Hepatitis B virus

Hepatitis B virus (HBV) is the most common cause of liver cancer worldwide. Chronic hepatitis B (CHB) is defined as the presence of HBsAg for >6 months. Transmission occurs via pregnancy, sexual intercourse, and contact with infected blood. CHB is rarely symptomatic; therefore a high index of suspicion is needed and routine screening should be employed, especially in high-risk populations. Risk of developing CHB is highly dependent on age of exposure (>90% if exposed as a newborn, ~5% if exposed as an adult). Most treatments for HBV aim to control but not cure the infection. Treatment is indicated in the presence of cirrhosis or in the presence of active viral replication plus evidence of liver inflammation or fibrosis. HBV is vaccine preventable. While all patients will benefit from vaccination, newborns, children, and pregnant woman should be prioritized.