Hepatitis E is a viral hepatitis (liver inflammation) caused by infection with a virus called hepatitis E virus. It is one of five known human hepatitis viruses: A, B, C, D, and E. HEV is a positive-sense single-stranded non-enveloped RNA icosahedral virus, HEV has a fecal-oral transmission route
Infection with this virus was first documented in 1955 during an outbreak in New Delhi, India.A preventative vaccine (HEV 239) is approved for use in China.
Although Hepatitis E often causes an acute and self-limiting infection (the virus usually resolves itself and the individual recovers) with low mortality rates in the western world, it bears a high risk of developing chronic hepatitis in immunocompromised patients with substantial mortality rates. Organ transplant recipients who receive immunosuppressive medication to prevent rejection are thought to be the main population at risk for chronic hepatitis E.