1 Epidemiology of hepatitis B in Ireland Last updated October 2016

2 Hepatitis B virus (HBV) (1)Hepatitis B is a viral infection, which causes inflammation of the liver It is transmitted through contact with semen, blood or other body fluids from an infected person Most common means of transmission: unprotected sex, sharing needles when injecting drugs, from mother to baby around the time of birth Less common means of transmission: unscreened blood or blood products (outside Ireland), accidental needlestick/blood exposure in healthcare settings, household/close contact particularly in early childhood, sharing razors or toothbrushes times more infectious than HIV Incubation period (time from infection to onset symptoms) is 6 weeks to 6 months, average 2-3 months

3 Hepatitis B virus (HBV) (2)Acute (new infection): <10% children and 30-50% adults develop symptoms when first infected Symptoms include: loss appetite, nausea, vomiting, abdominal discomfort, joint pain, fever, fatigue, dark urine, pale stools, jaundice Chronic (long-term) infection develops in 80-90% of those infected as infants, 30-50% of children <6 years and <10% of those infected as adults Chronic infection can lead to chronic liver disease, cirrhosis, liver cancer or liver failure, usually over years World Health Organization (WHO) estimates that approximately 240 million people are chronically infected worldwide Vaccine preventable – universal infant vaccination introduced in Ireland in Vaccine also recommended for high risk groups

4 Worldwide prevalence hepatitis B (Source: CDC http://www. cdc

5 Number of notifications of hepatitis B, 1997-2015Hepatitis B notifications increased steeply between 2000 and 2008 This was mostly attributable to large numbers of people migrating to Ireland from hepatitis B endemic countries, with chronic hepatitis B infections. Immigration to Ireland has decreased in recent years, correlating with a reduction in hepatitis B notifications. However, there was a 24% increase in notifications in 2015 compared to 2014, notifications are slightly lower year to date in 2016 (mid-October) Notifications of chronic cases (long-term infections) peaked in 2008 (n=769). 502 chronic cases were notified in 2015 (35% decrease compared to peak levels) The number of acute cases (new infections) notified has generally been low, but has also decreased in recent years. Notifications of acute cases peaked in 2006 (n=95). 26 acute cases of hepatitis B were notified in 2015 (73% decrease compared to peak levels)

6 Hepatitis B notification rates per 100,000 population, by HSE area, 2004-2015Highest rates in the HSE-E

7 Trends in acute hepatitis B notifications by sex and median age, 2004-2015

8 Mean annual notification rates per 100,000 for acute cases of hepatitis B by age and sex, 2004-2015

9 Notification rates per 100,000 for acute cases of hepatitis B by age and sex, 2015

10 Trends in chronic hepatitis B notifications by sex and median age, 2004-2015

11 Mean annual notification rates per 100,000 for chronic cases of hepatitis B by age and sex,

12 Notification rates per 100,000 for chronic cases of hepatitis B by age and sex, 2015

13 Most likely risk factor for acute cases, 2004-2015 (data available for 70%, n=462)Approximately one fifth of acute cases were born in an endemic country or were asylum seekers

14 Most likely risk factor for chronic cases, 2004-2015 (data available for 50%, n=3422)Born in endemic country/asylum seeker is used as a proxy for risk factor, where no other risk factor has been identified. Over a third (39%) of the cases with risk factor data were also born in endemic countries.

15 Region of birth, Acute cases with region of birth data (80%, n=531) Chronic cases with region of birth data (43%, n=2,926)

16 Hepatitis B notifications (acute & chronic) and CSO immigration numbers from EU16-28 & non EU/EEA countries (excl North America & Australia), EU countries: Bulgaria, Croatia, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Romania, Slovakia, Slovenia, Cyprus

17 Summary of acute hepatitis B in Ireland, 2004-20159% of cases notified were acute infections 662 acute HBV notifications in this time period (annual average: n= 55) 26 acute cases of hepatitis B were notified in This is the lowest number reported since acute/chronic case definitions were introduced in 2004 82% of acute cases notified were male (M:F = 5:1) Mean ages at notification: 37 for males, 34 for females, 36.5 for both Median ages at notification: 34 for males, 30 for females, 33.5 for both Where risk factor data available, 77% of cases were sexually acquired Sexual orientation available for 95% of sexually acquired cases: 51% heterosexual, 49% men who have sex with men Where country of birth available, 73% of acute cases were born in Ireland

18 Summary of chronic hepatitis B in Ireland, 2004-201591% of cases notified were chronically infected 6819 chronic HBV notifications in this time period (annual average: n= 568) 502 chronic cases of hepatitis B were notified in 2015 55% of chronic cases notified were male Mean ages at notification: 35 for males, 31 for females, 33 for all Median ages at notification: 33 for males, 29 for females, 31 for all Data indicate that most chronic cases were born and infected outside of Ireland, mostly in Central & Eastern Europe, Asia and Sub-Saharan Africa It is likely that most became infected at birth or in early childhood and have been infected for decades Trends in chronic cases are heavily influenced by immigration trends

19 Hepatitis B prevalence data – Ireland, Low risk populationsGeneral pop (residual sera, 2003)1: HBsAg 0.1%, anti-HBc 1.7% Oral fluid, postal (1998-9)2: anti-HBc 0.51% Blood donors ( )3: HBsAg 0.011% Antenatal, Rotunda : HBsAg 0.03% Irish, 4.2% non-EU, 0.35% overall Antenatal, West of Irl : HBsAg 0.21% 1Nardone A et al. Epidemiol Infect 2009;137(7):961-9. 2O ’Connell T et al. Epidemiol Infect 2000;125(3):701-4. 3Personal communication, Dr Joan O’Riordan, IBTS 4Healy CM et al. Ir Med J 2001;94(4):111-2,4. 5O ’Connell K et al. Ir Med J 2010;103(3):91-2.

20 Hepatitis B prevalence data – Ireland, High risk populationsPrisoners 19981: anti-HBc 8.7% (18.5% in IDU prisoners) Prisoners, 20112: HBsAg 0.3% IDU : HBsAg 2%, anti-HBc 17% Homeless, Dublin : anti-HBc 9% Asylum seekers, HSE East : HBsAg 5% Asylum seekers, Screening in Balseskin, : HBsAg 3.6% 1Allwright S et al. BMJ 2000;321(7253):78-82. 2National Advisory Committee on Drugs and Alcohol. Study on the prevalence of drug use, including intravenous drug use, and blood-borne viruses among the Irish prisoner population. 2011 3Grogan L et al. Ir J Med Sci 2005;174(2):14-20. 4Immunisation Guidelines for Ireland 5Doyle S. Thesis submitted for MFPHMI, RCPI; 2006. 6Brennan M et al. ICGP Forum. 2013