Sub-Saharan Africa

  • Malaria rapid diagnostic tests fuel unintended outcomes

    Stephanie Achieng’

    25/08/17

Speed read

  • Researchers analysed impact of malaria rapid diagnostic tests (mRDTs) on fever

  • Although mRDTs led to use of antimalarials, it led to antibiotics overuse

  • Findings call for building capacity in laboratory diagnosis, says an expert

[NAIROBI] Malaria rapid diagnostic tests (mRDTs) could improve the use of antimalarials in Africa but may lead to unintended negative consequences such as overuse of antibiotics, a new study finds.

A WHO policy change in 2010 that malaria cases should be confirmed before treatment has led to increased use of mRDTs on a large scale,  according to researchers from countries including Afghanistan, Ghana, Nigeria, Sweden, Tanzania, Uganda and the United Kingdom.

In an analysis of more than 500,000 patient visits across five African countries — Cameroon, Ghana, Nigeria, Tanzania and Uganda — and Afghanistan, the researchers found that even patients who were not confirmed by mRDTs as having malaria were prescribed artemisinin-based combination therapies (ACTs) and those who had malaria were denied ACTs.

“These findings call for strengthening of health systems in malaria-endemic areas, especially diagnostic capacity and training of healthcare workers.”

Simon Kariuki, Kenya Medical Research Institute


“Prescribing did not always adhere to malaria test results,” says the study published in the American Journal of Tropical Medicine and Hygiene this month (7 August). “In several settings, ACTs were prescribed to more than 30 per cent of test-negative patients or to fewer than 80 per cent of test-positive patients. Either an antimalarial or an antibiotic was prescribed for more than 75 per cent of patients across most settings.”

According to Heidi Hopkins, co-author of the study, and an associate professor of malaria and diagnostics at the UK-based London School of Hygiene and Tropical Medicine, the negative test results for malaria prompted a significant shift to antibiotic prescriptions, thus trading one potential problem of overuse of malaria drugs with overuse of antibiotics.

The researchers analysed harmonised data from ten ACT Consortium studies conducted between 2007 and 2013.

“To our knowledge, this is the largest and most comprehensive analysis that directly compares treatment practices in settings with and without mRDTs,” Hopkins tells SciDev.Net.

Whereas mRDTs help healthcare workers diagnose malaria, there is still no such simple point-of-care diagnostics for other common illnesses that cause fever, meaning that when a malaria test is negative, healthcare workers are not sure what to do, Hopkins explains.

Unnecessary use of antimalarials and antibiotics drives malaria resistance and there is a need to ensure that the benefits of introducing mRDTs does not come at the cost of increasing antibiotic use, says Hopkins.

Simon Kariuki, chief research officer and malaria branch chief at the Kenya Medical Research Institute, says that the findings are not totally unexpected given that the introduction of mRDTs was meant to curb the indiscriminate use of antimalarials and to ensure appropriate drugs use.

Kariuki adds that the increase in antibiotic prescriptions is an interesting and significant finding although not totally unexpected: “This is because many countries in Sub-Saharan Africa don’t have the laboratory capacity to investigate other causes of fever in those who are mRDT negative, which could be due to viral or bacterial infection.”

The findings call for an urgent need to strengthen diagnostic capacities in malaria-endemic areas when mRDTs are introduced, he adds. On those who test positive but are not being treated with an antimalarial or those who test negative but are being treated with antimalarials, Kariuki says it is a complex issue involving cadre and training of healthcare workers, patient perceptions and lack of availability of antimalarials at certain times.

“These findings call for strengthening of health systems in malaria-endemic areas, especially diagnostic capacity and training of healthcare workers at all levels,” he tells SciDev.Net.
 
This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.