Hepatitis E virus: new faces of an old infection.

Hepatitis E virus is one of the most common causes of acute hepatitis worldwide, with the majority of cases occurring in Asia. In recent years, however, an increasing number of acute and chronic hepatitis E virus infections have been reported in industrialized countries. The importance of this infection resides in the associated morbidity and mortality. In acute cases, a high mortality rate has been reported in patients with previously undiagnosed alcoholic liver disease. Hepatitis E infection can become chronic in immunocompromised patients, such as solid organ transplant recipients, patients receiving chemotherapy, and HIV-infected patients, and lead to the development of hepatic fibrosis and cirrhosis. Hence, treatment strategies involving reductions in immunosuppressive regimens and therapy with ribavirin or peg-interferon have been evaluated. In terms of prevention, a promising new vaccine was recently licensed in China, although its efficacy is uncertain and potential adverse effects in risk groups such as chronic liver disease patients and pregnant women require investigation. In conclusion, physicians should be aware of hepatitis E as a cause of both acute and chronic hepatitis in immunocompromised patients. The best treatment option for HEV infection remains to be defined, but both ribavirin and peg-interferon may have a role in therapy for this condition.