New research suggests that pigs may serve as a reservoir for a strain of the hepatitis E virus (HEV) commonly found in rats, which has recently been discovered to infect humans. The Rocahepevirus ratti strain, known as “rat HEV”, is primarily seen in rats, but has been found to infect humans, with at least 20 reported cases thus far. The cause of human infection with rat HEV remains unknown, but the consumption of raw pork has been suggested as a potential route of transmission, as it is with other forms of HEV.
Researchers at The Ohio State University conducted a study in which they found that a strain of rat HEV isolated from humans was capable of infecting pigs and being transmitted among animals in farm-like conditions. The presence of rats in swine barns indicates that the pork production industry could be a setting through which rat HEV may be transmitted to humans. This finding highlights the importance of understanding the genetics of the virus to anticipate any potential risks associated with its spread.
Hepatitis E is a common cause of acute viral liver infections in humans, particularly in regions with poor sanitation. While the virus is also found in pigs in the United States, it is primarily located in the liver rather than the muscle and is eliminated through cooking. Previous studies testing the infectiousness of rat HEV in non-human primates showed no infection, but recent cases in humans have raised concerns and emphasized the need for further investigation.
The study focused on a strain of rat HEV known as LCK-3110, which was linked to human disease. By constructing an infectious clone of this strain, researchers were able to demonstrate its ability to replicate in human and mammal cells, as well as in pigs. Pigs injected with the infectious strain showed higher levels of viral particles in their blood and feces compared to pigs infected with the native U.S. strain of HEV. The virus was also detected in the cerebrospinal fluid of infected pigs, raising concerns about potential neurological consequences in humans.
While infected pigs did not show signs of illness, the presence of rat HEV in their bodily fluids and organs, as well as in the feces of co-housed animals, suggests the potential for fecal-oral transmission. The virus was also found in the cerebrospinal fluid of infected pigs, highlighting the growing concern that HEV strains can cause neurological disorders, including meningoencephalitis. This finding calls for further research into the safety of pork products, particularly those containing liver, to prevent the spread of rat HEV to humans.
This study underscores the importance of understanding the transmission and potential risks associated with rat HEV, particularly in the pork production industry. With the detection of the virus in pigs and its potential to infect humans, there is a need for vigilance in monitoring and controlling the spread of this strain of HEV. Further research is necessary to explore food safety procedures to prevent the transmission of rat HEV through pork products and to protect vulnerable populations, such as transplant recipients, from potential infection.
