Exposure to and infection by Leishmania infantum among domestic dogs in an area of the Cerrado biome, Maranhão, Brazil.

Visceral Leishmaniasis is a serious public health problem and dogs are considered to be the main source of infection in urban areas. In Brazil, this disease is present in all regions, but with high concentration of cases in the Northeast, and the state of Maranhão is considered to be an endemic region. The aim of this study was to conduct an epidemiological, spatial, molecular and serological survey on Leishmania infantum among domestic dogs in the municipality of Belágua, Maranhão. Blood samples were collected from dogs and questionnaires were applied to their owners to obtain epidemiological data and risk factors relating to this zoonosis in the region. The coordinates of the dogs' homes were obtained to produce a disease risk map. Serological diagnoses were made using the indirect immunofluorescence reaction (IFAT) and the dual-path platform chromatographic immunoassay test (DPP®) (Bio-Manguinhos/FIOCRUZ, Brazil). A molecular investigation was undertaken using the polymerase chain reaction (PCR). Georeferencing was performed using the global positioning system (GPS) and cases of canine visceral leishmaniasis in the municipality were spatially represented and analyzed using QGIS version 3.16.6 (QGIS Development Team, 2021). A total of 205 blood samples were collected, of which 122 (59.51%) were seroreactive for L. infantum through IFAT, while the DPP test showed 84 reactive samples (40.97%). IFAT and DPP detected 16 positive animals simultaneously. One sample that was seroreactive through IFAT was also positive through PCR. In the clinical evaluation, it was observed that among the seropositive dogs, 112 (91.80%) were symptomatic and 10 (8.20%) were asymptomatic. In the spatial analysis, the Kernel density estimator enabled determination of the place at greatest risk of occurrence of the disease. The areas with the highest concentrations of cases were in districts with large quantities of precarious housing and lack of basic sanitation. This was the first report on the occurrence of L. infantum among dogs in the municipality of Belágua. The results show that canine visceral leishmaniasis is well dispersed in this municipality, thus putting at risk the human population.

Litomosoides brasiliensis (Nematoda: Onchocercidae) infecting chiropterans in the Legal Amazon region, Brazil.

Chiropterans play an important role in the maintenance of the environmental balance, since they are pollinators, seed dispersers and predators. They contribute to transmission and spreading of microorganisms such as helminths, fungi, protozoa, bacteria and virus. The aim of the present study was to investigate natural filariid infection among bats in the Legal Amazon region, Brazil, by means of parasitological and molecular analyses. Blood samples were collected from 82 bats for blood smears and for DNA extraction via the polymerase chain reaction (PCR) assay. Microfilariae were observed in blood smears from Carollia perspicillata (2), Artibeus lituratus (1), Artibeus fimbriatus (2), Dermanura gnoma (2) and Glossophaga soricina (1). Five positive samples were detected through the PCR assay and four of these were also positive in blood smears. From genome sequencing and comparative analysis with sequences deposited in GenBank, one sample showed 99.31% similarity to the species Litomosoides brasiliensis. The present study expands the geographical distribution of L. brasiliensis, to include the state of Maranhão as an area of occurrence of this species and includes D. gnoma and A. fimbriatus as hosts in Brazil.