Ewen C. D. Todd Advertising, Public Relations and Retailing Michigan State University Train the Trainer Workshop at the

1. What We Can Learn from the Role of the Food Worker in Outbreaks Ewen C. D. Todd Advertising, Public Relations and Retailing Michigan State University Train the Trainer Workshop at the International Food Safety Conference Dubai, February 2009

2. What Have We Learned from Investigation of Outbreaks Where Food Workers Were Implicated?

3. Impact of the Infected Food Worker • CDC estimates 76 million cases of foodborne illness each year in the United States • Estimated that between 18-20% of foodborne illness associated with an infected food worker in the US, and 7% of salmonellosis in the UK • Thus, there may be up to 13-15 million cases in the US associated with an infected food worker (18-20% of 76 million)

4. Definition of Food Worker The term food worker is used in this context to describe individuals, who harvest, process, prepare and serve food It is broader in context than food handler although the two terms are used interchangeably in the literature and investigative reports

5. Purpose of Study of Infected Food Workers Implicated in Outbreaks • Project of the Committee on Control of Foodborne Illness (CCFI) of the International Association for Food Protection (IAFP) • Goal: to develop an understanding of the dynamics of transmission of infectious agents to and from the food worker in a variety of settings • The CCFI approached the task with the premise that all foodborne illness is fundamentally preventable and that by influencing human behavior there will be fewer opportunities for spread of infectious disease agents by workers and others

6. Papers Prepared on Outbreaks Where Food Workers Have Been Implicated in the Spread of Foodborne Disease in the Journal of Food Protection (2007-2009) • Part 1: Description of the problem, methods and agents involved • Part 2: Description of outbreaks by size, severity, and settings • Part 3: Factors contributing to outbreaks and description of outbreak categories • Part 4: Infective doses and pathogen carriage • Part 5: Sources of contamination and pathogen excretion from infected persons • Part 6: Transmission and survival of pathogens in the food processing and preparation environment • Part 7: Barriers and sanitizers in reducing contamination • Part 8: Hand hygiene

8. Outbreaks by Geographical Region

9. Summary of Data on Pathogens • 816 outbreak reports with 80,682 cases • Pathogens in order of frequency: • norovirus/probable norovirus (338) • Salmonella enterica (151) • hepatitis A virus (84) • Staphylococcus aureus (53) • Shigella spp(33) • Streptococcuspyogenes Group A (17) • Parasites Cyclospora, Giardia, and Cryptosporidium (23)

10. Outbreaks by Food Category Commodity

11. Foods Associated with Outbreaks Where Food Workers Were Implicated Multiple foods and multi-ingredient foods were noted most frequently • Salads, including potato, pasta and coleslaw (92) • Sandwiches (74) • Chinese, Mexican type food, and pizza (19) • Hors d’oeuvres and other RTE cold snacks with sauces and glazes (8)

12. Outbreaks by Settings * * Mainly restaurants

13. Most Extreme Outbreaks • Largest outbreak: • 6350 cases [1987, North Carolina: S. sonnei] • Largest number hospitalized: • 396 [1998, Brazil: S. aureus] • Largest number of deaths: • 68 [1990, Mozambican refugees in Malawi: V. cholerae]

14. 2b Offsite food worker(s) infects other workers at a different location 1 Single worker causes an outbreak that affects patrons 6 Food contaminated by offsite workers 2a, 4a, 4b, 5 Multiple workers cause outbreak at the same location (2a), through contamination of food (4a), no clear source (4b), or workers may be the victims (5) 3a, 3b Foods contaminated by infected worker are temperature abused leading to outbreak 8 Worker(s) are infected but deny illness and outbreaks not reported as caused by infected worker(s) 7 Infected consumers (patrons, families, institutional residents, etc) likely source of infectious agent Ill Consumers (Patrons, Families, Institutional Residents, etc)

