Processos de difusão espacial da Zika, dengue e chikungunya no município de Duque de Caxias em simultaneidade das três epidemias.

Abstract

In recent decades, epidemics emerging and reemerging diseases have mobilized public health and research institutions around the world. In this context, dengue, Zika and chikungunya arboviruses, transmitted by the vector Aedes aegypti have gained importance due to the high potential of transmissibility and the impact on the morbimortality of the population of several countries, such as Brazil. Studies on spatial diffusion aim to identify patterns of how a disease or phenomenon moves in time and space. Several authors have investigated patterns of spatial diffusion of dengue fever, its vector and viruses that cause this disease. There is, however, a gap in the understanding of the diffusion of dengue, Zika and chikungunya, once the simultaneously occur in the same territory. This research aimed to identify the diffusion patterns of Zika, dengue and chikungunya in municipality of Duque de Caxias during the epidemics from November 2015 to May 2016. It is an exploratory epidemiological study with two study designs: a cross-sectional for points data, referring to the residence addresses of the cases and an ecological study for area data, considering the neighborhoods as unit of analysis. The notified cases of the three diseases were obtained from the Brazilian Information system for notifiable diseases. For point data, map sequences for the Kernel density estimation, the Knox method, and the regression curve estimation for the distance ratio of the nearest neighbor were used. For area data, sequences maps were constructed for incidence rates, spatial correlograms and changes in local spatial dependencies were evaluated. The results suggest that the spatial diffusion pattern of the three arboviruses in Duque de Caxias was diffusion by expansion, with important focuses of dispersion of the diseases located in the 1st and 2nd districts. Knowledge about the patterns of spatial diffusion might contribute to the generation of hypotheses of factors that influence the transmission about arboviruses in this territory and to assist in the planning of actions of health surveillance and control of epidemics.