What is Hepatitis B?

Hepatitis is an inflammatory condition of the liver. It is typically caused by viral infection, though there are other ways of acquiring the condition such as alcohol abuse. There are several known viruses responsible for hepatitis but the most common by far are Hepatitis A, B and C.

The viruses are spread in different ways and are more common in different areas of the world. Hepatitis infections can be asymptomatic but common symptoms include jaundice, vomiting, diarrhoea, dark urine and pale stools. Chronic hepatitis infection can lead to significant liver damage and liver failure. Hepatitis B is caused by hepatitis B virus (HBV), it is usually transmitted through the blood. HBV is commonly spread from infected pregnant mothers to their babies, in rare cases it can be spread through unprotected sex or intravenous drug administration with shared needles.

Adults infected with HBV generally recover without medication, but infected children can present with chronic hepatitis B, which drastically increases the risk of liver cancer. There is a vaccine for HBV. Antigens are markers unique to particular cells and viruses, which are targeted by antibodies produced by the immune system. There are several different components of HBV which produce antigens targeted by different antibodies. Core antibodies target the core of the virus, envelope antibodies (E antibodies) target the outer shell of the virus and surface antibodies target the viral surface.

Why take the test?

This test screens for IgM antibodies to hepatitis B virus (HBV). The presence of these antibodies means you have been exposed to HBV within the last 12 months, as IgM antibodies will not be present for longer than this. It is used to diagnose recent or active HBV infection.