Clinical and molecular evaluation of dogs from endemic area with visceral leishmaniasis

Abstract

Leishmaniases are diseases caused by flagellate protozoa belonging to the family Trypanosomatidae, genus Leishmania that is transmitted through the bite of family Plebotomidae female mosquitoes. Leishmaniases presents a broad spectrum of clinical manifestations: visceral, cutaneous and mucocutaneous. In urban areas, dogs are considered the main reservoir for visceral leishmaniasis (VL). The World Health Organization (WHO) considers VL as the second most important protozoan infection. It is associated with malnutrition, population displacement, poor housing, weak immune system and lack of resources. The diagnosis of this disease should be performed based on clinical symptomatology, epidemiological characteristics of region, and laboratory tests contributing to the correct destination of the truly positive animals. The use of Nested-PCR for diagnosis allows the identification of more sensitive and specific parasite sequences. The use of ITS-1 for genus Leishmania, provides an adequate number of polymorphisms to distinguish the species level and also intraspecific changes between species of the same region. The main objective of this study is to use the Nested-PCR technique to diagnosis of canine VL through the ITS-1. The specific objectives include evaluation of the presence of Leishmania DNA in blood samples and conjunctival swabs of at least 100 dogs from an endemic area for VL, sequencing of the positive samples and clinical evaluation of the animals, classifying them into four types stage clinical. The Nested-PCR and sequencing results will be compared with clinical signs shown by the animals.