What is Hepatitis B?

This page was reviewed or revised on Thursday, August 13, 2009.

Hepatitis B is a viral infection of the liver.

Many people who become infected with Hepatitis B do not have any symptoms and feel fine. Those who have symptoms may feel sick, tired and weak, have a poor appetite, headaches, may vomit, develop a fever, have darker urine, abdominal pain and jaundice (a yellowish colour of the skin and whites of the eyes).

You can get Hepatitis B from: sex with an infected person, sharing needles, or contact with the blood, saliva, semen, or vaginal secretions of an infected person or items contaminated by these body fluids. Infected people who feel fine can still pass the virus to others.

When someone becomes infected with the Hepatitis B virus, their immune system develops antibodies to fight the infection. Most people (90%) will fight the infection and recover. While they are fighting the infection they are considered acute carriers. But some people (9%) will carry the virus forever, which may lead to liver damage or liver cancer. They are called chronic carriers. A very few people (1%) will develop an acute illness and die.

The National Advisory Committee on Immunization recommends vaccine for:

• Infants born to Hepatitis B (HBsAg) positive mothers.
• Those receiving repeated infusions of blood or certain blood products (e.g. Factor VIII or IX concentrates).
• Patients on haemodialysis.
• Health Care workers and students repeatedly exposed to blood products or those who are at risk of needle-stick injury.
• Dentists, dental assistants and hygienists.
• Residents and staff of institutions for the mentally handicapped.
• Men who have sex with men.
• Users of illicit injectable drugs and those who share needles.
• Sexual and household contacts of a hepatitis B case or carrier.
• Heterosexual individuals with multiple sex partners.
• Embalmers.
• International travellers residing more than six months with high levels of endemic Hepatitis B, or other travellers likely to contact blood from residents of such areas or to have sexual contact with them.