How do viruses enter the fruit and vegetables food chain and estimation of consumer risk

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1 How do viruses enter the fruit and vegetables food chain and estimation of consumer risk Leena Maunula, PhD Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki IAFP European Symposium, Athens, Greece 1

2 The most important foodborne viruses RTE category NoV HAV HEV Raw animal food Raw fruits and vegetables (washed and plant food not washed, cooked, processed) Spices, seasonings, sugar (plant substances) Yes (Shellfish fresh or frozen: oysters, clams, mussels) Yes (Soft berries, leafy greens) Yes (Shellfish fresh or frozen: oysters, clams, mussels) Yes (Soft berries, leafy greens, green onions, dates) Possible Possible Not known Virus detected in shellfish Virus detected in berries (not common) Bakery items (bread, cakes, pies, fillings, uncooked icings) Yes (Berry-containing icings, fillings) Yes (Berry-containing icings, fillings) Not known Dry fermented sausages, salt-cured or dried meat products Not known Not known Yes (Fermented pork liver sausages) Mod. from Maunula & von Bonsdorff, in Food Hygiene and Toxicology in Ready to Eat Foods, ed. by P. Kotzekidou,

3 NoV is the most common foodborne virus About 59% of all foodborne illnesses are caused by NoV (Scallan et al., 2011 EID 17;7) About 14% of NoV infections are linked to food (Verhoef et al., 2015, EID 21;592) Person-to-person transmission, secondary infections are common in disease outbreaks 19/05/16 3

4 FOOD DISTRIBUTION BY SINGLE PERSON IN FAMILY POSSIBLE NUMBER OF VICTIMS a < 10 FOOD HANDLER IN CANTEEN KITCHEN FOOD HANDLER IN LOCAL MARKET FOOD INDUSTRY: NATIONAL SALE FOOD INDUSTRY: INTERNATIONAL COMMERCE a Not in linear scale Mod. from Maunula & von Bonsdorff, in Food Hygiene and Toxicology in Ready to Eat Foods, ed. by P. Kotzekidou, 2016

5 Cross-section of food chain Barrier: Processing Barrier leaks Outcome: outbreak Learning from outbreaks Humans Large-scale accidents (communal waterborne outbreaks) Fomites Food chain Water Microbial source tracking (MST) Ingredients Animals Pets, production animals, rodents, game 19/05/16 5

6 Several influencing factors Features of the food item (e.g. raspberry vs. strawberry) Fomites: surface material, textiles, computer keyboards Persistence and stability of viruses: norovirus, adenovirus, hepatitis A virus (HAV), hepatitis E virus (HEV) Processing methods: freeze-frying, fermentation, pasteurization etc. Exposure: consuming habits 19/05/16 6

7 Water: Main drivers for spatial differences in virus emissions Population size, sanitation type Virus removal by wastewater treatment plants athogens 2015, 4 Table 3. Deduction of rotavirus shedding rates in the population from sewage surveillance data. Country Concentration in Sewage Seasonality in Wastewater per Capita RV Incidence Shedding (Genome Copies (Genome copies/l) Sewage (m/y) (L per day) (Episodes per person per year) per case per day) Brazil 1.0E E+10 China 6.8E E+08 NL 4.6E E+09 USA 1.0E E+10 Kiulia et al., 2015 Pathogens

8 Role of harvesters hands and irrigation water 56 M. Bouwknegt et al. / International Journal of Food Microbiology 198 (2015) Fig. 2. Contribution of harvesters' hands and irrigation water to the estimated contamination of lettuce heads with hadv (A) and NoV (B) for supply chain A. Each marker represents a single iteration from the Monte Carlo simulation. The gray line represents an equal contribution for both potential contamination points. Markers positioned above this line indicate a greater contribution for irrigation water (than hands) and markers below the line indicate a greater contribution for hands. for the consumption of 200 g (Table 4). No HAV was found on lettuce smaller effects on the estimated contamination levels than the concen- 19/05/16 8

9 Transfer of NoV during food handling: Preparation of cucumber sandwiches simulation in lab Computationally about 1 out of 1000 NoV transmits from hands to sandwich In case 1000 viruses on hands, it is possible to transfer NoV to 8 sandwiches Virus transmission was more efficient from gloves to food than the other way round Rönnqvist et al., 2014 AEM

10 Presence of NoV genome on surfaces of premises in settings (n=30) with a suspected foodborne outbreak Kitchen NoV AdV Cutting board 0/23 1/23 Table surface 2/32 3/32 Knife/ladle 1/22 2/22 Door handle refrigerator or freezer 3/30 0/30 Cold drawer 0/12 2/12 Handwashing facility 3/25 2/25 Other 1/22 0/22 Total 10/166 (6.0%) 10/166 (6.0%) Staff toilet NoV AdV WC door handle 3/24 3/24 WC tap 2/25 1/25 WC light switcher 3/17 0/17 Other 3/5 1/5 Total 11/71 (15.5%) 5/71 (7.0%) Maunula L, Rönnqvist M, Åberg R, Lunden J, Nevas M. in preparation, 2016 FOOD CONTROL 10

11 Berry fruit supply chain FARM Storing as fresh Mixing berries Freezing Bulking Sorting Packaging SUPERMARKET Storing as frozen

12 Berry supply chain and human adenovirus Irrigation water (n=95), hadv: 9.5% Harversters hands (n=243), 5.8% Production Toilets (n=44), 9.1% farm Raspberries: Fresh (n=137), 0.7% Frozen (n=95), 3.2% Frozen raspberries Market Pesticides, Dust? Conveyor belts (n=55), hadv 0% Food handlers hands (n=51), 2.0% Processing plant 12 Maunula et al., 2013 Intl. J Food Microbiol.

13 Trace back: Foodborne norovirus outbreak in a canteen in July 2010 Production Farm 1 Raspberries (Fin) NoV - Farm 2 Raspberries (Fin) NoV G1+ Processing plant Crushed raspberries (Pol) NoV - Crushed raspberries (Fin) NoV G1 + Raspberries (Fin) NoV - Food in canteen Black currents (Fin) Nov - Crushed raspberries (Fin) NoV G1 + Food prepared from berries NoV G1+ 13

14 One-year survey: Gastroenteritis illness among staff in food industry plants o Questionnaire completed after the 1 st period and the 2 nd period of the year o The total numbers of respondents were 90 (spring) and 59 (autumn) o 38.9 % of the food industry employees had suffered gastroenteritis symptoms at least once during the first period and 20.3 % during the second period o about 50 % of them admitted working at least once while suffering the gastroenteritis symptoms Was it norovirus? TEKES: UH, EVIRA, VTT

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16 Thanks for your attention! University of Helsinki Maria Rönnqvist Elina Aho Maija Summa Tuija Kantala Satu Oristo Kirsi Söderberg Carl-Henrik von Bonsdorff Leena Maunula University of Helsinki Food Control: Janne Lundén Mari Nevas Tekes project EVIRA, Finland: Pirkko Tuominen, Jukka Ranta, Antti Mikkelä VTT, Finland: Marjaana Rättö, Satu Salo, Hanna Miettinen, IrinaTsitko Vital project VRI, Brno, Czech Republic, Dr. I. Pavlik Novi Sad, Serbia, Dr. T. Petrovic NVRI, Pulawy, Poland, Dr. A. Rzezutka RIVM, The Netherlands, Dr. De Roda Husman STRI, Belgium, Dr. K. Willems Sandfield Center, Ireland, Dr. R. Moloney Wageningen University, Dr. W van der Poel FERA, UK Dr. N. Cook