tag:theconversation.com,2011:/fr/topics/malaria-treatment-26772/articlesmalaria treatment – The Conversation2023-03-07T10:10:16Ztag:theconversation.com,2011:article/2007532023-03-07T10:10:16Z2023-03-07T10:10:16ZA new invasive mosquito has been found in Kenya – what this means for malaria control<figure><img src="https://images.theconversation.com/files/513173/original/file-20230302-19-92bytq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Malaria transmission in Kenya has been largely limited to the coast and western parts of the country.</span> <span class="attribution"><span class="source">Shutterstock </span></span></figcaption></figure><p>The Kenya Medical Research Institute <a href="http://kemri.go.ke/wp-content/uploads/2023/02/Evidence-Brief-Anopheles-stephensi-in-Kenya-potentially-substantial-threat-to-malaria-transmission-in-urban-and-rural-areas.pdf">recently detected</a> an invasive mosquito species in Laisamis and Saku subcounties of Marsabit county in Kenya’s northern region. </p>
<p>This mosquito, <em>Anopheles stephensi</em>, is native to South Asia and the Middle East. It <a href="https://pubmed.ncbi.nlm.nih.gov/33496217/">transmits the two malaria parasites</a> that pose the greatest risk of severe illness and death: <em>Plasmodium falciparum</em> and <em>Plasmodium vivax</em>. </p>
<p>The detection of this mosquito poses a major public health threat to Kenya for several reasons. </p>
<p>Malaria transmission in Kenya has been largely limited to the coast and western parts of the country. This is far from its major urban centres. The areas where <em>Anopheles stephensi</em> has been detected are urban and peri-urban. This mosquito thrives in urban settings. </p>
<p>Until now, Kenya’s malaria transmission has been driven by <a href="https://www.kemri.go.ke/wp-content/uploads/2023/02/"><em>Anopheles gambie</em></a> and <a href="https://www.kemri.go.ke/wp-content/uploads/2023/02/"><em>Anopheles funestus</em></a>. These vectors don’t cope very well with polluted water in urban centres.</p>
<p><em>Anopheles stephensi</em> on the other hand, <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-016-1321-7">can breed in</a> cisterns, jerrycans, tyres, open tanks, sewers, overhead tanks, underground tanks and polluted environments. Furthermore, the mosquito is invasive. It spreads very fast to new areas. It can adapt to various climatic conditions, unlike the non-invasive malaria vectors whose survival in cold temperatures in high altitude areas is restricted.</p>
<p>The invasion by this mosquito could pose a significant threat to Kenya’s efforts to control and eliminate malaria. The country must take immediate action to assess the threat and put prevention strategies in place. </p>
<h2>What are the consequences?</h2>
<p>If <em>Anopheles stephensi</em> were to spread in a city like Nairobi, the consequences would be serious. </p>
<p>First, malaria could spread to the inner-city areas. Until now, these areas have had little or no transmission and their populations have not acquired immunity against malaria. </p>
<p>Secondly, urban development would no longer be assumed to contribute to malaria elimination. Urbanisation has added to many health problems. But it has tended to “<a href="https://www.nature.com/articles/s41586-019-1050-5">build out</a>” malaria through better housing and gradual pollution of the landscape. Traditional malaria vectors can’t breed in small containers or in water with organic pollution. The new invasive species may mean that the development of new suburbs is building malaria into the landscape.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mosquito-species-from-asia-poses-growing-risk-to-africas-anti-malaria-efforts-188837">Mosquito species from Asia poses growing risk to Africa's anti-malaria efforts</a>
</strong>
</em>
</p>
<hr>
<p>Traditional malaria vectors are <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-021-03891-z">already finding space</a> in urban areas because of extensive urban agriculture, untended green space, and unplanned urban sprawl with poor water management. Some of these characteristics have enabled mosquito vectors to maintain malaria transmission, in some cases like in Bioko Island, Equatorial New Guinea, at <a href="https://link.springer.com/article/10.1186/1756-3305-5-253">prevalence rates</a> as high as 30% to 40%. </p>
<p>There is also the risk that malaria from the cities will be exported to the rural areas. Regions in western Kenya and the coast are likely to suffer from spikes especially during the seasons where town dwellers visit during holiday seasons like Christmas.</p>
<p>The densely populated urban centres in these regions are likely to suffer the most. They are <a href="https://www.pnas.org/doi/10.1073/pnas.2003976117">seen as</a> highly suitable for <em>Anopheles stephensi</em> expansion due to the high population and conducive environmental and ecological factors like warm temperatures.</p>
<p>Traditional anti-malaria tools such as insecticide residual spraying are harder to use against <em>Anopheles stephensi</em> because its resting and feeding behaviour are different from other vectors.</p>
<p><em>Anopheles stephensi</em> has also proved to be <a href="https://malariajournal.biomedcentral.com/articles/10.1186/s12936-021-03801-3">resistant</a> to most of the publicly available insecticides.</p>
