New Variant of Porcine Epidemic Diarrhea Virus, United States, 2014

of two influenza A viruses from a pilot whale. et al. Mass mortality of harbor seals: pneumonia associated with influenza A virus. Pathogen exposure and blood chemistry in the Washington, USA population of northern sea otters (Enhydra lutris kenyoni). pathogen exposure and general health status of live and beach-cast Washington sea otters (Enhydra lutris kenyoni). Zambon MC. Sialic acid receptor specificity on erythrocytes affects detection of antibody to avian influenza haemagglutinin. To the Editor: Porcine epidemic diarrhea (PED) was first reported in the United Kingdom in 1971 (1). The disease was characterized by severe enteritis, vomiting, watery diarrhea, dehydration, and a high mortality rate among swine. Subsequently, the causative agent of PED was identified as porcine epidemic diarrhea virus (PEDV), which belongs to the family Coronaviridae (2) and contains an enveloped , single-stranded positive-sense RNA genome. PEDV has been reported in many other countries, including and Vietnam (3) and was first identified in the United States in May 2013. By the end of January of 2014, the outbreak had occurred in 23 US states, where 2,692 confirmed cases (www.aasv.org/ news/story.php?id = 6989) caused severe economic losses. Recent studies have shown that all PEDV strains in the United States are clustered together in 1 clade within the subgenogroup 2a and are closely related to a strain from China, AH2012 (4,5). In the state of Ohio, the first PED case was identified in June of 2013; since then, hundreds of cases have been confirmed by the Animal Disease Diagnostic Laboratory of the Ohio Department of Agriculture. In Janu-ary of 2014, samples from pigs with unique disease, suspected to be PED, were submitted to this laboratory. Sows were known to be infected, but piglets showed minimal to no clinical signs and no piglets had died. According to real-time reverse transcription PCR, all samples from the piglets were positive for PEDV. Subsequently, the full-length genome sequence of PEDV (OH851) was determined by using 19 pairs of oligonu-cleotide primers designed from alignments of the available genomes from PEDVs in the United States (6,7). On the basis of BLAST (http:blast.ncbi. nlm.nih.gov/Blast.cgi) searches, strain OH851 showed 99% and 97% nt identity to PEDVs currently circulating in the United States (Colorado, Iowa, Indiana, Minnesota) for the whole genome and the full-length spike (S) gene, respectively. By distinct contrast, strain OH851 showed only 89% or even lower nucleotide identity to PEDVs currently circulating in the United States in the …