Clinical course and treatment of viral hepatitis

Acute hepatitis can be caused by the enterically spread hepatitis A and E v iruses and the parenterally spread hepatitis B, C or D viruses. The clinica l features of acute viral hepatitis are similar among the five viruses and include non-specific symptoms and icterus. In general, a specific therapy i s not necessary, but patients with fulminant hepatitis may require liver tr ansplantation. For acute hepatitis C, the effect of interferon-alpha on the risk of chronicity is evaluated in clinical trials. Chronic hepatitis is d efined as inflammatory reaction in the liver that continues without improve ment for at least 6 months after infection with hepatitis B, C or D viruses . Hepatitis B resolves in more than 90% of the patients, but chronic infect ion can lead to liver cirrhosis and hepatocellular carcinoma. Chronic hepat itis C is an insidious disease, because early diagnosis is missed easily du e to asymptomatic presentation and about 70 % of infected patients develop chronic hepatitis. The benefits of interferon-alpha and/or nucleoside analo gues have been proven in recent clinical trials that show sustained respons es in more than a third of all patients with chronic viral hepatitis. The f uture treatment of chronic viral hepatitis will likely include immunomodula tion and gene therapy.