Viral hepatitis is a serious global health problem affecting over two billion people worldwide and approximately one million people die each year due to cirrhosis of the liver and hepatocellular carcinoma (HCC), which are commonly associated with chronic hepatitis. The majority of hepatitis viral infections are caused by three distinct virus types: Hepatitis A (HAV), Hepatitis B (HBV) and hepatitis C (HCV). The risk of developing chronic infection by HBV varies inversely with age and is highest for infants infected at birth compared to older children and adults. Up to 90% of infants infected with HBV will develop chronic infection leading to cirrhosis of the liver or HCC compared to 6-10% of adults who acquire HBV infection. Determination of antibodies directed against HBV surface antigen (anti-HBs) is used to evaluate a person’s immune status to HBV infection or to aid in the laboratory diagnosis of HBV infection when used in conjunction with other laboratory methods. The test is performed to assess the need for vaccination (if anti-HBs is absent or below levels considered protective), following completion of vaccination against HBV in high risk groups (healthcare workers, Chronic renal failure patients, HIV infected persons), or to monitor recovery from acute HBV infection. The presence of anti-HBs following acute infection generally indicates recovery and immunity from reinfection.