Epidemiology of hepatitis B in Ireland Updated August 2014

Hepatitis B virus 50-100 times more infectious than HIV Chronic HBV infection develops in 90% of those infected as infants and 1-10% infected as adults Chronic infection can lead to chronic liver disease, cirrhosis, liver failure and liver cancer (usually over 20-30+ years) Premature death from liver disease occurs in 15-25% of chronically infected people >350 million people chronically infected worldwide Vaccine preventable – universal infant vaccination introduced in Ireland in 2008

Worldwide prevalence hepatitis B (Source: CDC Health information for international travel 2014 http://wwwnc.cdc.gov/travel/content/yellowbook/2014/map_3-04.pdf)

Number of notifications of hepatitis B, 1997-2013 Hepatitis 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. Notifications of chronic cases peaked in 2008 (n=902). 431 chronic cases were notified in 2013 (52% 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). 31 acute cases of hepatitis B were notified in 2013 (67% decrease compared to peak levels)

Trends in acute hepatitis B notifications by sex and median age, 2004-2013

Trends in chronic hepatitis B notifications by sex and median age, 2004-2013

Mean annual notification rates per 100,000 for acute cases of hepatitis B by age and sex, 2010-2013

Mean annual notification rates per 100,000 for chronic cases of hepatitis B by age and sex, 2010-2013

Hepatitis B notification rates per 100,000 population, by HSE area, 2010-2013 Highest rates in the HSE-E

Mean annual hepatitis B notification rates per 100,000 population by HSE area, 2010-2013 3.8 8.1 7.4 7.1 Highest rates in the HSE-E 20.7 7.8 3.9 10.2

Most likely risk factor, 2010-2013 Acute cases with risk factor data (90%, n=147) Chronic cases with risk factor data (50%, n=952)

Region of birth, 2010-2013 Acute cases with region of birth data (92%, n=151) Chronic cases with region of birth data (46%, n=874)

Summary of acute hepatitis B in Ireland, 2010-2013 8% of cases notified 2010-2013 were acute infections 164 acute HBV notifications in this time period (annual average: n= 41) 31 acute cases of hepatitis B were notified in 2013. This is the lowest number reported since acute/chronic case definitions were introduced in 2004 84% of acute cases notified 2010-2013 were male (M:F =5) Mean ages at notification: 39 for males, 34 for females Median ages at notification: 37 for males, 29 for females Where risk factor data available, 74% of cases were sexually acquired Sexual orientation available for 93% of sexually acquired cases: 57% heterosexual, 43% men who have sex with men Where country of birth available, 70% of acute cases were born in Ireland

Summary of chronic hepatitis B in Ireland, 2010-2013 92% of cases notified 2010-2013 were chronically infected 1910 chronic HBV notifications in this time period (annual average: n= 478) 386 chronic cases of hepatitis B were notified in 2013. This is the lowest number reported since acute/chronic case definitions were introduced in 2004 53% of chronic cases notified 2010-2013 were male Mean ages at notification: 36 for males, 32 for females Median ages at notification: 34 for males, 29 for females 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

Hepatitis B prevalence data – Ireland Low risk populations General pop (residual sera, 2003)1: HBsAg 0.1%, anti-HBc 1.7% Oral fluid, postal (1998-9)2: anti-HBs 0.51% Blood donors (1997-2010)3: HBsAg 0.012% Antenatal, Rotunda 1998-20004: HBsAg 0.03% Irish, 4.2% non-EU Antenatal, West of Irl 2004-95: 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.

Hepatitis B prevalence data – Ireland High risk populations Prisoners 19981: anti-HBc 8.7% (18.5% in IDU prisoners) IDU 2001-22: HBsAg 2%, anti-HBc 17% Homeless, Dublin 1999-20003: anti-HBc 9% Asylum seekers, HSE East 1999-20034: HBsAg 5% 1Allwright S et al. BMJ 2000;321(7253):78-82. 2Grogan L et al. Ir J Med Sci 2005;174(2):14-20. 3Immunisation Guidelines for Ireland 2008. http://www.immunisation.ie/en/HealthcareProfessionals/ImmunisationGuidelines2008/. 4Doyle S. Thesis submitted for MFPHMI, RCPI; 2006.