Cases and distribution of visceral leishmaniasis in western São Paulo: A neglected disease in this region of Brazil.

Regiane Soares Santana,Edilson Ferreira Flores,Karina Briguenti Souza,Lourdes Aparecida Zampieri D’Andrea,Elivelton Silva Fonseca,Cristiane Oliveira Andrade,Fernanda Lussari,Marcia Mitiko Kaihara Meidas,Ivete Rocha Anjolete,Francisco Assis Silva,Luiz Euribel Prestes-Carneiro,Luther A Bartelt

doi:10.1371/journal.pntd.0009411

Abstract

Visceral leishmaniasis (VL) is one of the most prevalent parasitic diseases worldwide. In 2019, 97% of the total numbers of cases in Latin America were reported in Brazil. In São Paulo state, currently 17.6% of infected individuals live in the western region. To study this neglected disease on a regional scale, we describe the spread of VL in 45 municipalities of the Regional Network for Health Assistance11(RNHA11). Environmental, human VL (HVL), and canine VL (CVL) cases, Human Development Index, and Lutzomyia longipalpis databases were obtained from public agencies. Global Moran's I index and local indicators of spatial association (LISA) statistics were used to identify spatial autocorrelation and to generate maps for the identification of VL clusters. On a local scale, we determined the spread of VL in the city of Teodoro Sampaio, part of the Pontal of Paranapanema. In Teodoro Sampaio, monthly peri-domicile sand fly collection; ELISA, IFAT and Rapid Test serological CVL; and ELISA HVL serum surveys were carried out. In RNHA11 from 2000 to 2018, Lu. longipalpis was found in 77.8%, CVL in 69%, and HVL in 42.2% of the 45 municipalities, and 537 individuals were notified with HVL. Dispersion occurred from the epicenter in the north to Teodoro Sampaio, in the south, where Lu. longipalpis and CVL were found in 2010, HVL in 2018, and critical hotspots of CVL were found in the periphery. Moran's Global Index showed a weak but statistically significant spatial autocorrelation related to cases of CVL (I = 0.2572), and 11 municipalities were identified as priority areas for implementing surveillance and control actions. In RNHA11, a complex array of socioeconomic and environmental factors may be fueling the epidemic and sustaining endemic transmission of VL, adding to the study of a neglected disease in a region of São Paulo, Brazil.

Highlights

Visceral leishmaniasis (VL) is one of the most prevalent parasitic diseases worldwide
The presence of Lu. longipalpis in the municipalities of RNHA11 mesoregion In São Paulo, Lu. longipalpis sand flies were found for the first time in Aracatuba, an area surrounding the western region in January 1997
In RNHA11 mesoregion, Lu. longipalpis was detected for the first time in Dracena in 2003 in the north; the sand flies dispersed toward the south in the direction of the municipalities of Pontal of Paranapanema and Paranastate

Summary

Introduction

Visceral leishmaniasis (VL) is one of the most prevalent parasitic diseases worldwide. In 2017, 94% of new cases occurred in seven countries: Brazil, Ethiopia, India, Kenya, Somalia, South Sudan, and Sudan [1]. In 2019, 97% of the total numbers of cases in Latin America were reported by Brazil [2]. 25 of 27 Brazilian states notified autochthonous cases of canine visceral leishmaniasis (CVL) and 23 notified cases of human visceral leishmaniasis (HVL) [3]. In São Paulo, the richest and most populous state, Lutzomyia longipalpis sand flies were found in 1997, infected dogs in 1998, and infected humans in 1999. In 2020, 106 of 645 (16.4%) municipalities registered cases of HVL [4]

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Conclusion