Hepatitis B (formerly known as serum hepatitis) is transmitted by infected blood or blood products contaminating hypodermic needles, blood transfusions, or tattooing needles, by unprotected sexual contact, or (rarely) by contact with any other body fluid. It often occurs in drug users. Symptoms, which develop suddenly after an incubation period of 1–6 months, include headache, fever, chills, general weakness, and jaundice. Treatment includes *interferon alfa and other oral antivirals (e.g. *lamivudine, *adefovir dipivoxil, entecavir). Most patients make a gradual recovery but the mortality rate is 5–20%. A vaccine is available.
Hepatitis C (formerly known as non-A, non-B hepatitis) has a mode of transmission similar to that of hepatitis B (predominantly intravenous drug abuse). Treatment is with interferon alfa, peginterferon alfa, ribavirin, telaprevir, and boceprevir.
Hepatitis D is a defective virus that can only proliferate when there is infection with hepatitis B. Patients with D virus usually have severe chronic hepatitis.
Hepatitis E is transmitted by infected food or drink and can cause acute hepatitis; it is especially severe in a pregnant patient.
Chronic hepatitis continues for months or years, eventually leading to *cirrhosis and possibly to malignancy (see hepatoma). It is usually caused by chronic viral hepatitis, alcohol, or autoimmune disease.... hepatitis