<h2>A few solutions</h2>
<p>What can be done to stop the spread of this invasive species: </p>
<ul>
<li><p>Increase collaboration and encourage integrated management. Since this is an urban malaria vector, the ministries of agriculture, health, education, environment, sanitation and water resources and county governments all need to work together. National responses to <em>Anopheles stephensi</em> should be integrated with efforts to control malaria and other mosquito-borne diseases, such as dengue fever, yellow fever and chikungunya. </p></li>
<li><p>Develop guidance for national malaria control programmes on appropriate ways to respond to <em>Anopheles stephensi</em>.</p></li>
</ul>
<hr>
<p>
<em>
<strong>
Read more:
<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>
</strong>
</em>
</p>
<hr>
<ul>
<li><p>Strengthen surveillance. The extent of the spread and the impact <em>Anopheles stephensi</em> has on malaria transmission in Kenya is not clear yet. Confirming both would be important in laying down management strategies to protect against disease outbreaks, particularly in urban settings, in the coming years. </p></li>
<li><p>Improve information exchange. Awareness of <em>Anopheles stephensi</em> should be boosted in communities most at risk. They should be advised to frequently replenish stored water for domestic use. People must also keep their environments free of discarded containers as these could be good breeding grounds for this invasive species.</p></li>
<li><p>A global policy and cross-border collaboration between the affected countries. Eradicating <em>Anopheles stephensi</em> from the Horn of Africa would be much cheaper in the long run than leaving it to spread to towns and cities.</p></li>
</ul><img src="https://counter.theconversation.com/content/200753/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eunice Anyango Owino receives funding from National Research Fund of Kenya (NRF) and International Foundation For science. </span></em></p>This mosquito spreads very fast to new areas and can adapt to various climatic conditions, unlike the non-invasive malaria vectors.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/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>
<hr>
<p>
<em>
<strong>
Read more:
<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>
</strong>
</em>
</p>
<hr>
<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>
<hr>
<p>
<em>
<strong>
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>
</strong>
</em>
</p>
<hr>
<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>
<hr>
<p>
<em>
<strong>
Read more:
<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>
</strong>
</em>
</p>
<hr>
<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>
<hr>
<p>
<em>
<strong>
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>
</strong>
</em>
</p>
<hr>
<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/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/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/854822017-10-17T05:01:10Z2017-10-17T05:01:10ZWhat 115 years of data tells us about Africa’s battle with malaria past and present<figure><img src="https://images.theconversation.com/files/190628/original/file-20171017-30381-111agig.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The prevalence of malaria infection in sub-Saharan Africa today is at the lowest point since 1900.</span> <span class="attribution"><span class="source">Penn State/Flikr</span></span></figcaption></figure><p>It’s difficult to accurately measure the number of people who get malaria each year. This is because the malaria symptoms are <a href="https://www.fic.nih.gov/news/globalhealthmatters/pages/malaria-misdiagnosis.aspx">shared with many other diseases</a> that lead to death or illness, especially among young children. </p>
<p>However, there is a measure of malaria that is precise. Testing for the malaria parasite among large numbers of people provides a Parasite Rate, a useful measure of the quantity of malaria in any given area.</p>
<p>Surveys are done on a known number of people by malaria control programmes, non governmental organisations and researchers. Although they don’t tell us how many people are sick, the number of infected people in an area is indicated.</p>
<p>We spent the last <a href="http://www.tropicalmedicine.ox.ac.uk/115-years-of-malaria-in-africa">21 years tracking down malaria survey reports</a> done across Africa. The greatest challenge was that they were mostly hidden in old government archives or curated by the World Health Organisation. </p>
<p>Most of the records were either poorly stored, burnt or were missing. In some countries like Kenya, Senegal, Tanzania, South Africa, Botswana, Namibia and Burkina Faso the surveys dated back 1950s. Conversely, recent surveys have been easier to locate through more modern web based searches.</p>
<p>To obtain village or school level data published in most journals or reports, scientists and government officials provided the raw data. This is a testament to a new era of data sharing where over 800 people have contributed finer resolution data.</p>
