A cholera outbreak in Kenya’s capital, Nairobi, has prompted the health authorities to withdraw all medical licences issued to food handlers countrywide. About 336 cholera cases have been treated in Nairobi since May this year. The Conversation Africa’s Health and Medicine Editor Joy Wanja Muraya spoke to Sam Kariuki on the need for an improved rapid response when there is an outbreak and how to deal with drug resistance of some cholera medicines.
Why is cholera a public health concern?
Cholera is an old disease that first occurred in the Bengal region of India, near Calcutta starting in 1817 through 1824.
Since then it has mostly affected Africa and other developing countries particularly in informal settlements that have poor sanitation and water supply infrastructure.
Cholera is caused by a gram negative bacterium called Vibrio cholerae usually transmitted through contaminated water or food in areas with poor sanitation and lack of clean drinking water.
Cholera outbreaks are likely to increase as more people migrate from rural areas to the city in search of jobs. The low starting income limits most of the young job seekers to live in poorly developed and crowded urban slums.
Cholera is easily managed usually by giving oral rehydration salts to replace lost fluids and electrolytes. Some severe cases may require antibiotic treatment. But there’s a need for timely diagnosis and immediate treatment for anyone who tests positive to cholera. Cholera can kill within hours if untreated.
How big is the threat of resistance to antibiotics?
Drug resistance to the bacteria that causes cholera would be a big blow to the treatment of the disease, especially in developing countries.
Our study found out that bacteria that causes cholera has become resistant to some antibiotics needed to treat the disease effectively.
In the last 10 years, we investigated antimicrobial resistance in Vibrio cholerae strains. The findings showed that it had become resistant to nalidixic acid, trimethoprim, sulphamethoxazole, streptomycin and furazolidone.
Whereas these medicines can no longer treat cholera, the good news is that it is still treatable with doxycycline, which has remained a preferred drug of choice.
The observed strains of cholera that occurred during outbreaks between 2012 and 2016 in Kenya were resistant to ceftriaxone in a class of antibiotics known as third generation cephalosporins. This is a reserve drug commonly used to treat severe infections. The resistance was first observed in patients with salmonella, a type of bacteria that cause bloodstream infections especially in people with low immunity.
Some types of drug resistance are caused by a natural interaction of the Vibrio cholerae bacteria with other drug resistant bacteria in the environment. The overuse of antibiotics by people also contributes to drug resistance.
Although tetracyclines are currently used to treat cholera, ceftriaxone resistant strains have been found to transmit resistance to other bacteria. Drug resistance has made it possible for these cholera strains to stay longer in the environment where they are more likely to cause disease.
What is the way forward?
Preventing outbreaks is the first step. This can only be done by having a multi sectoral approach to public health intervention including messages that encourage hand washing, boiling water and other preventive measures.
Community health extension workers are key in getting these messages across as well as for distributing supplies during an outbreak.
Drug resistance is a survival mechanism for bacteria which have no boundaries. We need to use antibiotics prudently. Drug resistance encourages further spread of infections, making treatment longer and more expensive.
Government agencies should develop ways to monitor the use of antibiotics and restrict their prescription. Regulation of antibiotic use in animals should also be improved.
Health care workers also need to be trained on the proper use of antibiotics to ensure they are given to patients responsibly.
And finally, the effective management of cholera begins with better surveillance to diagnose and treat infections promptly. Better record keeping and data management at health care facilities is vital for this to happen.