Iowa State University Veterinary Diagnostic Laboratory says it has identified a strain of Porcine Epidemic Diarrhea virus that is not similar to the cases identified in U.S. swine since April 2013.
During the time periods of January 24-29, sequencing was performed on 15 PEDV cases at ISU's VDL. Among them, PEDV S1 sequences from 10 cases are similar to each other and to the PEDV strains identified in U.S. swine since April 2013.
In distinct contrast, the PEDV S1 sequences from the other five cases only have 93.9-94.6% nucleotide identities to the PEDV strains previously identified in U.S. swine. However, these five PEDV cases shared 99.6-100% nucleotide identities to each other based on the S1 sequences.
Analysis based on the S1 sequences demonstrated that the 10 similar cases clustered together with PEDV strains identified in U.S. since April 2013. However, the remaining five clustered very differently from the PEDV strains previously identified in the U.S.
Sequence alignment showed that the S1 sequences of these five PEDV cases had some deletions and insertions compared to PEDV viruses previously identified in the U.S.
Based on the data currently available, it appears unlikely that this strain is a mutant evolved from PEDV previously identified in U.S. swine, according to a statement from ISU's lab.
Determination of the entire genome sequences of these new PEDVs are in progress and will help determine the origin of the viruses, the statement said.
PEDV is a contagious disease that often presents itself as vomiting and diarrhea, mostly affecting young piglets.
Source: ISU VDL