Evaluation of rapid diagnostic tests for malaria case management in Gabon

A laboratory-confirmed diagnosis is the basis of malaria case management. Rapid diagnostic tests (RDTs) create new opportunities for improved care in endemic areas. Diagnostic performance of OptiMAL-IT® and Acon® was assessed in comparison with microscopy at 2 sites in Gabon. Between February 2008 and January 2009, 2125 febrile children under 11 years old were diagnosed using microscopy and RDTs. Plasmodial infection was detected more frequently using Acon® (27%) and OptiMAL-IT® (27%) compared to microscopy (20%) (P < 0.01). Among the samples diagnosed positive by OptiMAL-IT®, 78% were infected by Plasmodium falciparum, whereas 99% of positive blood smears were P. falciparum infections, 0.5% Plasmodium malariae, and 0.5% Plasmodium ovale. Both RDTs had similar sensitivity (Se) (94.0%; 95% confidence interval [CI], 92–96), which varied depending on the site. When parasite density was >100 p/μL, the Se of the 2 tests was >98% (95% CI, 96–100). Likewise, the negative predictive values were high and comparable (>98%). Overtreatment with antimalarial drugs was 12%. These tests should be considered as a good alternative to microscopy, allowing not only an efficient and rapid diagnosis of malaria in primary health facilities but also to aid in promoting changes for antimalarial prescription behavior.