Temporal trend, distribution and spatial autocorrelation of leprosy in Brazil: ecological study, 2011 to 2021

Abstract

Objective: To characterize the temporal trend and spatial behavior of leprosy in Brazil, from 2011 to 2021. Methods: This is an ecological study, with data from the Notifiable Diseases Information System, obtained in June 2022. The annual detection rate of new leprosy cases per 100 thousand inhabitants was calculated. To estimate the trend of the 2011–2019 and 2011–2021 series, the polynomial regression model was used, testing first-, second-, and third-order polynomials. For spatiality, natural breaks were used and, later, the univariate global and local Moran’s indexes. A significance level of 5% was adopted and the analyses were performed using SPSS®, GeoDa®, and QGIS® software. Results: The findings indicated an upward trend in the incidence of leprosy in Brazilian regions and in 20 federative units between 2011 and 2019. However, there was a decrease in most of the country when considering the COVID-19 pandemic years. Spatiality showed that the highest detection rates throughout the period were observed in the North, Midwest, and Northeast regions, with high-risk clusters, and the lowest detection rates in the South and Southeast regions, with low-risk clusters. Conclusion: The leprosy detection rate showed an upward trend in Brazil between 2011 and 2019, with greater spatial concentration in the North, Northeast, and Midwest regions. Nevertheless, the study raises an alert for the programmatic sustainability of leprosy control in Brazil, considering the drop in the COVID-19 pandemic, presumably due to the influence of the reorganization of the development of initiatives and provision of services in face of COVID-19.

Bacilloscopy for leprosy in Brazil's public health system between 2013 and 2022

“…It is worth considering that data between 2011 and 2021 pointed to the North, Central-West, and Northeast macro-regions with the highest disease detection rates, whereas the South and Southeast had the lowest. Lima et al 23 pointed out that such macroregional differences can be attributed to several factors, from socioeconomic aspects, such as inequality in the distribution of resources, to weaknesses in the diagnosis and qualification of healthcare for leprosy, considering that the South and Southeast belong to the socioeconomic level considerably favorable (which does not apply to the others).…”

“…Although leprosy control actions, primarily operated by the Unified Health System (SUS), have reduced the burden of morbidity and mortality, there are disparities in macroregions related to the disease, including its endemic persistence in vulnerable regions. This outcome is influenced by socioeconomic, demographic, and environmental factors that result in late diagnosis 7,8 . Furthermore, there is a constant need to evaluate temporal trends related to leprosy and its outcomes and indicators in Brazil's macro-regions 7 , in addition to strengthening actions that lead to timely diagnosis 8 .…”

“…This outcome is influenced by socioeconomic, demographic, and environmental factors that result in late diagnosis 7,8 . Furthermore, there is a constant need to evaluate temporal trends related to leprosy and its outcomes and indicators in Brazil's macro-regions 7 , in addition to strengthening actions that lead to timely diagnosis 8 . However, to the best of our knowledge, there has been no consistent investigation into the dynamics involving the performance of skin smear microscopy for leprosy in SUS.…”