Intestinal schistosomiasis-related mortality in Minas Gerais, Brazil, 2000-2019: Temporal trends and spatial patterns for determining priority areas

Objective: To identify priority areas for schistosomiasis control, we analysed the epidemiological characteristics, temporal trends and spatial patterns of schistosomiasis-related mortality in the state of Minas Gerais from 2000 to 2019.

Methods: Ecological and time-series study with spatial analysis techniques on deaths from Schistosomiasis mansoni. A log-linear regression model was used to identify changes in mortality rates. Moran's global index, local indicators of spatial association and a retrospective spatio-temporal permutation model were applied to identify the spatial and temporal distribution of mortality rates and assist in identifying priority areas for interventions.

Results: A total of 1290 deaths from schistosomiasis were recorded between 2000 and 2019, with an average mortality rate of 0.33 deaths/100,000. Although the overall mortality rate in the state of Minas Gerais decreased significantly over time (average annual percentage change = -9.6; 95% confidence interval = -14.4 to -4.6; p < 0.001), it increased in the mesoregions of Jequitinhonha, Mucuri Valley, and Rio Doce Valley. Spatial analysis identified the displacement and emergence of high-risk clusters from the central region of the state to the mesoregion of Rio Doce Valley.

Conclusion: Temporal changes and shifting of high-risk areas from the central region to the mesoregion of Rio Doce Valley may indicate possible failures in early diagnosis and treatment of the schistosomiasis control program in these areas. Our research contributes to a better understanding of the spatio-temporal dynamics of death rates due to schistosomiasis infections and might help health authorities to direct resources most efficiently to avoid serious clinical outcomes in Minas Gerais.