Epizootic Hemorrhagic Disease Virus Serotype 6 Infection in Cattle, Japan, 2015.

Yuka Kamomae,Yuichi Kagawa,Tohru Yanase,Hiroaki Shirafuji,Tomoko Kato,Mikoto Nabe,Yuji Ogura,Yasuyuki Ohta,Shogo Tanaka,Masahiro Kamomae

doi:10.3201/eid2405.171859

Abstract

During October–December 2015, an epizootic hemorrhagic disease outbreak occurred in cattle in Japan. Forty-six animals displayed fever, anorexia, cessation of rumination, salivation, and dysphagia. Virologic, serologic, and pathologic investigations revealed the causative agent was epizootic hemorrhagic disease virus serotype 6. Further virus characterization is needed to determine virus pathogenicity.

Highlights

In October 2015, an outbreak of febrile illness occurred in cattle in Hyogo Prefecture, Japan, and lasted 3 months
We designed RT-PCR primers to amplify segments 2 and 3 from the full-length cDNA on the basis of sequence data of Epizootic hemorrhagic disease virus (EHDV) strains from Japan and Australia available in GenBank
LC320036) showed that EHDV-6 HG-1/E/15 sorted into the E1 subgroup of the Eastern group (Figure 2, panel B) [8] and had highest identity to the Ibaraki isolate EHDV serotype 2 (EHDV-2) JPN1959/01 (95.96% nucleotide and 99.77% amino acid identities). We determined this febrile illness affecting 46 cattle in Japan in 2015 was an epizootic hemorrhagic disease outbreak caused by EHDV-6 infection on the basis of clinical findings, RT-PCR results, neutralization tests, and sequence analyses

Summary

Ocular discharge

We conducted immunohistochemical assays with necropsy tissue samples from this cow using rabbit antiserum against EHDV-6 AUS1981/07 CSIRO 753 and detected antigen in the vascular endothelium of the esophageal muscle layer (Figure 1, panel C). We further characterized the causative agent by performing sequence analysis of genome segment 2, which correlates with serotype, and segment 3, which correlates with geographic genetic type, of outbreak isolate HG1/E/15. We designed RT-PCR primers to amplify segments 2 and 3 from the full-length cDNA on the basis of sequence data of EHDV strains from Japan and Australia available in GenBank. We used the sequence data to analyze the phylogenetic relationships between EHDV HG-1/E/15 and other EHDV isolates. Sequence identities between EHDV HG-1/E/15 and the other EHDV isolates were calculated with GENETYX version 10 (GENETYX Corporation, Tokyo, Japan).

After outbreak

Conclusions