EARLIER this month, the Ohio Department of Agriculture (ODA) announced the discovery of a new coronavirus detected in pig fecal samples from four different swine farms in the state. Dr. Yan Zhang, a virologist from the ODA Animal Disease Diagnostic Laboratory (ADDL) said that while the virus cannot spread to humans or other species, and poses no risk to food safety, it is a significant concern to producers already reeling from Porchine Epidemic Diarrhea virus (PEDv).
The farms from which the samples were taken experienced outbreaks of a diarrheal disease in sows and piglets in January and early February. The clinical signs of the disease were similar to that of PEDv and transmissible gastroenteritis (TGE), which are both caused by coronaviruses.
Subsequent electronmicropy of fecal samples from the four farms showed the presence of coronavirus-like viral particles. In one of the four farms, polymerase chain reaction (PCR) 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.
On the PEDv front, ODA announced a scientific breakthrough that could help pork producers fight the virus. Genetic sequencing of a new PED strain conducted by ODA’s diagnostic laboratory may lead to a marketable vaccine for swine in the near future, according to the department's chief veterinarian Tony Forshey.
Forshey said ADDL virologist Dr. Yan Zhang and a team of scientists at ODA worked to complete genetic sequencing of a new PED virus that differs in a fragment of one gene (1,170 nucleic acids in the S1 domain of the Spike 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, he said, this new virus is associated with reduced mortality in piglets, based on the field observation, which may enhance its use as a potential vaccine.
“Pork production is very important in Ohio, contributing more than $650 million to the state’s economy every year,” Forshey said. “Producers both in Ohio and nationwide have been searching for ways to fight back against this virus and we see this discovery as an important step in that fight.”
This discovery will 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.
LISTEN IN: Ohio Department of Agriculture state veterinarian Tony Forshey discusses the latest discoveries - including the sequencing of a PED virus and the discovery of a new coronavirus - during a recent Feedstuffs In Focus podcast interview. You can listen to the interview here.