Infection by agents of leishmaniasis, Chagas disease and Brazilian spotted fever in free-ranging wild mammals from an environmentally protected area of the municipality of Campinas, São Paulo

Author(s)

Laís Moraes Paiz

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2018-02-26

Examining board members

Maria Rita Donalisio Cordeiro; Cáris Maroni Nunes; Guilherme Loureiro Werneck; Simone Baldini Lucheis; Mariângela Ribeiro Resende

• Advisor: Maria Rita Donalisio Cordeiro

Abstract

In recent decades, there has been a growing discussion about the involvement of wildlife in the epidemiology of zoonoses, especially due to the emergence and reemergence of infectious and parasitic diseases, increasing environmental changes and consolidation of the "One Health" approach. The environmentally protected area (EPA) of the municipality of Campinas, São Paulo State, Brazil, has undergone intense environmental changes since the 1960s, mostly due to urban expansion. In this degraded environment, wild fauna cohabit with man and domestic animals, which may be related to the occurrence of zoonoses in EPA, such as cutaneous leishmaniasis, visceral leishmaniasis (VL) and Brazilian spotted fever (BSF). Thus, this study aimed to investigate the circulation of the agents of these three zoonotic infections, in addition to the agent of Chagas disease (Trypanosoma cruzi), among free-ranging wild mammals of the EPA-Campinas. For this purpose, serological and molecular techniques were applied in biological samples collected from 82 wild mammals, which were captured in 18 areas of EPA between April 2014 and March 2015. The detection of antibodies to the main agent of BSF, Rickettsia rickettsii, was performed by the indirect fluorescent antibody test in serum samples from 54 opossums (Didelphis spp.), considered to be amplifier hosts. One D. albiventris (white-eared opossum) presented antibody titre of 128. In addition, the DNA of rickettsia was screened in blood samples from all the captured mammals. There was no molecular detection, which was an expected result when considering the location of the agent in endothelial cells and the generally short period of rickettsemia. On the other hand, the infection by pathogenic trypanosomatids was observed among mammals sampled. Ten animals had anti-Leishmania antibodies and five presented the DNA of the parasite in blood and/or skin samples. Genetic sequencing allowed the identification of infection by the agent of VL, Leishmania (L.) infantum, in four animals (one marmoset and three opossums). Infection by Leishmania subgenus Viannia was verified in one D. albiventris, but it was not possible to determine the parasite species by the analysis of restriction fragment length polymorphism and high resolution melting. The DNA of T. cruzi was detected in blood samples from three D. albiventris. One of them presented the DNA of the parasite in samples from two captures, conducted at a three-month interval. All animals infected by the agents of leishmaniasis and Chagas disease were in close proximity to human dwellings at the time of capture, particularly in two condominiums where there is canine VL transmission. The results raise concern regarding wildlife-man-domestic animals interface in fragmented habitats. Surveillance activities are necessary to clarify other factors related to the transmission cycle of T. cruzi in the EPA, such as the triatomine fauna and the infection of dogs, considered to be sentinels to the risk of human infection. With regard to VL, the Brazilian control program must consider the particularities of each transmission area. Measures such as the elimination of the canine reservoir may be ineffective in areas such as EPA, where the parasite circulates among wildlife (AU)

• FAPESP's process: 16/02572-0 - Infection survey of Leishmaniasis, American Trypanosomiasis and Brazilian Spotted Fever agents in free-ranging wild mammals from the environmentally protected area of the municipality of Campinas, São Paulo
• Grantee: Lais Moraes Paiz
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)