Identification of Leishmania spp. in horses and a dog from rural areas of Uruguaiana, Rio Grande do Sul, Brazil

Abstract

Visceral leishmaniasis (VL) is a zoonosis caused by the protozoan of the genus Leishmania. The disease is transmitted by the bite of a sand fly vector. Although the main reservoirs are dogs, other hosts can be infected and may play this role. Rio Grande do Sul western region, located on the triple border of Brazil-Uruguay-Argentina, represents a VL transmission area. The goal of the present study was to identify Leishmania spp. infection in animals from rural areas of Uruguaiana, Rio Grande do Sul. Nine farms in the Uruguaiana municipality, Rio Grande do Sul state, were included. Peripheral blood samples were collected from 113 animals (canine [n=22], equine [n=91]) for detection of Leishmania spp. DNA was isolated and polymerase chain reaction was performed. Eight (7%) animals with Leishmania spp. infection were detected on two farms in the same geographical area, seven of which were horses and one was canine, all of which were asymptomatic. To investigate the species of Leishmania, one of the positive equine samples was subjected to direct sequencing, which confirmed the presence of L. infantum genetic material. Results of this study confirm the presence of L. infantum-infected animals in rural areas of Uruguaiana, and provide evidence supporting further investigation of risk factors for dissemination in such areas.