Análise espaço-temporal da malária no estado de Mato Grosso : identificação das áreas de alto risco

Abstract

Malaria is a neglected infectious disease that, according to the World Health Organization, in 2020 alone, 241 million new cases occurred in 85 countries and about 627,000 deaths worldwide. In the American continent, the populations of the Legal Amazon are among those at greater risk of infection. Almost 80% of cases are caused by Plasmodium vivax, with Brazil, Colombia and Venezuela accounting for 80% of estimated cases. About 99% of transmission in Brazil is concentrated in the Legal Amazon region, which comprises nine states, including Mato Grosso. Epidemiology is an important tool for understanding the situation of diseases, but spatial analysis research related to malaria is scarce and those that exist are mostly of a classic nature, bringing general information that does not provide effective tools for control and eradication of the disease. In view of the above, the current research was carried out, with the objective of identifying high-risk areas for malaria infection and the individual and socioeconomic variables that may be related. This is an ecological study, in which the units of analysis were the municipalities of the state of Mato Grosso and the population consisted of positive cases for malaria between 2011 and 2021 registered in the Malaria Epidemiological Surveillance Information System (SIVEP-malaria) from the state of Mato Grosso. High risk areas were identified using the sweep statistic known as Scan. Thematic maps of the clusters were constructed, characterizing the relative risk (RR). Statistical analysis of trend-time data (Prais-Winsten autoregression) was performed using the STATA software. During the period studied, 20,819 cases of malaria were identified, with a higher incidence in males and the most affected age groups being 20 to 59 years. The mean incidence showed values ranging from 0.01 to 2,849.85 with higher means in the North, West and Northwest regions of the state. Spatial autocorrelation using the Moran Global index identified a positive correlation between the incidence and the regions where malaria cases occur in the state, 0.472299; p<0.001. Moran Local analysis located well-defined regions for malaria infection such as the Northwest. Eight malaria risk clusters with the highest RR=90.09 (p=<0.001) were identified by scanning statistics. The space-time scan classified three statistically significant high-risk clusters, RR=80.50 located in the Northwest region. The time-trend scan of the clusters was classified as stationary. The results obtained show the existence of high-risk areas for malaria infection. Multisectoral approaches focused on these locations and that strategically consider the variables identified in this study can collaborate to reduce the number of infected people in the state of Mato Grosso. It is expected that the findings obtained in this study can serve as indicators for the implementation of public policies that seek to solve the problem of malaria in the state of Mato Grosso, especially in places of greater risk.