Transmission

Hepatitis B virus (HBV) is highly contagious and may be present in blood and body fluids, including semen and vaginal secretions. The saliva of people with hep B may contain evidence of the virus but in such small concentrations that kissing does not spread HBV. Here are the most common ways hepatitis B is transmitted:

  • Sex with an infected partner
  • Acquired at birth from an infected mother
  • Sharing injection drug equipment (including needles, syringes, cookers, drug-preparation equipment)
  • Contact with blood or open sores of an infected person
  • Needle stick or other skin puncture
  • Sharing items such as glucose monitors, razors or toothbrushes with an infected person.

Hepatitis B may also be spread through non-injection drugs (e.g., cocaine straws and crack pipes) as a result of exposure to blood. An unsterilized instrument may transmit HBV during acupuncture, tattooing and body piercing. A human bite may spread hepatitis B.

Hep B is not spread through food or water, sharing eating utensils, breast feeding, hugging, kissing, hand holding, coughing or sneezing.

HBV may live outside the body for at least seven days and still be potentially infectious.

Risk Factors

Hepatitis B vaccination has dramatically reduced the risk of HBV in the United States. To further reduce risk of transmitting hepatitis B, all health care workers and pregnant women are screened and or immunized. Contact your health care provider for a blood test if you haven’t been immunized and have any of the following hep B risk factors:

  • Your mother was living with hepatitis B at the time of your birth.
  • You had sex with a person living with hepatitis B.
  • You used drugs or shared injection drug equipment with someone who may be living with hepatitis B.
  • You had household contact with a person who is living with hepatitis B.
  • You had an occupational exposure to blood or blood-contaminated body fluids, because you work in health care or public safety, for example.
  • You have HIV.
  • You are a man who has had sex with men.
  • You have ever been on long-term kidney dialysis.
  • You are in a correctional facility.
  • You are a resident or work in a facility for developmentally disabled persons. 
  • You have evidence of liver disease (e.g., persistently abnormal liver function tests).
  • You were born in or traveled to regions with a moderate to high prevalence of HBV infection: Asia, Africa, the Pacific Islands, the Middle East, Eastern Europe (except Hungary), Malta, Spain, and indigenous populations of Greenland, Caribbean, Mexico, Guatemala, Honduras, South America, Alaska Natives and indigenous populations in Northern Canada.

Read the Hepatitis B Transmission and Risks in Chinese.

閱讀中文的乙型肝炎傳播與風險。

Read the Hepatitis B Transmission and Risks in Vietnamese.
Đọc các truyền lây nhiễm viêm gan B và Rủi ro bằng tiếng Việt.

Last Reviewed: June 6, 2019