An emerging coronavirus strain that causes gastrointestinal illness in swine — and is especially dangerous to baby pigs — could wreck the pork industry and has the potential to jump species and infect humans, a University of North Carolina study has found.
The study, published this week in the Proceedings of the National Academy of Sciences, looked at a virus called swine acute diarrhea syndrome, or SADS-CoV, that began to infect swine herds in China in 2016, causing diarrhea and vomiting.
It killed 90 percent of the piglets under 5 days old that contracted it.
The virus, which has not been detected in the United States, is in the same family as SARS-CoV-2, which causes COVID-19. Both viruses are thought to have emerged from bats.
Last year, a group of 14 UNC-Chapel Hill epidemiologists, immunologists and microbiologists studied SADS-CoV to see if it could cross species and infect humans.
Caitlin Edwards and Rachel Graham of UNC’s Department of Epidemiology said Thursday in a phone interview with The News & Observer that the team submitted its findings for publication in early 2020, before the COVID-19 pandemic hit.
But the swift spread of COVID-19 around the globe this year has emphasized the need for developing interventions for coronaviruses.
“If this virus did occur in the U.S., the primary concern would be the swine industry,” Graham said. But in experiments, the virus was able to adapt and use human liver, gut and airway cells as hosts.
“We know it infects human cells,” Graham said.
The most likely way for the virus to move to humans would be through contact such as between workers and animals at hog farms.
China is the world’s larger swine producer, followed by the European Union and the United States. In this country, the industry is concentrated in the Midwest and in Eastern North Carolina.
In reporting its findings, the team recommended continued surveillance in China, for spread of SADS-CoV in swine herds but also for the appearance of unexplained illnesses in people.
China is monitoring for the virus among animals, Edwards said, because of the cost of the ongoing outbreak. But knowing that it could jump species means China also needs to monitor for “spill over” into humans.
In terms of human illness, Edwards said, the Chinese need to be looking for “anything that we haven’t seen before.”
Graham added, “The tricky part is we don’t know what kinds of diseases would manifest” if the virus crossed over to humans.
While the virus causes gastrointestinal issues in swine, it might produce respiratory or other issues in people, she said.
The team’s research was funded by the N.C. Coronavirus Relief Fund, created by the General Assembly, and by several grants from the National Institutes of Health.