Foodborne viruses: the known unknowns. Martin D Agostino Virologist, Campden BRI 8 th June 2016

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1 Foodborne viruses: the known unknowns Martin D Agostino Virologist, Campden BRI 8 th June 2016

2 What are Foodborne Viruses? Submicroscopic organisms No intrinsic metabolism Obligate parasites They cannot multiply outside of their host Transmitted by the faecal/oral route Main foodborne viruses have very simple structure protein shell with nucleic acid inside

3 What are Foodborne Viruses They do not grow on or in foods, BUT They can be carried by foods, either on the surfaces of soft fruits and salad vegetables (mainly NoV and HAV) Within the foods such as bivalve molluscs (e.g. Oysters, mussels) mainly NoV Undercooked pork products.(e.g. sausage meat) HEV. They may be on the surfaces of handler s hands or They may be carried by contaminated irrigation water

4 What do they cause: Norovirus Projectile vomiting / diarrhoea / stomach cramps / fever Onset of symptoms12 48 hours after ingestion Duration h. Can be longer in elderly and immunocompromised. Up to 10 8 (100,000,000) particles can be shed per g stool Shedding the virus in stools can occur before onset of symptoms ~18 particles is the estimated infectious dose

5 Norovirus transmission

6 What do they cause: Norovirus Projectile vomiting / diarrhoea / stomach cramps / fever Onset of symptoms12 48 hours after ingestion Duration h. Can be longer in elderly and immunocompromised. Shedding the virus in stools can occur before onset of symptoms Up to 10 8 (100,000,000) particles can be shed per g stool ~18 particles is the estimated infectious dose Shedding can last 2 to 6 weeks after symptoms clear.

7 What do they cause: Norovirus Oral rehydration therapy treatment for severe cases Deaths uncommon 16 % of infections asymptomatic

8 What do they cause - Hepatitis A Acute hepatitis in >70% of those affected Headaches, fever, vomiting, jaundice Fatality rate 0.3 to 1.8% Incubation period 3 to 5 weeks Duration several weeks depending on severity Infectious dose is unknown but presumed to be virus particles Shedding of virus approx particles per g stool Shedding can last 4-6 weeks

9 What do they cause - Hepatitis A Increasing severity of illness as age increases Highly endemic in developing regions of the world, with infections among adults rare exposed at an early age Low and declining endemicity in developed countries, with adults at risk of severe infection Infection confers long-term immunity HAV vaccine available no global vaccination program

10 What do they cause - Hepatitis E Acute self limiting Hepatitis, jaundice, fever, vomiting Fulminant Hepatitis (acute liver failure) Mortality- 0.5 to 4% - up to 20% in pregnant women Incubation Period 6 weeks Recovery- several weeks Infective dose is not known Questions raised on increased heat resistance China has produced and licensed first vaccine to prevent hepatitis E virus infection, although it is not yet available globally

11 Outbreaks: NoV and HAV Year Country Food Cases Virus 2009 Australia Semi dried tomatoes 2010 Denmark Lettuce Finland 2010 France & Netherlands 2012 Germany USA 10 European countries Frozen raspberries Semi dried tomatoes Frozen strawberries Frozen blackberries and redcurrants Pomegranate seed 144 HAV NoV 46 NoV 72 HAV NoV 1444 HAV 165 HAV 2016 Denmark Lettuce >400 NoV

12 RASFF the Rapid Alert System for Food and Feed NoV and HAV Virus Year Counry of origin / via Food Hazard Action Norovirus 2016 Norovirus 2016 Poland / France, Luxembourg France / Denmark, Norway Frozen broken raspberries Lettuce Outbreak suspected Outbreak suspected Norovirus 2016 Belgium /France Raspberry sauce Presence Norovirus 2016 France / Italy Live oysters Presence Withdrawal from market Withdrawal from market Recall from consumers Authorities informed Norovirus 2016 France, Spain Live clams Presence None Norovirus 2016 Bulgaria / Poland Norovirus 2016 China / Belgium Norovirus 2016 Chile / France Frozen organic raspberries Deep Frozen raspberries Frozen broken raspberries Presence Presence Presence Recall from consumers Withdrawal from recipients Public warning / press release. Hepatitis A 2016 Tunisia Live clams Presence Destruction Hepatitis A 2014 Morocco Frozen strawberries Presence Hepatitis A 2014 Germany Hepatitis A 2014 Poland, Bulgaria / Belgium Berry mix buttermilk cake Mixed frozen berries Outbreak Presence Detained by operator Withdrawal from market Detained by Operator

13 How can we control them? Physical controls Intrinsic Physical and chemical properties ph, A w, Nutrient content etc. Extrinsic Chemical disinfection Heating Novel processes However! Treatments can be too little, too late. If NoV, HAV or HEV is present, something has failed somewhere in the supply chain. Need to focus on preventing contamination entering the supply chain

14 How can we control them? Procedural controls Prerequisite programs (e.g. GLOBALG.A.P. - worldwide scheme using by accredited Certification Bodies) Virus Specific Guidelines and recommendations (e.g. Codex Code of Good Hygienic Practice for Fresh Fruit and Vegetables) No legislation specifically directed to control of viruses in fresh produce No regulatory requirements specifying microbiological criteria with regard to virus contamination.

15 What issues do we face? Detection Methods (NoV & HAV) : ISO Technical Specification: Detects Viral Genome (RNA) If we detect - is it infective? Detection Methods (HEV) : No standardised methods for detection of HEV in foods Non-culturable We cannot determine if virus particles are infective How can we test control measures (heat, ph, Aw, disinfectants) No reproducible cell culture suitable for routine testing for NoV, HAV or HEV (yet!)

16 What is Campden BRI doing? Ongoing MSFR project / Looking at virus controls e.g. ph, Aw, Acid resistance Using culturable surrogate viruses Phage and Mouse Norovirus (Murine Norovirus)

17 Work so far: a=ms2; b=øx 174

18 The future viruses at Campden BRI MSFR project on control measures will continue (ends 2017) Methods for detection to be validated (UKAS) Foodborne viruses are not going away! Rapidly expanding area new methodologies / development of culturing capabilities / increased government interest Campden BRI dedicated to providing advice on virus related issues

19 Campden BRI Publications CampdenBRI RSS Effect ph on persistence of viruses Campden BRI Blog-The known-unknowns- S.Jordan, 26 th Oct 2015 Campden BRI Website/Newsletter article March Foodborne virus research Campden Newsletter. April Article on the Virus Focus Group within P Trade Journal International Meat Topics V5 No Foodborne Viruses- the unseen hazards in foods. R.Betts International Food Hygiene V26 No Foodborne Viruses the hazard in a variety of Foods. R. Betts New Food-On Line- Viruses- an increasing hazard in Meat. 25 th Jan R.Betts International Meat Topics V7 No Hepatitis E. R. Betts International Food Hygiene V27, No Hepatitis E. R.Betts Fresh Produce. Viruses and Fresh Produce-A new hazard. Submitted 3/16. R.Betts

20 Contacts Annette Sansom Tel: +44 (0) Martin D Agostino - martin.d agostino@campdenbri.co.uk - Tel: +44 (0) Roy Betts roy.betts@campdenbri.co.uk Tel: +44 (0)