What causes Hepatitis B?
Hepatitis B is caused by the hepatitis B virus (HBV).
In highly endemic areas, HBV is most commonly spread from mother to child at birth, or from person to person in early childhood.
Perinatal or early childhood transmission may also account for more than one third of chronic infections in areas of low endemicity, although in those settings, sexual transmission and the use of contaminated needles, especially among injecting drug users, are the major routes of infection.
The hepatitis B virus can survive outside the body for at least 7 days. During this time, the virus can still cause infection if it enters the body of a person who is not protected by the vaccine. The incubation period of the hepatitis B virus is 75 days on average, but can vary from 30 to 180 days. The virus may be detected 30 to 60 days after infection and persists for variable periods of time.
Hepatitis B infection can be spread through having contact with the blood, semen, vaginal fluids, and other body fluids of someone who already has a hepatitis B infection.
Ways of infection include:
Blood transfusions (not common in the United States) Direct contact with blood in health care settings Sexual contact with an infected person Tattoo or acupuncture with unclean needles or instruments Shared needles during drug use Shared personal items (such as toothbrushes, razors, and nail clippers) with an infected person
The hepatitis B virus is not spread by contaminated food or water, and cannot be spread casually in the workplace. </s>