Estimation of malaria-attributable fever in malaria test­positive febrile outpatients in three provinces of mozambique, 2018

Like most malaria-endemic countries, Mozambique relies on tabulation of confirmed malaria test­positive febrile patients to track incidence of malaria. However, this approach is potentially biased by incidental malaria parasitemia in patients with fever of another etiology. We compared pan-Plasmodium aldolase and lactate dehydrogenase and Plasmodium falciparum histidine-rich protein 2 (PfHRP2) antigen concentrations measured using a laboratory bead-based assay of samples collected from 1,712 febrile and afebrile patients of all ages in Maputo, Zambézia, and Cabo Delgado provinces. We used a Bayesian latent class model to estimate the proportion of malaria-attributable fevers in malaria test­positive febrile patients. Depending on the antigen, estimated rates of malaria-attributable fever in malaria test­positive febrile patients were 100% in Maputo, 33­58% in Zambézia, and 63­74% in Cabo Delgado. Our findings indicate that most malaria test­positive febrile patients in the three provinces of Mozambique had a fever that was likely caused by the concurrent malaria infection. Counting malaria test­positive febrile patients for estimation of malaria incidence appears to be appropriate in this setting.