Epidemic of Equine Coronavirus at Obihiro Racecourse, Hokkaido, Japan in 2012

Abstract

ABSTRACT. Equine coronavirus (ECoV) outbreaks have occurred three times at Obihiro Racecourse in Hokkaido, Japan. The third ECoV outbreak occurred between late February and early April 2012. The main clinical signs of affected horses were anorexia, pyrexia and leucopenia; gastrointestinal disease was observed in about 10% of affected horses. Two ECoV strains were isolated from diarrheal samples. All paired sera (9/9) collected from febrile horses showed seroconversion by neutralization test. Sequence and phylogenetic analysis of the ECoV isolated showed that putative amino acid sequences in S and N genes were highly conserved among ECoV strains. In contrast, sequences of the region coding 4.7kDa non-structural protein (p4.7) differed among the strains. Because of the diversity of the p4.7 region, this region should be useful for epidemiological investigation of ECoV.

First detection of equine coronavirus (ECoV) in Europe

“…The full-length genome of the ECoV-NC99 strain was then sequenced and published in 2007 (Zhang et al, 2007). Recently in Japan, ECoV was detected from the feces of adult horses with pyrogenic and enteric disease (ECoV-Tokachi09), and from fecal samples collected in three outbreaks that occurred at Obihiro Racecourse in Hokkaido (Oue et al, 2011(Oue et al, , 2013. In October 2012, 4 outbreaks were associated with ECoV in adult horses in 4 different states in the USA (Pusterla et al, 2013).…”

Clinical Approach to Commonly Encountered Problems

“…Although primarily a respiratory pathogen, Rhodococcus equi also can cause diarrhea, particularly in foals 2 to 4 months of age. [571][572][573][574][575] Since 2011 several outbreaks of equine coronavirus have been identified in adult horses, causing it to be named as an emerging pathogen. However, enterotoxigenic strains, characterized by the presence of virulence factors, have been identified in foals.…”

Application of Transmission Electron Microscopy Techniques in the Veterinary Diagnosis of Viral Gastroenteritis in Livestock Animals

“…Since 2010, there have been several reports of ECoV-associated respiratory and enteric infections in adult horses in Japan, Europe and the United States, but its global distribution is still poorly defined [10,[140][141][142][143]. In Brazil, the first outbreak of enteritis in horses was reported in 1988 by transmission electron microscopy in a horse livestock, in São Paulo, SP, affecting animals ranging from 1 week to 4 months that presented aqueous diarrhea [144].…”