Download Foodborne Viruses in the European Union

Foodborne Viruses in the
European Union
Patricia Garvey
EPIET fellow
Health Protection Surveillance Centre, Dublin
Outbreaks of foodborne viral disease, European
Union, 2011-2013
•2223 viral foodborne outbreaks reported to European Food Safety Authority
(EFSA) between 2011 and 2013
•275 where there was strong evidence implicating a foodstuff
•Calicivirus (including norovirus):
260/275 (95%)
•Hepatitis A:
10/275 (6 of which were in 2013)
•Other viruses:
5/275
Data source: EFSA and ECDC. EU summary reports on zoonoses, zoonotic agents and foodborne outbreaks, 2011,
2012 and 2013
What is Norovirus?
•Along with Rotavirus, Norovirus (NoV) is the most common cause of
gastroenteritis
•AKA 'winter vomiting viruses', 'small round structured viruses' or 'Norwalklike viruses‘
•Belong to a group of viruses called 'caliciviruses'.
•Extremely hardy: survives for at least one week on stainless steel and other
“touch” surfaces (PC keyboards, light switches, TV remote buttons)
What is Norovirus infection?
•Incubation period: 12 to 72 hours
•Traditional described as a “mild illness”, symptoms include:
•watery diarrhoea (>80%), vomiting (75%), abdominal pain (50%),
nausea (50%), cramps (45%), Fever (33%), and occasionally, muscle aches
and headaches
•Duration:
•Diarrhoea –5 days
•Vomiting persists for 1-2 days
•Malaise for 2-3 days.
•A minority (usually the very young or elderly) may become very dehydrated
and require hospital treatment
Surveillance of Norovirus Disease
•Notifiable in Ireland (as individual cases
and as outbreaks) -1000-2000 notifications
annually
•Reported cases represent a minority of
cases (Tam and O’Brien GUT 2012 estimated that
there were 288 cases in community for every case
reported to national surveillance in UK )
•Not notifiable at EU level
•Member state level surveillance of NoV is useful to describe timing of onset and
severity of season compared to other years
•Outbreak surveillance useful to understand the relative importance and trends in
transmission routes and in settings affected
“Notifiable” infectious diseases are those whereby there is a statutory obligation upon all medical practitioners, including clinical
directors of diagnostic laboratories, to notify the Medical Officer of Health(MOH)/Director of Public Health (DPH). This list of 80+
diseases are of such clinical/Public Health importance that the information is gathered on them in a systematic manner is used to
investigate cases thus preventing further spread
Norovirus transmission
•Highly contagious and can spread easily from person to person (R0 of NoV ≈
4.0*) - most outbreaks have an attack rate of >50%
Transmission:
•Contact with an infected person e.g. when caring for someone with
norovirus infection.
•Contact with contaminated surfaces or objects and then spread to
mouth or mucous membranes via fingers/fomites.
•Consuming contaminated food or water
•Commonly associated with congregate settings in winter, e.g. hospitals,
residential institutions, hotels, schools, etc.
*R0= Reproduction Rate; the number of new cases of a contagious disease generated by a single case of that
disease (HAV=1.3; Measles = 16)
Foodborne transmission
•The proportion of NoV illness that is
foodborne is difficult to establish
•Because of the low severity of illness among
healthy individuals, many foodborne
outbreaks are not recognised or investigated
NoV outbreaks by reported
transmission route Ireland 2004-2014
12%
1% 0%
•Detection of NoV in food is difficult
hampering evidence gathering
•Food was reported to have contributed to
1.2% of NoV outbreaks in Ireland 2004-2014
•Other countries with more foodborne-disease
oriented surveillance systems have produced
higher estimates
87%
Foodborne+/- Person to person
Waterborne +/- person to person
Person to person/airborne
Unknown
Distribution of food vehicles in foodborne outbreaks with
strong evidence caused by calicivirus* in the EU, 2011
Data source: EFSA and ECDC. EU summary reports on zoonoses, zoonotic agents and foodborne outbreaks, 2011
*Is used as a proxy for NoV infection
•Numerous NoV outbreaks
in Scandinavia linked to
frozen raspberries from
mid 1990s
•Large outbreak of NoV in
Germany in 2012 linked to
frozen strawberries
(>10,000 cases)
•Multistate outbreaks of
HAV linked to frozen
berries in 2013
Tavoschi et al Eurosurv 2015
Hepatitis A virus
• Associated with poor hygiene and sanitation - primarily transmitted from
person-to-person via the faecal-oral route
• Incubation period commonly 28-30 days (range 15-50)
• Common source outbreaks due to contaminated food or water also occur
• Quite contagious when spread from person to person (R0 HAV= 1.3)
• Acute disease – does not have a chronic form. Protective antibodies develop
after infection
• Vaccine preventable
• Clinical severity tends to increase with age. Adults can experience severe illness
lasting several months
• 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 people who
travel to endemic countries, household or sexual contacts of known cases,
injecting drug users (IDU) and men who have sex with men (MSM)
Geographic distribution of hepatitis A virus
infection (Source CDC, Atlanta, USA)
Number of notifications of hepatitis A
Ireland 1988-2013
Number of notifications
600
564
538
500
432
400
424
367
321
313
309
300 261
218
205
200
133
112
94
100
50
47 55 39 32 42 50 46
26 25
19 30
