SciDev.Net Examines Rapid Diagnostic Tests
SciDev.Net examines the use of rapid diagnostic test (RDT) kits to identify malaria cases. RDTs use antibodies to detect proteins from the malaria parasite. According to SciDev.Net, accurate tests can reduce the number of people who unnecessarily take malaria medication to treat fevers that are not malaria-related. “Diagnosing and treating patients appropriately has the added benefit of cutting medical costs and minimising drug resistance,” according to SciDev.Net.
Recently the Foundation for Innovative Diagnostics (FIND), the WHO and the WHO-based Special Program for Research and Training in Tropical Diseases published an evaluation of 41 commercially available RDTs (Nightingale, SciDev.Net, 5/26). The laboratory-based evaluations found that some tests remained stable at tropical temperatures and were able to detect even low parasite densities in blood samples. However, most tests only detected the parasite at high parasite densities (FIND release, 4/24). The results indicate that some RDTs currently available are “adequate for malaria case management in most areas,” David Bell, head of malaria diagnostics at FIND, said.
Bell said that there is growing demand for tests that identify low parasite levels in people who do not have symptoms. According to Bell, this is the result of more programs focusing on malaria elimination, not just control. But the market for RDTs is unregulated and the quality of tests varies, he said. Only a few tests were able to detect low levels of Plasmodium falciparum and P. vivax parasites, in addition to producing low false-positive results, remaining reliable at tropical temperatures and being easy to use, SciDev.Net reports (SciDev.Net, 5/26).