Hepatitis E was not recognized as a distinct human disease until 1980. It is caused by infection with the hepatitis E virus, a non-enveloped, positive-sense, single-stranded RNA virus.
Acute hepatitis E is uncommon in the United States and very rarely results in chronic hepatitis, particularly in solid organ transplant recipients, patients with cirrhosis, and those on immunosuppressive therapies. Currently there is no FDA-approved treatment for HEV infection. It usually resolves on its own over several weeks to months. For those rare instances in which the infection becomes chronic, treatment with ribavirin has been reported to be effective. Hepatitis E is spread through food or water contaminated by feces from an infected person. There is considerable evidence that because swine may carry the infection, ingestion of pork or pork products may transmit infection. Person-to-person transmission is uncommon. There is no evidence for sexual transmission or for transmission by transfusion in the United States.
People most likely to be exposed to the hepatitis E virus include international travelers, particularly those traveling to developing countries where hepatitis E is endemic, those who come in contact with swine, and those who ingest pork products and venison.
Typical signs and symptoms of hepatitis include jaundice (yellow discoloration of the skin and sclera of the eyes, dark urine and pale stools), anorexia (loss of appetite), an enlarged, tender liver (hepatomegaly), abdominal pain and tenderness, nausea and vomiting, and fever, although the disease may range in severity from subclinical to fulminant. The disease is especially severe in pregnant women in whom the case fatality rate may be as high as 10%.
Outbreaks of hepatitis E have been reported in Central and South-East Asia, North and West Africa, and in Mexico, especially where fecal contamination of drinking water occurs.
Testing for anti-HEV is usually reserved for individuals with hepatitis in whom the other more common hepatitis viruses cannot be detected.Prevention is based on consumption of clean drinking water, avoidance of contaminated foods, and good sanitation. At present, no commercially available vaccines exist for the prevention of hepatitis E.