Spatial and spatiotemporal patterns of human visceral leishmaniasis in an endemic southeastern area in countryside Brazil

Abstract

Visceral leishmaniasis (VL) has shown endemic pattern and epidemic episodes in urban and rural areas, however, there are still gaps in knowledge with regards to disease transmission. This study aimed to analyze the spatiotemporal dispersion of VL cases in the municipality of Araçuaí, Minas Gerais. A study of confirmed VL cases was conducted considering the endemic and epidemic periods between 2012 and 2017. The incidence rate was calculated, and for spatial analysis, the kernel map, directional distribution ellipse, and space-time scanning techniques were used. The correlations between VL cases and exposure variables (precipitation, humidity, and temperature) were calculated. The mean incidence of VL in the endemic period was 18.5 (95% confidence interval (CI) 5.9-32.5) and 44.4 in the epidemic period (95%CI, 12.0-28.6) by 100,000 inhabitants. The relative risk for the epidemic period was 2.4 (95% CI 1.4-4.1) when compared to the endemic period. A higher incidence of the disease was observed in rural areas of the municipality. Kernel mapping analysis revealed hotspots in the urban area of the municipality. The directional distribution ellipse encompasses the urban perimeter and part of the rural area of the municipality, expanding eastward during the epidemic period. Spatial analysis revealed a high-risk cluster for VL in rural areas. A positive correlation was observed between VL cases and temperature during the endemic period. Spatial analysis allowed us to outline the epidemiological scenario of human VL cases. These findings may be useful in case surveillance and in the work of health professionals and managers in Brazil.

Increased Risk of American Tegumentary Leishmaniasis in an Urban and Rural Area of Caratinga, Brazil between 2016 and 2021

“…As previously noted, together with migration, agricultural practices, deforested areas, and disordered human occupation also can contribute to ATL transmission by favoring proximity to the vectors. 32 The urban area of Caratinga had hotspots since 2007, reinforcing that ATL is already urbanized there for a long time. In the last triennium evaluated, not only the central area of the city but also the entire southern area had a greater coverage of cases.…”

Visceral Leishmaniasis Associated with HIV Coinfection in Pará, Brazil

“…43 There is overcoming the paradigm of being VL a typically rural disease. 44 A recent study shows that there is no change in the epidemiological pattern in the process of transmission of the disease, 45 the change has been happening in the geographic expansion of VL, to an area designated as an urban area, which has environments very similar to the rural environment, [46][47][48] providing a better adaptation of the vector to the place.…”