16. Social Gathering and Staphylococcus aureus • 8,000 people gathered in a community to celebrate a Catholic priest’s ordination in 1998 in Brazil • After eating food provided, 4,000 were acutely ill and 2,000 hospitalized, 16 died • Eight food workers began preparing the chicken, roast beef, rice, and beans over 48 h on the Friday before the event, and stored in aluminum containers at room temperature until Sunday morning • These food workers had positive fingernail swabs for Staphylococcus aureus, and five of them had the same strain isolated from their nasopharynxes • Leftover food was also found to contain S. aureusat 2.0 x 108 CFU/g, which produced 6 µg of enterotoxin A/g

17. Social Gathering and Staphylococcus aureus • 8,000 people gathered in a community to celebrate a Catholic priest’s ordination in 1998 in Brazil • After eating food provided, 4,000 were acutely ill and 2,000 hospitalized, 16 died • Eight food workers began preparing the chicken, roast beef, rice, and beans over 48 h on the Friday before the event, and stored in aluminum containers at room temperature until Sunday morning • These food workers had positive fingernail swabs for Staphylococcus aureus, and five of them had the same strain isolated from their nasopharynxes • Leftover food was also found to contain S. aureusat 2.0 x 108 CFU/g, which produced 6 µg of enterotoxin A/g

18. Examples of S. aureus Outbreaks • 2 handlers sores on hands, 5 handlers same strain in nose • S. aureus isolated from infected cut on hand of person who baked cake • 11 hospitalized S. aureus isolated from stool, vomitus, sandwich and infected finger of food handler, sandwiches stored 8-10 hours without refrigeration • S. aureus in food and on food handler, inadequate storage temperature for 5 hours • S. aureus phage 6 patients and 6 food handlers, infected cut on hand of one food worker who mixed food ingredients with bare hands • Cook handled and cooked ham with open cuts, sores and finger lesion • Contamination from hand of a symptomatic food worker, stored at inappropriate temperature

19. School Children and Norovirus • 3,236 (41.5%) of 7,801 schoolchildren and 117 (39.4%) of 297 teachers were ill in Japan in 1989 after eating catered food • Food had been provided by a catering company to nine elementary schools • Workers had bare-hand contact with the food, and a worker reported symptoms of gastrointestinal illness on the day the food was prepared

20. School Children and Norovirus • 3,236 (41.5%) of 7,801 schoolchildren and 117 (39.4%) of 297 teachers were ill in Japan in 1989 after eating catered food • Food had been provided by a catering company to nine elementary schools • Workers had bare-hand contact with the food, and a worker reported symptoms of gastrointestinal illness on the day the food was prepared

21. Frosted Cakes Leading to Norovirus Infections • A bakery worker in Minnesota in 1982 prepared 76 litres of frosting using his arm up to the elbow to break sugar lumps and scrape the sides of the vat • There were subsequently 3,000 cases of norovirus infection • He had five episodes of diarrhea and two of vomiting during his 6-h shift when he frosted the cakes • Also he had sick children at home

22. Frosted Cakes Leading to Norovirus Infections • A bakery worker in Minnesota in 1982 prepared 76 litres of frosting using his arm up to the elbow to break sugar lumps and scrape the sides of the vat • There were subsequently 3,000 cases of norovirus infection • He had five episodes of diarrhea and two of vomiting during his 6-h shift when he frosted the cakes • Also he had sick children at home

23. Giardiasis from Salad • In 1990, a food worker in the cafeteria of a large Connecticut insurance company was infected with Giardialambliaand used her bare hands while slicing raw vegetables, causing 27 cases of giardiasis • She tested positive and had used gloves for most food preparation activities but not for salad bar items • The investigators noted that the outbreak was probably only detected because the affected individuals were insurance company employees whose medical care was administered by a single health management team

