Mapping of the country-wide prevalence of non-malarial febrile illnesses in areas with varying malaria transmission intensities in Mainland Tanzania

Abstract Recent reports revealed a declining malaria burden, but non-malaria febrile illnesses (NMFIs) have either remained unchanged or increased. This study assessed the country-wide prevalence of NMFIs and their patterns across various malaria transmission settings in Mainland Tanzania. A cross-sectional study recruited patients aged ≥ 6 months from 86 health facilities in all 26 regions of Tanzania. All patients were tested for malaria using rapid diagnostic tests (RDTs) and the prevalence of NMFIs was determined for all patients with negative results. Logistic regression was used to determine factors associated with NMFIs. Of the 18,568 patients tested, 8,273 (44.6%) had NMFIs due to negative RDT results. Higher prevalence of NMFIs occurred in females (45.8%) than males (42.8%), adults (aged ≥ 15 years, with 50.6%) compared to under-fives (42.6%) and school children (aged 5 -< 15 years, 34.3%), and in very low (71.5%) compared to high transmission areas (33.9%). NMFIs were significantly more likely in females than in males (aOR = 1.14, 95% CI = 1.07–1.22), in very low transmission areas (aOR = 4.85, 95% CI = 4.42–5.33), adults (aOR = 1.60, 95% CI = 1.46–1.75) and under-fives (aOR = 1.60, 95% CI = 1.47–1.76). The findings show high prevalence of NMFIs overall, and higher prevalence and odds of NMFIs in females, under-fives and individuals from low and very low transmission areas. These groups should be targeted with appropriate point-of-care tests and treatment strategies.