Human and canine visceral leishmaniasis in an emerging focus in Araçuaí, Minas Gerais: spatial distribution and socio-environmental factors

Abstract

This study aimed to analyse the spatial distribution of human (2007-2013) and canine (2013) visceral leishmaniasis (VL) in the city of Araçuaí, Minas Gerais, Brazil, and identify the socio-environmental factors related to their occurrence. The spatial distribution of human and canine cases was analysed by kernel density estimation (KDE) and the K function. The KDE values were analysed for correlation between human and canine LV and for normalised difference vegetation index (NDVI). Socio-environmental aspects of household structures and surroundings were evaluated. The spatial distribution of human and canine VL cases exhibited a significant aggregated pattern in distances greater than 350 and 75 m, respectively. The higher occurrence of human and canine infection occurred in the central area of the city. A positive correlation between the densities of human and canine cases was observed, as well as a negative correlation between NDVI and densities of human and canine cases. Socio-environmental analysis revealed that the large amount of animals, organic material from trees and deficiencies in environmental sanitation are possibly contributing to the continuation of the transmission cycle of Leishmania infantum in Araçuaí. These results can contribute to the planning by competent agencies to reduce the incidence of infection in the city.

Spatio-temporal analysis of the occurrence of human visceral leishmaniasis in Araçatuba, State of São Paulo, Brazil

“…Similar to a previous study conducted in Araçatuba, Souza et al 11 , Vieira et al 12 , and Cardim et al 13 performed a spatial and spatio-temporal analysis of HVL in the Cites of Bauru, Birigui, and Adamantina, SP and clusters were detected. Furthermore, Ripley's K-function was applied in a study on CVL and HVL occurrence in the City of Araçua, Minas Gerais State, Brazil 14 . We expected that the highest agglomeration distance of HVL cases is about 250m, based on the phlebotomine flight radius that, in urban areas, hardly exceeds this distance 15 .…”

“…Considering that the HVL case distribution is mainly associated with areas with higher vector density [16][17][18] , higher canine presence and CVL prevalence 11,14,[24][25][26][27][28] , and worse socioeconomic, demographic, and environmental conditions [21][22][23] , the HVL clustering would be seen as a consequence of all these conditions collectively.…”

Spatial and temporal trends of visceral leishmaniasis by mesoregion in a southeastern state of Brazil, 2002-2013

“…A study performed in Montes Claros showed that VL in this region is associated with poor domiciles and precarious sanitation conditions, which facilitates the accumulation of organic material and other factors that enable the life cycle of the main vector of VL, Lutzomya longipalpis [ 12 ]. The maintenance of the disease cycle explained by similar reasons was also observed in the Jequitinhonha (Araçuaí) [ 53 ]. The findings reported herein corroborate these previous observations, since the highest VL incidence rates were found in the North of Minas Gerais, a region that presents low Human Development Index [ 54 ].…”

Leishmaniose visceral canina nos municípios de Araçatuba e Birigui, estado de São Paulo, Brasil

“…Estudos epidemiológicos têm verificado, em áreas urbanas, sobreposição entre locais com incidência de casos humanos e elevada soroprevalência canina (TEIXEIRA-NETO et al, 2014;TELES et al, 2015;URSINE et al, 2016;CAMPOS et al, 2017). De acordo com ROSALES & YANG (2006), essa relação entre a doença humana e a infecção canina é tão estreita que casos humanos são observados após dois anos de níveis de soroprevalência canina maiores de 20%.…”

“…Nesse contexto, o uso de sistemas de informação geográfica e de análise espacial podem auxiliar na compreensão da dinâmica de transmissão da infecção. Vários autores têm apontado sua importância na identificação de áreas prioritárias e avaliação da efetividade de medidas de vigilância e controle (VIEIRA et al, 2014, TEIXEIRA-NETO et al, 2014, URSINE et al, 2016OLIVEIRA et al, 2016;CARDIM et al 2016;CAMPOS et al, 2017).…”