/wr/mm7034e4.htm?s_cid=mm7034e4_w">as well against the new delta variant</a>. Someday a variant may emerge that completely escapes the vaccine immune response.</p>
<p>For malaria, there are many variants of many different proteins, so finding a vaccine that covers all of these was a huge challenge.</p>
<p>[<em>Like what you’ve read? Want more?</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=likethis">Sign up for The Conversation’s daily newsletter</a>.]</p><img src="https://counter.theconversation.com/content/169501/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Dr Miriam K. Laufer is affiliated with the WHO Malaria Vaccine Advisory Committee. This group was not involved in the recent RTS,S recommendation.</span></em></p>Malaria is one of the world’s oldest and deadliest diseases. So why has it taken so long to get a vaccine?Miriam K. Laufer, Professor of Pediatrics, Medicine, Epidemiology and Public Health at the Center for Vaccine Development and Global Health, University of MarylandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1594602021-04-23T13:14:01Z2021-04-23T13:14:01ZWhat Nigeria must do to eliminate malaria: three researchers offer insights<figure><img src="https://images.theconversation.com/files/396622/original/file-20210422-23-q4yulg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Reliable and affordable tests are crucial in eliminating malaria </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/health-official-takes-blood-sample-of-a-woman-for-malaria-news-photo/522828816?adppopup=true">Pius Utomi Ekpei/AFP via Getty Images </a></span></figcaption></figure><p>Nigeria accounts for nearly a <a href="https://www.who.int/news-room/feature-stories/detail/world-malaria-report-2019">quarter</a> of deaths from malaria in the world – in 2018 the numbers stood at 95,000. Three of the country’s top malaria researchers reflect on why the numbers remain so high.</p>
<p>What does Nigeria need to do to eliminate malaria?</p>
<h2>Olukemi K. Amodu: research and innovate</h2>
<p>Malaria remains an important public health hazard globally. It is <a href="https://www.malariaconsortium.org/news-centre/pregnant-women-and-children-under-five-are-still-at-grave-risk-from-malaria-says-whoandrsquo-s-annual-report.htm#:%7E:text=According%20to%20the%20report%2C%20there,Africa%20were%20infected%20with%20malaria.">responsible</a> for high disease and death rates especially among children under five and pregnant women.</p>
<p>The malaria burden in Nigeria is high – <a href="https://www.who.int/news-room/feature-stories/detail/world-malaria-report-2019">25%</a> of cases globally. The causes include the climate, high transmission potential, socioeconomic development, an overstretched health care system and displaced populations.</p>
<p>Eliminating the disease will take sustained local funding and a strong political commitment at the federal and state levels. This requires a strong recognition of the risk to children and pregnant women.
The elimination plan must include focused research and strengthening health systems. It must also be population specific.</p>
<p>It must incorporate <a href="https://www.who.int/heli/risks/vectors/malariacontrol/en/">World Health Organisation-recommended</a> core interventions. One of these is vector control: protective measures such as insecticide treated materials, spraying to kill mosquito larvae and indoor spraying. The other is diagnostic testing and prompt treatment with effective medicines.</p>
<p>Nigeria needs sustained, interdisciplinary and multi-faceted research. This should be an interplay of basic sciences, clinical epidemiology, field epidemiology, social and behavioural studies. This will ultimately help in studying the differences and diversities in the population. Our federal government must invest more in this type of research.</p>
<p>Malaria prevalence data, clinical epidemiology, parasite diagnostics and rates are important tools for evaluating control efforts. Studies of population biology, genetics and density of the malaria parasite and vector will help find effective diagnostics, new indigenous drugs and new vector control methods. </p>
<p>There must be equal access to health management tools for malaria at all levels. This must embrace educating patent medicine sellers and incorporating knowledge of traditional or herbal medicine practices.</p>
<p>We need to develop new interventions for malaria control suitable for our population. </p>
<p>For example, people say insecticide treated nets are inconvenient, so we also need to develop new ways to use the available protective measures.</p>
<h2>Olusegun George Ademowo: beat the mosquitoes</h2>
<p>Efforts should be geared towards drastic reduction of contact between humans and mosquitoes. Surveillance is a very important component of malaria elimination.</p>
<p>Environmental management aims to control mosquitoes by removing their breeding sites and larvae. This can be done through clearing bushes around the house and other buildings. It’s important to dispose of broken pots and bottles, fix potholes on our roads and keep gutters clean.</p>
<p>We must also have reliable and affordable diagnostic means for detection of malaria parasites. The most user friendly is the rapid diagnostic test. It detects specific malaria antigens in a person’s blood if they are infected. The most sensitive tests should be identified and made available in health care facilities. They are needed in primary health care and recommended for home use. Expert microscopy should be used to validate the kits periodically.</p>
<p><a href="https://www.malariaconsortium.org/pages/112.htm">Artemisinin-based combination drugs</a> are the most acceptable for treatment. They should be made accessible and affordable. Special attention should be given to vulnerable groups: children, pregnant women and non-immune individuals visiting Nigeria from non-malarious countries.</p>
<p>The government must also be willing to eliminate malaria in Nigeria. <a href="https://health.gov.ng/doc/Final-NMEP-M_E-Plan-2014-2020-May-3rd-updated-09_05_16.pdf">The Malaria Elimination Programme</a> should be strengthened to evolve relevant home grown means to achieve its goals. The staff must be accountable and dedicated and a monitoring and evaluation system should be put in place.</p>
<h2>Segun Isaac Oyedeji: from nets to vaccines</h2>
<p><a href="https://www.reuters.com/article/us-africa-malaria-events-timeline-idUSKCN0YU0ER">In 1955</a>, the WHO launched the Global Malaria Eradication Programme to eradicate malaria globally. </p>
<p>But not all countries were involved in the programme. After some achieved elimination, its financiers stopped financial support and it stalled. Consequently, the responsibility to eliminate malaria now falls on individual countries. </p>
<p>To eliminate malaria in Nigeria, there must be sincere and sustained commitment by the government, policy makers and citizens. We must be ready to scale up existing malaria control measures and targeted interventions. </p>
<p>Available tools and strategies are currently targeted towards vector control, prompt and accurate diagnosis and effective treatment. These have enormous impact on malaria elimination programmes, succeeding in countries that have <a href="https://www.who.int/malaria/areas/elimination/malaria-free-countries/en/">eliminated malaria</a> and others at the pre-elimination phase. </p>
<p>The following control measures must be enforced and implemented:</p>
<p>We must ensure that at least 75% of the population use long-lasting insecticidal nets to kill or repel the mosquito that transmits the infection. This would give us “herd-protection” because mosquitoes would find less infected hosts and transmission of the parasite will reduce drastically. Those who have the nets must use them effectively. </p>
<p>We must make sure all pregnant women get treatment.</p>
<p>Government and policy makers may also consider the need for mass drug administration for the entire population at the same time.</p>
<p>Our health systems must be restructured, strengthened and made ready to face the challenges of malaria elimination.</p>
<p>Governments must commit to scale up funding for malaria control, the same way they aggressively pursued COVID-19 <a href="https://ncdc.gov.ng/diseases/guidelines">prevention and control</a>.</p>
<p>Development of an antimalarial vaccine will also be important for regional malaria elimination and future eradication effort. Getting a vaccine is a global effort and we are at <a href="https://www.gavi.org/gavi-statement-on-latest-trial-data-on-malaria-vaccine-candidate-rts-s?gclid=Cj0KCQjwvYSEBhDjARIsAJMn0liPzKALNoWuhGDC3jPl9d-7pOVC8AcZe2ttwKvndJJXNWP6J3D-fSAaAugEEALw_wcB">phase III trial</a> currently. Ghana, Kenya, Malawi, Tanzania and Mozambique are involved as study centres or trial sites.</p><img src="https://counter.theconversation.com/content/159460/count.gif" alt="The Conversation" width="1" height="1" />
Nigeria must invest more in research and incorporate World Health Organisation-recommended interventions to eliminate malaria.Wale Fatade, Commissioning Editor: NigeriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1474312020-10-19T15:07:57Z2020-10-19T15:07:57ZMalaria parasites in Nigeria are genetically diverse: a danger but also a useful tool<figure><img src="https://images.theconversation.com/files/362148/original/file-20201007-20-ozffrs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/illustration/protozoan-plasmodium-falciparum-in-the-stage-royalty-free-illustration/1193685708?adppopup=true">Kateryna Kon/Getty Images </a></span></figcaption></figure><p>Malaria is one of the world’s most dangerous <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6254980/">parasitic disease</a> and a major public health challenge, especially in Africa. </p>
<p>Each year, over <a href="https://www.who.int/publications/i/item/world-malaria-report-2019">200 million</a> new cases of malaria occur globally. This leads to the death of over 400,000 individuals, most of whom are children below the age of five. <a href="https://www.who.int/publications/i/item/world-malaria-report-2019">Nigeria accounts</a> for about a quarter of all malaria cases and deaths worldwide. </p>
<p>Malaria is caused by parasites of the genus <em>Plasmodium</em>. Humans acquire malaria when an infected female <em>Anopheles</em> mosquito bites an individual and injects <em>Plasmodium</em> parasites into the bloodstream. Five species of <em>Plasmodium</em> parasites are able to cause malaria in humans but the most dangerous and deadly is <em>Plasmodium falciparum</em>. It accounts for over <a href="http://apps.who.int/iris/bitstream/10665/200018/1/9789241565158_eng.pdf?ua=1">96%</a> of all <em>Plasmodium</em> species in Nigeria.</p>
<p>It has the ability to vary or mutate its genetic make-up, especially when under pressure, to generate diverse strains or <a href="https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000336">variants</a>. The result is enormous genetic diversity in natural populations. And this has consequences for malaria control and treatment. The high genetic diversity in the parasite population could lead to gradual selection of more virulent or powerful strains. That could lead in turn to the emergence and proliferation of <a href="https://www.nature.com/articles/s41598-019-50152-w">drug-resistant parasites</a>. </p>
<p>But the genetic diversity of malaria parasites is also a strong tool for monitoring the emergence, increase and spread of drug-resistant parasites. Scientists can use the information from the genetic differences to distinguish between parasites carrying drug-sensitive genotypes and those carrying drug-resistant genotypes.</p>
<p>Our research has already <a href="https://www.sciencedirect.com/science/article/pii/S1995764513601029?via%3Dihub">confirmed</a> that in malaria-endemic countries such as Nigeria, infected individuals carry <em>P. falciparum</em> parasites that are <a href="https://www.tandfonline.com/doi/abs/10.1179/136485908X252340">genetically complex or diverse</a>. What we didn’t know was how diverse the parasites are in the micro environment, such as within households and among children of the same family. </p>
<p>We thought that knowing the population structure within households could help us understand more about the pattern and development of the disease. It could also inform development of appropriate guidelines and control measures. </p>
<p><a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-020-03415-1">We found that</a> even in the micro environment, <em>P. falciparum</em> parasites exhibit high genetic diversity. This finding was similar to results from larger communities in malaria endemic regions and has the same important implications. The implication is that a one-size fits all intervention or approach against the parasites may not be effective. </p>
<h2>Different types in one home</h2>
<p>We <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-020-03415-1">investigated </a> the genotypes of malaria parasite populations in children from 43 unrelated households or families in Lafia, North-central Nigeria. </p>
<p>We used a very sensitive molecular technique to determine parasite genotypes in each blood sample. We focused on a gene called MSP-2. This gene has two types, called FC27 and 3D7. Only one of these types (either FC27 or 3D7) is present in a single parasite at the stage when it enters a person’s blood.</p>
<p>Our findings showed that parasites in the study population carry genotypes containing both FC27 and 3D7. But the types were not uniformly distributed among the children in the study households. There were children living under the same roof and infected by parasites that were genetically different. This diversity could help explain why siblings of the same household experience different disease patterns or outcomes. The genetic differences in the parasites could also make the children respond differently to treatment as some children may carry drug-sensitive parasites while others carry drug-resistant parasites.</p>
<p>In some households, all the infected children may have parasites carrying mixed genotypes of both FC27 and 3D7 alleles – two parasite genotypes in one child. In other households, one of the children could be infected with parasites carrying FC27, while another child would have parasites carrying another genotype. In a few households, all the children had infection with parasites carrying genotype of only one MSP-2 type (either FC27 or 3D7), which may suggest inoculation by a single or related mosquito.</p>
<h2>Implications of our findings</h2>
<p>High genetic diversity of <em>P. falciparum</em> populations in an area is an indication that malaria transmission in the area is high. This can lead to competition for survival in the parasite population. That may in turn lead to the emergence of mutant parasites, gradual selection and spread of more virulent strains. These strains would have acquired mutation in genes associated with resistance, especially when under drug or immune selection pressure. </p>
<p>Genetic diversity of the parasite population may also be a tool for surveillance and monitoring of the status or emergence of drug-resistant parasites in a community. </p>
<p>Parasites that become drug-resistant through mutation may <a href="https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1002450">increase the risk of treatment failure</a>. The relationship is not direct, though, and remains to be established. </p>
<p>Similarly, genetic diversity could be a challenge for developing a malaria vaccine. A vaccine is designed to target a particular antigen, the substance that causes the human body to recognise and fight an infection. If the parasite has several other antigens, the vaccine won’t work for them all.</p>
<p>Genetic diversity also matters when it comes to diagnosing malaria. The blood test kit is looking for a particular feature in the parasite’s genes. If the feature is slightly different from the standard, it <a href="https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(18)30631-1/fulltext">won’t be</a> picked up.</p>
<h2>Conclusion</h2>
<p>Our studies have shown that <em>P. falciparum</em> parasites exhibit high genetic diversity in natural populations, including the micro environment, in areas where malaria transmission is high. </p>
<p>Genetic diversity is a survival strategy the parasites use to escape from host immune defences and fight against malaria control interventions. But it is also a way to keep a watch for mutants that may be resistant to drugs. And it’s a tool for evaluating intervention programmes.</p><img src="https://counter.theconversation.com/content/147431/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Segun Isaac Oyedeji receives funding from:
Deutscher Akademischer Austausch Dienst (DAAD), Germany.
