Categories used for analysis of contributing factors in restaurant-associated foodborne disease outbreaks, Foodborne Disease Outbreak Surveillance System, 1998–2013* (n = 6907 contributing factors)
| Category | Contributing factors 1998–2008 |
Contributing factors 2009–2012 |
No. of outbreaks (%) |
|---|---|---|---|
| Bare-handed contact by handler/worker/preparer (e.g. with ready-to-eat food) | Bare-hand contact by a food handler/worker/preparer who is suspected to be infectious | 1451 (62) | |
| Food worker health & hygiene | Handling by an infected person or carrier of pathogen (e.g. Staphylococcus, Salmonella, norovirus) | Other mode of contamination (excluding cross-contamination) by a food handler/worker/preparer who is suspected to be infectious | 1073 (46) |
| Glove-handed contact by handler/worker/preparer (e.g. with ready-to-eat food) | Glove-hand contact by a food handler/worker/preparer who is suspected to be infectious | 463 (20) | |
| Any of the above | 2344 (34) | ||
| Raw product/ingredient contaminated by pathogens from animal or environment (e.g. Salmonella Enteriditis in egg, norovirus in shellfish, E. coli in sprouts) | Contaminated raw product – food was intended to be consumed after a kill step | 396 (52) | |
| Contamination of food before reaching the restaurant | Toxic substance part of tissue (e.g. ciguatera) | Toxic substance part of the tissue | 220 (29) |
| Ingestion of contaminated raw products (e.g. raw shellfish, produce, eggs) | Contaminated raw product – food was intended to be served raw or undercooked/under processed | 187 (29) | |
| Obtaining foods from polluted sources (e.g. shellfish) | Foods originating from sources shown to be contaminated or polluted (such as a growing field or harvest area) | 22 (3) | |
| Any of the above | 761 (11) | ||
| Improper adherence of approved plan to use time as a public health control | 962 (32) | ||
| Inadequate thawing of frozen products (e.g. room thawing) | Food preparation practices that support proliferation of pathogens (during food preparation) | ||
| Insufficient thawing, followed by insufficient cooking (e.g. frozen turkey) | 957 (32) | ||
| Foods contaminated by a non-food handler/worker/preparer who is suspected to be infectious | 954 (32) | ||
| Cross-contamination from raw ingredient of animal origin (e.g. raw poultry on the cutting board) | Cross-contamination of ingredients (cross-contamination does not include ill food workers) | 710 (24) | |
| Preparing foods a half day or more before serving (e.g. banquet preparation a day in advance) | No attempt was made to control the temperature of implicated food or the length of time food was out of temperature control (during food service or display of food) | 566 (19) | |
| Insufficient time and/or temperature during hot holding (e.g. malfunctioning equipment, too large a mass of food) | Improper hot holding due to malfunctioning equipment | 426 (14) | |
| Insufficient time and/or temperature during initial cooking/heat processing (e.g. roasted meats/poultry, canned foods, pasteurization) | Insufficient time and/or temperature control during initial cooking/heat processing | 382 (13) | |
| Food handling and preparation practices in the restaurant | Inadequate cold-holding temperatures (e.g. refrigerator inadequate/not working, ice holding inadequate) | Improper cold holding due to malfunctioning refrigeration equipment | 311 (10) |
| Insufficient time and/or temperature during reheating (e.g. sauces, roasts) | Insufficient time and/or temperature during reheating | 303 (10) | |
| Storage in contaminated environment B leads to contamination of vehicle (e.g. store room, refrigerator) | Storage in contaminated environment | 268 (9) | |
| Improper cold holding due to an improper procedure or protocol | 110 (4) | ||
| Allowing foods to remain at room or warm outdoor temperature for several hours (e.g. during preparation or holding for service) | Improper hot holding due to improper procedure or protocol | 72 (2) | |
| Slow cooling (e.g. deep containers or large roasts) | Improper/slow cooling | 61 (2) | |
| Insufficient or improper use of chemical processes designed for pathogen destruction | 44 (1) | ||
| Prolonged cold storage for several weeks (e.g. permits slow growth of psychrophilic pathogens) | Prolonged cold storage | 35 (1) | |
| Anaerobic packaging/modified atmosphere (e.g. vacuum packed fish, salad in gas flushed bag) | Inadequate modified atmosphere packaging | 7 (0) | |
| Insufficient time and/or temperature control during freezing | 5 (0) | ||
| Inadequate acidification (e.g. mayonnaise, tomatoes canned) | Inadequate processing (acidification, water activity, fermentation) | ||
| Inadequate fermentation (e.g. processed meat, cheese) | 4 (0) | ||
| Insufficiently low water activity (e.g. smoked/salted fish) | |||
| Insufficient acidification (e.g. home canned foods) | |||
| Any of the above | 2995 (43) | ||
| Other source of contamination | Other source of contamination | 475 (59) | |
| Other process failures that permit the agent to survive | Other process failures that permit the agent to survive | 246 (30) | |
| Other | Other situations that promote or allow microbial growth or toxic production | Other situations that promote or allow microbial growth or toxic production | 130 (16) |
| Toxic container of pipelines (e.g. galvanized containers with acid food, copper pipe with carbonated beverages) | Toxic container | 15 (2) | |
| Poisonous substance intentionally added (e.g. cyanide or phenolphthalein added to cause illness) | Poisonous substance intentionally/deliberately added | 9 (1) | |
| Addition of excessive quantities of ingredients that are toxic under these situations (e.g. niacin poisoning in bread) | Addition of excessive quantities of ingredients that are toxic in large amounts | 4 (1) | |
| Poisonous or physical substance accidentally/incidentally added (e.g. sanitizer or cleaning compounds | Poisonous substance accidentally/inadvertently added | 2 (0) | |
| Any of the above | 807 (12) | ||
*
Contributing factor definitions were revised in 2009 and outbreaks may be listed under more than one factor.