24. Giardiasis from Salad • In 1990, a food worker in the cafeteria of a large Connecticut insurance company was infected with Giardialambliaand used her bare hands while slicing raw vegetables, causing 27 cases of giardiasis • She tested positive and had used gloves for most food preparation activities but not for salad bar items • The investigators noted that the outbreak was probably only detected because the affected individuals were insurance company employees whose medical care was administered by a single health management team

25. Hepatitis at a Resort • In 2004, a large outbreak with 351 hepatitis A cases occurred involving tourists at a specific hotel in the Egyptian resort city of Hurghada • Guests who developed HAV infection after their vacation were 2.6 times more likely to have ingested orange juice than were healthy controls • None of the hotel staff in Egypt was positive • The juice was not pasteurized and came from a site where hygiene problems were identified • Although an infected worker at the juice production company was the most likely source, none of the company staff was IgM positive, but staff members often changed and were not available for testing

26. Hepatitis at a Resort • In 2004, a large outbreak with 351 hepatitis A cases occurred involving tourists at a specific hotel in the Egyptian resort city of Hurghada • Guests who developed HAV infection after their vacation were 2.6 times more likely to have ingested orange juice than were healthy controls • None of the hotel staff in Egypt was positive • The juice was not pasteurized and came from a site where hygiene problems were identified • Although an infected worker at the juice production company was the most likely source, none of the company staff was IgM positive, but staff members often changed and were not available for testing

27. Norovirus in a Restaurant (1) • In Michigan in 2006, 364 restaurant patrons became ill with norovirus GI illness after dining at a restaurant where employees had reported to work while ill • On Jan 28, a line cook vomited at home before reporting to work at 11:00 a.m. and then vomited again into a waste bin beside the frontline workstation at approximately 2:00 p.m. while preparing antipasti platters, pizzas, and salads • After vomiting, he remained on site (but off the cooking line) and left work at 4:15 p.m. • This cook also reported to work on Jan 29 from 11:00 a.m. to 4:30 p.m. while still experiencing loose stools • Because of the open physical layout of the restaurant, no barrier impeded airborne spread of the virus from the kitchen to the main dining area

28. Norovirus in a Restaurant (2) • There was a significant association between the platter and the ill persons • Patron attack rates increased after the cook vomited and among employees, particularly cooks vs. servers, who worked on Jan 28 • The investigation revealed deficiencies in employee hand washing practices, cleaning and sanitizing of food and nonfood contact surfaces, temperature monitoring and maintenance of potentially hazardous food, and maintenance of hand-sink stations for easy accessibility and proper use • A quaternary ammonium based sanitizer normally used to clean the restaurant was ineffective against the norovirus • Then, a bleach solution used to disinfect the restrooms and all surface areas within at least a 25-ft radius of the vomiting site was effective for preventing further illnesses

29. Norovirus in a Restaurant (1) • In Michigan in 2006, 364 restaurant patrons became ill with norovirus GI illness after dining at a restaurant where employees had reported to work while ill • On Jan 28, a line cook vomited at home before reporting to work at 11:00 a.m. and then vomited again into a waste bin beside the frontline workstation at approximately 2:00 p.m. while preparing antipasti platters, pizzas, and salads • After vomiting, he remained on site (but off the cooking line) and left work at 4:15 p.m. • This cook also reported to work on Jan 29 from 11:00 a.m. to 4:30 p.m. while still experiencing loose stools • Because of the open physical layout of the restaurant, no barrier impeded airborne spread of the virus from the kitchen to the main dining area

30. Norovirus in a Restaurant (2) • There was a significant association between the platter and the ill persons • Patron attack rates increased after the cook vomited and among employees, particularly cooks vs. servers, who worked on Jan 28 • The investigation revealed deficiencies in employee hand washing practices, cleaning and sanitizing of food and nonfood contact surfaces, temperature monitoring and maintenance of potentially hazardous food, and maintenance of hand-sink stations for easy accessibility and proper use • A quaternary ammonium based sanitizer normally used to clean the restaurant was ineffective against the norovirus • Then, a bleach solution used to disinfect the restrooms and all surface areas within at least a 25-ft radius of the vomiting site was effective for preventing further illnesses

