Difusão espacial do Sars-CoV-2 (novo coronavírus) no município de Niterói – RJ.

Abstract

At the end of 2019, after the emergence of the new coronavirus in the capital of Wuhan, Chinese province of Hubei, there was, in a short time, its rapid spread to all continents, which led the World Health Organization (WHO) to declare a pandemic situation on March 11, 2020. In this context, a global effort was developed to combat COVID-19, involving the enactment of legislation and administrative acts on an emergency basis: social isolation, closing borders and mass vaccination. In the field of Geography, there is a need for studies that reveal the spatial dynamics of the spread of the new virus, identifying those territorial structures that favored (or did not) its spread, even serving as useful knowledge for coping with other diseases for which, in many cases, there is no clinical control. In this perspective, the municipality of Niterói, located in the Metropolitan Region of Rio de Janeiro, was chosen as a study area to understand how the spatial diffusion of Sars-CoV-2 occurred. The first phase of the research was oriented towards understanding the time series of notifications of confirmed cases and deaths in the municipality during the period from January 2020 to March 2022, with this, the Pettitt test was applied to identify ruptures and trend changes in the series, which, when confronted with data on the distribution of SARS-CoV-2 variants and vaccination of the population, revealed that both had an impact on the trend of confirmed cases, especially deaths, explained by the lower lethality of the variant Delta and immunization induced by vaccination of the most vulnerable population in the municipality. From the previous step, it was possible to individualize the first phase of virus diffusion between January 2020 and July 2021, which served as the basis for the next phase of the study. In the second stage, the emphasis was on the dynamics of spatial diffusion of the virus between the cutout stipulated by the Pettitt test, taking the epidemiological week as the temporal unit of analysis and the neighborhood as the spatial unit. From the elaboration of choropleth maps and the application of kernel and cluster techniques (Moram and LisaMap) considering the Epidemiological Week of occurrence of the first case and the 50th case, as well as the incidence rate, it was possible to reveal the temporal-spatial dynamics of confirmed infections for the study area, expressing a model of diffusion from the urban center to the outskirts of the municipality. Additionally, by incorporating the mapping of the territorial infrastructure and census data, it was possible to identify the importance of transport axes as inducers of the spread of the virus, as well as in the case of Niterói, probably due to the high coverage rate of the sanitation and the policy for coping with the pandemic by the municipality, and the receptivity of households (dimension of vulnerability to COVID-19) did little to explain the spread of SARS-CoV-2.