International Centre for Theoretical Physics (ICTP) Trieste, Italy.
International Centre for Theoretical Science (ICTS) Bengaluru, India.
</span></em></p>Genetic diversity of a parasite population might help us watch for drug-resistant parasites.Segun Isaac Oyedeji, Lecturer, Federal University, Oye EkitiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1447832020-08-28T14:49:50Z2020-08-28T14:49:50ZMalaria: new map shows which areas will be at risk because of global warming<figure><img src="https://images.theconversation.com/files/355292/original/file-20200828-18-1fj9oj6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3794%2C2525&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">mycteria / shutterstock</span></span></figcaption></figure><p>Of an estimated <a href="https://www.who.int/news-room/feature-stories/detail/world-malaria-report-2019">228 million cases</a> of malaria worldwide each year, around 93% are in Africa. This proportion is more or less the same for the 405,000 malaria deaths globally.</p>
<p>That’s why there are huge efforts underway to provide detailed <a href="https://malariaatlas.org/">maps of current malaria cases</a> in Africa, and to predict which areas will become more susceptible in future, since such maps are vital to control and treat transmission. Mosquito populations can respond quickly to climate change, so it is also important to understand what global warming means for malaria risk across the continent. </p>
<p>We have just published a new set of maps in <a href="https://www.nature.com/articles/s41467-020-18239-5">Nature Communications</a> giving the most accurate picture yet of where in Africa will – and won’t – become climatically suitable for malaria transmission.</p>
<p>The malaria parasite thrives where it is warm and wet. Air temperature controls several parts of the transmission cycle, including the mosquito lifespan and rates of development and biting. </p>
<p>If it is too warm or too cold then either the malaria parasite or the mosquito that transmits the parasite between humans will not survive. This suitable temperature range is relatively well established by field and laboratory studies and forms the basis for current projections of the impact of climate change on malaria.</p>
<p>Yet, surface water is equally crucial as it provides habitat for the mosquitoes to lay their eggs. While flowing water in large rivers does not provide suitable larval habitat for African vector mosquitoes, nearby smaller water bodies, such as bankside ponds and floodplains can be highly productive, as can associated irrigation schemes or ponds and puddles forming anywhere in the landscape.</p>
<p>But estimating future surface water is tricky. River levels fluctuate with the seasons, ponds and puddles emerge and disappear, and it’s hard to predict exactly where will be farmed and irrigated years from now. </p>
<p><a href="https://www.mara-database.org/docs/ENG_MARA_Tech_Rep.pdf">Previous models</a> of malaria transmission suitability across Africa used simple monthly rainfall totals to estimate how much habitat would be available for mosquitoes. We instead looked at the formation of water bodies in more detail. When we include these hydrological processes in our model, we observe a different pattern both today and into the future.</p>
<h2>Beyond rainfall</h2>
<p>In the tropics, if it rains a lot then mosquitoes can breed and the area is probably suitable for malaria transmission. If this location is also within the right <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/ele.12015">temperature range</a>, we can say it is climatically suitable for malaria transmission. It may not presently experience transmission – perhaps because the disease has been eradicated there – but the climate would be suitable for it.</p>
<figure class="align-center ">
<img alt="Island on the River Nile with palm trees and boats." src="https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/355323/original/file-20200828-19-1pvtt2p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Egypt doesn’t get much rain, but the Nile still has mosquitoes.</span>
<span class="attribution"><span class="source">Nebojsa Markovic / shutterstock</span></span>
</figcaption>
</figure>
<p>Generally, this approach works well, especially over the whole of Africa. But it isn’t really how surface water works. To take an extreme example, it barely rains at all along much of the Nile River yet there are <a href="https://link.springer.com/article/10.1186/1475-2875-8-123">plenty of mosquitoes</a> and we know malaria was prevalent in Ancient Egypt.</p>
<p>Rain water can infiltrate the soil, evaporate back into the atmosphere, be absorbed by vegetation and, of course, flow downslope into streams and rivers. Since rainfall doesn’t always match up with how much water is left on the surface, a new approach was needed.</p>
<h2>A more complex pattern</h2>
<p>In our recent study, we applied a <a href="https://www.tandfonline.com/doi/full/10.1080/13658810802549154?casa_token=9wgwyjTG6QMAAAAA%3ASqj9SZSqqrAigE6Qf6_k5DydwZ1xnNURee8rh9-CPhQLcYka5EltIycdvZrWIEwNLyKK3nkKDORlHQ">continental-scale hydrological model</a> to estimate surface water availability. This highlighted a much more complex and arguably more realistic pattern of hydro-climatic suitability. Unlike rainfall-based approaches, our model highlights river corridors as potential year-round focal points of transmission.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Africa showing current malaria climatic suitability." src="https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=532&fit=crop&dpr=1 600w, https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=532&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=532&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=668&fit=crop&dpr=1 754w, https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=668&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/355328/original/file-20200828-22-qmibdr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=668&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Climatic-suitability for malaria in Africa today. Note this does not match up with the actual presence of malaria, as the disease has been eradicated in some places.</span>
<span class="attribution"><span class="source">Nature Communications</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Our work shows that some areas which were very obviously missing from previous models are in fact suitable for malaria transmission. This includes the Nile system, where our estimate of present day suitability for transmission extends prominently to the north coast of Africa, supported by historical observations of malaria outbreaks. </p>
<p>Similarly, the Niger and Senegal rivers and Webi Juba and Webi Shabeelie rivers in Somalia extend beyond the geographical ranges previously estimated to be climatically suitable. This is especially important since human populations tend to concentrate close to such rivers.</p>
<p>When we compare projections of the hydro-climatic model into the future with those from previous rainfall-threshold models we again see differences. Both suggest only very small changes in the total area suitable across the continent up to 2100, even under the <a href="https://www.carbonbrief.org/explainer-the-high-emissions-rcp8-5-global-warming-scenario">most extreme global warming scenario</a>. However, once hydrological processes were taken into account, we observed a greater shift in the areas that are hydro-climatically suitable and locations projected to change were very different.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of Africa showing future malaria hydro-climatic suitability." src="https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=644&fit=crop&dpr=1 754w, https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=644&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/355319/original/file-20200828-19-tvmxnr.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=644&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">How malaria suitability will change by 2100 under the most extreme global warming scenario (RCP 8.5). Red = more suitable, blue = less; bolder colours = more certainty.</span>
<span class="attribution"><span class="source">Nature Communications</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>For example in South Africa, rather than increased suitability being focused in the east of the country centred on Lesotho, our approach predicts that the area of increased suitability will stretch along the courses of the Caledon and Orange rivers to the border with Namibia. We no longer observe aridity-driven decreases in suitability across southern Africa, particularly in Botswana and Mozambique. </p>
<p>Conversely, projected decreases across west Africa are more pronounced. The largest difference is in South Sudan where our hydrological approach estimates substantial decreases in malaria suitability in the future.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Sunset over a river." src="https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=308&fit=crop&dpr=1 600w, https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=308&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=308&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=387&fit=crop&dpr=1 754w, https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=387&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/355316/original/file-20200828-15-u8ihub.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=387&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Orange River, South Africa’s longest, will become more suitable for malaria.</span>
<span class="attribution"><span class="source">Richard van der Spuy</span></span>
</figcaption>
</figure>
<p>Routing water through the landscape in a realistic way maps a very different pattern of malaria transmission suitability both today and into the future. But this is only a first step. </p>
<p>There is a lot more we can do to embed state-of-the-art hydrological and flood models into estimates of malaria suitability and even early warning systems of local malaria epidemics. The exciting challenge now is to develop this approach at the local scales required by public health agencies, to help in their fight against the disease.</p><img src="https://counter.theconversation.com/content/144783/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mark Smith receives funding from the UK Natural Environment Research Council (NERC)</span></em></p><p class="fine-print"><em><span>Chris Thomas receives funding from the UK Natural Environment Research Council (NERC)</span></em></p>We modelled surface water across Africa to show which parts of the continent are climatically-suitable for malaria – and how this will change.Mark Smith, Associate Professor in Water Research, University of LeedsChris Thomas, Global Professor in Water & Planetary Health, University of LincolnLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1391402020-06-07T08:42:48Z2020-06-07T08:42:48ZBreakthrough: microbe found to block the transmission of malaria<figure><img src="https://images.theconversation.com/files/337019/original/file-20200522-124851-1cvpf6i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Anopheles Stephensi, Sem. </span> <span class="attribution"><span class="source">Photo By BSIP/Universal Images Group via Getty Images</span></span></figcaption></figure><p>Malaria has been a terrible human disease from before the neolithic period up to present day. It has likely <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC126857/">caused more</a> human deaths than any other infectious agent. If realised, malaria eradication could be amongst humankind’s most significant achievements.</p>
<p>Malaria is caused by parasites in the genus <em>Plasmodium</em>, of which there are five different species that infect humans. These parasites enter the female Anopheles mosquitoes (males don’t bite humans) when they feed on the blood of an infected human. <em>Plasmodium</em> must then cross the Anopheles mosquito’s gut and become established in their salivary glands, at which point it can be transmitted to another human when the mosquito feeds again.</p>
<p>Globally, the burden of malaria has decreased by about half this century, but in recent years, the rate of malaria gains <a href="https://www.who.int/news-room/feature-stories/detail/world-malaria-report-2019">have slowed</a> and there is a serious risk of biological threats. For instance, some malaria mosquitoes are evolving resistance to insecticides used in bed nets.</p>
<p>The tools currently being used to tackle malaria were developed in the last century, some more than 40 years ago. For example, <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-019-2969-6">indoor residual spraying</a> is affected by resistance of mosquitoes, must be repeated at regular intervals and is prohibitively expensive for many African countries. </p>
<p>New tools are desperately needed. I do not mean a silver bullet, just additional entry points that will enable us to simultaneously exert pressure on the malaria transmission cycle from different angles. </p>
<p>For the last five years, my team and I have been studying microbes - tiny microorganisms - that naturally live in Anopheles mosquitoes in Kenya. </p>
<p><a href="https://www.nature.com/articles/s41467-020-16121-y">We discovered</a> that a microsporidian - a tiny parasitic fungus - called <em>Microsporidia MB</em> can block the transmission of malaria - <em>Plasmodium falciparum</em> - to the mosquito. </p>
<p>We are currently investigating the mechanisms behind the protective effect and have found that the immune systems of mosquitoes with Microsporidia MB are activated. </p>
<p>I believe there is great potential in harnessing the power of microbes that block the transmission of diseases by insects. For instance the <em>Wolbachia</em> bacterium has <a href="https://www.cell.com/current-biology/pdfExtended/S0960-9822(19)31446-0">proved useful</a> in the battle against Dengue fever - another mosquito-borne disease. Wolbachia-based control strategies have the potential to be effective because the bacterium spreads on its own. It will stay in a mosquito population provided it benefits mosquito fitness and can be transferred from mother to offspring.</p>
<p>Our end goal is to find a cost effective strategy to increase Microsporidia MB levels to a point where the Anopheles mosquitoes are no longer able to spread malaria to humans. </p>
<p>We are currently investigating the best way to spread the microbe through mosquito populations. Essentially we want to find out about all the different ways it can be transmitted and then find the best way to “help” it become a mosquito “pandemic”. </p>
<h2>Road to discovery</h2>
<p>Six years ago, my team started to screen mosquitoes for bacterial symbionts known to protect host insects from diseases. We hoped to find a symbiont that could block the transmission of human disease (such as malaria) by mosquitoes.</p>
<p>In addition, we decided to investigate symbionts called microsporidians. Microsporidians are related to fungi, but specialise on living inside cells of their hosts. Many cause disease, but a significant number also have symbiotic tendencies and protect their host. </p>
<p>Anopheles mosquitoes harbour a number of microsporidians that are “known” because they were associated with diseased mosquitoes. We became curious about Microsporidia MB because it hadn’t been found in mosquitoes before, yet seemed to be the most common type in our sampling sites. One of the sampling sites (Mwea) has been known to have a high abundance of Anopheles mosquitoes but a relatively low malaria burden. </p>
<p>We hypothesised that Microsporidia MB might have been overlooked because it didn’t cause overt disease in mosquitoes. From previous experiments, we knew that a significant number of wild caught Anopheles mosquitoes from these field sites were not able to become infected with Plasmodium, we wondered if this could partly be attributed to Microsporidia MB. </p>
