The Distribution Of Bovine Leukemia Virus Genotypes In Cattle From Japan And Diagnostic Performance Of Agar Gel Immuno Diffusion (Agid) And Polymerase Chain Reaction (Pcr) Tests

A study to investigate the types and distribution of bovine leukemia virus (BLV) genotypes and to estimate diagnostic test performance of agar gel immunodiffusion (AGID) was conducted on 807 cattle drawn from 68 farms found in 16 prefectures in Japan from June 2002 to December 2003. AGID test on serum samples and polymerase chain reaction (PCR), to detect BLV provirus, from peripheral blood lymphocytes (PBL) were performed. To identify genotypes, restriction fragment length polymorphism (RFLP) was done on the 444 bp fragment of env gene on PCR amplified product using endonucleases Bcl I, Hae III, PVu II, BamH I, and Bgl I. In this study, six genotypes were identified. These are genotypes 1, 2, 3, and 5. Two of the genotypes were unusual in that they exhibited unique band fragmentation; we named these genotypes 2-3 and 3-4. Genotypes 1, 3, and 5 are the most dominant types in Japan, which are recorded in 48.3%, 32.7%, and 16.9% of tested cattle, respectively. The sensitivity and specificity of AGID was found to be 89.3% and 58.8%, respectively. The test agreement between AGID and PCR was 0.48. Une etude pour enqueter sur les types et la repartition des genotypes de virus de la leucemie bovine (VLB) et pour evaluer la performance du test de diagnostic d\'immunodiffusion en gelose (AGID) a ete menee sur 807 bovins issus de 68 fermes dans 16 prefectures au Japon pendant la periode allant de juin 2002 a decembre 2003. On a effectue le test AGID sur des prelevements de serum et le test PCR pour detecter le provirus VLB a partir des lymphocytes du sang peripherique. En vue d\'identifier les genotypes, le test RFLP a ete effectue sur le fragment 444 bp du gene env sur le produit amplifie par PCR en utilisant les endonucleaes Bcl I, Hae III, PVu II, BamH I et Bgl I. Dans la presente etude, six genotypes etaient identifies, a savoir: les genotypes 1, 2, 3 et 5. Deux de ces genotypes etaient peu communs dans la mesure ou ils exposaient une fragmentation de bande unique ; nous avons appele ces genotypes 2-3 et 3-4. Les genotypes 1, 3 et 5 sont les types predominants au Japon que l\'on a releves chez 48,3%; 32,7% et 16,9% des bovins testes respectivement. La sensibilite et la specificite de l\'AGID etaient de 89,3% et 58,8% respectivement. La concordance entre les tests AGID et PCR etait de 0,48%. Bulletin of Animal Health and Production in Africa Vol. 55 (4) 2007: pp. 244-253