Spatial-temporal diffusion of yellow fever in a state in Southeast Brazil in 2017

The objective was to analyze the diffusion of cases of yellow fever in time and space in the epidemic of 2017 in the state of Espírito Santo, Brazil. An ecological observational study was performed with spatial analysis of yellow fever cases. Georeferencing of information and spatial analysis used the digital grid for the state of Espírito Santo, divided into 78 municipalities (counties), using the Arcgis software, 10.3. Geostatistical analysis was performed using the ordinary kriging function. The study found an incidence of 4.85/100,000 inhabitants of sylvatic yellow fever in Espírito Santo in 2017, with 29.74% case-fatality. Sylvatic yellow fever cases were distributed across 34 of the state’s 78 municipalities, representing 43% of its territory. The temporal distribution of reported yellow fever cases in the current study occurred from the 1st to the 19th Epidemiological Weeks (EW). The geostatistical spatial analysis via ordinary kriging demonstrated spatial diffusion by yellow fever contagion among the municipalities in the state of Espírito Santo, with spatial continuity. The disease emerged in the state in the EW 1 through municipalities bordering on the state of Minas Gerais. Geoprocessing showed that yellow fever reached the state of Espírito Santo through the municipalities bordering on the state of Minas Gerais, moving eastward in the state and reaching the Atlantic coastline. There was a higher concentration of cases and persistence in the state’s Central and Metropolitan regions, which have areas of Atlantic Forest, showing a pattern of diffusion continuity by contagion.

Keywords:
Yellow Fever; Spatial Analysis; Geographic Mapping