Serological evidence of exposure to Rift Valley, Dengue and Chikungunya Viruses among agropastoral communities in Manyara and Morogoro regions in Tanzania: A community Survey (original) (raw)

Introduction: Tanzania has recently experienced outbreaks of dengue in two coastal regions of Dar es Salaam and Tanga. Chikungunya and Rift Valley Fever outbreaks have also been recorded in the past decade. Little is known on the burden of the arboviral disease causing viruses (Dengue, Rift Valley and Chikungunya) endemically in the inter-epidemic periods. We aimed at determining the prevalence of the dengue, rift valley and chikungunya among humans in two geo ecologically distinct sites. Methodology: The community-based cross-sectional study was conducted in Magugu in Manyara region and Mvomero in Morogoro region in Tanzania. Venous blood was collected from participants of all age groups, serum prepared from samples and subjected to ELISA tests for RVFV IgG/IgM, DENV IgG/IgM, and CHIKV IgM/IgG. Samples that were positive for IgM ELISA tests were subjected to a quantitative RT PCR for each virus. A structured questionnaire was used to collect socio-demographic information. Data analysis was conducted using SPSSv22. Results: A total of 191 individuals from both sites participated in the study. Only one CHIKV was detected in Magugu site but none of the 69 participants from Magugu site was seropositive or positive for RVFV and DENV. Of the 122 individuals from Wami-Dakawa site, 16.39% (n=20) had recent exposure to RVFV while 9.83% (n=12) were recently infected by Chikungunya virus. All samples were negative by RVFV and CHIKV qPCR. Neither Infection nor exposure to DENV was observed in participants from Wami-Dakawa. Risk factors associated with RVFV and DCHIKV seropositivity were being more than 5 in a household, having no formal education and having recently travelled to an urban area. .