Serological Evidence of Infection byLeishmania (Leishmania) infantum(Synonym:Leishmania (Leishmania) chagasi) in Free-Ranging Wild Mammals in a Nonendemic Region of the State of São Paulo, Brazil

Abstract

Concerns about the interface between wildlife, domestic animals, and humans in the transmission of visceral leishmaniasis (VL) have been growing due to natural or anthropogenic environmental changes. In this context, investigations of the infection in wild mammals are important to assess their exposure to the vector and the parasite. A study of anti-Leishmania (Leishmania) infantum antibodies was carried out using the direct agglutination test (DAT) on 528 free-ranging wild mammals of 38 species from the region of Botucatu, state of São Paulo, Brazil, a municipality that has no records of the vector or of human or canine autochthony. Antibodies were detected, with a cutoff of 1:320, in 9/528 (1.7%; 95% confidence interval [CI] 0.6-2.8%) mammals of the species Callithrix jacchus, Lepus europaeus, Sphiggurus villosus, Nasua nasua, Eira barbara, and Galictis cuja, with high titers (≥1280) for the last three. These three are little-studied species, and previous records of the detection of anti-Leishmania spp. antibodies in Brazil exist only for coatis (N. nasua), whereas worldwide, infection by L. (L.) infantum has been confirmed only in hares (Le. europaeus). On the other hand, opossums and canids, the species most commonly reported to be naturally infected by L. (L.) infantum, were not seropositive. Fifty-eight (58/528; 10.9%) mammals were found to have antibody titers ranging from 20 to 160 and were not included among the seropositive animals due to the adopted cutoff. However, the possibility of infection in these animals should not be discarded, because there is no standard cutoff point for the different wild species. Our findings indicate the need for investigations into the exact role of the seropositive species in the epidemiology of VL and for effective epidemiological surveillance to prevent its expansion, because even in regions where there are no records of canine or human autochthonous cases, there may be parasite circulation among wild mammals.

Leptospira reservoirs among wildlife in Brazil: Beyond rodents

“…Regarding leptospirosis, our results contradict these thoughts. Likewise, in preliminary studies, we found low prevalence of toxoplasmosis (Fornazari et al, 2011), leishmaniasis (Paiz et al, 2015) and brucellosis (Antunes et al, 2010). Thus, contrary to our initial thoughts, so far there is no evidence that opossums are important carriers of zoonoses in Botucatu.…”

A Systematic Review (1990–2021) of Wild Animals Infected with Zoonotic Leishmania

“…Several studies investigated free-ranging carnivores by serology using a direct agglutination test (DAT), and positive values were found in tayras (Eira barbara), lesser grison (Galictis cuja) and coatis (Nasua nasua) in Brazil at high serum dilutions (≥1:1280) [92]. In carnivores kept in captivity, serology was also employed to demonstrate the presence of antibodies against the parasites in ocelots (Leopardus pardalis), hoary foxes (Lycalopex-Pseudalopex vetulus), jaguars (Panthera onca), Siberian tigers (Panthera tigris altaica), African lions (Panthera leo) and cougars (Puma concolor) (Supplementary Materials File S4) [84,90,93,94].…”

“…Lagomorphs were scarcely reported as exposed to L. infantum in the Americas, with one European hare (Lepus europaeus) found positive in Brazil by DAT and with a low antibody titre (1:320) [92].…”

“…Rodents occupied most of the attention of researchers investigating L. infantum in the Americas, and twelve studies fulfilled the inclusion criteria of this systematic review [21,36,39,50,53,58,86,92,101,106,107,110]. Most of the studies employed different PCR approaches in several tissues, although in one study the authors detected antibodies.…”

“…Brazilian guinea pigs were reported to be infected in Brazil by PCR in heart tissue [86]. The infection was also found in two species of porcupines from Brazil: the prehensile tailed porcupine (Coendu-Sphiggurus villosus) by serology (DAT) [92], which is indirect evidence of the parasitism, and the Paraguayan hairy dwarf porcupine (Coendou-Sphiggurus spinosus) by PCR and sequencing from several tissues (Supplementary Materials File S4) [86]. Agouties were also reported to test positive for L. infantum in the spleen (16.7%), skin and blood by PCR [36,110].…”