Sheep infection by caprine lentivirus

• Published in: Revista brasileira de saúde e produção animal 2018-09, Vol.19 (3), p.268-276
• Main Authors: Souza, Thiago Sampaio de, Pinheiro, Raymundo Rizaldo, Lima, Carla Caroline Valença de, Brito, Roberta Lomonte Lemos de, Azevedo, Dalva Alana Aragão de, Dias, Ronaldo Pereira, Santos, Vanderlan Warlington Souza dos, Andrioli, Alice, Costa, Joselito Nunes
• Format: Article
• Language: English
• Subjects: AGRONOMY
• ISSN: 1519-9940; 1519-9940
• DOI: 10.1590/s1519-99402018000300004

SUMMARY The objective of this study was to demonstrate iatrogenic transmission of small ruminant lentivirus (SRLV) from goats to sheep and horizontal transmission between sheep. The study was conducted on a farm with separate goat and sheep rearing, and animals were monitored for lentivirus occurrence by clinical examination and testing by immunoblotting (IB), agar gel immunodiffusion (AGID), and nested polymerase chain reaction (nPCR). Positive results had not been observed in the sheep flock until this study. Conversely, virus positive dairy goats were known. For this reason, the farm performed the caprine arthritis-encephalitis (CAE) control program. The study was designed with a sheep group that presented positive animals for SRLV by nPCR. It was verified that three newborn animals in this group were rejected by their mothers and consequently received milk from the goat herd. These three animals remained with another 20 sheep of the same age, totaling 23 animals. After one year, during monitoring, 11 of the 23 animals in the group presented positive results in the nPCR and three demonstrated seroconversion by IB. Of the animals that had received goat milk, two had positive results in the nPCR and IB. The 11 animals positive in the nPCR were followed and it was verified that five animals did not present further positive results in the nPCR, nor seroconversion; two continued presenting positive results in the nPCR but were negative in the IB and AGID and four were positive in the nPCR, IB, and AGID. Thus, it was possible to demonstrate iatrogenic interspecific infection and the occurrence of horizontal caprine lentivirus transmission among sheep. RESUMO O objetivo foi demonstrar a transmissão iatrogênica de lentivírus de pequenos ruminantes (LVPR) de caprinos para ovinos e a transmissão horizontal entre ovinos. O estudo foi conduzido em propriedade com criação não consorciada de caprinos e ovinos, monitorada para ocorrência de lentiviroses, a partir de acompanhamento clínico e testes de immunoblotting (IB), imunodifusão em gel de agarose (IDGA) e reação em cadeia da polimerase do tipo nested (nPCR). Resultados positivos no rebanho ovino não haviam sido observados até então. Por outro lado, sabia-se que o rebanho caprino leiteiro era positivo. Por este motivo, a propriedade realizava programa de controle da artrite-encefalite caprina (CAE). O estudo foi delineado em um lote de ovinos que apresentou animais positivos para LVPR na nPCR. Verificou-se que trê