International Journal of Infectious Diseases 111 (2021) pp. 271–280
Background: This study was conducted to determine the seroprevalence and risk factors of chikungunya
(CHIKV), dengue (DENV), and Zika (ZIKV) viruses in Tanzania.
Methods: The study covered the districts of Buhigwe, Kalambo, Kilindi, Kinondoni, Kondoa, Kyela,
Mvomero, and Ukerewe in Tanzania. Blood samples were collected from individuals recruited from house-
holds and healthcare facilities. An ELISA was used to screen for immunoglobulin G antibodies against
CHIKV, DENV, and ZIKV.
Results: A total of 1818 participants (median age 34 years) were recruited. The overall CHIKV, DENV,
and ZIKV seroprevalence rates were 28.0%, 16.1%, and 6.8%, respectively. CHIKV prevalence was highest in
Buhigwe (46.8%), DENV in Kinondoni (43.8%), and ZIKV in Ukerewe (10.6%) and Mvomero (10.6%). Increas-
ing age and frequent mosquito bites were significantly associated with CHIKV and DENV seropositivity
( P < 0.05). Having piped water or the presence of stagnant water around the home ( P < 0.01) were as-
sociated with higher odds of DENV seropositivity. Fever was significantly associated with increased odds
of CHIKV seropositivity ( P < 0.001). Visiting mines had higher odds of ZIKV seropositivity ( P < 0.05).
Conclusions: These findings indicate that DENV, CHIKV, and ZIKV are circulating in diverse ecological
zones of Tanzania. There is a need to strengthen the control of mosquito-borne viral diseases in Tanzania.