Hepatitis B is a viral infection, which causes inflammation of the liver. The most common ways people become infected with hepatitis B are: sexual contact with an infected person, from an infected mother to her baby around the time of birth, and sharing needles and other drug equipment by people who inject drugs. Over 90% of adults clear the hepatitis B virus within six months of infection. However, most babies who become infected develop chronic (long-term) infection. This can cause them to develop serious liver disease, such as cirrhosis (scarring of the liver) and liver cancer as adults. Liver damage usually occurs gradually over 20-30 years in people with chronic infection. Most hepatitis B cases notified in Ireland are in people who have immigrated to Ireland from countries with a higher prevalence of hepatitis B. Many were infected at birth or in early childhood and developed chronic infection. Hepatitis B became a notifiable disease in Ireland in 1981.
Hepatitis B is preventable by vaccination. The vaccine has been part of the primary immunisation schedule for infants since 2008. Vaccination is also recommended for adults who are in “at risk” groups. For more details on vaccination, please see https://www.hse.ie/eng/health/immunisation/hcpinfo/guidelines/chapter9.pdf.
Number of hepatitis B notifications and notification rate per 100,000 population, 1997-2020
Last updated: 5 March 2021