New research suggests that pigs may function as a transmission vehicle for a strain of the hepatitis E virus (HEV) common in rats that has recently been found to infect humans. The Rocahepevirus ratti strain is called "rat HEV" because rats are the primary reservoir of the virus. Since the first human case was reported in a person with a suppressed immune system in Hong Kong in 2018, at least 20 total human cases have been reported – including in people with normal immune function.
People infected with rat HEV did not report exposure to rats, leaving the cause of infection undefined. The suspected cause during other human HEV infections, in many cases, is consumption of raw pork – making it a potential route for rat HEV as well. Researchers at The Ohio State University found that a strain of rat HEV isolated from humans could infect pigs and was transmitted among co-housed animals in farm-like conditions.
Rats are common pests in swine barns – suggesting that the pork production industry may be a setting in which rat HEV could make its way to humans. "We always want to know which viruses might be up and coming, so we need to know the genetics behind this virus in the unlikely event something happens in the United States that would enable rat HEV to expand," said senior author Scott Kenney, an associate professor of veterinary preventive medicine at Ohio State based in the Center for Food Animal Health at the College of Food, Agricultural, and Environmental Sciences' Woo.
