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Ovine herpesvirus 2 (OvHV-2) causes sheep-associated malignant catarrhal fever (SA-MCF), and is responsible for economic losses in cattle and other susceptible species around the world. A survey of 154 serum samples from 14 flocks in 3 Japanese prefectures (Hokkaido, Aomori and Iwate) was undertaken between 2007 and 2008 to test for antibodies to OvHV-2. OvHV-2 was present in 56 sheep and 2 goats, with 37.66% of samples having a positive reaction using a serum neutralization test. The immune reaction reported in goats could result from Caprine herpesvirus-2. These results indicate that sheep are reservoirs for OvHV-2 in the field in Japan, and they might transmit the virus to susceptible cattle and wild fauna.

A serological survey was carried out in the northern prefectures of Hokkaido, Iwate and Aomori in Japan, for the presence of antibodies against Toxoplasma gondii, Chlamydiapsittaci var. ovis, Mycobacterium paratuberculosis, Coxiella burnetii, Brucella spp., Leptospirosis and Orf virus (ORFV). Out of 267 samples tested, highest overall prevalence (28.78%) was found for T. gondii. The 12.59% of tested sheep were positive for C. psittaci var. ovis. A total of 8.67% were found to be seropositive for C. burnetii. Levels of these infections were found in all three prefectures. Seroconversion to ORFV was detected in Hokkaido and Iwate Prefectures (2.57%). Animals were positive only for L. ballum (1.50%), in Hokkaido and Aomori Prefectures. No animals tested positive for Brucella spp. and M. paratuberculosis.

The first epidemiological survey of Border disease virus (BDV) was undertaken in small ruminants in Japan. Ovine sera, collected from the northern prefectures of Hokkaido, Aomori and Iwate, were examined for the presence of antibodies against BDV using the neutralization peroxidase-linked antibody test. Twenty-nine (17.6%) of one hundred and sixty-five samples were seropositive for BDV. Results were specific, excluding cross-reactions with bovine viral diarrhea virus (BVDV). Only one sample (0.6%) was positive for BVDV, and was negative for BDV. Despite serological evidence of virus circulation, there have been no clinical cases of border disease in sheep in Japan. Although no diagnostic measures were performed, the infection did not appear to be associated with a reduction in ewe fertility nor with lamb mortality.

Bovine viral diarrhea virus 2 (BVDV-2) strains demonstrated in cattle, sheep, and adventitious contaminants of biological products have been evaluated by the palindromic nucleotide substitutions (PNS) method at the three variable loci (V1, V2 and V3) in the 5' untranslated region (UTR), to determine their taxonomical status. Variation in conserved genomic sequences was used as parameter for epidemiological evaluation of the species in relation with geographical distribution, animal host and virulence. Four genotypes, BVDV-2a, BVDV-2b, BVDV-2c, and BVDV-2d have been identified within the species. Taxonomical segregation corresponded to geographical distribution of genotype variants. Genotype 2a was present worldwide, and was the only circulating also in sheep, in addition to cattle. Genotypes 2b, 2c and 2d were restricted to South America. Contamination of biological products was related to genotypes 2a and 2d. Genetic variation could be related with chronological diffusion of the BVDV-2 species variants in different geographic areas. Chronologically, the species emerged in North America in 1978, spreading in UK and Japan, continental Europe, South America and New Zealand. Correlation between clinical features related with isolation of BVDV-2 strains and genetic variation indicated that subgenotype 1, variant 4 of genotype 2a was related with hemorrhagic syndrome. These observations suggest that evaluation of genomic secondary structure, by identifying markers for expression of virus biological activities and species evolutionary history, may be applied as useful tool for epidemiological evaluation of the BVDV-2 species, and possibly for other species of the genus Pestivirus.

Two strains of Bovine viral diarrhea virus 2 (BVDV-2) were isolated from calves in northern Italy. Variations in the 5'-untranslated region (UTR) of the genome were studied by primary structure alignment and neighbor-joining method based phylogenetic tree analyses and by palindromic nucleotide substitutions at the three variable loci in the 5'-UTR. Genetic analysis indicated their appurtenance to genovar BVDV-2a. Nucleotide sequence at the 5'-UTR of strain BS-95-II, one of the Italian isolates from healthy calves, showed 98% homology to that of the Japanese isolate OY89, a cytopathic strain derived from cattle with mucosal disease.