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Leishmaniasis is a vector-borne parasitic protozoan infection that affects mammals and involves a complex epidemiology. Although dogs are considered the main reservoir in zoonotic visceral leishmaniasis (VL), the possible presence of other mammalian species acting as reservoirs has been associated as a possible cause of lack of success in the control of human VL in many endemic areas. The knowledge about natural infections of some species is still scarce, such as nonhuman primates (NHP), especially from the genus Callithrix (marmosets). We investigated the infection by Leishmania (Leishmania) infantum, the agent of VL in the Americas, in 26 marmosets captured monthly, from April 2014 to March 2015, in an environmentally protected area (EPA) in Southeastern Brazil. The EPA has undergone significant environmental changes and has a transmission focus of canine VL since 2009. Serology was performed through the direct agglutination test, which detected low antibody titers in seven marmosets (7/26; 26.9%, 95% confidence interval 9.9-44.0), being five Callithrix penicillata (black-tufted-ear marmoset) and two Callithrix jacchus (white-tufted-ear marmoset). The presence of the DNA of Leishmania was investigated in blood and skin samples by PCR and genetic sequencing. This is the first report of the detection of L. (L.) infantum in the skin of a marmoset, which was verified in a sample from one C. penicillata. The results demonstrate the natural infection of marmosets by L. (L.) infantum and may suggest the participation of these animals as hosts in the parasite's transmission cycle in the EPA. However, more comprehensive studies are needed to elucidate their role on the VL epidemiology in this area and also in different endemic areas, especially because these NHP are increasingly in contact with humans and domestic animals, particularly due to environmental changes.

Background: Leishmaniasis is a rapidly expanding zoonosis that shows increasing urbanization. Concern exists regarding the role of wildlife in visceral leishmaniasis (VL) transmission, due to frequent natural or anthropogenic environmental changes that facilitate contact between wildlife, humans and their pets. The municipality of Campinas, in southeastern Brazil, initially recorded VL in 2009, when the first autochthonous case was confirmed in a dog living in an upscale residential condominium, located inside an environmentally protected area (EPA). Since then, disease transmission remains restricted to dogs inhabiting two geographically contiguous condominiums within the EPA., Methodology/principal Findings: We conducted a cross-sectional study of the VL focus to investigate Leishmania spp. infection in domestic dogs, wild mammals and sand flies using molecular tools and recommended serological techniques. Canine seroprevalences of 1.5% and 1.2% were observed in 2013 and 2015, respectively. Six insect species, confirmed or suspected vectors or potential transmitters of Leishmania, were identified. Two specimens of the main L. (L.) infantum vector in Brazil, Lutzomyia longipalpis, were captured in the EPA. Natural infection by L. (L.) infantum was recorded in one Expapillata firmatoi specimen and two Pintomyia monticola. Natural infection by L. (L.) infantum and Leishmania subgenus Viannia was also detected in two white-eared opossums (Didelphis albiventris), a known reservoir of VL. Geographical coordinates of each sampling of infected animals were plotted on a map of the EPA, demonstrating proximity between these animals, human residences, including the dogs positive for VL, and forest areas., Conclusions/significance: The EPA, which is inhabited by humans, has an active VL focus. The risk of establishing and maintaining disease transmission foci in similar scenarios, i.e. wild areas that undergo environmental modifications, is evident. Moreover, different epidemiological profiles of VL must be included to elaborate prevention and control measures that consider the particularities of each transmission area.

There is a growing concern about the participation of wild hosts and reservoirs in the epidemiology of leishmaniasis, particularly within the context of increasingly frequent environmental changes and the expansion of the One Health concept. This work is a molecular research of infection by Leishmania spp. among the wildlife of an environmentally protected area located in the municipality of Campinas, São Paulo, Brazil. The studied area has a history of intense environmental changes, with notifications of human cases of cutaneous leishmaniasis in the 1990s, and a focus of canine visceral leishmaniasis since 2009. Eighty-two wild mammals were sampled by monthly captures in this region over a 1-year period. Blood samples were collected from each animal and subjected to DNA extraction and PCR using primers for the region of the internal transcribed spacer-1. The results of gene sequencing for the first time revealed the infection of opossums (Didelphis albiventris) by Leishmania spp., subgenera Leishmania and Viannia, in Campinas. These findings, in addition to environmental and historical characteristics of the studied area, indicate a possible role of wildlife in the introduction and/or maintenance of natural foci of leishmaniasis transmission.

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.

Leishmaniasis is a vector-borne zoonotic disease caused by protozoa in the genus Leishmania, typical of rural and peri-urban environments. The causative agent of American visceral leishmaniasis is Leishmania (Leishmania) infantum chagasi and the main insect vector in Brazil is Lutzomyia longipalpis. Dogs (Canis familiaris) are important in the transmission of the disease, as a reservoir closely related to humans and an infection source for phlebotomine vectors. Since 1990, an increasing number of feline leishmaniasis cases have been reported, suggesting that domestic cats (Felis catus) might be involved in the epidemiology of the disease. The present study analyzed the prevalence of anti-Leishmania spp. antibodies in naturally infected domestic cats from various neighborhoods in the municipality of Belém, Pará, Brazil, using the indirect immunofluorescence assay (IFA) and the direct agglutination test (DAT). Among the 443 samples tested, 18 (4.06%) presented positive reactions in the IFA. The observed titers were 40 IU in 4.97% of the samples and 80 IU in 0.90%. In the DAT test, positive results were found in 25 (5.64%) of the samples. The observed titers were also 40 IU (4.97%) and 80 IU (0.68%). The agreement rate between the two tests was considered low (Kappa coefficient = 0.10).