Food Safety Hazards 1
Biological Hazards • Include bacterial, viral, and parasitic organisms that cause illness Dennis Kunkel F. P. Williams, U. S. EPA Dennis Kunkel 2
Biological Hazard Groupings • Nonspore-forming bacteria • Spore-forming bacteria • Parasites • Viruses
Nonspore-forming Bacteria – • Found on raw animal foods (meat, fish, eggs, milk), sometimes fruits and vegetables and processed foods • Examples – – – Salmonella E. coli Listeria monocytogenes Vibrio spp. Staphylococcus aureus Yersinia • Control Measures – – – Cooking No Bare Hand Contact with RTE Handwashing Employee Health Temperature Control 4
Spore-forming Bacteria • Spore formers – Clostridium perfringens – Clostridium botulinum – Bacillus cereus • Control Measures – Proper Cooling – Hot and Cold Holding – Reheating (C. perfringens only) 5
Parasites PROTOZOA WORMS • • • Giardia Cryptosporidium Entamoeba histolytica Cyclospora cayetanensis Toxoplasma gondii Taenia saginata (beef tapeworm) Taenia solium (pork tapeworm) Trichinella spiralis 6 Anisakis
Key Microbiological Concepts • Competitive Microflora • p. H, Aw, ROP • Time/Temperature 7
Use of Time as a Control 8
Time and Temperature • Key control measures in Food Code • Used to control almost all potential biological hazards except viruses • Easily monitored and food quality minimally affected
Use of Temperature as a Control Temperature Danger Zone 41ºF to 135ºF True or False. Bacteria of foodborne significance generally do not grow above 127ºF. 1. True 2. False
Foodborne Viruses • FECAL – ORAL do not grow in food • Hepatitis A • Noroviruses 11
Percentage of Foodborne Illness Attributable to Various Pathogens 12 Mead et al. , 1999
13 No Bare Hand Contact Em pl oy ee H ea lth Foodborne Illness Disease Reduction Ad Ha eq nd ua wa te sh & P in ro g pe r
THE “BIG SIX” PATHOGENS listed in the Food Code Norovirus Salmonella Typhi Hepatitis A Virus Shigella spp. Enterohemorrhagic or Shiga toxin-producing 14 Source: CDC E. coli Salmonella spp.
Symptoms of Concern • Gastrointestinal Symptoms of Concern: – Vomiting – Diarrhea – Jaundice n Other Symptoms of Concern: Sore Throat with Fever n Infected wound or pustular boil Note: Fever is Deleted as a Symptom of Concern n 15
Camp Crud? 16
No. V The Public Health Problem • The greatest public health impact: In institutions such as hospitals and nursing homes, where No. V outbreaks commonly occur. • Gastroenteritis: The most common illness experienced by ground troops during the Gulf War, and – 70% of these cases were attributed to No. V • No. V outbreaks on naval vessels have resulted in removing ships from active service for brief periods 17
No. V The Public Health Problem • Secondary Infections: Attack rate >50% in areas where a large population is enclosed within a static environment, such as: – – – 18 institutions, schools, military operations, hotels, recreational camps, or aboard cruise ships
CDC Estimated % of Total Foodborne Illnesses, Hospitalizations, and Deaths 19 Data from Mead, et. al. , Food Related Illness and Death in the United States, Emerging Infectious Disease, 1999. Vol. 5, No. 5, pp. 38
All Food Code Listed Pathogens Have an Extremely Low Infectious Dose Ø Hepatitis A virus ~ 10 or less viral particles Ø Norovirus ~ 10 to 100 viral particles Ø EHEC is as low as 10 bacterial cells Ø Shigella spp. can be as low as 10 bacterial cells Ø S. Typhi is considered low for bacteria ~ 1000 bacterial cells 20
Potential Contamination Level per Gram of Feces: Ø Hepatitis A (HAV): 108 viral particles Ø Norwalk-like Viruses: 106 viral particles Ø Cryptosporidium & Giardia: 108 oocysts Ø Bacterial infections: 106 21
Combination of High Levels Shed in the Feces and Low Infectious Dose • Adds up to create a highly infectious microorganism 22
Why are Norovirus and Other Viruses so Hard to Control? • 1, 000, 000 – – # of viral particles you start with in 1 ml of feces* • 10, 000, 000 – • # left after properly washing your hands (2 log reduction) (Ayliffe et al. , 1978) • In contrast, it takes 1 -10 virus particles to make you sick* 23 *Teunis & Moe, 2008
Hand Antiseptics are effective at deactivating foodborne viruses and killing parasites 1. True 2. False 24
Norovirus Outbreaks 20061 Month Facility Type Number Ill Jan. 14 Indiana Middle School 245 Jan. 27 -30 Michigan Italian Restaurant > 430 February Chicago, IL Hotel AMA Meeting >150 Jan. -Feb. Minnesota Restaurants, hotels, nursing homes, and schools >29 Outbreaks March Florida & California Cruise Ships >500 April Florida University 150 April 25 State Vancouver, WA Assisted Living Facility 55 residents & staff — 3 deaths 1 As Reported in 2006 News Articles
No. V Environmental Contamination--RTPCR Environmental surface tests--Hotel outbreak (Cheeseborough, 2000) Surface # Pos. % Pos Carpets (known recent vomit) 62% Carpets (no known recent vomit) 9 of 12 75% Toilet rims/seats 8 of 11 73% Toilet handles, taps, basins & surfaces 13 of 39 39% Horizontal surfaces below 1. 5 m (railings, switches, table tops, counters, ‘phones) 11 of 29 37% Horizontal surf. (light fittings, switches, wardrobe tops, counter tops) above 1. 5 m 6 of 12 50% Phones, door handles, etc. 7 of 29 24% Soft furnishings, cushions, curtains, ect. 26 5 of 8 2 of 10 20% Total 61 of 144 42%
Transmission of Norovirus • Fecal-Oral Route: Primary route responsible for causing foodborne outbreaks • Airborne Inhalation of microscopic droplets: Aerosols enhance dissemination of No. V in the environment during an outbreak; has been important means of transmitting No. V to staff • Person-to-Person: Important means of sustaining & spreading an outbreak • Environment-to-Person: Important means of sustaining & spreading an outbreak 27
NV vs. Duke University & Florida State Football Teams---Norovirus Won • 9/18/98, Duke Univ. football team ate turkey sandwiches, prepared by ill foodworker. • 9/19/98: Duke team players - suddenly ill during game, with vomiting & diarrhea & continued to play • NV crossed the line of scrimmage – Transferred via football, & player’s hands – 11 FSU players became sick • 1 st documented case of person-to-person transmission of NV at sports event 28 Duke lost the game, 62 -13.
