Detecção molecular de Leishmania infantum e Trypanosoma cruzi em equídeos em condições semiáridas.

Abstract

Leishmaniasis and Chagas disease are infections caused by protozoa belonging to the genera Leishmania and Trypanosoma, respectively, considered the most important within the Trypanosomatidae family, due to their zoonotic character. Classified as neglected tropical diseases, they occur with greater prevalence in poor countries, causing economic, social and political problems. This thesis was divided into three chapters, which aimed to describe epidemiological and diagnostic aspects of infection by Leishmania infantum and Trypanosoma cruzi in equids. In chapter I, a systematic review with meta-analysis about the clinical characteristics and prevalence of leishmaniasis in equids was developed. The main symptoms of leishmaniasis in equids are cutaneous (papules, nodules, ulcers, crusts), self-limiting and mainly located on the head and limbs. The meta-analysis showed a combined prevalence of 25%. In conclusion, it was shown that leishmaniasis in equids is a benign disease and should be included as a differential diagnosis for skin diseases in these species. In chapter II, a survey of Leishmania infantum infection in donkeys and mules in semi-arid conditions in Brazil was carried out. Whole blood from 72 equidae (65 donkeys and 7 mules) was used to perform molecular diagnosis through the Real Time Polymerase Chain Reaction (qPCR) technique. A total of 25% samples (18/72) were positive in the qPCR, with no significant difference between species, sex and abandonment status of the animals (yes or no). Donkeys and mules living in rural area of the semiarid region of Brazil have a high frequency of infection by L. infantum, and it is valid to attribute importance to these species in the epidemiological cycle of leishmaniasis. Chapter III aimed to detect Trypanosoma cruzi infection in donkeys and mules from rural areas of the Brazilian semiarid region. Whole blood from 72 equidae (65 donkeys and 7 mules) were analyzed by Nested Polymerase Chain Reaction (nested-PCR). A total of 51.39% samples (37/72) were positive. Phylogenetic analysis identified the TcI and TcII types of T. cruzi. This is the first report of T. cruzi infection in donkeys and mules in Brazil, and their way of life, the adaptability of vectors in the Caatinga and the socioeconomic characteristics of the semi-arid population create interactions that can favor the transmission and overlap of wild, peridomestic and domestic cycles of T. cruzi infection.