[Evaluation of the OptiMal test in the diagnosis of imported malarial outbreak]

The OptiMal test is an immuno-chromatographic dipstick test that permits indiscriminate detection of Plasmodium falciparum and other species of human malaria. The purpose of this study was to evaluate the efficacy of the test for diagnosis of imported malaria. A total of 244 patients with a presumptive diagnosis of imported malaria in France were included during the study period. The reference test, i.e., combined thick and thin blood films, demonstrated infection by Plasmodium falciparum in 58 cases, Plasmodium vivax in 12, P. ovale in 8 and Plasmodium malariae in 2. The OptiMal test detected only 46 of the 55 Plasmodium falciparum cases. The sensitivity of the test for diagnosis of that species was 80%, its specificity was 98%, and its positive and negative predictive values were 95 and 93% respectively. Parsitemia studies showed poor test reliability for densities lower than 150/ul. Detection of other species was accurate in 21 out of 22. The results of this study demonstrate that the current version of the OptiMal test should be used with great caution for the diagnosis of malarial infection in hospital practice.