Spatial distribution and factors associated with the seroprevalence of arboviruses in Guinea: a nationwide cross-sectional survey

BACKGROUND: Although arboviruses constitute a growing global public health threat, data on their circulation in Guinea remain limited. This study aimed to estimate the seroprevalence, spatial distribution, and associated factors of arboviruses in Guinea. METHODS: We conducted a population-based cross-sectional survey between May and July 2023 among individuals aged ≥5 years in households across Guinea. Household, environmental, and socio-demographic data were collected by using a questionnaire. IgG antibodies against eight arboviruses were detected using Luminex MagPix assays: dengue (DENV), Zika (ZIKV), West Nile (WNV), Usutu (USUV), chikungunya (CHIKV), O'nyong'nyong (ONNV), Rift Valley fever (RVFV), and Crimean-Congo haemorrhagic fever (CCHFV). Seroprevalence and associated factors were analysed by using descriptive statistics and multilevel logistic regression with spatial components. RESULTS: A total of 1098 participants from 367 households were included. Overall seroprevalence of arboviruses was 25.0% [95% confidence interval (CI): 22.0-28.0]. The highest seroprevalences were observed for ZIKV (12.0%; 95% CI 9.8-15.0) and WNV (11.6%; 95% CI 9.5-14.0). Boké and Kindia showed higher seroprevalence for ZIKV (33.0% and 22.9%, respectively), WNV (15.0% and 46.6%, respectively), and USUV (19.0% and 23.7%, respectively). In multilevel logistic regression, age [adjusted odds ratio (aOR) = 1.51; 95% CI 1.32-1.77], female sex (aOR = 1.59; 95% CI 1.17-2.16), and people from rich households (aOR = 1.67; 95% CI 1.11-2.43) were associated with seropositivity, with regional heterogeneity (intercept variance = 1.22; 1.10 SD). CONCLUSION: This nationwide survey confirmed widespread arbovirus circulation in Guinea, highlighting a largely underestimated burden. Strengthening epidemiological surveillance and vector control are essential to mitigate future outbreaks.