31. Norovirus from Salad • In 2000, a catered meal and distributed to 52 car dealerships in the US as a reward for high car sales was responsible for multiple gastroenteritis outbreaks in 13 states, resulting in at least 333 cases • Pasta salads from one caterer was strongly associated with illness • Pasta was placed in large plastic bins, other ingredients were added, and food workers mixed the salad by immersing their ungloved arms up to the elbow • Although the workers denied any history of illness in the preceding week, 2 of 15 employees had elevated IgA antibody titres to norovirus • This caterer had been cited by health inspectors for multiple sanitary code violations and was temporarily closed pending sanitary improvements

32. Norovirus from Salad • In 2000, a catered meal and distributed to 52 car dealerships in the US as a reward for high car sales was responsible for multiple gastroenteritis outbreaks in 13 states, resulting in at least 333 cases • Pasta salads from one caterer was strongly associated with illness • Pasta was placed in large plastic bins, other ingredients were added, and food workers mixed the salad by immersing their ungloved arms up to the elbow • Although the workers denied any history of illness in the preceding week, 2 of 15 employees had elevated IgA antibody titres to norovirus • This caterer had been cited by health inspectors for multiple sanitary code violations and was temporarily closed pending sanitary improvements

33. Characteristics of Pathogens

34. Infectivity of Pathogens Transmitted by Infected Food Workers IT = Intestinal Tract, RT = Respiratory Tract, F = Feces, N= Nasal Secretions, S = Skin/Skin Lesions, U = Urine, V = Vomitus

35. Foodborne Pathogens Transmitted by Infected Food Worker and Periods of Infectivity Time After Exposure (Days) 0 50 100 150 200 250 300 Norovirus (SRSV/NLV) Hepatitis A Salmonella spp. S. Typhi/Paratyphi Shigellaspp. Staphylococcus aureus Streptococcus pyogenes Giardialamblia Campylobacter jejuni Cryptosporidiumparvum Vibriocholerae E. coli O157:H7 Yersinia enterocolitica Incubation Incubation/ Pre-symptomatic Pre-symptomatic Shedding Phase Symptomatic Period Extended Symptomatic Post-symptomatic Phase Extended Post-symptomatic Phase Carrier State

36. Levels of Pathogens in Body Excretions • Salmonella in feces • Ill or early convalescence: 105-107 CFU/g • Late excretion (infants excrete longer): 100-103 CFU/g • 10-19 days after illness: 100-106 CFU/g • 69-102 days after illness: 100-104 CFU/g • Sneeze with Streptococcus pyogenes • up to 106 CFU/sneeze • up to 500 CFU/154 cm2 1.5 – 9.5 feet from sneeze source • HAV in feces just before hepatitis symptoms begin • 108 infectious particles/g • Norovirus in feces while ill • 105 – 1010 copies/g • Cryptosporidium in one bowel movement:108 – 109 oocysts

37. Fecal Contamination of Hands During Toilet Use With and Without Toilet Paper • Mean fecal weight/hand (g) after cleansing • Without toilet paper 8.5 x 10-6 - 9.8 x 10-7 • With toilet paper 5.0 x 10-9 • Pathogens can be present in feces at levels of from 105 to 1011 per g. A tenth of a milligram of fecal material (10-4 g), an amount barely perceptible, might contain up to a million infectious bacterial cells or viral particles • At 10-7 g fecal matter of contamination per hand and a pathogen that present at 1011 per g, if hands were washed and/or sanitized, a 2 to 3 log reduction (99%-99.9%) could still allow a worker to transmit a few cells • Add to the fact that those ill may be more careless with fecal cleanliness (continual cleanup from diarrhea, fecal accidents, and not focused on the job and hygienic practices), and the risk increases greatly