<p>We collected live mosquitoes from the field and rushed them across many hundreds of kilometres to our laboratories. Here we encouraged them to lay eggs so we would have a larger group to study and because the Microsporidia MB can be transmitted from mother to young. </p>
<p>We were struck by the fact that Microsporidia MB-infected mosquitoes had very high loads of the symbiont but also seemed very healthy.</p>
<p>The next step was to determine if this symbiont might have the capacity to protect mosquitoes from malaria. We began to notice a clear trend; the mosquitoes that had Microsporidia MB did not became infected with Plasmodium. </p>
<p>Future studies will hopefully enable us to better understand exactly how protection works. </p>
<h2>Further studies</h2>
<p>These microbes haven’t been well studied before because they can be hard to find and they tend to leave the host under lab conditions. </p>
<p>Being based at the <a href="http://www.icipe.org/">International Centre for Insect Physiology and Ecology (icipe)</a>, my team and I are well-positioned to overcome some of these challenges. This is because studying the symbionts of Anopheles mosquitoes requires the capacity to study alive, wild caught mosquitoes. To keep microbial relationships intact, rearing had to be done in laboratory facilities that are in or near to the field. Adapting mosquitoes for mass rearing under sterile conditions usually eliminates important microbes before they can be investigated in detail.</p>
<p>Our next steps are to figure out how to spread the microbe through mosquito populations. I think we might be able to mass produce the “spore” stage and release this into the environment just before the rains when mosquito populations are lower. Additionally, we have found evidence that the microbe is likely to be sexually transmitted and we might be able to release infected male mosquitoes (that do not bite humans) that would infect females. Females will then infect their offspring. For this strategy to be effective, we wouldn’t need all mosquitoes to have Microsporidia MB, just enough to impede the transmission cycle and cause case numbers to steadily decline. </p>
<p>There is still a lot of work to do before we find a viable strategy to increase Microsporidia MB in the field, but it is promising.</p><img src="https://counter.theconversation.com/content/139140/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeremy Herren receives funding from The Wellcome Trust, BBSRC ANTi-VeC Network and icipe's core donors (the UK’s Department for International Development (DFID); Swedish International Development Cooperation Agency (Sida); the Swiss Agency for Development and Cooperation (SDC); Federal Democratic Republic of Ethiopia and the Kenyan Government).</span></em></p>Mosquitoes that had Microsporidia MB - a tiny parasitic fungus - never became infected with malaria.Jeremy Herren, Scientist, International Centre of Insect Physiology and EcologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1071932018-11-22T13:25:20Z2018-11-22T13:25:20ZFight against malaria needs combination of innovative science and communities<figure><img src="https://images.theconversation.com/files/246219/original/file-20181119-76140-w3rflg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Bed nets treated with insecticide have been effective in fighting malaria in Africa.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Current strategies to prevent malaria using bed nets and insecticides protect millions of people from malaria-transmitting mosquitoes. Last year <a href="http://apps.who.int/iris/bitstream/handle/10665/275867/9789241565653-eng.pdf?ua=1">175 million bed nets</a> treated with insecticide were delivered across sub-Saharan Africa. Between 2000 and 2015 bed nets are estimated to have prevented an estimated <a href="https://www.givingwhatwecan.org/post/2015/12/bednets-have-prevented-450-million-cases-of-malaria/">450 million malaria cases</a>. </p>
<p>But these measures offer only limited protection. According to the latest <a href="http://www.who.int/malaria/publications/world-malaria-report-2018/en/">World Malaria Report</a>, 44% of people in African countries with high malaria rates don’t have access to bed nets and insecticides. Even when they are available, they’re not failsafe. For example, the use of bed nets has been linked to an increase in mosquitoes <a href="https://wellcomeopenresearch.org/articles/2-22/v3">biting outdoors</a>, and they can also develop <a href="http://www.who.int/malaria/areas/vector_control/insecticide_resistance/en/">resistance</a> to the insecticide.</p>
<p>Worldwide there were <a href="http://www.who.int/malaria/publications/world-malaria-report-2018/en/">435,000 deaths last year</a> from malaria. Over 90% were in Africa. This means that scientists need to redouble efforts to develop new, complementary measures to eliminate the disease.</p>
<p>One promising solution includes <a href="https://targetmalaria.org/our-work/">reducing the population of malaria mosquitoes</a> through genetic modification to help reach the target of ending transmission. </p>
<p><a href="https://targetmalaria.org/">Target Malaria</a>, a research consortium working across the USA, Europe and Africa, is in the early stages of developing a genetically modified mosquito that can either produce only male offspring or reduce female fertility in subsequent generations.</p>
<p>Where I work in Mali, we are currently studying local mosquito populations to help inform work on genetic modification. </p>
<p>Though the scientific research often gets the limelight, the process also involves working side by side with local communities from the very beginning. This engagement helps us get not only the communities’ feedback but also their active participation.</p>
<h2>Genetic modification</h2>
<p>Our work in Mali involves trying to understand the mosquito species that are responsible for malaria transmission and to gather as much baseline data as possible on the local malaria mosquitoes. These data include: abundance, biting and resting behaviour, migration, effective population size. This is a crucial first step that will be the basis for further work in our country.</p>
<p>Genetic modification could be achieved in one of two ways. </p>
<p>The first is to bias the sex ratio so future offspring would be all males. This is done by fragmenting the X chromosome in the males so they only pass on a Y chromosome. As a result, their offspring is male (XY), as a female would need to inherit an X from each parent (XX). </p>
<p>The second way is to reduce female fertility. This is achieved by targeting the gene responsible for fertility in females. A female that has one copy of this fertility gene disrupted will be able to reproduce normally, but when both copies within her chromosomes are disrupted, the female cannot produce viable offspring, reducing the <a href="https://www.imperial.ac.uk/news/188291/mosquitoes-that-carry-malaria-eliminated-experiments/">mosquito population</a>. </p>
<p>But as the science to make <a href="https://genedrivenetwork.org/">this possible</a> gets closer, we must ensure that the public debate around such a novel and potentially transformative technology also keeps up.</p>
<p>This means not only exploring what we can do in a laboratory, but exploring and understanding what is acceptable to the communities most affected by such innovations. We need to ensure that any new malaria control method fully meets their needs.</p>
<h2>Involving communities</h2>
<p>In Mali, where Target Malaria has been working since 2012, there is an ongoing dialogue at national, regional and community levels.</p>
<p>Our teams visit the communities around our in-sectary where insects are kept and studied, as well as field sites nearly every week and community members visit our laboratories. We also get permission from individual households to collect mosquitoes from homes or compounds. And we ask communities before we catch mosquitoes in swarms.</p>
<p>But engagement is not just about information and acceptance, it’s also about collaboration. Our “relay” staff, who live in the communities, can provide information even when we are not there. </p>
<p>On top of this we respect the decision-making processes of each individual village regardless of how different the processes can be.</p>
<p>We will continue following this way of doing things for each subsequent phase of our work. </p>
<p>The reason for such extensive and transparent engagement is clear. </p>
<p>As researchers, our role is not only to determine whether the genetic alteration of mosquitoes to stop malaria is scientifically possible. It is also to ensure that this can be done ethically and responsibly to meet the needs of the affected population. We can only do this by involving them.</p><img src="https://counter.theconversation.com/content/107193/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mamadou Coulibaly does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The fight against malaria needs scientific innovation. But community buy-in is just as important.Mamadou Coulibaly, Head, Malaria Research and Training Center, Université des sciences, des techniques et des technologies de BamakoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1063682018-11-07T13:10:46Z2018-11-07T13:10:46ZSouth Africa investigates sterilising mosquitoes in anti-malaria drive<figure><img src="https://images.theconversation.com/files/244111/original/file-20181106-74787-1d6j2in.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A close-up of a female Anopheles arabiensis feeding. </span> <span class="attribution"><span class="source">Author supplied</span></span></figcaption></figure><p>South Africa is one of four southern African countries aiming to <a href="https://medpharm.tandfonline.com/toc/ojid20/current">eliminate malaria transmission</a> by 2023. Indoor residual spraying using DDT and pyrethroid insecticides constitutes the backbone of South Africa’s <a href="http://www.samj.org.za/index.php/samj/article/view/7447/5462">malaria control programmes</a>. </p>
<p>Effective vector control by indoor residual spraying has been key in the reduction of malaria cases. This was instrumental in creating malaria-free zones in most parts of the country. Malaria transmission is now <a href="http://www.samj.org.za/index.php/samj/article/view/7441/5461">limited</a> to the north-eastern parts of Limpopo province, the low-veld areas of Mpumalanga province and the far northern parts of KwaZulu-Natal province. </p>
<p>Despite a concerted effort to eliminate malaria in these provinces, transmission has remained steady over the <a href="http://www.samj.org.za/index.php/samj/article/view/7441/5461">past decade</a>.</p>
<p>Failure to eliminate malaria transmission is attributed, in part, to resistance to the insecticides being used. Added to this is the challenge of controlling the outdoor-biting <em>Anopheles arabiensis</em> population that’s largely considered responsible for most malaria transmission in the country. </p>
<p>Indoor spraying isn’t completely effective against this mosquito because it mainly targets indoor biting and resting mosquitoes. This strategy is not adequate against vectors that sometimes feed and rest outdoors, such as <em>An. arabiensis</em>. </p>
<p>Other, complementary vector control strategies are needed to eliminate the disease. These must be able to control outdoor feeding and resting mosquito populations. </p>
<p>One possible approach is a technique that involves sterilising the insects. The technology is currently being assessed in South Africa. The technique involves a genetic birth control method in which laboratory mass-produced sterile male insects are released into the wild at a ratio that effectively inundates a target population. This forces most females to mate with sterile males, substantially reducing their fecundity, and resulting in population suppression. </p>
<p>The sterile insect technique has been piloted against <a href="https://www.springer.com/us/book/9781402060588">mosquito vectors</a> of the Zika, yellow fever, chikungunya and dengue viruses, but has never been used for malaria control efforts. The South African sterile insect technique initiative together with a similar trial in <a href="https://link.springer.com/chapter/10.1007/978-1-4020-6059-5_34">Sudan</a> are a first for African malaria vectors. </p>
<p>Preparations for the South African project are at an advanced stage. A pilot mass-rearing facility has been built and the size of the natural mosquito population has been estimated. In addition, a local community has been drawn into preparations and is now ready for a trial run. All these steps pave the way for a pilot demonstration.</p>
<h2>The project</h2>
<p>The sterile insect technique has been applied successfully against <a href="http://agris.fao.org/agris-search/search.do?recordID=US9032290">other insect pests</a> including the fruit fly and the new-world screwworm fly . In South Africa this technology is routinely used in Citrusdal, Western Cape to control the <a href="http://www.bioone.org/doi/abs/10.4001/003.023.0112">false codling moth</a>.</p>
<p>The <a href="http://www.parasitesandvectors.com/content/4/1/208">project</a> involving <em>An. arabiensis</em> aims to show that the sterile insect technique can be successfully used to suppress mosquito populations that carry and spread malaria. If it works, the approach can be used as an alternative vector control method to complement existing strategies. </p>
<p>The project is being implemented in three phases. </p>
<p>Phase 1 included trials showed that sterilised <em>An. arabiensis</em> males mass-reared under laboratory conditions can compete with fertile males for mates. This milestone informed phase II of the project which is currently underway.</p>
<p>This phase aims to test the feasibility of the sterile insect technique through a small-scale pilot field demonstration in northern KwaZulu-Natal. Research activities for phase II are in progress. The biggest development here is the building of Africa’s first pilot mosquito mass-rearing facility.</p>
<p>The sterile insect technique relies heavily on inundating the wild population with sterilised male insects. For this to succeed, it’s important to know the size of the wild mosquito population as this will determine how many laboratory-reared sterilised males would need to be released. </p>
<p>To estimate mosquito population numbers, a mark-release-recapture method was used. About 30,000 yellow and orange-dusted laboratory-reared males sharing the same genetic background as the wild population were released over two release periods. Some of these mosquitoes were recaptured together with wild mosquitoes and a formula was used to estimate the wild population size. </p>
<p>Interestingly, marked males were recaptured in swarms of wild males. This indicates that the laboratory-reared males were able to locate and participate in mating swarms – a crucial step for the potential success of the sterile insect technique.</p>
<h2>Next steps</h2>
<p>The eventual rollout of the pilot trial will require successful mass rearing of competitive sterile males and a technique to separate males from female insects. Work on optimising mass production of quality sterile male and a system to separate males from females are at an advanced stage. </p>
