Trends in fever case management for febrile inpatients in a low malaria incidence setting of Tanzania.

OBJECTIVES In 2010, WHO published guidelines emphasizing parasitological confirmation of malaria prior to treatment. We present data on changes in fever case management in a low malaria transmission setting of northern Tanzania after 2010. METHODS We compared diagnoses, treatments, and outcomes from two hospital-based prospective cohort studies, Cohort 1 (2011-2014) and Cohort 2 (2016-2019), that enrolled febrile children and adults. All participants underwent quality-assured malaria blood smear-microscopy. Participants who were malaria smear-microscopy negative but received a diagnosis of malaria or received an antimalarial were categorized as malaria over-diagnosis and over-treatment, respectively. RESULTS We analyzed data from 2,098 participants. The median (IQR) age was 27 (3-43) years and 1,047 (50.0%) were female. Malaria was detected in 23 (2.3%) participants in Cohort 1 and 42 (3.8%) in Cohort 2, (P = 0.059). Malaria over-diagnosis occurred in 334 (35.0%) participants in Cohort 1 and 190 (17.7%) in Cohort 2, (P <0.001). Malaria over-treatment occurred in 528 (55.1%) participants in Cohort 1 and 196 (18.3%) in Cohort 2, (P <0.001). There were 30 (3.1%) deaths in Cohort 1 and 60 (5.4%) in Cohort 2, (P = 0.007). All deaths occurred among smear-negative participants. CONCLUSION We observed a substantial decline in malaria over-diagnosis and over-treatment among febrile inpatients in northern Tanzania between two time periods after 2010. Despite changes, some smear-negative participants were still diagnosed and treated for malaria. Our results highlight the need for continued monitoring of fever case management across different malaria epidemiologic settings in sub-Saharan Africa.