Risk Factors and Transmission
The Hepatitis B virus is spread when blood, semen, or other body fluids from an infected person enters the body of someone who is not infected.
The virus can be spread through:
Injection drug use. Sharing needles, syringes, and any other equipment to inject drugs with someone infected with Hepatitis B can spread the virus.
Sex with an infected person. Among adults, Hepatitis B is often spread through sexual contact.
Birth. Hepatitis B can be passed from an infected mother to her baby at birth. Worldwide, most people with Hepatitis B were infected with the virus as an infant.
Outbreaks. While uncommon, poor infection control has resulted in outbreaks of Hepatitis B in healthcare settings.