Year
Data source: Computerised Infectious Disease Reporting System (CIDR), HPSC
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
0
HAV outbreaks notified by transmission route,
Ireland 2004-2014
7
Number of outbreaks
6
5
Unknown
Person-to-person & waterborne
Person-to-person
Foodborne
4
3
2
1
0
2004 2006 2007 2008 2009 2010 2012 2013 2014
Year of notification
Data source: Computerised Infectious Disease Reporting System (CIDR), HPSC
Foods implicated in recent HAV outbreaks
internationally
Liver paté –France
[Schwarz et al Eurosurv 2008]
Oysters –France [Guillois et al Eurosurv 2009]
Semi-dried tomatoes –Netherlands, England [Petrignani et al. Eurosurv 2010; Fournet et al
Eurosurv 2012; Carvalho et al Eurosurv 2012]
Raw seafood –Italy [Montano-Ramacha et al Eurosurv
Bakery products –Germany [Harries et al Eurosurv
2013]
2014]
Pomegranate seeds –Canada [Swinkels et al Eurosurv 2014]
Frozen strawberries –Scandinavia [Eurosurv
2014]
Strawberries/Mango –European travellers (including Irish tourists) to Egypt [Sane et
al 2015]
Frozen berries –Multistate including Ireland [Rizzo et al Eurosurv
2013; Severi et al
Eurosurv 2015; Fitzgerald et al 2014; Guzman-Herrador et al Eurosurv 2014]
May 2013: European alert re HAV outbreak in Italy
June 2013: HAV subgenotype IA with an identical sequence identified in Ireland in
three cases who had not travelled to Italy
In total, 21 outbreak cases (between 31 January and 11 October 2013
Epidemiological evidence implicated frozen berries (linked with different products
containing the berries)
Sixteen food samples tested
were all negative for HAV
The public were advised to
heat-treat frozen berries before
consumption
Fitzgerald et al Eurosurv 2014
•Identification of the outbreak
•May 2013, Italy declared a national outbreak of hepatitis A
•Also affected several foreign tourists who had recently visited Italy
•An identical strain of HAV subgenotype IA identified in additional EU/EEA countries
•An international outbreak investigation team was convened
•Burden of illness
•1,589 hepatitis A cases
•1,102 (70%) hospitalised
• two related deaths
Severi et al Eurosurv 2015
•Vehicle of infection:
•Mixed frozen berries epidemiological and
microbiological evidence
•Control measures:
•Suspected or contaminated food
batches were recalled
•the public was recommended to
heat-treat berries
•post-exposure prophylaxis of
contacts
•Large food-borne hepatitis A
outbreaks may affect the increasingly
susceptible EU/EEA general population
•With the growing international food
trade, frozen berries are a potential
high-risk food
Severi et al Eurosurv 2015
•14 EU-EFTA countries (including Ireland) reported 107 cases
•sub-genotype IB with identical RNA sequences, suggesting a common source
outbreak.
•Associated with exposure to strawberries or mango
•None of the 43 cases interviewed had been vaccinated
•Unawareness that HAV vaccination was recommended (23/43, 53%) and
perceiving low infection risk in all-inclusive luxury resorts (19/43, 44%)
•Recommendation: public health authorities should emphasize the importance of
vaccination before visiting HAV-endemic areas, including Egypt
Sane et al Eurosurv 2015
At least 103 reported
cases
A study in Denmark,
Finland, Norway and
Sweden identified frozen
strawberries as the likely
cause of the outbreak
The origin of the berries
was being investigated
Guzman-Herrador et al Eurosurv 2014
Hepatitis E (HEV)
•
Common cause of acute hepatitis worldwide
•
Traditionally associated with poor hygiene and transmission via the faecal-
oral route in endemic regions
•
Now recognised as an emerging disease in many developed countries
-increasing evidence for a rise in locally acquired zoonotic HEV
•
Increasing number of human cases across Europe
•
Causes large outbreaks of acute hepatitis in endemic areas and sporadic
cases in industrialised countries
Clinical aspects of HEV
•
Incubation period 15 to 64 days
•
Most HEV infections asymptomatic
•
Symptoms include fever, fatigue, abdominal pain, nausea, vomiting, loss of
appetite and jaundice
•
Symptomatic infection more common in middle-aged and elderly men
•
Usually a self-limiting illness -4-6 weeks
•
In rare cases can be fatal, especially in pregnant women
•
Persistent infection can occur in persons with suppressed immune systems
•
Uncertain whether infection confers lifelong immunity
•
Period of communicability is not known; secondary spread is rare
HEV genotypes
Reservoirs
Distribution
Transmission
HEV1 and HEV2
HEV3 and HEV4
Humans
Humans, pigs, and other mammalian species
Developing countries
Both developing and developed countries;
HEV3 has a worldwide distribution; HEV4
mostly occurs in southeast Asia but recently
isolated in European pigs
Via contaminated water
in developing countries
Consumption of raw or undercooked pork or
game meat; through occupational exposure to
animals, particularly pigs; transmission of HEV
through infected blood products has also been
reported
HEV –non-food risk factors
Age: Autochthonous cases in Europe older than imported cases
Sex: Higher proportion male in case series of acute cases (but not
seroprevalence studies) could be due to higher risk for overt disease rather
than infection
Co-morbidities: those affecting the liver likely identified due to higher risk of
clinical disease rather than infection
Pig contact: reported in case studies and in seroprevalence studies [e.g.