Norovirus from Prep Sink 29 • August 3, 1996, food worker became suddenly ill and vomited in the prep sink in the hotel kitchen. • Sink was cleaned and disinfected with Mikro-Chlor sanitizing powder • Next day: sink was used to cool boiled potatoes for potato salad served at wedding reception • 47 guests reported illness with vomiting & diarrhea (attack rate > 50%) • Serves as example of important role environmental contamination can play & the difficulty in disinfecting contaminated environmental surfaces
Controlling Norovirus Depends on Preventing the Transmission 30 • Handwashing & prohibiting bare hand contact with RTE food items is critical • Removing food workers with active vomiting and/or diarrhea is critical • Reducing airborne transmission, and treat as infectious material • Cleaning Staff should use barriers, such as face masks, gloves, and aprons. • Dispose materials used to clean-up vomiting incident, and thoroughly disinfect the area.
When can you come back to work? Asymptomatic Time Period Required: Norovirus = > 48 hours Hepatitis A virus = > 7 days of jaundice or > 14 days of other symptoms EHEC = > 7 days Shigella spp. = > 7 days Exception: Typhoid Fever has no time period allowance 31
Barriers to Effective Employee Health Controls • Economics • Vomiting and Diarrhea: Not easy to talk about • Asymptomatic Infected Food Employees 32
Annex 7 • Revised Employee Interview Forms in Annex 7 -Form; 1 -A • Revised Food Employee Reporting Agreement Form; Form 1 -B • Revised Medical Referral Form; Form 1 -C • Revised Food Establishment Inspection Report; Form 3 -A 33
Hand Hygiene 34
Hand hygiene Overview 35 • Importance of handwashing as an intervention and the actual incidence of handwashing • The science of hand contamination • The science behind effective handwashing • Handwashing tools • Hand Antiseptics
Handwashing • Value has been recognized as the first line of defense in preventing illness for the past century • One of the most under-utilized public health prevention measures today 36
Handwashing Survey Results • 2003 ASM: 95% Americans report handwashing, but observed only 78% • Handwashing observation results-after using rest room --% not washing hands: 37 – – – Chicago: 26% Dallas: 19% San Francisco: 26% Miami: 26% New York: 29% Toronto: 4%
Hand contamination De Wit, et al. 1992 • Examined the fecal contamination level of the hands, after handwashing (E. coli as an indicator). • Found E. coli in 25% of sampled individuals after stools (avg. log 2. 3 CFU E. coli per sample) 38
No Bare Hand Contact With Ready to Eat Foods 39
The Science of Handwashing 40
HANDWASHING Every Stage of Handwashing is Important Ø Scrubbing w/ soap = 1 log virus reduction Ø Rinsing hands under strong velocity & volume of running water - increased effect in removing transient viruses Ø Drying hands = 1 log virus reduction 41
Active Managerial Control Employee Hygiene • Employee Health • Handwashing • No Bare Hand Contact with RTE Foods 42
Most Food Safety Education • Presented in print or verbally in unfamiliar abstract language • Presented by someone of power and/or someone who does not understand what it is like to work in a foodservice establishment • Good behavior is often not modeled or made a priority in restaurant environment (i. e. lack of food safety culture) 43
Most Food Safety Education • Often describes “how” but not “why” • If provided, the “why” is often presented: – In a language that is not familiar (maybe too technical) – In a way that does not relate to food employees’ personal experiences 44
Most Food Safety Education • Examples: – Classroom style/computer-based learning – Written manuals, pamphlets, SOPs – Step-by-step “how to” posters – Training provided by people of power • Health inspectors • Agents of the health department • Industry QA staff 45
Typical Food Safety Poster in Use Today 46
Recommendations for Communicating with Food Employees FDA ORAL CULTURE PROJECT 47
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Summary • It’s not enough to just teach “how. ” Reinforcing the “why” is also important. Use stories. • http: //www. fda. gov/Food/Guidance. Regulation/Retail. Food Protection/Industryand. Regulatory. Assistanceand. Training Resources/ucm 212661. htm – http: //www. outbreakdatabase. com/ – http: //www. foodpoisonjournal. com/ – http: //www. safetables. org/index. cfm • You can’t expect behavior change if the context of “why” is because “it’s the law” or simply “you will make people sick. ” 51
FDA Educational Videos for Retail Food Employees http: //www. fda. gov/Food/Guidance. Regulation/Retail. Food. Protection/Industryand Regulatory. Assistanceand. Training. Resources/ucm 212661. htm
Until next time, thank you for what you do! Katey Kennedy FDA Regional Food Specialist 9780 SW Nimbus Ave. Beaverton, OR 97008 Katey. kennedy@fda. hhs. gov 503/502 -5442 53
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