Malaria diagnosis - new perspectives
Report of a joint WHO/USAID informal consultation, 25-27 October 1999
Rapid diagnostic tests (RDTs) for malaria are now available that allow the detection of Plasmodium-specific antigens in a finger-prick blood sample in minutes, with sensitivity similar to that achieved by routine microscopy. RDTs have introduced a new dimension to the diagnosis and treatment of malaria. They permit, among other things, on-the-spot confirmatory diagnosis of malaria at the periphery of the health care system by health workers with minimal training. The rational use of RDTs as a complement to microscopy might give substantial health benefits (a) through earlier treatment and a consequent reduction in morbidity and mortality, (b) by targeting expensive drugs and drug combinations to high risk populations in multidrug resistant areas, and (c) through a more rational use of drugs that might effectively reduce drug pressure and might possibly delay the progress of drug resistance. Nevertheless, the optimal role and conditions for the use of RDTs in relation to microscopy remain to be determined.
In October 1999, TDR and Roll Back Malaria organized an informal consultation, co-sponsored by USAID, to examine the role of new rapid diagnostic tests in malaria control. The objectives of the meeting were:
- to define the rational use of microscopy and of RDTs for malaria control;
- to identify factors that determine the choice of approaches to the diagnosis of malaria;
- to define the desired specifications for new diagnostic tests; and
- to outline outstanding research questions and plan a research agenda.
This report outlines the discussions and outcomes of the consultation, defining situations and regions of appropriate use for RDTs, and highlighting the role of diagnostic confirmation in cost-effective disease management and in reducing the unnecessary and irrational use of antimalarial drugs. It includes a list of persisting issues that need to be addressed through laboratory or field research, and a bibliography of relevant publications in malaria diagnostics.