National Institute of Animal Health (NIAH)

Topics in Animal Health Research 2009

22. Molecular epidemiological analyses of bovine ephemeral fever virus based on the G gene sequence


  The G gene encoding the neutralization antigen of bovine ephemeral fever virus was characterized in order to define the virus's molecular epidemiology in Japan and the genetic relationships among the Japanese, Taiwanese, and Australian isolates. The nucleotide and amino acid sequences of the gene were highly conserved among the Japanese strains, regardless of the year of isolation and were closely related to the Taiwanese strains. By phylogenetic analysis, the Japanese and Taiwanese strains were clearly classified into 3 chronological clusters: 1966, 1984-1989, and 1996-2004, indicating that the epidemics of bovine ephemeral fever might have occurred almost simultaneously in both countries and have been caused by strains of the same genotype. On the other hand, the Australian strains were distantly related to these East Asian strains and could be placed in the independent fourth cluster of the phylogenetic tree. It is suggested that 3 amino acid substitutions at residues 224, 271, and 499 in the neutralizing epitopes, of which 2 generate new glycosylation sequences, are responsible for the antigenic variations of the bovine ephemeral fever virus. The cross-neutralization test with the bovine ephemeral fever virus isolated in Japan demonstrated that the vaccine developed on the basis of the oldest Japanese strain, YHL, appears to still be effective for controlling bovine ephemeral fever in Japan.
(Research Team for Environmental/Enzootic Diseases, Kyushu Research Station, TEL +81-29-838-7708)


  • Kato, T. et al. (2009) Vet. Microbiol. 137:217-223.
  • Aizawa, M. et al. (2008) J. Jpn. Vet. Med. Assoc. 61:363-366.