Persistence of leprosy in northeast Brazil: epidemiological characterization and spatial distribution over a decade.

Abstract

Leprosy is an infectious disease caused by Mycobacterium leprae, predominantly affecting vulnerable populations. This study analysed the spatial and spatiotemporal distribution of leprosy cases in northeast Brazil and their epidemiological characteristics. An ecological study used reported cases from the Notifiable Diseases Information System between 2013 and 2022. The incidence rate was the main indicator. Global and local Moran's I indices assessed spatial autocorrelation, while spatiotemporal scan statistics identified high-risk clusters. Results were significant at p<0.05. During the study period, 140 881 cases were reported, with the highest incidences in Maranhão, Pernambuco and Bahia. Individuals 40-69 y of age, males and those self-declared as brown race/colour were most affected. Borderline and Virchowian forms were most frequently reported (n=58 211 [41.32%] and n=24 195 [17.17%], respectively). Grade 0 accounted for most notifications, with a prevalence of 135.86 and an incidence rate of 9.72. Positive spatial autocorrelation was identified (I=0.052683). High-high clusters occurred in most states, except Sergipe, Alagoas, Paraíba and Rio Grande do Norte. Spatiotemporal analysis revealed a primary cluster comprising municipalities in Maranhão, Piauí, Bahia, Pernambuco and Ceará. These findings identify priority areas for surveillance and control in northeast Brazil.