38. Survival of Enteric Pathogens on Hands and Surfaces

39. Survival of Pathogens • Norovirus survived in carpets and toilet facilities for more than one day after an individual vomited on seats and washroom; infected clean-up crew and subsequent concert hall attendees infected by aerosols • Illnesses from carpet removers in a hospital ward 12 days after vomiting outbreak occurred • Pathogens tend to survive longer on surfaces such as ceramic tile, steel, dust, glass and plastic than on hands

40. Levels of Pathogens in Raw Meat and Poultry

41. Transfer of Organisms from Hands • The transfer efficiency between hands and lettuce was found to be 0.3% and from hands to spigots was 1% • The transfer rate of HAV from fingerpads of adult volunteers to pieces of fresh lettuce was determined to be 9% of the infectious load on the fingers • Lettuce touched by a washed hand may be contaminated with as many as 3.8 log10 CFU indicator bacteria • A 10% transfer rate of bacteria from food to hands or bare hand to food; and by using gloves, this rate was reduced to 0.01%

42. Outbreaks Associated with Lack of Adequate Hygienic Facilities • Inadequate toilet facilities (Yersinia, Shigella,Vibrio, Salmonella) • Non functional toilet(Shigella) • Lack of handwashing facilities(Shigella,Vibrio, HAV) • Inadequate handwash facilities(Shigella, norovirus) • Difficult to use faucets(HAV) • Lack of running water(Yersinia, Shigella,Vibrio) • Lack of fingernail brush(Giardia) • Lack of soap(Shigella,Vibrio, Giardia) • No paper towels for hand drying(Shigella, Salmonella, norovirus)

44. Handwashing Occasions • Wash hands thoroughly with disinfectant soap and water at appropriate times for the job description • Also after the following: • handing raw foods • after going to the toilet • after contact with persons suffering from acute GI symptoms • after being in contact with infants and incontinent individuals

45. Minimize Hand Contact Evaluate food handling procedures and modify to reduce or eliminate hand contact for RTE food: • Gloves • Utensils • Deli papers

46. Exclusion and Work Restrictions •Exclude infected symptomatic persons (GI) from preparing and serving food during communicable periods of illness • Exclude infected persons known to be asymptomatic carriers based on screening • Restrict food workers from preparing or serving food • Infected skin lesions • Sore throat • Acute respiratory infections • Food workers should be kept on sick leave for 48 h following disease cessation

47. Hygiene Education, Training and Supervision • Train food workers and supervisors: • in proper food handling practices and procedures • to report personal and family illness • Provide supervision of workers: • Surveillance of workers and correction of handling errors • Screen food workers (nasal and stool): • at start of employment • routine testing • upon return from travel in area having high endemic disease rates • Immunize workers when feasible (HAV, etc)

48. What Have Investigations of Outbreaks Where Food Workers Were Implicated Taught Us - Sources? • There are many sources where food workers have become infected • Ill family members, homosexual partners or diapering a sick child • Intravenous drug use • Eating contaminated food • Environmental sources, e.g., water, animals • Travel abroad • Contact with other infected workers

49. Spread in the Food Worker Environment • Once a worker has brought an agent into a food operation, it can easily be transferred from person to person, person to food contact surfaces and to food • Lack of adequate handwashing facilities and improper handwashing and drying • Long and artificial nails are too difficult to clean effectively • Lesions and wounds harboring pathogens are not properly covered • Workers continuing to work when infected and ill (diarrhea and vomiting): management or worker decision • Transmission between workers in food preparation area • Lack of use of gloves/bare hand contact

50. Removal of Contaminants • Fecal contamination can be extensive even after washing – use of toilet paper doesn’t prevent all fecal organisms from going on finger tips and from there to contact surfaces • Vomiting can spread viral particles over long distances despite any clean up afterwards and particles can persist for days or weeks • Thorough and frequent handwashing and use of gloves keeps contamination in food environment to a minimum