The prevalent genotypes of bovine viral diarrhea virus in Japan, Germany and the United States of America

Genotypes and subgenotypes of bovine viral diarrhea virus（BVDV）field isolates from Japan, Germany and the United States of America（USA）were identified, and the prevalent pattern of BVDV in individual countries was estimated genetically. Subgenotypes were determined based on phylogenetic analyses of nucleotide sequences of a part of the E２‐coding gene of BVDV. Forty-five，６１and５６BVDV strains were isolated from naturally infected cattle in Japan, Germany and USA, respectively, between１９８０and２００３．The most prevalent BVDV in these three countries was BVDV‐１b. The second most prevalent BVDV strains were １a，１d and BVDV‐２ in Japan, Germany and USA, respectively. The most prevalent subgenotype １b in each country constructed individual small clusters in the subgenotype１b branch in the phylogenetic tree. Although cattle and/or cattle products were moving among the three countries as part of international trade, the distribution of BVDV in the field in each country showed long-standing individual patterns