INTRODUCTION: The aim of the present study was to identify the presence of Leishmania (Leishmania) chagasi infection in dogs in the City of Palmas, Tocantins, Brazil, using the PCR technique to list the hot spots of infected dogs in the city and associate their occurrence to significant environmental changes at capture sites. METHODS: DNA was extracted from blood of dogs, and the PCR were performed with primers RV1/RV2. After screening the population studied, the regions of the city that had the highest occurrence of canine infection were detected. These sites were visited, and ecological parameters denoting anthropogenic disturbance were evaluated. RESULTS: Some important features were listed in the regions visited, such as low urbanization, lack of public collection of sewage, limited garbage collection, vacant lots with tall vegetation, decaying organic matter, and, most importantly, the occurrence of stray dogs and poultry in homes. CONCLUSIONS: The methodology for screening the population was very efficient, especially in evaluating a large number of individuals in a short time, with a high degree of automation. The results indicate an association between the observed parameters and the occurrence of infection in dogs. The model presented in the city is ideal for studies of disease progression and expansion and for the evaluation of control measures adopted for canine VL.

This study evaluated occurrences of Leishmania infantum in dogs in the municipality of Palmas, Tocantins, comparing diagnostic data obtained using the polymerase chain reaction (PCR) and parasitological diagnosis. Blood samples and lymph node aspirates were collected from 63 dogs of males and females and various ages and races, with or without owners, between August 2009 and June 2010. Slides containing smears of lymph node aspirates were stained with Giemsa stained. In PCR, the 145 bp target sequence of the LT1 fragment, located in the Leishmania donovani kDNA minicircle was detected using the RV1 and RV2 oligonucleotide primers. The chi-square test revealed that there was a significant relationship between the symptoms and dogs that were positive for visceral leishmaniasis (VL). The parasitological investigation showed concordance of 66.7% with PCR on blood and 84.1% with PCR on lymph node aspirate. In addition to these tests, evaluations of the diagnoses in parallel and in series were conducted, which showed concordances with the parasitological test of 76.2% and 74.6%, respectively. The results make it possible to suggest that PCR on lymph nodes should be used in evaluating large populations (surveys) and that the parasitological test should be used for initial clinical evaluations in veterinary consultation offices.Keywords: PCR, blood, lymph node aspirate, parasite, diagnosis. ResumoAvaliou-se a ocorrência de Leishmania infantum em cães do município de Palmas-TO, comparando dados diagnósticos obtidos pela Reação em Cadeia da Polimerase (PCR) e pelo diagnóstico parasitológico. Foram coletadas amostras de sangue e de aspirado de linfonodo de 63 cães machos e fêmeas, várias idades e raças, domiciliares ou não de agosto de 2009 a junho de 2010. As lâminas contendo esfregaço dos aspirados de linfonodos foram coradas pelo corante Giemsa. Na PCR, a sequência alvo de 145 pb do fragmento LT1, situado no minicírculo do kDNA do grupo Leishmania donovani, foi detectada através dos oligonucleotídeos iniciadores RV1 e RV2. O teste χ 2 (Qui-quadrado), demonstrou haver relação significativa entre a sintomatologia e a positividade dos cães para Leishmaniose Visceral (LV). O exame parasitológico mostrou uma concordância de 66,7% com a PCR em sangue e 84,1% com a PCR de aspirado de linfonodo. Além destas análises, houve a avaliação dos diagnósticos em paralelo e em série, onde as concordâncias com o exame parasitológico foram de 76,2% e 74,6%, respectivamente. Os resultados permitem sugerir a utilização da PCR de linfonodos na avaliação de grandes populações (inquéritos), e o exame parasitológico para a avaliação clínica inicial em consultórios veterinários.Palavras-chaves: PCR, sangue, aspirado de linfonodos, parasita, diagnóstico.

INTRODUÇÃO: A Leishmaniose Visceral (LV) ou calazar é uma doença grave, potencialmente fatal que acomete os mamíferos. Causada por protozoário da família Trypanosomatidae, gênero Leishmania, espécie Leishmania (L.) infantum chagasi. Transmitida pelo inseto flebotomíneo Lutzomyia longipalpis popularmente conhecido por mosquito palha, birigui e cangalinhas, é considerada endêmica em vários países tanto em áreas rurais quanto urbanas. No Brasil vem se expandindo, atualmente encontra-se distribuída nas cinco regiões. No município de Palmas está disseminada em toda a sua extensão, classificando-o como de transmissão intensa. MÉTODOS: Nesse contexto, foi definida e avaliada a prevalência do parasita Leishmania (L.) infantun chagasi em cães errantes, capturados pelo Centro de Controle de Zoonoses (Palmas – TO), utilizando diferentes metodologias diagnósticas, ELISA, reação de imunofluorescência indireta (RIFI) e reação de polimerização em cadeia (PCR). No estudo, 195 cães foram capturados em diferentes áreas do município e avaliados pelas três metodologias. RESULTADOS: Das 195 amostras submetidas à análise pelas três metodologias houve concordância de 85,64% entre RIFI e ELISA, 54,87% entre RIFI e PCR. CONCLUSÕES: A PCR mostrou ser uma potencial ferramenta auxiliar no diagnóstico da doença, associada a pelo menos uma metodologia de triagem. Quanto à regionalidade da doença, verificou-se variabilidade dos resultados entre as regiões estudadas no plano diretor, onde o maior número de casos positivos ocorreu nas regiões que correspondem ao setor sul de Palmas.   Palavras-chave: Leishmaniose visceral; reação em cadeia da polimerase; doenças endêmicas. ABSTRACT INTRODUCTION: Visceral Leishmaniasis (LV) or kalazar is a potentially fatal disease that affects mammals. Caused by a Trypanosomatidae protozoan, genus Leishmania, species Leishmania (L.) infantum chagasi. Transmitted by the phlebotomine Lutzomyia longipalpis known as mosquito straw, birigui and cangalinhas, leishmaniasis is endemic in rural and urban areas of several countries. In Palmas city it is disseminated in all its extension, classifying it as an area of intense transmission. METHODS: The Leishmania (L.) infantun chagasi prevalence in dogs captured by the Zoonoses Control Center (Palmas - TO) was evaluated using different diagnostic methodologies: ELISA, RIFI and polymerase chain reaction (PCR). In this study 195 dogs were captured in different areas of the city and evaluated by the three methodologies. RESULTS: Of the 195 samples analysed by the three techniques, there was agreement of 85.64% between RIFI and ELISA, 54.87% between RIFI and PCR. CONCLUSIONS: The PCR proved to be a potential auxiliary tool in the diagnosis of the disease, associated to at least one screening methodology. Regarding the regionality of the disease, the results between the regions studied in the master plan were varaible and the highest number of positive cases occurred in the regions corresponding to the southern sector of Palmas. Keywords: Visceral leishmaniosis; polimerase chain reaction; endemic diseases.