<p>The <a href="https://www.nature.com/nature/journal/vaop/ncurrent/full/nature24059.html">final report</a> covers over 50,000 surveys dating back 115 years. This is the largest repository containing information on over 7.8 million blood tests for malaria. We analysed malaria infection prevalence for each of 520 administrative units across countries south of the Sahara and Madagascar for 16 time periods.</p>
<p>The study suggests that the prevalence of malaria infection in sub-Saharan Africa today is at the lowest point since 1900.</p>
<h2>Declining malaria cases</h2>
<p>Overall, there was a decline in the number of children infected with malaria at 24% between 2010 and 2015 compared to 40% between 1900 and 1929.</p>
<p>The biggest historical reduction in malaria coincided with the introduction of new tools to fight malaria. After the <a href="https://www.britannica.com/event/World-War-II">Second World War</a>, the discovery of <a href="https://www.malarianomore.org/why-end-malaria/">DDT</a> for indoor spraying and <a href="http://apps.who.int/medicinedocs/en/d/Jh2922e/2.5.1.html">chloroquine</a> drugs made a difference in treating malaria. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=713&fit=crop&dpr=1 600w, https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=713&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=713&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=896&fit=crop&dpr=1 754w, https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=896&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/190787/original/file-20171018-32375-3cer7k.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=896&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Changing patterns of malaria in sub Saharan Africa.</span>
<span class="attribution"><span class="source">Bob Snow</span></span>
</figcaption>
</figure>
<p>Investment in malaria control in Africa has been sporadic in the past. The world has seen a reduction in malaria over the last 15 years, based largely on the use of treated bed nets and antimalarial drugs. If we take our eye off the ball then rising <a href="http://www.who.int/csr/resources/publications/drugresist/malaria.pdf">drug resistance </a> and falling control will lead to the sorts of increases we saw in the 90s.</p>
<p>Again, in 2005 the rolling out of <a href="https://www.cdc.gov/malaria/malaria_worldwide/reduction/itn.html">insecticide treated bed nets</a> and new anti antimalarial drugs, led to a <a href="http://apps.who.int/medicinedocs/documents/s18401en/s18401en.pdf">further drop of malaria cases</a>.</p>
<p>The lowest periods of malaria prevalence were evident when the international community abandoned specific malaria control investment in Africa, during the late 1960s, through the 1970s and early 1980s. As a result, every fever was treated with chloroquine, an amazingly effective drug. There was a <a href="http://www.bbc.co.uk/schools/gcsebitesize/geography/weather_climate/weather_human_activity_rev6.shtml">prolonged drought across the Sahel</a>. This was the perfect lull.</p>
<p>However, from the late 1980s <a href="http://www.sciencedirect.com/science/article/pii/S0960982298702180">chloroquine resistance</a> expanded across Africa. It was made worse in the 1990s when <a href="https://wwwnc.cdc.gov/eid/article/13/5/06-1333_article">unprecedented rainfall</a> led to flooding causing major malaria epidemics. Governments in Africa were unprepared because they did not have significant mosquito prevention and management strategies in place. <a href="https://wwwnc.cdc.gov/eid/article/13/5/06-1333_article">Malaria cases increased</a> and the prevalence was similar to those described before the Second World War. The perfect storm.</p>
<p>It took over five years for the international community to appropriately respond by providing free, and effective malaria treatments to vulnerable persons in the affected countries. They ensured access to effective malaria prevention tools which a decade earlier had reduced the malaria risk by half.</p>
<p>The <a href="https://www.theglobalfund.org/en/">Global Fund’s</a> financial boost and the revisions of the <a href="http://www.who.int/malaria/publications/atoz/9241593199/en/">2005 world malaria report</a> led to one of the largest drops in malaria infection prevalence witnessed.</p>
<h2>More effective strategies needed</h2>
<p>The gains made after 2005 have stalled since 2010. Declining <a href="https://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-13-39">malaria funding</a>, <a href="http://www.who.int/malaria/areas/vector_control/insecticide_resistance/en/">insecticide</a> and <a href="http://www.who.int/malaria/areas/drug_resistance/overview/en/">drug resistance </a> are the obvious threats to the elimination of malaria in Africa.</p>
<p>Despite an impressive overall decline in malaria prevalence since 1900, Africa has the highest infection risks globally. Large parts of West through to Central Africa and down to <a href="https://www.africanindy.com/environment/new-scheme-brings-hope-for-end-of-malaria-in-mozambique-11390127">Mozambique</a> continue to have intense malaria transmission.</p>
<p>Unfortunately DDT, new insecticides, chloroquine and new combination treatments and insecticide treated bed nets have not been effective enough to shrink this high malaria burden. We need new tools.</p>
<h2>What next?</h2>
