Dados do Trabalho

Título

The parasitism of Leishmania infantum in wild mammals at endemic area for human and canine leishmaniasis in Midwest Brazil: an epidemiological puzzle

Introdução

Campo Grande (CG), Midwest Brazil, is considered to be an intense transmission area for Leishmania infantum and, even with the massive removal of infected dogs (the main domestic reservoir host), the infection in both humans and dogs is still worrying.

Objetivo (s)

Since L.infantum is a multi-host parasite and CG presents many species of wildlife with high densities, this study aimed to evaluate the infection rates of L. infantum in free-living mammals from this municipality.

Material e Métodos

A total of 407 individuals of 16 species, including bats, small mammals, and the carnivore coati (Nasua nasua) were captured from May 2017 to November 2020 in urban parks and forested fragments. In order to isolate L. infantum, we cultivated lymphoid tissue (spleen of bats and small mammals and bone marrow of coatis) in tubes containing Novy-MacNeal-Nicolle (NNN) with Schneider’s medium overlay supplemented with 10% fetal bovine serum. For the detection of L. infantum, DNA extraction was performed in blood and lymphoid tissue of all sampled animals, besides skin fragments from coatis. Diagnosis was performed using kDNA as screening and HSP70 as confirmatory targets followed by gene sequencing and blast analysis. Furthermore, we surveyed anti-L. infantum IgG through ELISA test in serum of sampled coatis.

Resultados e Conclusão

An overall prevalence rate of 36.4% (40/110) was observed in coatis: we detected L. infantum DNA in the bone marrow of 16 individuals and from a single skin, and we isolated L. infantum from the bone marrow of one animal. Cryptic infections, characterized by molecular tests, were found in in A. lituratus (07/68), Artibeus planirostris (08/49), Carollia perspicillata (08/43), Glossophaga soricina (05/16), Molossus molossus (01/04), Myotis nigricans (03/03), Phyllostomus discolor (01/01), Platyrrhinus helleri (01/08), Platyrrhinus lineatus (09/32), Sturnira lilium (03/08), and Didelphis albiventris (14/43). Our results indicate that L. infantum circulates in wild mammals from CG, in addition to already known epidemiological scenario including Phlebotomine fauna, humans and dogs. As bats, opossums and coatis inhabit different habitats, L. infantum circulate in CG in a complex enzootic cycle and the epidemiological competencies of these host species must be carefully evaluated.

Palavras-chave

Reservoir system; urban fauna; visceral leishmaniasis; transmission cycles

Agradecimentos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); FAPERJ