Canine visceral leishmaniasis and Chagas disease among dogs in Araguaína, Tocantins Leishmaniose visceral canina e doença de Chagas em cães de Araguaína, Tocantins

Abstract

The present study analyzed serum samples from 111 male and female dogs of various ages from the municipality of Aragua&#237;na in the State of Tocantins, Brazil. Serological diagnosis of canine visceral leishmaniasis (CVL) was initially performed at the Central Laboratory (Laborat&#243;rio Central &#8211; LACEN) of Aragua&#237;na, resulting in 61 positive samples by an indirect immunofluorescence assay (IIFA) (&#8805;1:40) and 50 non-reactive samples. The same samples were analyzed at the S&#227;o Paulo Institute of Tropical Medicine (Instituto de Medicina Tropical de S&#227;o Paulo &#8211; IMTSP) by an enzyme-linked-immunosorbent assay (ELISA), resulting in 57 positive samples (51.35%) and 54 negative samples (48.64%). The Kappa coefficient of agreement between the tests was 0.74. The serum samples were also subjected to a diagnostic assay for Trypanosoma cruzi (Trypomastigote Excreted/Secreted Antigens -TESA-blot) that detected five suspect animals; three of those animals were positive for leishmaniasis by ELISA but negative by IIFA. These findings suggest that the canine population of Aragua&#237;na may be simultaneously infected with Leishmania chagasi and T. cruzi. The results obtained demonstrate the difficulty of using serology to detect CVL, thus emphasizing the necessity for a reference test to diagnose CVL, particularly in regions where the infection is endemic.<br>Neste estudo foram analisadas amostras de soros de 111 c&#227;es machos e f&#234;meas, de idades variadas, provenientes do munic&#237;pio de Aragua&#237;na, estado do Tocantins, Brasil. O diagn&#243;stico sorol&#243;gico para leishmaniose visceral canina foi realizado, inicialmente, no Laborat&#243;rio Central (LACEN) de Aragua&#237;na, resultando em 61 amostras positivas na Rea&#231;&#227;o de Imunofluoresc&#234;ncia Indireta - RIFI (&#8805;1:40) e 50 amostras n&#227;o reativas. As mesmas amostras foram analisadas no Instituto de Medicina Tropical de S&#227;o Paulo (IMTSP) pelo Enzyme-Linked-Immunosorbent Assay (ELISA), sendo 57 amostras positivas (51,35%) e 54 amostras negativas (48,64%), com coeficiente de concord&#226;ncia entre os testes (Kappa = 0,74). Os soros foram submetidos tamb&#233;m a um teste de diagn&#243;stico para Trypanosoma cruzi (Trypomastigote Excreted/Secreted Antigens -TESA-blot), o qual detectou cinco animais suspeitos, dos quais tr&#234;s foram positivos para leishmaniose no ELISA, mas negativos na RIFI. Estas observa&#231;&#245;es mostram que a popula&#231;&#227;o canina de Aragua&#237;na pode tamb&#233;m estar infectada simultaneamente com Leishmania chagasi e T. cruzi. Estes resultados mostram a dificuldade da sorologia na detec&#231;&#227;o da Leishmaniose Visceral Canina (LVC), refor&#231;ando a necessidade de um teste de refer&#234;ncia para o diagn&#243;stico da leishmaniose visceral canina, principalmente em regi&#245;es end&#234;micas para tais infec&#231;&#245;es.