Prevalence of antenatal hepatitis B virus carriage in the west of Ireland.

Hepatitis B virus (HBV) is a DNA virus. Transmission occurs as a result of mucosal or percutaneous contact with blood or body fluids of an infected person. Acute infection may be associated with an acute and sometimes fatal hepatitis. In most patients the immune response achieves clearance of the virus, however, in a significant proportion the virus is not cleared and the patient progresses to chronic infection. Approximately 90% of infections occurring in the perinatal period or early childhood progress from acute to chronic HBV infection. 1 Chronic infection may be asymptomatic but is associated with a number of complications including hepatic cirrhosis and hepatocellular carcinoma. Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality with an estimated 350 million people infected worldwide. 2