[Non-A non-B acute hepatitis].

Two distinct forms of non A non B viral hepatitis are now distinguished: (a) parenterally transmitted non A non B hepatitis, mainly due to hepatitis C virus, (b) enterically transmitted non A non B hepatitis, mainly due to hepatitis E virus. Hepatitis C virus is an enveloped, 50 to 60 nm in diameter, single stranded RNA virus. Its transmission is essentially parenteral and resembles that of hepatitis B virus. Individuals at risk are those in contact with blood products. Sexual transmission is uncommon. C virus hepatitis is characterized by a frequent course to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Fulminant hepatitis is rare. Chronic forms are associated with the presence of anti-HCV antibodies in the serum. These antibodies are rarely present in the acute stage of the disease. Hepatitis E virus is a non-enveloped, 30 nm in diameter, single stranded RNA virus. Its transmission is faecal-oral, thus similar to that of hepatitis A virus. The disease is almost exclusively encountered in developing countries. It is not observed in France, apart from imported cases. Like A virus hepatitis, chronicity never occurs. Fulminant hepatitis is possible in pregnant women in the third trimester of pregnancy. There is no routine serological test. Development of vaccines against these two viruses can be expected.