<p>In addition, it’s critical to get the community involved and addressing any social issues so that people cooperate and participate. This is particularly important because the sterile insect technique can be seen as increasing the numbers of mosquitoes in an area after the release of the sterile males. A malaria awareness campaign has already been conducted. Information on malaria transmission and control – including the potential of using the sterile insect technique – was shared through radio interviews, brochures, road shows and lectures in isiZulu.</p><img src="https://counter.theconversation.com/content/106368/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Givemore Munhenga receives funding from Department of Science and Technology, National Research Foundation and International Atomic Energy Agency. He is affiliated with University of the Witwatersrand. </span></em></p>South Africa is piloting a new technique as it drives to eliminate malaria.Givemore Munhenga, Senior Medical Scientist, National Institute for Communicable DiseasesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1062762018-11-07T13:10:37Z2018-11-07T13:10:37ZNovel approach brings African scientists closer to a malaria vaccine<figure><img src="https://images.theconversation.com/files/244103/original/file-20181106-74783-r02f38.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Scientists analysing data at the South-South Malaria Research Partnership project laboratory in Kenya. </span> <span class="attribution"><span class="source">Flora Mutere-Okuku</span></span></figcaption></figure><p>Malaria is still a major problem in Africa. There are over <a href="http://www.who.int/malaria/publications/world-malaria-report-2017/en/">200 million clinical cases</a> each year and approximately half a million deaths. </p>
<p>There are different ways in which malaria can be controlled. Preventive measures include use of insecticides in bed nets or indoor spraying programmes. Medicines can also be used to prevent or treat malaria, but resistance often develops and drugs lose their effectiveness. </p>
<p>The World Health Organisation <a href="http://www.who.int/en/news-room/detail/29-11-2017-global-response-to-malaria-at-crossroads">reported</a> that progress in controlling malaria has stalled. </p>
<p>As an immunologist, I dream that one day we will have an effective vaccine that will help eliminate malaria. I think this is possible because for over a century, we have known that humans do become immune to malaria. In places where there is lots of malaria adults don’t succumb to the disease, but their young children do. </p>
<p>In experiments conducted over 50 years ago, researchers showed that blood could be taken from <a href="https://www.nature.com/articles/192733a0">adults who had become immune</a> and used to treat children admitted to hospital with malaria. </p>
<p>Antibodies in the blood were responsible for this effect; in other words, antibodies could treat malaria. Researchers have been trying to isolate the exact antibodies that do this. The challenge is that our bodies make millions of antibodies, so pulling out those with the antimalarial activity has been difficult.</p>
<p>One way to identify these “good” antibodies is to compare the blood samples of people who get malaria with those who don’t with the aim of identifying the differences. This type of research has been going on for about 30 years, but the results have been <a href="https://www.ncbi.nlm.nih.gov/pubmed/20098724">inconclusive</a>. </p>
<p>Part of the reason is that in almost every study, the investigators do things differently. </p>
<p>It’s like cooking your favourite dish. You may have a particular recipe but if you check in with friends and ask how they prepare the very same dish, you will find that each of them does something slightly differently. In the same way, differences in the way scientists have conducted their experiments have contributed to a lack of clarity in the results. </p>
<p>We’ve embarked on a project that breaks this cycle. </p>
<h2>The project</h2>
<p>In experiments conducted over 50 years ago, researchers showed that blood could be taken from <a href="https://www.nature.com/articles/192733a0">adults who had become immune</a> and used to treat children admitted to hospital with malaria. </p>
<p>We used the latest technology to analyse our samples. We designed a small glass slide on which we stuck over 100 carefully selected proteins from the malaria parasite. With less than a drop of blood, we were able to simultaneously <a href="https://www.smartpartnership.net/science">measure antibodies</a> to all these proteins. </p>
<p>This was a major step-change. When I started this research 14 years ago, I used to measure antibodies to one parasite protein at a time, using a lot more blood, and in samples from one area in Kenya. </p>
<p>Developments in technology now mean that it’s possible to do this much more efficiently. And we’re really excited that we have been able to exploit these new innovations in Africa. </p>
<p>My team analysed antibodies in over 10,000 samples in three months. We are now working through the statistical analysis of this data to understand how people who are immune to malaria do it.</p>
<p>My team is also working on understanding how antibodies <a href="https://www.ncbi.nlm.nih.gov/pubmed/27546781">kill malaria</a> parasites. It’s still unclear if the antibodies attack the parasite from different angles or whether different antibodies are synergistic in their actions. </p>
<p>We also don’t know how much antibody is necessary. </p>
<h2>What we know</h2>
<p>So far, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2346713/">our studies</a> suggest that having a bit of one antibody is not good enough, and we may need high concentrations of antibodies against combinations of parasite proteins. </p>
<p>We are also <a href="https://www.ncbi.nlm.nih.gov/pubmed/26787721">learning</a> that antibodies kill parasites in many ways, and that studying any one of these in isolation may not adequately reflect reality. </p>
<p>I believe the key to making a better malaria vaccine is right here with us. With patience, perseverance and continued hard work, we will find the recipe required to make a really good malaria vaccine.</p><img src="https://counter.theconversation.com/content/106276/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Faith Osier receives funding from the Wellcome Trust, the MRC/DFID African Research Leader Award, the European and Developing Countries Clinical Trials Partnership (EDCTP), the Sofja Kovalevskaja Award from the Alexander von Humboldt Foundation and TIBA - Tackling Infections to Benefit Africa. She is Vice-President/President-elect of the International Union of Immunological Societies. </span></em></p>Progress in malaria control has stalled. Research towards an effective vaccine is underway.Faith Osier, Immunologist , Wellcome Trust Sanger InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/987742018-06-27T13:55:47Z2018-06-27T13:55:47ZWhy Cuban doctors in Kenya don’t deserve the treatment they’re getting<figure><img src="https://images.theconversation.com/files/224886/original/file-20180626-112614-1ttmssi.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Some of the 50 Cuban medical specialists who arrived in Kenya recently to work in under served rural areas.</span> <span class="attribution"><span class="source">Supplied</span></span></figcaption></figure><p>Cuban medical missions abroad are perhaps one of the most <a href="http://news.bbc.co.uk/1/hi/world/americas/8059287.stm">significant legacies </a> of the 1959 Cuban Revolution. The programme involves Cuban doctors offering health care services in host countries, often in impoverished rural communities where there’s little access. </p>
<p>The programme stemmed from Cuba’s foreign policy objectives of anti-colonialism and humanitarianism in the 1960s. It became one way in which Cuba could avoid the isolation intended by the <a href="https://www.bbc.com/news/world-latin-america-19583447">trade embargo</a> imposed by the US and its <a href="https://www.oas.org/en/about/offices_detail.asp?sCode=CUB">expulsion</a> from the Organisation of American States (OAS).</p>
<p><a href="http://en.granma.cu/cuba/2016-04-12/studying-medicine-in-cuba-an-option-for-international-youth">Well over</a> 131,993 Cuban doctors have taken part in international missions in 107 countries. Kenya is the latest.
<a href="https://www.standardmedia.co.ke/health/article/2001283029/cuban-doctors-arrive-in-kenya-photos">The first</a> 50 specialists arrived in the country recently, with 50 more to follow. All are expected to work in under served rural areas.</p>
<p>But their arrival has been met with a storm of protest. Some Kenyan health professionals have <a href="https://www.standardmedia.co.ke/health/article/2001284756/cuban-doctors-free-to-work-in-kenya-cour">strongly opposed</a> their arrival on the grounds that they’ll be taking away local jobs. </p>
<p>My understanding of the work of Cuban doctors has been greatly influenced by the fact that I spent 7 years studying medicine in Cuba, one of thousands of <a href="http://en.granma.cu/cuba/2016-04-12/studying-medicine-in-cuba-an-option-for-international-yout">students from all over the globe</a> who have had the opportunity to study medicine on the island. The experience gave me a keen understanding of how the Cuban health system works. It also helped me understand what lies behind the medical missions programme. </p>
<p>I accept that the way the programme is implemented in countries like Kenya leaves a lot to be desired. But I would also argue that the services being provided by Cuban doctors is invaluable and the reasons for not wanting them in Kenya are not justified.</p>
<h2>The national benefit is paramount</h2>
<p>The current fears of the Kenyan medical fraternity are understandable. But their fears may be based on misinformation. <a href="https://www.the-star.co.ke/news/2018/06/22/senators-accuse-state-of-being-vague-on-cuban-doctors-deal_c1776547">Prior consultations</a> between Kenyan government officials and the medical fraternity would have gone a long way to allaying these.</p>
<p>Nevertheless, I believe that Kenyan doctors should focus on the national benefits of the programme. Cuban doctors are sent to rural, under-served areas – areas that local doctors often refuse to work in. In these communities, the mere presence of a doctor can make a tremendous difference in health outcomes. </p>
<p>In addition, the Cuban doctors being sent to Kenya are highly specialised in areas such as oncology and nephrology, areas of medicine which are in demand the world over. Their presence can only improve access to specialised medical care while reducing congestion in referral hospitals.</p>
<h2>Cuba’s healthcare missions</h2>
<p>Despite a level of <a href="https://www.ft.com/video/33cefce5-50d7-497f-9fc7-c9f345642d99?playlist-name=editors-picks&playlist-offset=1">economic stagnation</a>, Cuba has managed to maintain a universal health care system viewed as a <a href="https://www.huffingtonpost.com/salim-lamrani/cubas-health-care-system-_b_5649968.html?guccounter=1">model</a> for other countries. Current data shows the doctor to patient ratio in Cuba is <a href="https://data.worldbank.org/indicator/SH.MED.PHYS.ZS?locations=CU">well above</a> the United Nation’s target of 1:1000, at 7.5:1000 in 2014. By comparison, Kenya
has a ratio of <a href="https://data.worldbank.org/indicator/SH.MED.PHYS.ZS?locations=KE">0.204 doctors per 1000 patients</a>.</p>
<p>Cuban trained doctors have been praised the world over for the level of service and compassion they offer. There are numerous examples of work that they’ve done. For example, Cuba were sent doctors to South Africa during a <a href="http://nuso.org/articulo/la-diplomacia-medica-cubana-recibe-una-pequena-ayuda-de-sus-amigos/">brain-drain in the post-apartheid era</a> as white medical doctors left that country in droves. </p>
<p>They also helped develop <a href="http://journals.sagepub.com/doi/abs/10.2190/HS.37.4.k">medical faculties</a> in Ghana, Guinea-Bissau, The Gambia and Haiti between 1963-2004. And they showed tremendous humanitarian spirit during the <a href="https://www.independent.co.uk/life-style/health-and-families/health-news/cuban-medics-in-haiti-put-the-world-to-shame-2169415.html">Haitian Earthquake</a> in 2010, the <a href="https://www.theguardian.com/world/2014/oct/12/cuba-leads-fights-against-ebola-africa">Ebola outbreak</a> of 2014 and even offered the US assistance in the aftermath of Hurricane Katrina. The offer <a href="http://www.nbcnews.com/id/9311876/ns/us_news-katrina_the_long_road_back/t/katrina-aid-cuba-no-thanks-says-us/">was rejected</a>. </p>
<p>The argument that Kenya should invest in its own citizens rather than sign a multi-million dollar deal with the Cuban government is a fair one and should be addressed. But I don’t believe that it’s simply a question of one or the other.</p>
<p>Studying medicine is costly and requires training for between six to seven years. This excludes specialisation. But what happens in the interim to sick, impoverished individuals in rural communities while doctors are being trained? Cuban doctors should be seen as a temporary reinforcement offering a level of service every Kenyan should demand.</p>
<h2>Why Cuban doctors?</h2>
<p>Is a Cuban doctor better than a Kenyan one? No. But Cuban doctors have specific expertise in dealing with tropical diseases such as malaria. This remains a major problem in Kenya even though it was <a href="https://www.nation.co.ke/lifestyle/artandculture/Cuba-to-help-in-malaria-control/1222-890294-4a2f3ez/index.html">eradicated</a> in Cuba more than three decades ago. </p>
<p>It’s also important to keep some perspective when it comes to the numbers. Foreign physicians make up below 10% of all doctors in Kenya. There are 939 foreign doctors in the country’s register – but the <a href="https://www.businessdailyafrica.com/news/358-American-doctors-licensed-to-practise/539546-4565608-2qqb2j/index.html">majority (358) are from the US</a>. Only 100 are from Cuba. This is a tiny number.</p>
<p>The presence of these foreign doctors should be seen as a benefit to the country’s health care service. It offers the opportunity for Kenyan physicians to learn from the Cubans’ experiences working in a universal health care system with emphasis on preventative medicine. They could also learn from their integrated community medicine approach, how they’ve managed to eradicate various diseases as well as policies and guidelines in place in Cuba that could be implemented in Kenya. </p>
<p>Cuban physicians will also be able to learn from their Kenyan counterparts how their system operates, difficulties and challenges of working as a physician in Kenya as well as the cultural norms that Cuban physicians would have to consider when offering services to Kenyans.</p>
<p>Ultimately, the Kenyan health care system and its people will reap the rewards of the presence of Cuban doctors.</p><img src="https://counter.theconversation.com/content/98774/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rich Warner does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Cuban doctors have specific expertise in dealing with diseases like malaria which remains a major problem in Kenya.Rich Warner, PhD Candidate, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/953232018-04-24T14:36:10Z2018-04-24T14:36:10ZScientists design a novel formula that repels and kills mosquitoes<figure><img src="https://images.theconversation.com/files/216150/original/file-20180424-57584-1vi4yah.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mosquitoes have started developing resistance to topical repellents.</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Long-lasting insecticide treated nets and indoor spraying are the main <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-1987-5">malaria vector control interventions</a> recommended by the World Health Organisation. Both target mosquitoes that feed indoors. </p>
<p>The challenge is that a significant portion of malaria infections in Africa may be due to people being exposed to mosquito vectors outdoors. This means that current control methods need to be updated to include methods or strategies that protect people all the time and not only when they are inside their homes.</p>
<p>Topical mosquito repellents that prevent or at least reduce contact between the blood seeking female mosquitoes and humans have been touted as the best way to reduce the possibility of the disease spreading.</p>
<p>There are several options on the market but <em>N,N-diethyl-meta-toluamide</em> – more commonly known as DEET – is the gold standard. All other <a href="http://www.ingentaconnect.com/content/resinf/opm/2014/00000025/00000004/art00005">mosquito repellents are measured against it</a>.
