HBs is not a virus but a virusâs antigen (HBs-Ag) that serves as a serological marker for proving infection with Hepatitis B â virus (HBV). HBs can be detected in people who have acute Hepatitis-B or chronic Hepatitis-B and in people who are virus carriers but who do not have Hepatitis-B. People who overcame Hepatitis B do not have HBs in their blood but only antibodies against HBs.
HBV can be transmitted parenterally which means the virus should reach your blood. Such direct contacts are possible during unprotected sex, using a needle that is contaminated with infected blood (intra venous drug abusers or accidentally in the medical personal), or during pregnancy from infected mother to fetus. The virus can neither live long outside human body nor can it pass through intact skin or mucosa. This means that you can get infected when you hold a contaminated object only if you have a fresh wound on the hand and if the object is freshly contaminated by the virus. The same stands for kissing. If you have cuts or erosions on the lips or inside the mouth you can get infected with HBV.