Earlier this year, researchers identified a new strain of swine flu that they said had “all the essential characteristics of a candidate pandemic virus.”
In addition to finding out that the virus – designated G4 – was highly contagious, they also found that 10.4 percent of workers treating the pigs had antibodies to the disease, indicating that transmission to humans was possible. However, there is as yet no evidence that the virus can pass from person to person.
In the paper published in PNAS, they wrote that pigs are important “mixers” for influenza viruses with the potential to infect humans, and therefore monitoring for new viruses in pigs provides an important early warning for strains that could become a pandemic.
Enter another potentially zoonotic pathogen with an alarming name. In a new study from the University of North Carolina at Chapel Hill, researchers have taken a closer look at yet another virus in pigs with the potential to spread to humans. The highly pathogenic virus, called acute diarrhea syndrome coronavirus (SADS-CoV), first appeared in bats before infecting flocks of pigs across China in 201
The team that published their findings in PNAS injected a synthetic version of SADS-CoV into different cell types in the laboratory to determine if it could replicate in human cells, including human liver, lung, and intestinal cells.
“Of concern, rSADS-CoV also replicated efficiently in several different primary human lung cell types as well as primary human intestinal cells,” the team wrote in the newspaper. “Effective growth in primary human lung and intestinal cells implies SADS-CoV as a potentially higher risk-growing coronavirus pathogen that may have a negative impact on the global economy and human health.”
The virus replicated with a higher growth rate in intestinal cells; this is in contrast to SARS-CoV-2, the virus that causes Covid-19, which mainly infects lung cells. However, although it is necessary to monitor, the virus has not yet been shown to infect humans outside of laboratory settings. The team also tested broad-spectrum antiviral remdesivir – which has also shown promise in Covid-19 treatment – and in preliminary results found that it “effectively blocked rSADS-CoV replication in vitro.”
“Promising data with strap divisions provide a potential treatment option in the event of a human accident,” Caitlin Edwards, a research specialist and master of public health at UNC-Chapel Hill, said in a statement. “We recommend that both pig workers and the pig population be continuously monitored for indications of SADS-CoV infections to prevent outbreaks and massive economic losses.”
The team is now investigating possible vaccines for the virus to protect pig herds.
“While monitoring and early separation of infected piglets from sows provides the opportunity to mitigate major outbreaks and the potential for spread to humans,” Edwards said, “vaccines may be key to limiting global spread and human-occurring incidents in the future.”