But DEET has several challenges.</p>
<p>Mosquitoes have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3150595/">started developing resistance</a> to it and consumers have been complaining about its odour, high adsorption rate, oily feel and the skin irritation it causes. </p>
<p>These problems have led to calls for a replacement. But <a href="https://www.nature.com/articles/nature12594">finding new active compounds</a> to commercialise into repellents is time consuming and expensive because it involves the <a href="https://www.researchgate.net/publication/236163078_Discovery_and_Design_of_New_ArthropodInsect_Repellents_by_Computer-Aided_Molecular_Modeling">lengthy process of establishing their safety</a>. </p>
<p>As a result scientists have started looking into the viability of combining mixtures of approved repellents. This is exactly what we did. In <a href="https://www.nature.com/articles/s41598-017-10548-y?WT.feed_name=subjects_immunology">our study</a> we evaluated a compound that’s used in a repellent along with another compound that has no link to repellents, to test how effective they would be together. This had never been done before. </p>
<p>The result was a novel repellent that has a longer lifespan than commercially available repellents. It has the added benefit of not only repelling mosquitoes but killing them too if they make contact with it. </p>
<p>Our findings set us up with a compound that can be developed into a commercially viable repellent that can protect people when they are outside. </p>
<h2>How repellents are formed</h2>
<p>Most repellents are made up of compounds that are mixed with carrier oils. But they evaporate quickly and need to be reapplied often. </p>
<p>We wanted to solve this problem and believed that a mixture that was a negative pseudo-azeotrope which are used in perfumes would do the trick. A pseudo-azeotrope is a mixture of substances that retains the same composition in vapour and liquid states. In particular, a negative pseudo-azeotrope evaporates slower and this makes it last longer. </p>
<p>We took nonanoic acid – a compound which is used as an additive in the food industry – and added it to a compound used in most repellants: ethyl butylacetylaminopropionate, more commonly known as IR3535. </p>
<p>We tested the formula by applying it to someone’s forearm and then placing a cup with 20 hungry, female <em>Anopheles arabiensis</em> mosquitoes against it. A cup with mosquitoes in it was also placed against a person’s arm that didn’t have repellent on it. </p>
<p>After three minutes we tested how many times the mosquitoes had bitten the respective arms. </p>
<p>Our results showed that our formula was better at repelling the mosquito throughout the three minutes and that the effect lasted for up to six hours on the skin. The result also showed that most mosquitoes that came into contact with our formula died.</p>
<h2>A multidisciplinary approach</h2>
<p>The spread of malaria is dependent on a number of factors. These include how many mosquito vectors there are in a particular area, how susceptible they are to the malaria parasite, what hosts the mosquitoes are feeding off, and the survival period of the mosquito. </p>
<p>Two big challenges have developed that are making the elimination of malaria difficult. The first is that the vectors have started developing resistance against the main control method: insecticides. The second is that the parasite that spreads malaria <em>Plasmodium falciparum</em> has developed resistance to anti-malarials. </p>
<p>What this means is that malaria won’t be eliminated with the use of one type of control method. An integrated multi and trans-disciplinary approach is needed. </p>
<p>New, innovative, safe and sustainable methods need to be researched and developed to overcome current resistance trends and prevent transmission of malaria from all angles.</p>
<p>Our research opens the door to a new mosquito repellent formulation that improves the armoury against malaria.</p><img src="https://counter.theconversation.com/content/95323/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Walter Focke receives funding from Faculty Research Team, the DFG and SA MRC. </span></em></p><p class="fine-print"><em><span>Mthokozisi Sibanda works for the University of Pretoria. He receives funding from the National Research Foundation. </span></em></p><p class="fine-print"><em><span>Taneshka Kruger does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A novel mosquito repellent has been found to have a longer lifespan than those commercially available.Walter Focke, Professor, Department of Chemical Engineering and Director of Institute of Applied Materials, University of PretoriaMthokozisi Sibanda, Postdoctoral fellow in Chemical Engineering, University of PretoriaTaneshka Kruger, Project Manager to the UP ISMC, University of PretoriaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/951012018-04-22T09:51:18Z2018-04-22T09:51:18ZWhy Kenya isn’t winning the war against malaria in some counties<figure><img src="https://images.theconversation.com/files/215752/original/file-20180420-75114-879d0s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>In the past 15 years the Kenyan government has made great strides in preventing and controlling malaria. It has issued insecticide treated bed nets, sprayed people’s homes with insecticides and ensured that there is widespread diagnostic testing. These efforts have resulted in a <a href="http://www.who.int/features/2017/vector-control-kenya/en/">significant drop</a> in transmission rates. </p>
<p>But progress has not been uniform. Parts of Kenya – particularly the counties in the west of the country along the Rift Valley – are still plagued by serious seasonal cases of the deadly disease. </p>
<p>Seasonal outbreaks of malaria in these counties are most common in the wet season which runs from March to June and then again from October to December. But in years with high rainfall it also rains in January and February, which was the case this year. As a result, in February this year, for example, the arid counties of Baringo, West Pokot and Marsabit saw an outbreak where hundreds of people were <a href="https://www.standardmedia.co.ke/article/2001269063/another-malaria-outbreak-hits-baringo-county">hospitalised</a>. Most of the patients were children under the age of five – a group that’s globally considered a <a href="http://apps.who.int/iris/bitstream/10665/200018/1/9789241565158_eng.pdf?ua=1#page=47">high risk for severe malaria</a>. </p>
<p>The outbreak follows a similar one in October last year where in less than a weak more than 400 people were hospitalised and at least <a href="https://www.the-star.co.ke/news/2017/10/03/10-dead-400-admitted-after-malaria-outbreak-in-baringo-west-pokot_c1646017">10 had died</a> from malaria.</p>
<p>In Baringo county, malaria is of particular concern – accounting for 11.8% of the <a href="http://www.humanitarianresponse.info/system/files/">outpatient cases recorded</a>. This is higher than the nationwide malaria prevalence of 8%.</p>
<p>So what’s preventing <a href="http://www.e-kconsulting.co.ke/Resources%20/kenya-malaria-indicator-survey-report-2015-kmis-2015">Baringo county and other areas</a> from reducing its malaria caseload like other parts of the country? </p>
<p>A number of factors are at play. These include weak health systems, which are a common feature of the counties in the arid and semi arid areas of the country. In these areas the health facilities are sparsely distributed, have poor equipment and are understaffed. The areas also have poor road networks. On top of this, these areas are affected by conflict which in turn gets in the way of the government providing decent healthcare. </p>
<p>And finally, the environment also poses a challenge because they increase the number of larval breeding sites for the mosquitoes in the wet months, which increases the outbreaks of malaria. </p>
<h2>County challenges</h2>
<p>Health facilities in the arid and semi arid counties of Kenya are <a href="http://www.baringo.go.ke/index.php?option=com_content&view=article&id=1580:proposed-health-projects-for-the-financial-year-2016-2017&catid=10&Itemid=188">sparsely distributed</a>. On average most patients in remote villages need to walk more than 15 kilometres to the nearest facility. The facilities are also understaffed with inadequate medical equipment and insufficient anti-malarial drugs. </p>
<p>On top of this, criminal gangs have taken control in many areas in the wake of the ongoing conflict between two communities – the Pokot and Marakwet. As a result nurses regularly <a href="https://www.standardmedia.co.ke/article/2001269063/another-malaria-outbreak-hits-baringo-county">flee medical facilities</a> leaving no one in charge.</p>
<p>The fact that herding is the main economic activity in Baringo has also been a contributory factor to the higher rates of malaria. Research into the breeding habits of one of the mosquitoes that spreads malaria in the region – the <em>Anopheles arabiensis</em> – shows that it feeds on humans as well as livestock. Therefore, high livestock densities in an area where herders converge in communal grazing lands translate into more people being <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3120729/">bitten</a>. </p>
<p>The seasons also play a role. In the dry season, the vector is sustained by permanent habitats like swamps and drainage canals from these swamps <a href="https://www.ncbi.nlm.nih.gov/pubmed/21352608">malaria vectors</a>. </p>
<p>During the <a href="https://www.ncbi.nlm.nih.gov/pubmed/?term=Plasmodium+falciparum+transmission+and+aridity%3A+a+Kenyan+experience+from+the+dry+lands+of+Baringo+and+its+implications+for+Anopheles+arabiensis+control">rainy season</a>, the breeding sites increase when seasonal rivers and manmade habitats such as pan dams, concrete tanks, ditches and trenches get filled up with water. This increases the number of vectors and hence the outbreaks.</p>
<p>Living conditions are also a challenge. Most of the houses have thatched roofs and don’t have adequate screening on the doors and windows. This means that mosquitoes can easily enter.</p>
<h2>A few solutions</h2>
<p>The challenges in Baringo can be tackled in a few ways. But these require the resources of Kenya’s national and county governments. </p>
<p>Firstly, the national government needs to improve security so that medical staff aren’t forced to flee for their safety. </p>
<p>Secondly, the county governments need to come to the party too:</p>
<ul>
<li><p>provide adequate supplies of anti-malarials as well as enough diagnostic facilities and equipment</p></li>
<li><p>increase their distribution of insecticide-treated bednets as only 52% of the population living in malaria risk zones has been covered. </p></li>
<li><p>improve the way they manage their environments and introduce targeted larval control. This includes filling up the unnecessary ditches and trenches, draining stagnant water and applying larvicides into the irrigation canals to reduce the vector population. The highly localised nature of breeding sites in these semi-desert environments provides a good opportunity. </p></li>
<li><p>improve public health education and awareness. Pregnant women should be told of the benefits of taking antimalarial drugs during pregnancy and other residents should be encouraged to sleep under insecticide treated nets and to avoid unnecessary exposure to mosquito bites. </p></li>
</ul>
<p>There are other, more radical steps, county governments could take. Because house types have become an important <a href="https://www.ncbi.nlm.nih.gov/pubmed/21352608">factor in malaria transmission</a> they could consider encouraging people to shift from mud grass thatched huts to concrete houses with sealable windows. </p>
<p>They could also consider deploying mobile clinics and investing in ambulances to ferry patients from far-flung parts of the counties. </p>
<h2>A malaria-free Kenya</h2>
<p>Kenya is one of the three countries in Africa selected for the trials of a <a href="https://www.businessdailyafrica.com/news/Kenya-picked-for-key-global-anti-malaria-vaccine-trial/539546-3902510-9wfahcz/index.html">malaria vaccine</a> administered to infants who are five-months-old. </p>
<p>If the vaccine does prove effective during these trials it could become part of the core package of World Health Organisation recommended interventions and could provide a solution for residents in seasonal transmission zones. </p>
<p>It is clear that Kenya has made substantial progress towards eliminating malaria and other communicable diseases. If the Ministry of Health remains committed to further reducing the malaria burden in coming years, a malaria-free Kenya is possible.</p><img src="https://counter.theconversation.com/content/95101/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eunice Anyango Owino works for the University of Nairobi as a lecturer and consults with the International Centre of Insect Physiology and Ecology. She receives funds from the National Commission for Science Technology and Innovation (NACOSTI) and the International foundation for Sciences (IFS). </span></em></p>Baringo county and other areas on the western side of Kenya are struggling to reduce their seasonal malaria caseloads.Eunice Anyango Owino, Medical Entomologist at the School of Biological Sciences, University of NairobiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/914202018-04-11T14:14:12Z2018-04-11T14:14:12ZWhy Kenya needs policies to tackle dengue and chikungunya viruses<figure><img src="https://images.theconversation.com/files/214267/original/file-20180411-577-1osrtcj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Kenya is one of several countries across the world experiencing an unprecedented outbreak of the <a href="https://www.cdc.gov/chikungunya/symptoms/index.html">chikungunya</a> and <a href="http://www.who.int/mediacentre/factsheets/fs117/en/">dengue</a> viruses. </p>
<p>Dengue fever and chikungunya are two of several arboviral diseases – which are spread to people when they’re bitten by an infected mosquito or tick. </p>
<p>Globally there’s been an <a href="http://www.who.int/mediacentre/factsheets/fs117/en/">increase in the emergence</a> and recurrence of these diseases. </p>
