Analysis and spatial distribution of schistosomiasis mansoni in a historically endemic area of northeastern Brazil

Abstract

Objective To perform a descriptive analysis of the activities of the Schistosomiasis Control Program, as well as the spatial distribution of the condition in the state of Alagoas, Brazil, for the period from 2007 to 2016. Methods Descriptive ecological study. Data from positive human cases and operational data were collected in the Information System of the Schistosomiasis Control Program, and data for spatial analysis were collected on the website of the Brazilian Institute of Geography and Statistics. An analysis of spatial autocorrelation (Moran statistics) was performed, where a spatial pattern was established, which showed the Q1 and Q2 patterns to be the most important, and Q3 and Q4 representing transition areas. Results In the years under study, at least 85% (n = 60/70) of the municipalities carried out the activities recommended by the PCE (Schistosomiasis Control Program). Alagoas presented an average positivity rate of 7.1%, which is very high compared to the prevalence of 3.3% at the last national schistosomiasis survey conducted between 2010 and 2015. Moran's statistics showed 22/70 municipalities forming a Q1 cluster, of high/high pattern, and 32/70 municipalities forming a Q2 cluster, of low/low pattern, with the others in a transition area. Moran Map data, however, showed only 7/70 municipalities in the endemic area with a spatial autocorrelation, with these municipalities having the Mundau River as a common element. Conclusion Schistosomiasis mansoni is of great importance for public health in Alagoas and that the use of spatial analysis can identify priority areas for preventive and control measures against schistosomiasis mansoni.

Indicadores epidemiológicos e operacionais do programa de controle da esquistossomose: estudo ecológico em região endêmica no estado de Alagoas, Brasil, 2008 – 2016

“…Uma cobertura de tratamento inadequada, no tocante ao tratamento dos casos positivos, como observado na maior parte dos anos analisados no presente estudo, contribui para a ocorrência de portadores assintomáticos, que em virtude da ausência de tratamento, continuam liberando ovos no ambiente e contaminam coleções hídricas, que caso habitadas pelo hospedeiro intermediário, podem se tornar focos de transmissão do S. mansoni (Alencar et al, 2016;Barreto et al, 2015;Gomes de Amorim Santos et al, 2020;Inobaya et al, 2014).…”