Hepatitis B virus infection: understanding its epidemiology, course, and diagnosis.

Although hepatitis B virus (HBV) infection is not as common in the United States as in some countries, 5000 Americans die from it every year. This number can be significantly decreased with proper screening and by vaccinating people at risk. Internists should be aware of the natural history of HBV infection, a vital prerequisite to correctly assessing disease severity and subsequently determining the need for antiviral therapy.