<p>Outbreaks have been reported in Europe – in <a href="http://www.who.int/csr/don/2012_10_17/en/">Portugal</a> in particular – as well as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3578748/">South East Asia</a> and the <a href="https://vector.amsa.org.au/2017/10/26/441/">Pacific Island countries</a>. Reports of <a href="https://www.japantimes.co.jp/news/2014/09/29/national/another-type-of-dengue-virus-found-in-japan/#.Ws39sn--nIU">dengue fever in Japan</a> have arisen after a lapse of more than 70 years. </p>
<p>And in Africa, Burkina-Faso has also seen <a href="http://www.who.int/csr/don/6-november-2017-dengue-burkina-faso/en/">recurrent dengue outbreaks</a> in the last two years. In <a href="http://outbreaknewstoday.com/dengue-cases-rise-in-brazil-as-does-dengue-spending-90861/">Brazil</a> more than 1.4 million people were infected with dengue in 2016 and have suffered serious after effects. </p>
<p>Kenya’s caseload has seen more than 100 people infected with chikungunya in Mombasa since January 2018 after another 100 were infected with dengue in the seaside town last year.</p>
<p>These are not the first incidents. In the last five years, there have been several outbreak reports of the same diseases in the North Eastern part of Kenya. According to <a href="http://www.who.int/csr/don/09-august-2016-chikungunya-kenya/en/">World Health Organisation records</a>, the town of Mandera in the north east of the country recorded 1700 positive cases of chikungunya in May 2016.</p>
<p>The challenge with these two viruses are that they have no vaccines or treatment. Controlling the vector is the only way to prevent and control these diseases so that outbreaks don’t get out of control. </p>
<p>But part of the problem is that the Kenyan government has not instituted any policies that could regulate the control of these diseases. The government has done this with malaria by instituting several policies in the <a href="http://ghdx.healthdata.org/organizations/national-malaria-control-program-nmcp-kenya">national malaria control programme </a> that has helped control the spread of the disease.</p>
<p>Unless the government establishes policies to deal with dengue fever and chikungunya, like it did for malaria, it will have challenges managing the spread. </p>
<h2>Malaria vector control</h2>
<p>Policies that prevent the spread of malaria in Kenya have been in place for over a decade. There are two main methods: <a href="https://www.malariaconsortium.org/media-downloads/802/Malaria%20prevention%20through%20insecticide%20treated%20nets">insecticide treated bednets</a> and <a href="https://www.malariaconsortium.org/pages/107.htm">indoor spraying of homes</a>. In parts of the country, these methods have resulted in the disease’s caseload <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-2119-y">decreasing by over 70%</a>. </p>
<p>But these measures would do little to contain the vector that spreads dengue and chikungunya. </p>
<p>This is because unlike for the malaria vectors that bite at night and can be controlled by sleeping under bed nets, <a href="https://www.ncbi.nlm.nih.gov/pubmed/5301574"><em>Aedes aegypti</em></a> – the main vector that spreads dengue fever and chikungunya – bites during the day. Sleeping under bed nets would therefore have minimal impact in the control of the diseases. </p>
<p>The spraying of insecticides is not advocated because it targets unintended organisms and has a detrimental effect on the environment. In addition, there is the challenge of insecticide resistance. </p>
<h2>A few suggestions</h2>
<p>There are two approaches that the national and county governments could try: urban planning policies as well as policies that target land use. Some of these could be simple and easy to achieve. </p>
<p><a href="https://www.ncbi.nlm.nih.gov/pubmed/29284522">Recent research</a> on the <em>Aedes aegypti</em> – also known as the black mosquito – has shown that the mosquito prefers breeding in:</p>
<ul>
<li><p>garbage like abandoned car tyres, plastic containers and tins,</p></li>
<li><p>water tanks and pots, and </p></li>
<li><p>shady areas </p></li>
</ul>
<p>Urban planning policies that tackle these three areas could reduce the transmission risks of dengue and chikungunya. </p>
<p>One example is a policy that encourages a cleaner environment and for people to dispose their solid waste properly. This would rid urban centres of garbage lying around that provides artificial man-made habitats for the black mosquito.</p>
<p>Another would be for government to provide enough tap water to residents so that water is not stored in pots and tanks. These should be accompanied by education campaigns which sensitise citizens about the importance of covering, emptying and cleaning their domestic water storage containers weekly.</p>
<p>And a third policy could be improved environmental management. This includes better drainage systems around residential areas, and clearing bushes and shady areas. This would help destroy the breeding sites for these mosquitoes. </p>
<p>In terms of land use, <a href="https://www.ncbi.nlm.nih.gov/pubmed/26711512">novel research</a> suggests that attempts to <a href="https://parasitesandvectors.biomedcentral.com/track/pdf/10.1186/s13071-016-1675-2?site=parasitesandvectors.biomedcentral.com">intensify agricultural production</a> could be linked to a high prevalence of dengue fever and chikungunya. In Kenya this could be caused by plants that have been imported into Kenya bringing in invasive weeds like <a href="https://keys.lucidcentral.org/keys/v3/eafrinet/weeds/key/weeds/Media/Html/Parthenium_hysterophorus_(Parthenium_Weed).htm">parthenium hysterophorous</a>. This weed is the <a href="https://www.ncbi.nlm.nih.gov/pubmed/2441221">preferred source of sugar</a> for mosquitoes. Similarly to the protein mosquitoes get from blood, sugar is important for the biology and ecology of mosquitoes. For male mosquitoes, it’s the main source of energy. </p>
<p>There could be a benefit for government to turn vast areas of agricultural land into conservancies.</p>
<p>It’s clear that with proper policies and planning, dengue and chikungunya can be controlled but the government must take the first steps.</p><img src="https://counter.theconversation.com/content/91420/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eunice Anyango Owino is a medical entomologist and works for the University of Nairobi. She consults with the International Centre of Insect Physiology and Ecology and has received funding from the International Foundation for Sciences (IFS), the National Commission For Science, Technology & Innovation, Kenya. </span></em></p>Kenya must establish policies to tackle dengue fever and chikungunya, like it did for malaria.Eunice Anyango Owino, Medical Entomologist at the School of Biological Sciences, University of NairobiLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/900942018-03-06T12:17:42Z2018-03-06T12:17:42ZMalaria control strategies reduce the caseload - but bring new challenges<figure><img src="https://images.theconversation.com/files/201913/original/file-20180115-101495-z6ksid.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Treated bed nets are effective in preventing malaria where mosquitoes bite indoors and late at night.</span> <span class="attribution"><span class="source">Katrina Manson /Reuters</span></span></figcaption></figure><p>Kenya’s <a href="https://theconversation.com/kenyan-study-shows-why-reusing-old-mosquito-nets-should-be-encouraged-76358">two major malaria prevention strategies</a> – indoor residual spraying of homes in high transmission areas and the issuing of insecticide treated nets – have led to a significant <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-2119-y">reduction in malaria transmission</a>.</p>
<p>The two methods were introduced in the country’s western highlands, traditionally considered a high transmission area, about a decade ago and have resulted in the disease’s caseload <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-2119-y">decreasing by about 80%</a>. </p>
<p>But the drop in cases has brought a new challenge: people have begun <a href="https://www.ncbi.nlm.nih.gov/pubmed/9186382">losing their immunity to the disease</a>. The consequence is that they are prone to contracting more complicated forms of the malaria that could result in death.</p>
<p>There are two types of immunity that people are able to develop naturally: clinical immunity and parasitological immunity. </p>
<p>People living in high transmission areas develop clinical immunity naturally after being exposed to the parasite and receiving successful treatment. Their bodies are able to resist infection. </p>
<p>They are also able to develop parasitological immunity. After being bitten by many infected mosquitoes over a long period, their bodies are able to withstand higher numbers of parasites in their blood. </p>
<p>When people don’t have parasitological immunity, they face the risk of becoming severely ill when the number of parasites in the blood increases. This can take the form of severe anaemia, cerebral malaria and eventually death. Children are particularly susceptible. </p>
<p>In our <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-2119-y">study</a> we focused on parasitological immunity in children. We wanted to understand how malaria prevention interventions such as bed nets and indoor spraying were preventing people from developing parasitological immunity. </p>
<p>We found that children who were less exposed to malaria as they grew up had lower levels of parasitological immunity. This exposed them to developing more severe strains of malaria.</p>
<p>Our findings should be taken on board as part of Kenya’s broader malaria prevention strategies. The government needs to maintain strong monitoring and surveillance networks to ensure that existing interventions are still sufficient. And it needs to work out new interventions to deal with the consequences of its interventions. </p>
<h2>Our study</h2>
<p>There is no functional test to measure the level of immune protection a person has developed. Some people have higher levels of immunity with fewer parasites in their blood. </p>
<p>Even though it’s not possible to pin down how individuals will react to malaria it is nevertheless possible to work out a person’s parasitological immunity. </p>
<p>Parasitological immunity is established by measuring the proportion of red blood cells that are infected in the body. Most people who get malaria have less than 1% of their red blood cells infected with the parasite, which rapidly multiplies. A person with 5% of their red blood cells infected is considered severely toxic. </p>
<p>We compared two sets of children, looking at the relationship between age and parasite density. We did two sets of surveys nine years apart. The first was done between June 2002 and December 2003 and the second between January 2012 and February 2015. School children between the ages of six and 13 were tested for malarial parasites in both periods. </p>
<p>When we did the first set of tests, malaria prevention tools had not yet been introduced in the highlands. The second set of children were exposed to the prevention tools. </p>
<p>We recorded the blood parasite densities – and thus infections trends – in each of the age groups. By doing this we were able to compare how the parasite density had changed between those who had grown up with bednets and indoor spraying or taken anti-malarial drugs, and those who hadn’t. </p>
<p>We found that people who had not experienced early interventions had high levels of immunity. </p>
<h2>A new gap</h2>
<p>But there’s a knock-on effect that complicates the scenario even further. People who hadn’t taken anti-malarial medicines or used treated bed nets were more likely to <a href="http://www.who.int/ith/diseases/malaria/en/">infect mosquitoes</a> because they continued to carry parasites in their blood. </p>
<p>This makes the rest of the population more susceptible to infections, with implications for the country’s broader malaria prevention strategy. </p>
<p>The risk of increased infection brings added complexity to government’s efforts. The only way to meet the challenge is to ensure that there are sufficient monitoring and surveillance strategies. </p>
<p>Another reason monitoring and evaluation matters is because mosquitoes are able to evolve and <a href="https://www.ncbi.nlm.nih.gov/pubmed/22861380">develop resistance to insecticides</a>. In addition malaria parasites can <a href="https://www.ncbi.nlm.nih.gov/pubmed/11517439">become resistant</a> to anti-malarial drugs.</p>
<p>Mosquitoes have also been shown to <a href="https://www.ncbi.nlm.nih.gov/pubmed/26209103">change their behaviour</a>, such as avoiding contact with insecticide treated surfaces. Where bed nets are used they have been shown to change from night time feeding to <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-015-0763-7">daytime or evenings before people go to sleep</a>. </p>
<p>If the government does not pick up these new trends early, as well as new and more severe infections, it will lose the gains it’s made against fighting malaria.</p><img src="https://counter.theconversation.com/content/90094/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andrew Githeko receives funding from NIH.</span></em></p><p class="fine-print"><em><span>Ednah Ototo does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Kenya has managed to reduce the number of malaria cases in parts of the country. But this, in turn, has led to immunity levels dropping.Andrew Githeko, Chief Research Officer, Kenya Medical Research InstituteEdnah Ototo, PhD Candidate , Medical Parasitologist, Kenya Medical Research InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/875302017-12-14T17:39:20Z2017-12-14T17:39:20ZPeople stay vigilant to the threat of malaria, even when infections fall<figure><img src="https://images.theconversation.com/files/198118/original/file-20171207-28921-i5c6y8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Karen Kasmauski/MCSP)</span></span></figcaption></figure><p>Since the turn of the century great strides have been made to reduce the burden of malaria in sub-Saharan Africa. But the disease, spread by the Anopheles mosquito, still remains a major threat: in 2015 there were an estimated 212 million cases worldwide, according to the most recent <a href="http://www.who.int/malaria/publications/world-malaria-report-2016/report/en/">World Malaria Report</a>. </p>
<p>Malaria can be prevented in several ways, in particular by sleeping under an insecticide-treated bed net and spraying homes with an insecticide. </p>
