ENZOOTIC BOVINE LEUCOSIS: A CASE REPOR T LEUCOSE ENZOÓTICA BOVINA: UM RELATO DE CASO Thales Ricardo Rigo. (3) Cadavid G. Impacto del virus de la leucosis bovina en la produccion (9) Algorta A. Leucosis Bovina Enzoótica en un campo de recría de. Hemoglobinuria infecciosa de los bovinos. Presente. Hipodermosis del ganado. Nunca Señalada. Leucosis bovina enzoótica. Presente. Mastitis enzoótica.
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The natural host of BLV is cattle. Besides structural and enzymatic genes required for virion production, BLV contains an oncogene coding for leeucosis protein called Tax and expresses microRNAs of unknown function. Because the oncogenic properties of the virus were discovered early, a search for evidence of pathogenicity humans started soon after discovery. Mostly nezootica workers drinking raw milk were tested for disease, especially for leukemia. But neither leukemia nor other signs of infection could be detected.
High prevalence of virus was found from testing by USDA. Results showed that In Europe attempts were made to eradicate the virus by culling infected animals.
Bovine leukemia virus – Wikipedia
The first country considered to be free of infection was Denmark. Soon the United Kingdom followed.
Like the North American states, those of the Eastern block in Europe did not try to get rid of the virus. But the Eastern Europe states started to become leukosis free after the political changes at the end of the leufosis century. A quote from a USDA fact sheet, “The high individual animal prevalence of BLV reported in the Dairy study suggests that testing and culling seropositive animals may not be a cost effective method to control the disease. Instead, preventing disease transmission bocina implementing preventive practices would likely be more cost-effective.
Natural infection of animals other than cattle and buffalo are rare, although many animals are susceptible to artificial infection.
After artificial infection of sheep most animals succumb to leukemia. Rabbits get a fatal AIDS like disease similar to rabbit-snufflesdifferent from the benign human snuffles. But it is not known whether this naturally occurring rabbit disease is linked to BLV infection. Sheep are very susceptible to experimental inoculation and develop tumours more often and at a younger age than cattle.
A persistent antibody response can also be detected after experimental infection in deer, rabbits, rats, guinea-pigs, cats, dogs, sheep, rhesus monkeys, chimpanzees, antelopes, pigs, goats and buffaloes. Some long term studies enzootuca be necessary, as there appears to be a correlation in instances of cancer among wnzootica and slaughterhouse workers.
There is, however, no conclusive evidence of transmission, and it is now generally thought that BLV is not a hazard to humans. Many potential routes of BLV transmission exist.
Molecular detection of bovine leukemia virus: A study in Colombia cluster
Transmission through procedures that transmit blood between animals such as gouge dehorning, vaccination and ear tagging with instruments or needles that are not changed or disinfected between animals is a significant means of BLV spread. Rectal palpation with common sleeves poses a risk that is increased by inexperience and increased frequency of palpation.
Transmission via colostrummilk, and in utero exposure is generally considered to account for a relatively small proportion of infections. While transmission has been documented via blood feeding insects, the significance of this risk is unclear.
Enzoptica bottom line appears to be that transmission relies primarily on the transfer of infected lymphocytes from one animal to the next and that BLV positive animals with lymphocytosis are more likely to provide a source for infection. In general BLV causes only a benign mononucleosis -like disease in cattle. Only some animals later develop a B-cell leukemia called enzootic bovine leukosis.
Under natural conditions the disease is transmitted mainly by milk to the calf. Infected lymphocytes transmit the disease too. So for artificial infection infected cells are used or the more stable and even heat resistant DNA.
Virus particles are difficult to detect and not used for transmission of infection. Enziotica is possible that a natural virus reservoir exists in the water buffalo. The variety of organs where white blood cells are to be found explains the many symptoms observed by veterinarians: Lymph node enlargement is often an early clinical sign.
An unexpected clinical finding is protrusion of cunjunctival membrane, due to enlargement of retro-ocular lymph nodes. Post mortem findings are characteristic and include widespread white tumours in most organs. No treatment is available for the disease.
Testing and removing positive animals from the herd is one method of control. In herds where the disease is widespread, it is important to limit spread by avoiding contact with blood between animals.
Consultado em 17 de agosto de Obtida de ” https: Artigos sem imagem tanto localmente quanto no Wikidata!