1. Epidemiology of hepatitis A in Ireland
2018 & 2019 data are provisional
Niamh Murphy, May 2019

2. Hepatitis A virus Associated with poor hygiene and sanitation
Virus shed in faeces and primarily transmitted from person-to-person via the faecal-oral route
Common source outbreaks due to contaminated food or water also occur
Incubation period (time from infection to symptoms) commonly days (range 15-50)
Period of Infectiousness - 2 weeks before until 1 week after onset of symptoms
Acute disease – does not have a chronic form
Lifelong immunity following infection
Clinical severity tends to increase with age. Adults can experience severe illness lasting several months, whereas young children are frequently asymptomatic
The most common symptoms are fever, loss of appetite, nausea, fatigue and abdominal pain, followed within a few days by jaundice
In developed countries, hepatitis A is most commonly seen among travellers to endemic countries, household or sexual contacts of known cases, people who inject drugs (PWID) and men who have sex with men (MSM)

3. Hepatitis A vaccination
Safe and effective vaccine
Hepatitis A vaccine alone
Combined hepatitis A and B vaccine
Gives life-long protection
Irish Immunisation Guidelines
Vaccination recommended for travellers to endemic countries, people with chronic liver disease, PWID, MSM and close contacts of cases, among others
Free in STI clinics
Student health services - may be a fee in some
GP – vaccine is free, fee for administration
If exposed, vaccination within 2 weeks is protective
For sexually acquired cases of hepatitis A – STI testing and partner notification important

4. Number of notifications of hepatitis A in Ireland, and notification rate per 100,000 population,
2019 to date: 21 cases of hepatitis A notified 1st Jan – 20th May 2019

5. Hepatitis A notification rate per 100,000 population in Ireland, by HSE area, 2015-2018

6. Mean hepatitis A notification rates per 100,000 population in Ireland, by age group, 2004-2018
Key point: Rates generally highest in children and young to middle age adults, reflecting lack of immunity and travel

7. Hepatitis A notification rates per 100,000 population in Ireland, by sex, 2000-2018
Key point: Rates generally similar for males and females, except 2017 when there was an outbreak in MSM

8. Hepatitis A outbreaks in men who have sex with men (MSM)
Hepatitis A not identified in MSM in Ireland prior to late 2016
Very large European-wide outbreak
About 4,500 cases in Europe, 20 in Ireland in 2017
Involved 3 strains of genotype IA hepatitis A: VRD_521_2016, RIVM-HAV16-090, V
Mostly male cases, and where known, mostly MSM
Some spillover into general population
6 hepatitis A cases in MSM in Ireland, Jan May 2019
European alerts issued 2019: 2 MSM clusters in Amsterdam, 1 in Vienna
Pride events in Dublin and several other European countries over the summer
Vaccination and good hygiene measures important

9. Hepatitis A notification rates per 100,000 population in Ireland, by sex and age group, 2017
Large European-wide outbreak in MSM – 20 Irish MSM cases + 10 additional cases associated with the outbreak

10. Summary of hepatitis A cases notified in Ireland in 2017
Increase in notifications, largely driven by European-wide outbreak in MSM
66 cases notified (1.4/100,000 population)
73% male (n=48, 2.0/100,000), 27% female (n=18, 0.7/100,000 population)
Highest notification rates in adult males and children aged 5-9 years
Country of infection: 33 outside Ireland, 30 Ireland, 3 unknown
The most common countries of infection for travel associated cases were India, Spain, Pakistan, Germany & Romania
Large European-wide outbreak in MSM
20 Irish MSM cases
13 MSM cases infected in Ireland, 6 outside of Ireland and country of infection was unknown for 1
10 additional cases were known contacts of MSM cases or were infected with an MSM outbreak strain of hepatitis A, but were not identified as MSM
5 other outbreaks with 10 associated cases were reported in 2017
The index case had travelled outside of Ireland for 3 of these outbreaks
The other 2 outbreaks were family outbreaks, all associated cases infected in Ireland
Remaining 26 cases: 17 associated with travel, 8 infected in Ireland, travel history unknown for 1

11. Hepatitis A notification rates per 100,000 population in Ireland, by sex and age group, 2018
Most cases travel related: 26 cases had a history of recent travel, 7 cases infected in Ireland, travel history not known for 2 cases
Of the cases infected in Ireland, 4 were part of clusters where the index case had been infected outside Ireland

12. Summary of hepatitis A cases notified in Ireland in 2018
2018 was a more typical year than 2017 – a lot of travel associated cases of hepatitis A
35 cases notified (0.7/100,000 population)
60% male (n=21, 0.9 per 100,000), 40% female (n=14, 0.6 per 100,000)
Highest notification rates in children and adults <45 years of age
86% of cases (n=30) were associated with travel outside Ireland (n=26), either directly or, in the case of outbreaks, via an index case infected outside Ireland (n=4)
The most common countries of infection for travel associated cases were Brazil, Pakistan and India
4 outbreaks with 10 associated cases were reported in 2018
The index case had travelled outside of Ireland for all of these outbreaks
Of the 7 cases infected in Ireland, 4 were linked to travel-associated outbreaks and 3 were sporadic cases
Travel history was not known for 2 cases

13. Recent hepatitis A outbreaks due to frozen berries in Europe
Very large European-wide outbreak, Jan 2013-Aug 2014
Linked to imported frozen berries
About 1,500 confirmed and probable cases in 13 European countries, 23 in Ireland
Genotype IA hepatitis A
Outbreak in Sweden & Austria, June-Sept 2018
linked to imported frozen strawberries
17 confirmed cases in Sweden and 14 in Austria
Genotype IB hepatitis A
Outbreak in the Netherlands, March-May 2017
linked to frozen raspberry/blueberry mix imported from Bulgaria
14 cases
Genotype IB hepatitis A - RIVM-HAV17-090
Strain of hepatitis A previously identified in Canadian outbreak associated with frozen berries
Current advice from Food Safety Authority of Ireland
“boil all imported frozen berries for at least one minute prior to consumption”

14. Acknowledgements
Departments of Public Health in all HSE areas: SPHMs, SMOs, Surveillance Scientists, IPCNs, Administration staff
Notifiers: Laboratory Directors and their staff, and Clinicians
Dr Paul McKeown, SPHM, HPSC
Dr Lelia Thornton, SPHM in HPSC (retired 2018)
Kirsty MacKenzie, PA to Director/Information Officer, HPSC