In areas of low transmission, is the presumptive treatment of febrile but bloodsmear-negative patients for malaria validated by the results of PCR-based testing?

Abstract

Presumptive malaria treatment (PMT) is a common strategy in many areas of the world, especially in settings where the facilities for diagnosis are limited. The subjects of a recent study in central Sudan, in an area with a low level of Plasmodium falciparum transmission, were 322 individuals who had each presented at one of seven suburban health facilities, complaining of repeated febrile episodes. Although all were found bloodsmear-negative for malarial parasites, all were presumptively diagnosed as cases of malaria and prescribed artemisinin-based combination therapy. When pretreatment samples of blood were, however, checked for P. falciparum histidine-rich protein 2, using a rapid diagnostic test (RDT), and for Plasmodium DNA, using a PCR-based assay, only one (0.03%) of the cases was found RDT-positive and none was found PCR-positive. Although more studies are needed, in different areas and seasons, to see if these results mirror the general situation, it appears that the wide use of PMT in central Sudan, among patients who are bloodsmear-negative, is unjustified, of little, if any, benefit, and a waste of resources that are already limited. An international consortium for the revision of the conceptual aspects of malaria diagnosis and PMT is suggested.