Objective: To compare actual and perceived causes of fever in northern Tanzania.

Methods: In a standardised survey, heads of households in 30 wards in Moshi, Tanzania, were asked to identify the most common cause of fever for children and for adults. Responses were compared to data from a local hospital-based fever aetiology study that used standard diagnostic techniques.

Results: Of 810 interviewees, the median (range) age was 48 (16, 102) years and 509 (62.8%) were women. Malaria was the most frequently identified cause of fever, cited by 353 (43.6%) and 459 (56.7%) as the most common cause of fever for children and adults, respectively. In contrast, malaria accounted for 8 (2.0%) of adult and 6 (1.3%) of paediatric febrile admissions in the fever aetiology study. Weather was the second most frequently cited cause of fever. Participants who identified a non-biomedical explanation such as weather as the most common cause of fever were more likely to prefer a traditional healer for treatment of febrile adults (OR 2.7, P < 0.001). Bacterial zoonoses were the most common cause of fever among inpatients, but no interviewees identified infections from animal contact as the most common cause of fever for adults; two (0.2%) identified these infections as the most common cause of fever for children.

Conclusions: Malaria is perceived to be a much more common cause of fever than hospital studies indicate, whereas other important diseases are under-appreciated in northern Tanzania. Belief in non-biomedical explanations of fever is common locally and has important public health consequences.