Dengue-fever, Zika, and chikungunya are arboviral infection diseases transmitted mainly by two vectors: Aedes aegypti and Aedes albopictus. We have available the weekly number of cases of the three diseases across the 160 neighborhoods of Rio de Janeiro, between January 2015 and December 2016, when there was an epidemic of the three diseases. We aim at understanding the evolution, and possible correlations, of the diseases across time and space. We have information available on the weekly variation of environmental covariates, and socio-economic covariates at the neighborhood level. As the diseases are transmitted by the same vectors, we propose a spatio-temporal hierarchical model that assumes a Poisson model for the total number of cases of arboviral infection diseases for each week and neighborhood and, conditioned on the total number of cases, we assume a multinomial model for the three diseases. We explore different structures for the log-relative risk of the total number of cases and, the parameters of the multinomial distribution, to learn how the three diseases are correlated across space, time and among themselves. Inference is performed under the Bayesian framework.
This is joint work with Laís P. Freitas(ENSP, Fiocruz, Brazil), Oswaldo Cruz(ENSP, Fiocruz, Brazil) and Marília S. Carvalho(ENSP, Fiocruz, Brazil). This work was supported by NSERC RGPIN-2017-04999 and Coordenação de Apoio ao Pessoal de Ensino Superior (CAPES, Brazil).