Is hepatitis B contagious?

In general, hepatitis B is a contagious disease mainly caused by the hepatitis B virus (HBV), which spreads from person to person through specific transmission routes. Primary modes of HBV transmission include bloodborne transmission, mother-to-child transmission, sexual contact transmission, close contact transmission, and iatrogenic transmission.

Bloodborne transmission can occur via transfusion of blood or blood products contaminated with the hepatitis B virus, or through the use of inadequately sterilized syringes, acupuncture needles, dental instruments, endoscopes, and similar devices. Additionally, sharing personal hygiene items such as razors and toothbrushes may also lead to HBV transmission if there is any skin damage. Mother-to-child transmission refers to the possibility of an infected mother transmitting the virus to her newborn during childbirth or through breast milk. Mother-to-child transmission is one of the major routes of HBV spread and mainly includes intrauterine infection, perinatal transmission, and postpartum transmission.

Sexual contact transmission refers to the possibility of transmitting the hepatitis B virus through unprotected sexual activity. If one sexual partner has hepatitis B, the virus may be transmitted to the other partner. Using condoms can effectively reduce the risk of infection, and sexual partners should receive hepatitis B vaccination. Household members or close contacts may contract the virus through sharing toothbrushes, razors, and other personal items. In cases of broken skin or mucous membranes, such as oral ulcers or skin wounds, contact with bodily fluids containing HBV may also lead to infection. During medical procedures, inadequate sterilization of medical instruments—such as surgical tools, dental instruments, and endoscopes—if contaminated with HBV, may transmit the virus to patients.

Key measures for preventing hepatitis B include receiving the hepatitis B vaccine, avoiding unnecessary blood transfusions and injections, practicing safe sex, and maintaining good personal hygiene. For individuals already infected with HBV, regular liver function monitoring is recommended, and antiviral treatment should be administered under a doctor's guidance to control disease progression.