About 5% of people in the U.S. will get infected with hepatitis B sometime during their lives. If you engage in certain behaviors, your risk may be much higher. You may be at risk if you:
- have a job that exposes you to human blood
- share a household with someone who has lifelong hepatitis B infection
- have sex with a person infected with hepatitis B
- have sex with more than one partner during a six-month period
- received blood transfusions in the past before excellent blood testing was available (1975)
- are a person whose parents were born in Asia, Africa, the Amazon Basin of South America, the Pacific Islands, Eastern Europe, or the Middle East
- were born in an area listed above
- were adopted from an area listed above
- are an Alaska native
- have hemophilia
- are a patient or worker in an institution for the developmentally disabled
- inject drugs
- are an inmate of a long-term correctional facility
- travel internationally to areas with a high prevalence of hepatitis B
The largest outbreak of hepatitis B in the U.S. occurred in 1942 in military personnel who were given vaccine to protect them from yellow fever. It was unknown at the time that this vaccine contained a human blood component that was contaminated with hepatitis B virus. The outbreak caused over 50,000 cases of hepatitis B with jaundice.