Recently Discovered Coronavirus Shows Potential for Cross-Species Transmission

Investigators from The Ohio State University in Ohio, and Utrecht University in the Netherlands, have made a startling discovery: a newly identified porcine virus that is able to get into human cells in the laboratory setting.

This is not the first time that an animal-originated virus has sparked concern in the health care community because of the threat it poses to human health. Indeed, health care experts such as Anthony Fauci, MD, head of the National Institutes of Health’s National Institute of Allergy and Infectious Diseases, all agree that almost all influenzas are zoonotic in nature, and so to thwart a severe outbreak, “you can at least keep an eye on what’s happening in the animal kingdom.” Dr. Fauci further acknowledged that, “[In 2009, H1N1] was percolating in the swine population for a while. We weren’t monitoring the swine population particularly well, and so we missed it.”

This also may have been the case with the severe acute respiratory syndrome (SARS) outbreak in 2002 through 2003 which began in China and was ultimately linked with more than 8000 cases and 774 deaths in 37 countries, according to the World Health Organization (WHO). Investigators have since learned that the virus originated in bats. Likewise, the Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak that remains ongoing has already led to 2206 laboratory-confirmed cases and 787 associated deaths, according to WHO. MERS-CoV has been found in camels and individuals who had close contact with the infected animals.

This new coronavirus, porcine deltacoronavirus, was identified first in pigs in China in 2012, according to a press release on the research, published in Proceedings of the National Academy of Sciences. In the United States, the virus was first detected in young Ohio pigs who had been experiencing a bout of acute diarrhea and vomiting in 2014. Since then, several other countries have detected the virus; however, no human cases have been documented. Still, investigators are concerned about the possibility of transmission, and it was this concern that prompted the Ohio State and Utrecht University investigators to perform their study.

“Before it was found in pigs—including in the Ohio outbreak—it had only been found in various birds,” shared Linda Saif, PhD, senior author on the study and a distinguished university professor at The Ohio State University in the Food Animal Health Research Program (OARDC) and the Veterinary Preventive Medicine Department (CVM, OSU) in the press release. “We're very concerned about emerging coronaviruses and worry about the harm they can do to animals and their potential to jump to humans.”

According to lead researcher Scott Kenney, PhD, assistant professor of veterinary preventive medicine based in the Food Animal Health Research Program at OARDC, viruses have the potential to move from one species to another if they are able to bind to receptors on the other species’ cells. Dr. Kenney stated in the press release that he and his colleagues specifically looked at the cellular receptor, aminopeptidase N, in this study because, “We know from other coronaviruses that these receptors on the cells are used and that they're found in the respiratory and digestive tracts of a number of different animals.”

What they found was that porcine deltacoronavirus was able to bind to the receptors not only in humans, but cats and chickens as well.

Although this finding does not prove that the virus can, in fact, cause disease in other species, it does encourage further investigation. According to Dr. Saif, the next step will be, a study looking for antibodies in the blood that would serve as evidence that the pig virus has already infected people. “We now know for sure that porcine deltacoronavirus can bind to and enter cells of humans and birds,” she stated in the press release, “Our next step is to look at susceptibility—can sick pigs transmit their virus to chickens, or vice versa, and to humans?”