Detecção de infecção por Leishmania infantum em felinos domésticos no estado da Bahia

Abstract

Leishmaniasis has a complex epidemiological cycle with participation of different hosts, reason why it is necessary to investigate and increase knowledge about animals’s infections living in endemic areas. Thus, the objective of this study was to determine the occurrence of infection by Leishmania infantum in domestic cats from endemic regions for zoonotic leishmaniasis in the state of Bahia, in addition characterize positive cases according to clinical aspects, serology for anti-Leishmania antibodies and the presence of common co-infections in felines. An active search was conducted in cities of Muritiba, São Félix, Simões Filho, Camaçari and Feira de Santana, also clinical evaluation of 104 cats and the collection of biological samples (peripheral blood and bone marrow aspirates), immunochromatographic serological test TR-DPP® (Biomanguinhos), cytological examination to investigate amastigote forms of Leishmania sp., qualitative conventional PCR for DNA detection of Leishmania infantum, FIV (Feline Immunodeficiency Virus), FeLV (Feline Leukemia Virus) and Mycoplasma sp. and clinical pathology exams were performed. Of the 104 cats evaluated, 14 were excluded from this study. Analyzes of samples from 90 cats revealed that L. infantum infection was confirmed in 7.8% (7/90) of the cats examined by PCR, three of them were residents in Muritiba, two in Camaçari and two in São Félix. One cat that was positive for PCR for L. infantum, also presence of amastigote forms detection in cytological examination of bone marrow aspirates and for TR-DPP® . Interesting, this cat did not present any alterations in physical examination at the first clinical exam (T1), as well as hematological and biochemical laboratorial tests were in the normal range at the second clinical exam (T2), 22 days after T1. However, 82 days after T2 (T3) the cat developed feline leishmaniasis (LFe), characterized by lymphadenomegaly, conjunctivitis, and ulcers located in oral cavity, associated with lymphocytosis, hyperproteinemia with hyperglobulinemia and elevated serum alkaline phosphatase, in addition to abundant presence of amastigotes in lymph node and eyelid conjunctiva cytology; however, the TR-DPP® test performed was negative at T3. Of the seven cats positive for PCR, only one was positive for TR-DPP® test, confirming 1.1% seropositivity. The clinical observations found in cats positive for PCR were weight loss, dehydration, crusted lesions on the tips of ears, alopecia, lymphadenomegaly, sneezing and gingivitis-stomatitis complex. There was only one 1.1% cat (1/90) co-infected with L. infantum and FeLV, it showed mild dehydration and circular alopecia areas at ventral cervical region. Based on the data obtained, we can say that infection by L. infantum also occurs in cats at Muritiba, São Félix and Camaçari cities. Cats infected with L. infantum at the present study were classified as showing mild disease. Further studies are necessary for a comprehensive dimensioning of the number of affected cats and establishment of the clinical and pathophysiological characterization of these hosts in other cities at the State of Bahia.