What should you know about mode of transmission of hepatitis B?

The virus may pass through blood, semen, or vaginal fluids. Exposure can happen during unprotected sex, sharing needles or other equipment that can carry blood, or a procedure involving unsterile instruments. A person who has hepatitis B can pass it to a baby around the time of delivery. The virus is not spread by ordinary social contact such as hugging, sharing food, coughing, or sitting beside someone.

Some people have no symptoms, so a person may not know they carry the virus. Possible signs include fatigue or dark urine, but symptoms cannot show whether transmission has occurred. A blood test is needed to check infection and immunity.

Vaccination is a strong preventive measure and is especially relevant for babies, household contacts, sexual partners, and people whose work or care may involve blood. Do not share needles, razors, toothbrushes, or equipment used for piercing or tattooing. Use condoms until a clinician confirms protection for an uninfected partner. If blood or body-fluid exposure has happened, arrange medical advice promptly because testing and preventive treatment may be time-sensitive.

Contact a clinician after a needlestick, sexual exposure, contact with another person’s blood, or possible exposure during pregnancy. Seek prompt assessment if you develop yellowing of the skin, dark urine, marked tiredness, vomiting, or pain under the ribs. A clinician may arrange hepatitis tests and a liver function test to assess what is happening.

Ask whether you need hepatitis B testing, vaccination, or urgent preventive treatment after an exposure. You can also ask which household or sexual contacts should be tested, how long to use barrier protection, and whether follow-up testing is needed.