The Ohio Department of Agriculture said Tuesday that it has detected a new coronavirus in pig fecal samples from four different swine farms in Ohio that is different from the Porcine Epidemic Diarrhea Virus and transmissible gastroenteritis, but shows similar clinical signs.
The farms from which the samples were taken experienced outbreaks of a diarrheal disease in sows and piglets in January and early February of 2014.
Animal Disease Diagnostic Laboratory virologist Dr. Yan Zhang discovered the virus; it cannot spread to humans or other species and poses no risk to food safety.
Though the clinical signs are similar to TGE and PED – the deadly diarrheal virus that was discovered in the U.S. in 2013 – Electronmicropy of fecal samples from the four farms showed the presence of coronavirus-like viral particles, different from either disease.
In one of the four farms, polymerase chain reaction tests for TGE viruses and PED viruses currently circulating in the U.S. were negative, but all 10 samples were positive for a new virus. PED and the new virus were detected in fecal samples from the other three farms.
Sequence analysis of the new coronavirus shows that it is a deltacoronavirus. The new virus has been designated as Swine DeltaCoronavirus.
This virus is closely related to a coronavirus which was detected in Hong Kong in 2012, ODA says, but further study is needed to confirm whether or not this virus is the cause of diarrheal disease in affected pigs.
Also Tuesday, ODA said it has completed genetic sequencing of a new PED strain, which they say may lead to a marketable vaccine for swine in the near future.
Led by Zhang, the sequencing shows the new PED virus differs in a fragment of one gene encoding a surface protein. The rest of the genome sequence is identical to the economically devastating PED virus currently circulating in the U.S.
Most important, this new virus is associated with reduced mortality in piglets, based on the field observation, which may enhance its use as a potential vaccine, ODA says.
Related: New Strain of PED Identified in U.S.
This discovery could lay the groundwork for producing a vaccine to immunize swine against PED. In a swine herd, the vaccine would be orally given to a sow, which would then pass on the immunization to its piglets through nursing. This may work to significantly reduce piglet death as a result of PED and create a positive impact to overall swine health, ODA says.
"The scientists at the Ohio Department of Agriculture have always been of the highest caliber, as this is not the first time they have broken new scientific ground to help secure our most important industry in our state and beyond," ODA Director David Daniels noted in a press statement. "Their tireless work in this important accomplishment will help ease the stress on pork producers and consumers nationwide."