New study suggests pigs could be a carrier of a strain of the hepatitis E virus. Another species of Roca Hepevirus ratti is known as “rat HEV” since its main reservoir is rats. Since the first human case was reported from a person with impaired immunity in Hong Kong in 2018, at least 20 total human cases have been reported, including those with normal immune function.
The patients infected by rat HEV did not report exposure to rats, which renders the source of infection undefined. The plausible cause in most cases of other human HEV infections is the consumption of raw pork, thereby making it a likely route of rat HEV as well.
One of the leading causes of acute viral liver infection in people worldwide, especially in developing areas where sanitation is poor, is hepatitis E. The virus is also endemic in pigs in the United States — but it is mainly present in liver rather than muscle, and is usually killed if the meat is cooked.
Earlier research studies on the testing of interspecies infectivity of rat HEV found that the used strain failed to infect nonhuman primates. “It dropped off the radar for six or seven years because it was thought not to be a human pathogen.”.
Although the organs and other bodily fluids of infected pigs contained viral RNA, the animals had no apparent clinical symptoms. Research conducted earlier also indicates that there are no clinical symptoms in rats. Even so, the rat HEV virus was found in the cerebrospinal fluid of infected pigs-another finding which jibes with emerging concern that many strains of HEV that affect humans can cause brain damage. One death attributed to rat HEV was due to meningoencephalitis.
HEV is gaining importance for neurological disorders, and much of the research now points towards how neuropathology is caused by the hepatitis E virus,” Yadav said.
“And though we have relatively few known human cases, a large percentage of them are immunosuppressed. That would mean transplant recipients in the United States could be at risk from general HEV as well as rat HEV”.
“Research could now focus on whether pork liver products contain rat HEV and explore food safety procedures to block the disease.
Yadav is currently at Virginia-Maryland College of Veterinary Medicine, Virginia Tech as a postdoctoral researcher.
Patricia Boley, Carolyn Lee, Saroj Khatiwada, Kwonil Jung, Thamonpan Laocharoensuk, Jake Hofstetter, Ronna Wood, and Juliette Hanson from Ohio State co-authored the research team.
Reference:
Caldwell E. Pigs may be transmission route of rat hepatitis E to humans [Internet]. Medicalxpress.com. Medical Xpres‌s
