The role of socioeconomic status, environment, and temperature in the spatio-temporal distribution of the first Chikungunya epidemic in the city of Rio de Janeiro, Brazil

• Activity Number: 388 - Advances in Disease Mapping
• Type: Invited
• Date/Time: Wednesday, August 5, 2020 : 1:00 PM to 2:50 PM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Alexandra Schmidt*
• Companies: McGill University
• Keywords: Areal data; Overdispersion; Transfer function

Abstract

Chikungunya is an Aedes-borne disease; its dynamics are impacted by the vector's ecology. We analyse the spatio-temporal distribution of the first chikungunya epidemic in Rio de Janeiro, estimating the effect of socioeconomic and environmental factors as proxies of mosquitoes abundance. We fit Poisson spatio-temporal models using notified cases counts by neighbourhood and week. The log-relative risk of the Poisson distribution is decomposed as the sum of different components. The effects associated with sociodevelopment index and the proportion of green area of the neighborhood vary smoothly with time. To capture the instantaneous and the memory effects of temperature on the relative risk, we use a transfer function approach whose parameters vary per neighborhood. Inference procedure follows the Bayesian paradigm. Our findings suggest that in the beginning of the epidemic, the sociodevelopment index is inversely associated with the relative risk, whereas the effect of the proportion of green area of the neighborhood is null for most weeks. Temperature increases the risk of Chikungunya in most areas and this effect propagates for longer where the epidemic is concentrated.