<p>Bed nets are a commonly used prevention method while indoor residual spraying is only done in specific high risk areas. In 2015, about 53% of the at-risk population in sub-Saharan Africa <a href="http://www.who.int/malaria/publications/world-malaria-report-2016/report/en/">slept under an insecticide treated net</a>. In the same period, 3.1% of the population at risk of contracting malaria in the region had their homes protected. </p>
<p>Bed nets are distributed through mass campaigns and at antenatal and child vaccination clinics. But of course people can decide not to use the nets, even if they receive one. Indoor residual spraying on the other hand is a public intervention carried out by national governments with the help of international organisations. </p>
<p><a href="https://hal-pjse.archives-ouvertes.fr/halshs-00911364/document">Our study</a> explores the effect of malaria risk in the area and of indoor residual spraying on individual decision to use bed nets. We focus on nine countries in sub-Saharan Africa in which malaria is endemic: Angola, Burundi, Cameroon, Liberia, Madagascar, Malawi, Mozambique, Tanzania and Uganda. Our data combines information on household behaviours and characteristics from <a href="http://dhsprogram.com/">the Demographic and Health Survey data</a> with information on malaria prevalence from <a href="http://www.map.ox.ac.uk/">the Malaria Atlas Project</a>.</p>
<h2>An eradication plan</h2>
<p>The World Health Organisation has set an ambitious goal of controlling and eradicating the disease by 2030. This includes reducing malaria cases and mortality rates by at least 90% and eliminating malaria in at least 35 countries by 2030.</p>
<p>But for eradication campaigns to be successful the relationships between malaria prevalence, indoor residual spraying and individual bed net usage are crucial. </p>
<p>Numerous studies have evaluated the effectiveness of bed nets and indoor residual spraying as malaria prevention interventions. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/198123/original/file-20171207-28958-nth8cd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A worker prepares a canister for internal residual spraying to prevent malaria in a high risk area in Ethiopia.</span>
<span class="attribution"><span class="source">flickr/USAID</span></span>
</figcaption>
</figure>
<p>But there are two points that may have been overlooked. The first is whether the risk of getting malaria – malaria prevalence in the area – has any effect on individual bed net usage. The second is whether bed nets are used in houses that are covered by an indoor residual spraying programme. </p>
<p>Our study investigates these two questions. Firstly, we ask whether the risk of being infected in an area influences people to use their bed nets. When the prevalence of the disease decreases in the area, does bed net usage decrease proportionally or more than proportionally? </p>
<p>Secondly, we investigate what effect spraying has on people using the nets: do people substitute the nets with spraying? Does a publicly provided intervention reduce the likelihood of people using the nets?</p>
<p>In most regions, bed nets are the main tool in the fight against malaria. If people are using bed nets less because they no longer see malaria as a threat, eradicating the disease may become impossible.</p>
<p>Our results show that as malaria prevalence falls, people reduce their bed net usage. Spraying does not reduce the proportion of people who chose to use a bed net. In fact, spraying increases the use of bed nets. </p>
<h2>A clear message</h2>
<p>One possible explanation for the increased use is that as governments and organisations go through houses spraying the insecticide, the households receive the message – either explicitly or implicitly – that malaria is a real threat and that one should do what they can to prevent it.</p>
<p>Individual responses to malaria risk and spraying programmes mean that international efforts to control the disease will not be hampered, as is feared. And it means that the global health community can continue its quest to eradicate malaria in the next 13 years.</p><img src="https://counter.theconversation.com/content/87530/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gabriel Picone receives funding from the Fogarty International Center for this project.</span></em></p><p class="fine-print"><em><span>Bénédicte Apouey received funding from the Fogarty International Center -- a branch of the United States government's National Institutes of Health -- for this project.</span></em></p><p class="fine-print"><em><span>Robyn Kibler does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When there are two malaria prevention interventions available people don’t take an either or approach – they consider that the two interventions are complementary.Gabriel Picone, Professor in the Department of Economics, University of South FloridaBénédicte Apouey, Chercheuse en sciences sociales au CNRS, Paris School of Economics – École d'économie de ParisRobyn Kibler, Postdoctoral Researcher, University of South FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/885772017-12-10T11:24:34Z2017-12-10T11:24:34ZGlobal malaria report reveals Africa’s hits and misses: here’s what to do<figure><img src="https://images.theconversation.com/files/197571/original/file-20171204-4062-tnv2cv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Most malaria cases and deaths occur in sub-Saharan Africa. </span> <span class="attribution"><span class="source">Susana Vera/Reuters</span></span></figcaption></figure><p>The <a href="http://www.who.int/malaria/publications/world-malaria-report-2017/report/en/">2017 World Malaria Report</a> provides a clear picture of the work required to control malaria. Data from over 90 countries reveals a dramatic reduction in the rates of disease and deaths between 2010 to 2015. But malaria deaths remained unchanged in Africa from 2015 to 2016.</p>
<p>During the same time period, the number of malaria deaths stalled in South-East Asia and Western Pacific while increasing in the Eastern Mediterranean and the Americas.</p>
<p>There is no magic bullet yet for malaria control. But it appears that even the most familiar prevention strategies are not being fully utilised. For example, under trial conditions, insecticide treated bednets convincingly demonstrated a <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000363/abstract">cut in malaria by half</a>. Yet this year’s report indicates that coverage of bednets is about 54%. This means that nearly half of the people who should be sleeping under the nets are not. The main drawback is funding to supply bednets and deliver them where they are needed most.</p>
<p>On top of that, <a href="https://wwwnc.cdc.gov/eid/article/20/10/14-0619_article">resistance to the only insecticide</a> currently used for treating bednets has been reported in <a href="http://apps.who.int/iris/bitstream/10665/259492/1/9789241565523-eng.pdf?ua=1%20**is%20it%20strange%20to%20have%20a%20link%20the%20world%20malaria%20report%20again%20here%20or%20is%20it%20ok?**">over two thirds of African sites</a> that have been monitored. There is a gap both in coverage of bednets and in research of new insecticides.</p>
<p>Although the 2017 World Malaria Report shows a plateau of the impact of malaria prevention and control strategies, this is not because they have reached their full potential. Far from it. The current interventions are hardly enough to eradicate malaria but if fully put to use, thousands of lives would be saved. </p>
<p>If the rate of decline of malaria disease and death has plateaued, we should not pretend that things will get better from this point. As <a href="http://who.int/malaria/publications/world-malaria-report-2017/WMR-2017-foreword-eng.pdf">Dr Tedros Adhanom Ghebreyesus, WHO secretary general says</a>:</p>
<blockquote>
<p>The choice before us is clear. If we continue with a “business as usual” approach – employing the same level of resources and the same interventions – we will face near-certain increases in malaria cases and death.</p>
</blockquote>
<p>New interventions are needed to suit a variety of malaria transmission patterns. New ways of utilising old methods have also been shown to work.</p>
<h2>New strategies needed</h2>
<p>Giving anti-malarials to healthy people to prevent malaria disease and death is not a new thing and <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD000169.pub2/full">is used routinely in pregnant women</a> , <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003756.pub3/full">pre-school children </a>,<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4647321/">school children</a> and <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD008846.pub2/full">whole communities</a> in malaria endemic areas. Despite the evidence available on the utility of this approach, it has been rolled out consistently as routine policy among pregnant women only. </p>
<p>However, in the Sahel region, which includes countries whose northern border is the Sahara desert like Burkina Faso, Cameroon, Chad, Gambia, Ghana, Guinea, Guinea-Bissau, Mali, Niger, Nigeria, Senegal and Togo, the malaria season is brief and intense. Almost all malaria disease and death occurs within the three to four month rainy season and <a href="https://www.msf-me.org/article/malaria-msf-provides-preventive-treatment-to-children-in-the-sahel-region">over 20 million children</a> are at risk.</p>
<p>Studies done in the 2000s to determine whether the monthly use of anti-malarials during the rainy season among children six months to five years reduced malaria cases showed that it <a href="http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD003756.pub4/abstract">reduced malaria disease by 75%</a>. </p>
<p>Using the evidence from this review, in 2012 the WHO made a <a href="http://www.who.int/malaria/publications/atoz/who_smc_policy_recommendation/en/">recommendation</a> that the seasonal intervention with sulphadoxine pyrimethamine and amodiaquine should be given at monthly intervals for three to four months in parts of sub Saharan Africa with highly seasonal malaria and where the parasite is sensitive to these drugs.</p>
<p>However, the 2017 World Malaria Report shows that over 13 million children who could have benefited from seasonal treatment with anti-malarials in 2016, were not covered due to lack of funding.</p>
<h2>Exploring new fronts</h2>
<p>Building on this strategy, malaria expert <a href="https://royalsociety.org/people/brian-greenwood-11537/">Professor Brian Greenwood</a> has suggested that <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-1841-9">the use of a partially effective malaria vaccine</a>, RTS,S/AS01, during the malaria season may also be useful in the Sahel region. </p>
<p>But rolling out the malaria vaccine will not be as straight forward as giving children medicine to swallow. The <a href="https://www.ncbi.nlm.nih.gov/pubmed/22940378">vaccine requires refrigeration</a> and the children will need to receive multiple injections to attain efficacy. The potential of seasonal vaccination would be worth the difficulties if new malaria vaccines with better efficacy would be developed. </p>
<h2>A promising future</h2>
<p>In the meantime, there are simpler ways to improve the delivery of seasonal anti-malarials to children. In a <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-017-1974-x">recently published study from Mali</a>, the health workers had to crush the tablets in water and add sugar to make it more palatable. How much better it would be if there was a sugar-free flavoured solution for children? Considering the millions of doses of the drug needed, a developing world pharmaceutical company should consider making a more edible version of the medicine. </p>
<p>Finally, all is not lost because African countries such as <a href="http://apps.who.int/iris/bitstream/10665/205565/1/WHO_HTM_GMP_2016.3_eng.pdf">Egypt and Morocco have been malaria free since 2000</a>. According to the WHO to attain this status requires a country to demonstrate that there have been no indigenous malaria cases reported for three years in a row. Algeria achieved this feat in 2016 and another five African countries: Botswana, Cape Verde, Comoros, South Africa and Swaziland have been identified as most likely to eliminate malaria by 2020. </p>
<p>It is encouraging to watch malaria disappear in some parts of Africa, raising hope for the fight against malaria.</p><img src="https://counter.theconversation.com/content/88577/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tabitha Mwangi does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>After an exceptional period of success in global malaria control, the progress has stalled. New strategies are needed to suit a variety of transmission patterns.Tabitha Mwangi, Senior Lecturer, Anglia Ruskin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/863552017-11-22T12:17:49Z2017-11-22T12:17:49ZHow drones are being used in Zanzibar’s fight against malaria<figure><img src="https://images.theconversation.com/files/195789/original/file-20171122-6013-yq6uu8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Makame Makame from the Zanzibar Malaria Elimination Programme holds one of the drones used to map malaria vectors.</span> <span class="attribution"><span class="source">Andy Hardy</span></span></figcaption></figure><p>On a typically hot and humid July day in Stonetown, the capital of Zanzibar, a gaggle of children, teenagers and the odd parents watched our small drone take flight. My colleagues Makame Makame, Khamis Haji and I had finally found the perfect launch spot.</p>
<p>With a high-pitched humming, the drone took to the air. It sounded like a big mosquito – appropriate, since we were testing the use of drones for mapping aquatic malaria habitats. These shallow sunlit water bodies teem with mosquito larvae. In a matter of days, the larvae will emerge as adult mosquitoes in search of a blood meal. If one of those mosquitoes bites a human infected with malaria, it will become a vector for the disease and continue its deadly transmission cycle.</p>
<p>Zanzibar is a Tanzanian archipelago off the coast of East Africa. Both it and mainland Tanzania have fought a long, well documented battle with malaria. <a href="http://www.who.int/gho/malaria/epidemic/deaths/en/">Globally</a>, the disease infects over 200 million people annually and is responsible for killing approximately 500,000 people each year.</p>
