Temporal patterns, spatial risks, and characteristics of tegumentary leishmaniasis in Brazil in the first twenty years of the 21st Century

BackgroundTegumentary leishmaniasis (TL) is a significant public health issue in Brazil. The present ecological study describes the clinical and epidemiological characteristics of TL cases reported in the country, and analyzes the spatial and temporal patterns of the incidences and risks of occurrence across the five geopolitical regions and 27 federative units. Methodology/Principal findingsData regarding new cases of TL notified between 2001 and 2020 were obtained from the Information System for Notifiable Diseases of the Brazilian Ministry of Health. Joinpoint and spatial and temporal generalized additive models were used to establish trends in the evolution of TL during the target period. The incidence rate for the entire period was 226.41 cases/100,000 inhabitants. All regions of Brazil showed trends of decreasing incidence rates, albeit with fluctuations at specific times, with the exception of the Southeast where rates have increased since 2014, most particularly in Minas Gerais state. The disease was concentrated predominantly in the North region, with Acre state leading the incidence rank in the whole country, followed by Mato Grosso (Midwest), Maranhao and Bahia (Northeast) states. The spatial distribution of the risk of TL occurrence in relation to the annual averages was relatively stable throughout the period. The cutaneous form of TL was predominant and cases most frequently occurred in rural areas and among men of working age. The ages of individuals contracting TL tended to increase during the time series. Finally, the proportion of confirmations by laboratory tests was lower in the Northeast. Conclusion/SignificanceTL shows a declining trend in Brazil, but its widespread occurrence and the presence of areas with increasing incidence rates demonstrate the persistent relevance of this disease and the need for constant monitoring. Our findings reinforce the importance of temporal and spatial tools in epidemiologic surveillance routines and are valuable for targeting preventive and control actions. Author summaryLeishmaniasis, a neglected tropical disease caused by parasitic protozoa, exists in various clinical forms, the most common of which is tegumentary leishmaniasis (TL). The lethality of TL is low, but the skin lesions may produce physical deformities and stigma. Brazil has the highest number of TL cases in the American continent and the disease is present in all federative units. However, studies performed so far have been restricted to localized areas of Brazil and do not provide a broad view of the situation in the country. Therefore, we described the clinical and epidemiological characteristics of TL cases in Brazil and evaluated the spatial and temporal patterns from 2001 to 2020. Our findings show that the occurrence of TL declined between 2001 and 2020 in all regions of the country except for the Southeast where incidence rates have recently increased. We have identified those areas of the country where the population remains at greater risk of contracting the disease and have found that the situation has changed little over the years. The knowledge gained about the spatial and temporal variations of the incidence of TL, the profiles of those affected by the disease, and the diagnostics and treatment employed might be valuable to improve the policies and actions against the disease.

Automated summary

This study describes the clinical and epidemiological characteristics of tegumentary leishmaniasis (TL) cases in Brazil and analyzes the spatial and temporal patterns of incidence and risk across regions and federative units. The overall incidence rate for the period was 226.41 cases/100,000 inhabitants. TL showed a declining trend in Brazil, except for the Southeast where rates have increased since 2014. The disease was concentrated in the North region, with Acre state leading in incidence. TL primarily occurred in rural areas and among men of working age.