<p>There is an urgent need to focus on the high burden countries in Africa, they should not be left behind in a new global agenda for malaria elimination.</p>
<p>It is complex and predicting a future malaria landscape based on climate or economic development alone would be foolhardy. It needs a more integrated approach.</p>
<p>What we can say however is that the malaria map in Africa might shrink a bit at the margins but that middle belt isn’t going anywhere in our lifetimes with what we have at our disposal now – bed nets and drugs. </p>
<p>When insecticide and drug resistance becomes established, unless we have new classes of both drugs and insecticides or a natural period of drought, malaria will revert in large parts of Africa to what it was in the 1990s, another perfect storm.</p><img src="https://counter.theconversation.com/content/85482/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bob Snow receives funding fromThe Wellcome Trust as a Principal Fellowship (# 103602) and acknowledges the support of the Wellcome Trust for the Kenya Major Overseas Programme (# 203077), he also receives support from the Department for International Development (UK) - Strengthening the Use of Data for Malaria Decision Making in Africa (DFID Programme Code # 203155)</span></em></p>The history of malaria prevalence in Africa is a long term cycle of highs and lows. However, there’s been little change in the high transmission belt that covers parts of West and Central Africa.Bob Snow, Professor of Malaria Epidemiology, Centre for Tropical Medicine & Global Health, Nuffield Department of Medicine,, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/575162016-04-20T04:36:40Z2016-04-20T04:36:40ZWhy over-treating malaria in Africa is a problem, and how it can be stopped<figure><img src="https://images.theconversation.com/files/119236/original/image-20160419-13898-h2wcv4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">In Africa, over-treatment happens when a person who has malaria symptoms gets medication without a test.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/worldbank/7826340142/">Arne Hoel/World Bank</a></span></figcaption></figure><p>Malaria policymakers and clinicians are concerned about the clinical, financial and public health harms associated with over-treating malaria. </p>
<p>Over-treatment happens when a person who doesn’t have malaria is given antimalarial drugs unnecessarily. This could be a person who has malaria-like symptoms such as fever. </p>
<p>About 88% of the world’s malaria cases are found <a href="http://www.who.int/malaria/publications/world-malaria-report-2015/report/en/">in Africa</a>. As a result, over-treatment of malaria is most common on the continent. </p>
<p>There are three main issues with over-treatment. </p>
<ul>
<li><p>The first is that because malaria has been so prevalent there is a danger that all fevers are diagnosed as being caused by the disease. This means that other serious infections could be missed. This is particularly true as the number of malaria cases has <a href="http://www.afro.who.int/en/downloads/cat_view/1501-english/1235-clusters-and-programmes/795-malaria-mal.html?start=15">dropped</a> in many countries. </p></li>
<li><p>Second, the <a href="http://www.who.int/malaria/publications/world-malaria-report-2015/report/en/">currently recommended</a> first-line antimalarial drugs – artemisinin-based combination therapies – are not cheap. Their unnecessary use leads to a waste of resources.</p></li>
<li><p>And third, in some countries, resistance against these drugs has emerged. They therefore need to be used sparingly.</p></li>
</ul>
<p>To help overcome this problem the use of rapid diagnostic tests should be expanded. The tests have been around for at least six years and have changed the way that malaria is diagnosed. They can detect the presence of malaria within minutes and can be used in basic health care services in remote places. </p>
<p>In 2010 the World Health Organisation <a href="http://www.afro.who.int/en/downloads/cat_view/1501-english/1235-clusters-and-programmes/795-malaria-mal.html?start=15">recommended</a> that countries switch to this method of universal testing before treatment can begin. </p>
<p>There has been a rapid scaling up of the use of the tests in recent years. Nevertheless, over-treatment of malaria remains a problem.</p>
<h2>Why over-treatment happens</h2>
<p>Up until about 15 years ago, policymakers such as the World Health Organisation promoted a strategy known as <a href="http://www.afro.who.int/en/downloads/cat_view/1501-english/1235-clusters-and-programmes/795-malaria-mal.html?start=15">“presumptive treatment of malaria”</a>. This meant that in areas where diagnostic testing was unavailable, patients with fever were treated with antimalarials. </p>
<p>This happened whether or not there were signs of any other illnesses. As a result, there was a substantial <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-10-107">overuse of chloroquine</a>, the drug used to treat malaria before artemisinin. Chloroquine was <a href="http://www.afro.who.int/en/downloads/cat_view/1501-english/1235-clusters-and-programmes/795-malaria-mal.html?start=15">cheap and well tolerated</a> by the body.</p>
