Time trend and identification of risk areas for physical disability due to leprosy in Brazil: An ecological study, 2001-2022

Abstract

Background

Leprosy is a chronic infectious disease that affects the peripheral nerves, leading to neurological damage and physical disability. This study analyzed the temporal trend in the rate of new leprosy cases with grade 2 physical disability in Brazil and identified spatial clusters of risk for physical disability.

Methods

This is an ecological study of all new cases of leprosy with grade 2 physical disability (G2D) at diagnosis between 2001 and 2022 in Brazil, macro-regions, states and municipalities. Data were extracted from the National System of Notifiable Diseases and the Brazilian Institute of Geography and Statistics. Sociodemographic and clinical variables such as age, sex, race/colour, education and clinical form of the disease were analyzed, as well as the rate of new cases of leprosy with grade 2 physical disability at the time of diagnosis per million inhabitants. Data analysis was divided into three stages: 1- Descriptive analysis of the socio-demographic and clinical profile; 2- Time series analysis: In this stage, the joint-point regression model was used; 3- Spatial analysis, using global and local Moran statistics.

Results

There were 50,466 new cases of leprosy with G2D during the period studied, 97.4% aged > 14 years, 70.2% male, 45.7% brown, 87.6% with low education, 90.2% multibacillary and 47.5% dimorphic clinical form. There was a downward trend in the detection of leprosy with physical disability grade 2, with an average annual reduction of 2.8% (13.6/1 million in 2001 and 9.1/1 million in 2022). The southeast, south and north regions showed a downward trend. A total of 14 states and 4 capitals showed a decrease in the rate, the most significant being Roraima (-11.0%/year). Tocantins was the only state with an upward trend (3.2%/year). 635 (14.1%) municipalities were in the high-high quadrant. These municipalities belong to 12 Brazilian states and accounted for 30% (n = 15,139) of all cases recorded in the country over the 22 years analyzed.

Conclusions

These results suggest an overall decrease in the detection of leprosy with physical disability in Brazil and highlight geographical disparities in the occurrence of leprosy disability. Interventions to promote early diagnosis should be targeted at areas with the highest rate of new cases with grade 2 disability.