Hepatitis B is a viral infection, which causes inflammation of the liver. It is caused by a small DNA virus, which can persist in a stable form in the nucleus of infected host cells (cccDNA), making cure of chronic infection difficult. HBV is transmitted through contact with semen, blood or other body fluids from an infected person. Most common modes of transmission: unprotected sex, from mother to baby during birth and delivery (common in endemic countries) & sharing needles, syringes and other equipment when injecting drugs. Less common modes of transmission: sharing tooters or straws when snorting cocaine, unscreened blood or blood products (100% screened in Ireland), accidental needlestick/blood or body fluid exposure in healthcare or other settings, household/close contact particularly in early childhood, sharing razors or toothbrushes

Hepatitis B in Ireland in 2024: key points:

• 607 cases of hepatitis B were notified in 2024, a notification rate of 11.8 per 100,000 population
• Other than the COVID-19 pandemic years (2020 & 2021), hepatitis B notification rates fluctuated between 9 and 12 per 100,000 between 2012 and 2024
• 96% of hepatitis B cases in 2024 were chronically infected (long-term/lifelong infection) when diagnosed, 2% were acute cases (recent infections – within past 6 months) & it was not possible to establish the acute/chronic status for 2% (98% chronic where status was reported)

P.4 Vaccination uptake in adult at-risk groups is not available currently in Ireland o Monitoring could help identify at-risk groups with lower uptake rates – a new National Immunisation Information System (NIIS) is in development o Immunity due to vaccination or past infection is likely to be relatively high in people who use drugs (PWUD). Vaccination and testing for hepatitis B have been recommended for PWUD for decades and injecting drug use is not commonly reported as a risk factor for notified cases of hepatitis B.

P.18 Risk factor/exposure for acute hepatitis B notifications in Ireland, 2007- 2024 - People who use drugs, 2%

P.31 Studies of PWUD (mostly heroin users) in Ireland, 1992-2002: HBsAg prevalence ranged from 1-5%

P.38 HSE Social inclusion Addiction services:

• Information on where to access addiction support, including free testing for hepatitis B, hepatitis C and HIV and vaccination against hepatitis A and B
• Health Research Board (HRB) Interactive national map of drug and alcohol services (launched in 2024)
• https://drugs.ie/ provides information about drugs, advice on harm reduction and information on addiction treatment
• Ireland’s first Medically Supervised Injection Facility (MSIF) opened in 2024, aiming to reduce drug injector deaths, bloodborne virus transmission, drug related litter and public injecting

Migrant health: 

• Safetynet Primary Care provides medical services, including infectious disease testing,to those without access to healthcare, including homeless people, people who use drugs (PWUD) and migrants