<p>Previous health worker training emphasised the danger of missing a case of malaria and sending a child home <a href="http://www.afro.who.int/en/downloads/cat_view/1501-english/1235-clusters-and-programmes/795-malaria-mal.html?start=15">without treatment</a>. This ingrained a belief in health workers and is likely to take time to change. They will require evidence based reassurance that the new policy of testing before treating is safe.</p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119238/original/image-20160419-13923-1v6lkn6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Antimalarial medication.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/worldbank/7826321350/">Arne Hoel/World Bank</a></span>
</figcaption>
</figure>
<p>In our <a href="http://www.bmj.com/content/352/bmj.i107">paper</a> we analysed three scenarios that can lead to over-treatment. When:</p>
<ul>
<li><p>treatment is based on symptoms and no tests done;</p></li>
<li><p>negative test results are ignored and treatment is administered; or</p></li>
<li><p>tests erroneously give positive results and treatment is administered.</p></li>
</ul>
<p>Studies have highlighted how these scenarios play out. In Uganda, around two-thirds of people seek malaria treatment from retail drug stores, where testing is rarely <a href="http://www.sciencedirect.com/science/article/pii/S0277953611000517">done</a>. This seems to be <a href="http://www.sciencedirect.com/science/article/pii/S1471492213000184">true</a> in other African countries.</p>
<p>In <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-6-57">Kenya</a>, over-the-counter malaria medicines are the most-popular first response to fever in children and adults with acute illnesses.</p>
<p>Another reason for not testing is a shortage of rapid tests. Surveys of facilities in <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-12-293">Tanzania</a>, <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-13-295">Mozambique</a> and the <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0071442">Democratic Republic of Congo</a> estimated that between 50% and 62% did not have rapid diagnostic tests in stock. </p>
<p>Even when the tests are available, in some instances they are not universally used. In one <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-12-293">Tanzanian study</a> staff reverted to presumptive treatment when the patient workload was high or there were staff shortages.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119237/original/image-20160419-13919-yrrlyy.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">A boy in Busia, Western Kenya, has a rapid diagnostic malaria test.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/livinggoods/20447469773/in/photolist-bLePu2-x9SCoi-xPf6gH-xPfiGK-y7rbWD-x9SHZP/">Living Goods Kenya/flickr</a></span>
</figcaption>
</figure>
<h2>Why rapid diagnostic tests are the answer</h2>
<p>Rapid diagnostic tests are accurate and can reduce over-treatment by 95% if they are available and used correctly. They are conducted next to the patient and the results are made available within minutes. There is no need to send blood samples to a laboratory, which can take several days and delay treatment. </p>
<p>But successful universal use of the test will need different interventions across public, private and retail sectors. The latest <a href="http://www.who.int/malaria/publications/world-malaria-report-%202015/report/en/">World Health Organisation data</a> shows that the use of diagnostic testing across the continent increased from 41% in 2010 to 65% in 2014. But this only reflects use in the public-sector health facilities. Many people still seek anti-malarial treatment from retail drug stores as a first response to fever.</p>
<p>There are three processes that can improve the use of these tests. </p>
<ul>
<li><p>First, improving the management at healthcare centres would mean they don’t run out of rapid diagnostic tests. </p></li>
<li><p>Second, technology can help. This was evaluated in rural districts in <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-9-298">Tanzania</a> and <a href="http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0054066">Kenya</a>. The use of mobile phones, particularly <a href="http://malariajournal.biomedcentral.com/articles/10.1186/1475-2875-9-298">SMS services</a>, and the internet means that health low stocks can be notified. The quality assurance of the tests can also be improved. </p></li>
<li><p>Third, the rapid diagnostic tests should be subsidised. Previously, a <a href="https://heapol.oxfordjournals.org/content/early/2015/04/09/heapol.czv028.full">subsidy</a>for artemisinin successfully increased its availability in the private sector. <a href="http://www.bmj.com/content/350/bmj.h1019.short">Research</a> has proposed that a similar approach could improve the use of rapid diagnostic tests.</p></li>
</ul><img src="https://counter.theconversation.com/content/57516/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Eleanor Ochodo 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>Despite tests which rapidly test for malaria being around for several years, overtreatment of malarial drugs still takes place in Africa.Eleanor Ochodo, Senior Researcher and Lecturer, Centre for Evidence-Based Health Care, Stellenbosch UniversityLicensed as Creative Commons – attribution, no derivatives.