HEPATITIS BS ANTIGEN STD'S BLOOD TESTS FOR SUBSTANCES IN THE BLOOD THAT SHOWS THAT THE VIRUS IS IN THE BODY. THIS REFERS TO THE OUTER SURFACE OF THE HEP B VIRUS THAT TRIGGERS AN ANTIBODY RESPONSE. ANTIGENS ARE MARKERS MADE BY BACTERIA OR VIRUSES, TESTIING POSITIVE FOR THIS ANTIGEN MEANS YOU HAVE AN ACTIVE HEP B INFECTION AND CAN EASILY PASS THE VIRUS TO OTHERS. IF THIS ANTIGEN IS PRESENT FOR MORE THAN 6MONTHS, THEN YOU PROBLULY HAVE A CHRONIC (LONG-TERM) HBV INFECTION. HEP B IS A SEXUAL TRANSMITTED DISEASE.