Etiologic Agents of Fever of Unknown Origin Among Patients Attending Mnazi Mmoja Hospital, Zanzibar



Fever of unknown origin (FUO) remains an important public health problem. With malaria transmission declining in some parts of Africa, the evidence suggests other infectious agents now account for most FUO. The purpose of this study was to identify the etiologic agents of FUO in a cross-section of patients at the Mnazi Mmoja hospital in Zanzibar, Tanzania.


A multiplex TaqMan gene expression Array Card (TAC) and plates were used for detection and classification of different pathogens in blood samples obtained from patients with FUO. Logistic regression analyses was performed using pathogens detected and sociodemographic characteristics as outcome and exposure variables respectively. Odd ratios and 95% confidence interval were calculated and statistical significance was set at P < .05.


Thirty-three different pathogens were detected in 27 patient blood samples. The following pathogens were detected in decreasing order of prevalence; Dengue virus, Plasmodium species, Rickettsia, Brucella species, Salmonella typhi, and less than 1% for each of Bartonella, Coxiella burnetii, Salmonella species, and Leptospira. Co-infections of Plasmodium with Dengue and S. typhi were also detected, including one case with three different pathogens—Plasmodium, Rickettsia and Brucella. There was no association between the etiologic agents of FUO and demographic or clinical characteristics.


Zoonotic and arboviral etiological agents of fever of unknown origin are present among patients at the Mnazi Mmoja hospital in Zanzibar, Tanzania. There is a need to develop a baseline of standardized diagnostic approaches particularly within the hospital setting. In areas with low malaria prevalence like Zanzibar, Dengue, Rickettsia, Coxiella burnetii, Brucellosis should be considered by clinicians in the differential diagnoses of FUO.

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Correspondence to Oghenekaro Omodior.

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Ali, M.A., James, O.C., Mohamed, A.A. et al. Etiologic Agents of Fever of Unknown Origin Among Patients Attending Mnazi Mmoja Hospital, Zanzibar. J Community Health 45, 1073–1080 (2020).

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  • Fever of unknown origin (FUO)
  • Zoonotic diseases
  • Arbovirus