EVALUATION OF METHODS FOR THE LABORATORY DIAGNOSIS OF MALARIA IN GUYANA

When 297 blood samples taken from patients attending a fever clinic in Georgetown Public Hospital were examined microscopically, after thick and thin blood films had been stained with Giemsa, one hundred and fo rty-two (47.8%) were microscopically positive for malaria. After proce ssing the patients' serum, samples by the Indirect Fluorescent Antibod y (IFA) technique, specific IgG and IgM antibodies were detected in 23 9 (81.3%) and 179 (60.1%), respectively, of the sera. Based on the mic roscopical findings, the IFAT gave positive predictive and negative va lues of 54.4% and 81.8% (IgG), and 57.5% and 67.8% (IgM), suggesting t hat the IgM would be more useful than the IgG in the diagnosis of curr ent malaria. An odds ratio analysis showed that the presence of sympto ms, IgG or IgM antibodies, as well as visits to endemic regions, could be good indicators of current malaria. Age and occupation were not. T he microscopical method will continue to be the gold standard - the be st available criterion for the validation of our tests - for diagnosis of acute malaria.