Dispersal of Lutzomyia longipalpis and expansion of canine and human visceral leishmaniasis in São Paulo State, Brazil

Abstract

Visceral leishmaniasis (VL), a neglected disease, is a serious public health problem that affects millions of people worldwide. The objectives of the study were to evaluate the sensitivity of Lutzomyia longipalpis and canine VL (CVL) autochthony early detection and describe the spatial and temporal dispersal of vector and expansion of VL in a Brazilian state. We obtained data on the leishmaniasis vector and VL cases in São Paulo State (SP), Brazil, from the Division of Endemic Disease Control and from the Epidemiological Surveillance Center of the São Paulo State Department of Health. Data were analyzed for 645 municipalities and 63 microregions and presented as thematic and flow maps. Following the verified presence of L. longipalpis in Araçatuba in 1997, the first autochthonous cases of canine VL (CVL) (1998) and of human VL (HVL) (1999) in São Paulo were reported, both in Araçatuba. From 1997 to 2014, the urban presence of the leishmaniasis vector was verified in 167 (25.9%) municipalities with cases of CVL reported in 108 (16.7%) and cases of HVL in 84 (13%). The sensitivities for vector presence early detection in relation to the identification of CVL and HVL autochthony were, respectively, equal to 76.4 and 92.5%. The sensitivity for CVL autochthony early detection in relation to the HVL autochthony identification was 75.8%. Vector dispersal and expansion of CVL and HVL were from the northwest to the southeast of the state, primarily flanking the Marechal Rondon highway at a constant rate of progression of 10, seven, and six new municipalities affected per year, respectively. We concluded that the sensitivity for vector presence and CVL autochthony presented reasonable accuracy and most of the time the vector presence and, specially, the CVL and HVL autochthony were identified in the main cities of the microregions of SP. Vector dispersal and expansion of VL started in 1997 near the state border of SP with the state of Mato Grosso do Sul. It has advanced from the northwest to the southeast flanking the Marechal Rondon highway at an arithmetic progression rate outward from the main cities of the microregions. Autochthonous cases of CVL and HVL emerged in SP, in general, after the verified presence of L. longipalpis.

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

“…Studying the temporal and spatial distribution of HVL in Araçatuba was important because it was the first municipality of the state to confirm autochthonous cases and it had played an important role in the dissemination of the disease in SP 4 . Furthermore, the dissemination of the disease in Araçatuba in the early years after its introduction occurred without a structured surveillance and control program in SP.…”

Current status and management of canine leishmaniasis in Latin America

“…Uruguay (Bravo et al, 2013;Salomón et al, 2001Salomón et al, , 2011Salomón and Orellano, 2005;Rangel and Vilela, 2008). Formerly associated with forested and rural areas, the epidemiological profile of leishmaniasis has changed and VL vectors now appear to be present also in urban and periurban areas of Latin America, including large cities in Brazil (Bejarano et al, 2001;Oliveira et al, 2016;Saraiva et al, 2009). Although Lu.…”

Human visceral leishmaniasis: epidemiological, temporal and spacial aspects in Northeast Brazil, 2003-2017

“…Present in all regions of Brazil, HVL has adapted to urban and peri-urban areas, directly impacting the endemicity and effectiveness of control actions 3 . The epidemiological profile of HVL in Brazil has been changing due to an increasing and disorganized urbanization, accentuated by a disordered land occupation and precarious living conditions 4,5 . Environmental factors play an important role in the dynamics of HVL transmission and they can explain, at least partially, its geographical expansion 6 .…”