Researchers at the Virginia-Maryland Regional College of Veterinary Medicine at Virginia Tech Tuesday announced they have traced porcine epidemic diarrhea virus to a strain from the Anhui province in China using virus strains isolated from the ongoing outbreaks in Minnesota and Iowa.
Dr. X.J. Meng, University Distinguished Professor of Molecular Virology, said the virus affects nursery pigs and has many similarities with transmissible gastroenteritis. The virus was first recognized in the U.S. in May, and has since led to infections in at least 17 U.S. states.
The researchers determined not only that the three U.S. strains of the porcine epidemic diarrhea virus are most closely related to the Chinese strains of the virus, but also that the U.S. strains likely diverged two or three years ago following an outbreak of a particularly virulent strain in China.
According to the researchers' study in the Oct. 15 issue of the American Academy of Microbiology's journal, the U.S. strains of the virus share 99.5% of their genetic code with their Chinese counterpart. Meng said it is unclear whether the U.S. strains of the virus diverged in China or in the United States.
Researchers have continued to find no evidence that the virus can spread to humans or pose a threat to food safety, however they determined that the U.S. strains share several genetic features with a bat coronavirus. That finding points to an evolutionary origin from bats and the potential for cross-species transmission, a VT news report said.
Though commonly accepted that the virus spreads through the fecal-oral route, Meng said scientists have not yet ruled out the possibility of other transmission routes. He recommends that veterinarians work to recognize the symptoms of the disease, since no vaccine is available.
"Practicing strict biosecurity and good sanitation procedures on the farm are important for prevention and control of this deadly disease," Meng said.
Source: Virginia-Maryland Regional College of Veterinary Medicine