Studies Find Unexpected Drawbacks of Malaria Rapid Diagnostic Tests

Studies Find Unexpected Drawbacks of Malaria Rapid Diagnostic Tests

Although the widespread use of rapid diagnostic tests for malaria has helped improve treatment with artemisinin-based combination therapies (ACTs), many patients still do not receive the life-saving drugs, ten linked studies conducted by the Bill & Melinda Gates Foundation-funded ACT Consortium find.

Based on data from eight studies in sub-Saharan Africa and two in Afghanistan, the report, The Impact of Introducing Malaria Rapid Diagnostic Tests on Fever Case Management: A Synthesis of Ten Studies From the ACT Consortium (39 pages, PDF), found that the use of malaria rapid diagnostic tests (mRDTs) resulted in fewer patients with non-malarial fever being prescribed ACTs overall. At the same time, the report found that fewer than 80 percent of those who tested positive for malaria were prescribed ACTs, while more than 30 percent of those who tested negative were prescribed ACTs.

Heidi Hopkins, a malaria diagnostics expert at the London School of Hygiene and Tropical Medicine and one of the study's authors, told the New York Times that while drug shortages were uncommon at most of the study sites, it was possible that nurses used to shortages held back free drugs from malaria patients who were not seriously ill or who appeared able to buy the drugs elsewhere.

Published in the American Journal of Tropical Medicine and Hygiene, the report also found that mRDT interventions were associated with higher rates of antibiotics being prescribed for those who tested negative — individuals who likely had viral infections, which cannot be treated with antibiotics — or were not tested, which could exacerbate the emergence of drug-resistant strains. Overall, 75 percent of patients in the studies received malaria drugs or an antibiotic, regardless of their test results. Although one study in Zanzibar found that only about 22 percent of causes of fevers were bacterial, doctors and nurses in poor countries where complex testing is impossible often offer antibiotics to be on the safe side.

"We definitely can't blame them for doing that," said Hopkins. "Some of these patients are mothers who bring their kids in from twenty kilometers away on motorcycles or in minibuses. You can certainly understand why a healthcare worker would be reluctant to just send them home with a pat on the head and advice to take paracetamol and drink fluids."