Researchers at The Ohio State University and Utrecht University in the Netherlands have identified a new pig virus that poses potential threat to humans and other animals.
Laboratory tests revealed that porcine deltacoronavirus, first detected in China in 2012, could jump from pig cells into human cells.
The pathogen bears a likeness to the virus responsible for SARS and MERS. This was particularly worrying because previous studies found that SARS originated in bats before spreading to people. Meanwhile, an ongoing MERS outbreak in Saudi Arabia showed that the virus originated from camels and spread through people who had close contact with the animals.
The ability of a virus to bind to the cellular receptors of animal or human cells gives the virus the capability to jump from one species to another. The receptor works like a lock in the door, explains Scott Kenney, lead researcher and assistant professor of veterinary preventive medicine at the Ohio Agricultural Research and Development Center. If the virus can bypass the lock, it can penetrate into the cell and potentially infect the host.
For the study, the researchers observed whether the cellular receptor aminopeptidase N, which is commonly found in coronaviruses, could bind to the receptors of the laboratory-cultured cells of humans and other animals.
The study, published in the journal Proceedings of the National Academy of Sciences, confirmed that the virus could infect cells of humans and other animals.
Linda Saif, senior author and an investigator from OARDC, explained that to date, there is no known case of porcine deltacoronavirus affecting humans. Their laboratory experiment, however, revealed the possibility that this could happen in the future.
"We know for sure that porcine deltacoronavirus can bind to and enter cells of humans and birds," Saif explains. Their next step is to detect the possible mode of transmission from pigs to other species.
2014 Porcine Deltacoronavirus Outbreak
In 2014, porcine deltacoronavirus reached the United States and affected pigs in Ohio. At the time, piglets suffered acute diarrhea and vomiting.
From Ohio, the virus also spread in other states, killing an estimated 7 million pigs or 10 percent of all the pigs in the country.
A swine biosecurity specialist from the Iowa State University in Ames estimated that a tablespoon of manure infected with the virus could infect an entire herd of hogs. In one Iowa farm, the virus killed a total of 850 piglets. Adult pigs usually recovered from the virus.
At the time, experts dismissed the possibility that the virus could jump to humans, hence, nullifying altogether any direct threat to public health.
Christopher Olsen, a professor of public health at the University of Wisconsin in Madison, and Juergen Richt, a distinguished professor of veterinary medicine at Kansas State University in Manhattan, said porcine deltacoronavirus first appeared in England in 1971.
This meant that it has been alive for more than 40 years in pigs found not only in the United States but in Europe and Asia as well. For four decades, there has been no evidence yet of anyone getting infected by the virus even among those people who worked closely with pigs.