<p>The <a href="http://www.who.int/topics/millennium_development_goals/diseases/en/">Millennium Development Goals</a> prompted a number of large scale campaigns across sub-Saharan Africa to combat malaria. <a href="https://www.cdc.gov/malaria/malaria_worldwide/reduction/itn.html">Millions of bed nets</a> were distributed. Insecticide was supplied to spray in homes across communities. The aim was to stop people getting bitten, interrupting the transmission cycle. </p>
<p>It’s been a real success story, leading to a notable decrease in the disease’s prevalence. Some areas of Zanzibar have seen <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3639098/">prevalence levels drop</a> from 40% of the population having malaria to less than 1%.</p>
<p>Now epidemiologists and public health managers are looking to complement indoor-based nets and spraying with outdoor based solutions. In effect, they’re taking the battle to mosquitoes. And drones are a crucial part of their armoury. One of the main challenges to disease managers is finding small water bodies that mosquitoes use to breed. This is where drones come in – for the first time, drone imagery can be captured over large areas which can be used to create precise and accurate maps of potential habitats.</p>
<h2>Tracking mosquitoes</h2>
<p>We <a href="https://www.cdc.gov/malaria/about/biology/mosquitoes/">know</a> that once an adult mosquito has fed and rested, it will typically go in search of a mate. Then it moves on to a suitable location – an aquatic habitat like the fringes of river channels, roadside culverts and irrigated rice paddies – to lay its eggs.</p>
<p>Public health authorities need to be able to locate and map these water bodies so they can be treated using a larvicide like DDT. This process is known as larval source management, and was successfully used in Brazil and Italy many decades ago. There, the DDT killed mosquito larvae – but could also be <a href="http://www.sciencedirect.com/science/article/pii/S0169475899016051">devastating</a> for local ecology as well as having adverse effects on human health.</p>
<p>Today much safer, low toxicity replacements have been developed. The problem is that they come at a cost. Resources are also needed to disseminate the larvicide and to locate the water bodies that host the mosquito eggs and larvae. Some of these hideaways are tough to find on foot, and if water bodies are accurately mapped a larvicide campaign could end up being a waste of time.</p>
<p>My institution, <a href="https://www.aber.ac.uk/en/dges/staff-profiles/listing/profile/ajh13">Aberystwyth University</a> in Wales, is working with the Zanzibar Malaria Elimination Programme to fly drones over known malaria hot spots. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=357&fit=crop&dpr=1 600w, https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=357&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=357&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=449&fit=crop&dpr=1 754w, https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=449&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/192794/original/file-20171101-19858-1muno94.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=449&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A rice paddy in Mwera, Zanzibar. These and other watery sites are perfect spots for mosquitoes to lay their eggs.</span>
<span class="attribution"><span class="source">Image collected by Andy Hardy using a DJI Phantom 3 drone.</span></span>
</figcaption>
</figure>
<p>In 20 minutes, a single drone is able to survey a 30 hectare rice paddy. This imagery can be processed and analysed on the same afternoon to locate and map water bodies. This has proved to be highly accurate and efficient. This is all using one of the most popular off-the-shelf drones, the Phantom 3 made by DJI. These are about the size of a shoebox, weighing a little more than a bag of sugar (1.2 kg) and are used throughout the world for both leisure and commercial photography.</p>
<p>We started off working in test locations across Zanzibar but now, with the support of the <a href="http://www.ivcc.com/">Innovative Vector Control Consortium</a> – a non-for-profit partnership aiming to create novel solutions for preventing disease transmission – we’re widening our range to explore how this technology can be incorporated into operational malaria eliminating activities.</p>
<p>It doesn’t stop there. We plan to incorporate the drone imagery into smartphone technology to help guide larvicide spraying teams to water bodies on the ground, and to track their progress and coverage. There’s also an exciting drive towards automatically disseminating larvicide from the drones themselves.</p>
<h2>Getting people involved</h2>
<p>Despite these exciting advances, operators need to be mindful of the negative side of drones: invasion of privacy; collisions with aircraft and birdlife; their association with warfare. These are very real concerns for the public.</p>
<p>In Zanzibar, we worked alongside village elders to show them the drones and explain exactly what we plan to use them for. We also encouraged people to gather around when we were looking at live-feed footage from the drone’s onboard camera. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/-pkmgpcNXFg?wmode=transparent&start=59" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Collation of drone imagery recorded using a DJI Phantom 3 over a range of sites across Zanzibar.</span></figcaption>
</figure>
<p>This introduced people to our work and gave them a chance to see how drones and similar technologies, used alongside traditional indoor-based interventions, can really help to make malaria elimination in their community a reality.</p><img src="https://counter.theconversation.com/content/86355/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Andy Hardy receives funding from the UK Natural Environment Research Council, the UK Space Agency and the Innovative Vector Control Consortium. </span></em></p>Epidemiologists and public health managers are looking to complement indoor-based malaria solutions with those that focus on the outdoors. Drones are a crucial part of their armoury.Andy Hardy, Lecturer in Remote Sensing and GIS, Aberystwyth UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/870202017-11-14T13:27:52Z2017-11-14T13:27:52ZSouthern Africa is slipping again after coming close to eliminating malaria<figure><img src="https://images.theconversation.com/files/194542/original/file-20171114-27625-6lfukr.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Brant Stewart/RTI</span></span></figcaption></figure><p><em>In the last five years, South Africa, Botswana, Namibia and Swaziland have all been on the verge of eliminating malaria. In fact, progress had been so good that the southern African region had been tipped to be malaria free by 2018. But a spike in cases this year means that it’s unlikely to meet the target. A new target has been set for 2020. The Conversation Africa’s Health and Medicine editor Candice Bailey asked Professor Rajendra Maharaj to explain why.</em></p>
<p><strong>Why has there been a spike in malaria cases in southern Africa? Is it unusual?</strong></p>
<p>Over the last few years there has been a downward trend in the number of malaria cases globally. There was a <a href="https://theconversation.com/parts-of-southern-africa-are-within-tantalising-reach-of-eliminating-malaria-49848">marked decrease in cases</a> in South Africa and in several other countries in the region including Swaziland, Botswana and Namibia. This trend was so encouraging that the region had become comfortable with the idea that it would reach the target of eliminating malaria by 2018. South Africa, for example, experienced a serious epidemic in the 1999/2000 malaria season where over 62 000 cases were recorded but with reinforced interventions, the cases decreased to under 5 000 in 2016.</p>
<p>The countries in the region achieved this by implementing evidence-based indoor residual programmes and improving diagnostics and treatment, introducing artemisinin-based combination therapy.</p>
<p>But this year <a href="http://www.nicd.ac.za/index.php/update-malaria/">figures</a> in some parts of South Africa were triple what they were last year. The reality is that in only some parts of the country will we have eliminated malaria. Although the number of cases reported from KwaZulu-Natal increased, it’s still possible to reach the 2020 goal but the same can’t be said for Mpumalanga and Limpopo. These two areas receive many imported cases from Mozambique and Zimbabwe. </p>
<p>This spike is not restricted to South Africa. It has happened in all <a href="http://www.nicd.ac.za/index.php/malaria-advisory-april-2017/">southern African countries</a>. But the increase has been the greatest in Namibia and Swaziland.</p>
<p>We have yet to confirm what caused the spike in the region. We know that the mild winter conditions created fertile ground for mosquito breeding. But we still need to understand what’s behind the increase in cases so that we can tackle the problem. </p>
<p>There are many questions. For example, was there a failure in the case management? Was there a relaxed attitude to implementing all the planned interventions? We still need to answer these questions. There are several possible reasons for the spike.</p>
<p>One possibility is the sub-optimal insecticide spray coverage contributed to the increased transmission. Another is the Malaria Control Programme was ill prepared for the epidemic. At one point this year there was as shortage of drugs in the province and these had to brought in as a matter of urgency after the epidemic struck. </p>
<p>A third possibility is that with heavy rains preceding a very dry period, there were many suitable pools for breeding and the hot conditions were ideal for mosquito breeding.</p>
<p><strong>How does the region handle malaria control currently. Are there weaknesses in the strategy?</strong></p>
<p>To control malaria, countries in the region use one of two strategies: <a href="http://apps.who.int/iris/bitstream/10665/177242/1/9789241508940_eng.pdf?ua=1&ua=1">indoor residual spraying</a> (IRS) and the use of <a href="http://www.who.int/mediacentre/factsheets/fs094/en/">Long-lasting Insecticide Treated Nets</a> (LLINs). These are either used in isolation or as part of an integrated programme. South Africa uses indoor residual spraying and little larval control measures that targets the breeding sites of mosquitoes. In Swaziland, Botswana and Namibia the focus has been on indoor spraying but net coverage has achieved high levels in these countries. </p>
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<p>The World Health Organisation <a href="http://www.who.int/heli/risks/vectors/malariacontrol/en/index6.html">recommends</a> the use of integrated mosquito control where more than one method is used.</p>
<p><strong>What are the other challenges in controlling malaria in the region? And why does the focus need to change?</strong></p>
<p>The region’s most powerful and effective vector control strategy has been spraying houses with the powerful insecticide DDT through the indoor residual spraying. But the impact of indoor residual spraying is often diluted due of <a href="http://www.who.int/malaria/publications/atoz/insecticide-resistance-implications/en/">insecticide resistance</a> to the currently used insecticides. Insecticides should be used on a rotational basis or in a mosaic spray pattern to mitigate resistance developing.</p>
<p>In areas where there’s been high levels of transmission, it was found that the spray coverage for insecticides recommended by the World Health Organisation wasn’t optimal. It’s <a href="http://apps.who.int/iris/bitstream/10665/177242/1/9789241508940_eng.pdf?ua=1&ua=1">recommendation</a> is that 80% of the houses in a malaria infected community should be sprayed. But the region is not achieving this coverage.</p>
<p>Another cause for concern is that there are an increasing number of people refusing to have their homes sprayed with insecticide. This may be due to a lack of awareness of the need to have the houses sprayed. The reasons for this are unclear, but its suspected to be linked to the disease burden being low. </p>
<p>Participating in the indoor residual spraying programme is purely voluntary. People can’t be forced to have their homes sprayed as there is no legislation in place to compel them to have their houses sprayed. If people refuse, there’s nothing that can be done except to educate the homeowner to gain permission to spray. </p>
<p><a href="http://www.who.int/heli/risks/vectors/malariacontrol/en/index6.html">DDT</a> is the cheapest insecticide. It has a long residual life on the market and as a result countries with limited resources use it as a tool to control vectors. There is very little resistance to DDT in the region but there is enormous political pressure to move away from using DDT.
What is needed in these countries are robust public awareness campaigns informing people that, even when there have the is no disease, malaria can resurge as long as there are vector mosquitoes in the area. </p>
<p>There is evidence from developing countries in other parts of the world that elimination can be achieved. Sri Lanka is the latest country to <a href="http://www.searo.who.int/mediacentre/releases/2016/1631/en/">achieve elimination</a>. They had a very strong vector control programme that succeeded in reducing the caseload significantly. Once this was achieved proper case management further reduced the case numbers. </p>
<p>And when there were no local cases an intensive surveillance programme was implemented. Although elimination was achieved, entomological surveillance and disease surveillance was strengthened.</p><img src="https://counter.theconversation.com/content/87020/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rajendra Maharaj does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A spike in the number of malaria cases in southern Africa means that the region will not meet its initial target of eliminating malaria by 2018.Rajendra Maharaj, Unit Director of the Office of Malaria Research , South African Medical Research CouncilLicensed as Creative Commons – attribution, no derivatives.