Individual and environmental risk factors for dengue and chikungunya seropositivity in North-Eastern Tanzania

Background Dengue and chikungunya are mosquito-borne viral diseases of major global health concern. In Tanzania, information on risk factors for dengue and chikungunya is limited. We investigated individual, household, socio-economic, demographic and environmental risk factors for dengue and chikungunya seropositivity. Methods A cross sectional study was undertaken which included a total of 1003 participants from North-Eastern Tanzania, to determine the sero-prevalence of dengue and chikungunya and to investigate associated risk factors. Logistic regression models were used to determine the risk factors for dengue and chikungunya seropositivity. Results Environmental factors such as living in a house with uncovered containers within the compound had higher odds of being chikungunya IgM seropositive (OR = 2.89; 95% CI: 1.76–4.76). Also, participants who kept hoofed animals in their home and who lived in a house surrounded by vegetation (<100 m) had higher odds of chikungunya IgM seropositivity ({OR = 1.67; 95% CI: 1.11–2.51} and {OR = 181; 1.10–3.00} respectively). Due to few dengue seropositive, dengue was excluded in the bi-and multivariate analysis. However, dengue IgM seropositivity was associated with G6PD status (p = 0.03) while there was no apparent association between genetic factors (G6PD, HbB or alpha-thalassemia) and chikungunya seropositivity. Conclusion Public health education on environmental management practices is needed to eliminate the identified risks such as simple removal of uncovered containers that may serve as breeding sites for mosquitoes, avoiding animal husbandry in the peri-domestic environment and clearing of vegetation surrounding houses. More studies are needed to investigate the association of dengue and G6PD deficiency.