Chaussade et al J Clin Virol 2013]
Having cats/dogs, contact with horses, living in rural areas –in enhanced
surveillance studies
Human HEV cases linked to food consumption
Consumption of processed pork products was associated with HEV
infection in England & Wales case control study [Said et al E&I 2014]
Case control study in France showed association with pig liver sausage
[Coulson et al JID 2010]
Spit-roasted piglet. Outbreak in France -independent association with
consumption of piglet liver-based stuffing; case, veterinary and
environmental strains identical [Guillois et al CID 2015]
Cases linked to consumption of wild boar [Kim et al J Clin Virol. 2011; Li et al
EID 2005]
Cases linked to consumption of deer meat [Tei et al Lancet 2003; Ja Joon et
al Clin Mol Hepatol. 2013]
HEV at EU level
•
Not notifiable in humans at EU level
•
The European Centre for Disease Prevention and Control (ECDC) established
an expert group -first meeting in December 2015
•
European Centre for Disease Control and Prevention (ECDC) will conduct an
inventory of HEV surveillance systems, case definitions, laboratory
methods, and epidemiological information across Europe. It is expected
that this will contribute to the development of a framework for HEV
surveillance
SCOTLAND: Laboratory Reported HEV cases by year
2011-2014 (Source: Health Protection Scotland)
Number of confirmed cases of HEV
180
•Rate in 2014: 3.0 per
160
140
100,000
120
•Predominantly older
100
males
80
•Some of increase due to
60
40
increased testing but
20
also believed due to real
0
2011
2012
2013
Year of reporting
2014
increase in incidence
ENGLAND: Confirmed HEV cases by year 2003-2014
(Source: Public Health England)
Number of confirmed cases of HEV
1000
900
800
700
Non-travel
600
associated cases are
500
likely to be older
400
300
men infected with
200
HEV3 (pig strain)
100
0
Year of reporting
FRANCE: Annual laboratory reporting HEV from
Centre National de Reference (CNR), 2002-2013
2000
Number of laboratory reports
1800
Autochtones
Imported
1600
• Increasing number of
1400
samples tested (35,416
1200
in 2013 compared to
1000
800
209 in 2002)
600
• Median age 55 years
400
200
• Predominant genotype
0
3f (57% in 2013)
Year of reporting
HEV diagnoses at NVRL
2014
•9 laboratory confirmed or probable cases of acute or chronic HEV in Ireland,
5 of which were RNA positive
•4 had no history of travel abroad
•4 were genotype 3
2015 Jan-Jun
4 cases of viraemic HEV with no history of travel abroad
•A decision was taken that from June 2015, all serum samples tested for hepatitis
A virus IgM at NVRL would automatically be tested for HEV
•Samples found to be positive for HEV IgM would be tested for HEV RNA
Personal communication: Dr Joanne O’Gorman, NVRL
Personal communication: Dr Joanne O’Gorman, NVRL
June 2015
HEV to become a notifiable disease in Ireland
Proposed case definition - Hepatitis E (acute and chronic) infection
Clinical criteria: Not relevant for surveillance purposes
Laboratory criteria:
Acute case
At least one of the following two:
•Hepatitis E virus IgM and IgG antibody positive
•Detection of hepatitis E virus RNA
Chronic case
Hepatitis E virus RNA persisting for at least 3 months
Epidemiological criteria: Not relevant for surveillance purposes
Case classification
•Possible case: N/A
•Probable: N/A
•Confirmed case: Any person meeting the laboratory criteria
Acknowledgements
Dr. Lelia Thornton, HPSC
Dr. Paul McKeown , HPSC
Ms Niamh Murphy , HPSC
Dr. Joanne O’Gorman, NVRL
Thank you for your attention