title: [Identification of an introduced bovine herpesvirus type 1 strain in a closed dairy herd by experimental virus reactivation followed by DNA restriction enzyme analysis].
abstract: In a closed dairy herd in the province of Utrecht in 1995, nine replacement heifers were erroneously intramuscularly vaccinated with Tracherine, a live virus IBR vaccine. More than 18 months later, serology of the herd revealed that a large part of the herd had developed an antibody response towards BHV1 (62 of 87 animals). To investigate whether Tracherine had recirculated on the farm, four BHV1 antibody positive animals, of which two had been vaccinated with Tracherine, were treated with corticosteroids to reactivate latent BHV1. Two virus isolates were obtained and subsequently analysed by resctriction enzyme analysis. Both isolates were identified as BHV1.1 subtypes. One of the isolates was clearly distinct from Tracherine and was most likely a BHV1 field virus. A BHV1 field virus was most likely introduced into the farm even though the herd was closed, the animals had not been in contact with other cattle, and preventive hygienic measures had been implemented. There was no indication that Tracherine had recirculated.
authors: Faculteit der Diergeneeskunde Hoofdafdeling Bedrijfsdiergeneeskunde en Voortplanting, Universiteit Utrecht, Postbus 80151, 3508 TD Utrecht. Wim.van.-der.Poel@rivm.nl
authors: W H
authors: WH
authors: van der Poel
authors: F A
authors: FA
authors: Rijsewijk
authors: F A
authors: FA
authors: Meijer
authors: J
authors: J
authors: Verhoeff
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000302:isolation & purification; D002417:Cattle; D002418:Cattle Diseases / Q000517:prevention & control / Q000635:transmission / Q000821:virology*; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D005838:Genotype; D006566:Herpesviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000635:transmission / Q000662:veterinary*; D007242:Herpesvirus 1, Bovine / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000276:immunology; D007273:Injections, Intramuscular / Q000662:veterinary; D016133:Polymerase Chain Reaction; D016896:Treatment Outcome; D014765:Viral Vaccines; D014775:Virus Activation
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D014765:Viral Vaccines; D004262:DNA Restriction Enzymes