PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

• rypanosomosis small ruminant PCR anatomopathology testicular degene-ration epididymitis extravascular foci

Abstract in Portuguese:

ABSTRACT.- Bezerra F.S.B., Garcia H.A., Alves H.M., Oliveira I.R.S., Silva A.E., Teixeira M.M.G. & Batista J.S. 2008. [Trypanosoma vivax in testicular and epidydimal tissues of experimentally infected sheep.] Trypanosoma vivax nos tecidos testicular e epididimário de ovinos experimentalmente infectados. Pesquisa Veterinária Brasileira 28(12):575-582. Laboratório de Patologia Veterinária, Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Cx. Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Four adult sheep (number 1, 2, 3 and 4), all males, were inoculated intravenously with 1ml of blood containing 1.25x105 trypomastigotes of Trypanosoma vivax, and Sheep 5, 6, 7 and 8 were used as control. After infection, clinical exams considering rectal temperature, respiratory and cardiac frequencies, and parasitaemia were recorded daily for a 30-day experiment period. Blood samples were obtained for 5-day intervals to hematocrit analysis. At the end of the experimental period, the sheep were orquiectomized. Testes and epididymides from these animals were studied anatomopathologically. Samples from these tissues of Sheep 1, 4 and 5 were taken to polymerase chain reaction (PCR). Clinical parameters remained for the infected group above the values observed in the control group during the experimental period. Parasitaemia was observed on day 3 post-infection, and the highest values occurred between day 6 and 10, and day 15 and 18 post-infection. Sheep 1 and 4 showed severe anemia on day 25 post-infection. All sheep of the infected group showed flabby and palid testes. Histologically, moderate to severe testicular degeneration, multifocal epididymitis and hyperplasia of epididymal epithelium were observed. The result of T. vivax PCR analysis in the testes and epididymal tissues was positive in 100% of the samples of the experimentally infected sheep. Epididymal and testicular lesions associated with the presence of the parasite in these tissues, shown by PCR, suggest the participation of T. vivax in the pathophysiological mechanism of reproductive damage.

Abstract in English:

ABSTRACT.- Batista J.S., Bezerra F.S.B., Lira R.A., Carvalho J.R.G., Rosado Neto A.M., Petri A.A. & Teixeira M.M.G. 2008. [Clinical, epidemiological and pathological signs of natural infection in cattle by Trypanosoma vivax in Paraíba, Brazil.] Aspectos clínicos, epidemiológicos e patológicos da infecção natural em bovinos por Trypanosoma vivax na Paraíba. Pesquisa Veterinária Brasileira 28(1):63-69. Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Caixa Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Two outbreaks of trypanosomiasis by Trypanosoma vivax, reported in cattle, occurred on two farms located in the state of Paraíba, northeastern Brazil. The epidemiology, clinical signs and pathology of the disease were studied from May 2005 to November 2006. T. vivax was identified morphologically and by polymerase chain reaction test (PCR). The affected cattle presented anorexia, depression, fever, anemia, weight loss, reduction in milk production, transitory blindness, abortion and some nervous signs as nystagmus, tetany and bruxism. All cattle that presented nervous signs died. Necropsy findings were enlarged lymph and spleen, serous atrophy of the fat depots, proeminence of the splenic white pulp, hydropericardium and pericardial petechiae and ecchymoses on the epicardium. Histologically there was meningoencephalitis. The treatment of the clinical cases with diminazena aceturate was efficient with clearance of the parasite from the blood or disappearance of clinical signs in up to 2 months after the beginning of the outbreak on the two farms studied. The epidemiologic factors favoring the occurrence of the outbreak were the abundance of mechanical vectors, as tabanids and Stomoxys sp., and the introduction into the herd of cattle from farms where the disease occurred. It is suggested that the semiarid of the Brazilian Northeast is an enzootic instability region for trypanosomiasis due to its prolonged periods of drought and high temperatures, constituting during most part of the year an unfavorable environment for the development of vectors.

• Trypanosoma vivax trypanosomiasis cattle outbreak Brazilian Northeast semi-arid

Abstract in Portuguese:

ABSTRACT.- Batista J.S., Bezerra F.S.B., Lira R.A., Carvalho J.R.G., Rosado Neto A.M., Petri A.A. & Teixeira M.M.G. 2008. [Clinical, epidemiological and pathological signs of natural infection in cattle by Trypanosoma vivax in Paraíba, Brazil.] Aspectos clínicos, epidemiológicos e patológicos da infecção natural em bovinos por Trypanosoma vivax na Paraíba. Pesquisa Veterinária Brasileira 28(1):63-69. Departamento de Ciências Animais, Universidade Federal Rural do Semi-árido, BR 110 Km 47, Caixa Postal 147, Mossoró, RN 59625-900, Brazil. E-mail: jaelsbatista@hotmail.com Two outbreaks of trypanosomiasis by Trypanosoma vivax, reported in cattle, occurred on two farms located in the state of Paraíba, northeastern Brazil. The epidemiology, clinical signs and pathology of the disease were studied from May 2005 to November 2006. T. vivax was identified morphologically and by polymerase chain reaction test (PCR). The affected cattle presented anorexia, depression, fever, anemia, weight loss, reduction in milk production, transitory blindness, abortion and some nervous signs as nystagmus, tetany and bruxism. All cattle that presented nervous signs died. Necropsy findings were enlarged lymph and spleen, serous atrophy of the fat depots, proeminence of the splenic white pulp, hydropericardium and pericardial petechiae and ecchymoses on the epicardium. Histologically there was meningoencephalitis. The treatment of the clinical cases with diminazena aceturate was efficient with clearance of the parasite from the blood or disappearance of clinical signs in up to 2 months after the beginning of the outbreak on the two farms studied. The epidemiologic factors favoring the occurrence of the outbreak were the abundance of mechanical vectors, as tabanids and Stomoxys sp., and the introduction into the herd of cattle from farms where the disease occurred. It is suggested that the semiarid of the Brazilian Northeast is an enzootic instability region for trypanosomiasis due to its prolonged periods of drought and high temperatures, constituting during most part of the year an unfavorable environment for the development of vectors.