Staphylococcal Foodborne Illness: High-Risk Foods
Staphylococcus aureus foodborne illness is primarily transmitted through ready-to-eat foods that have been handled by infected food workers, with the highest risk foods being those that require manual preparation and are stored improperly at room temperature or inadequately refrigerated. 1, 2
Primary High-Risk Food Categories
Foods Requiring Manual Handling
The most common sources of staphylococcal food poisoning are ready-to-eat foods that have been contaminated by colonized food handlers, particularly when these foods are held at room temperature for extended periods (12+ hours between preparation and consumption). 2 Key examples include:
- Delicatessen meats and prepared salads from deli counters 3, 4
- Hot dogs and other ready-to-eat meats that are consumed cold without reheating 4
- Prepared sandwiches and cold cuts handled during assembly 3
Protein-Rich Foods with Temperature Abuse
Improper cooling is the single most important contributing factor to staphylococcal food poisoning outbreaks, followed by allowing 12+ hours between food preparation and consumption. 2 High-risk items include:
- Cooked poultry and meat products left at room temperature or stored in large containers while refrigerating 2
- Egg-containing products such as mayonnaise-based salads, hollandaise sauce, and Caesar dressing 3
- Dairy products, particularly unpasteurized milk and soft cheeses 3
Specific Food Service Risks
Colonized food handlers are the primary source of contamination in restaurant and catered event outbreaks, with the organism proliferating when foods are held at improper temperatures. 1, 2 Critical risk foods include:
- Buffet items held at room temperature for extended periods 3
- Foods from street vendors where temperature control is inadequate 3
- Prepared foods at delicatessen counters that have been handled and stored 3, 4
Critical Timing and Temperature Factors
Staphylococcal enterotoxin causes rapid-onset symptoms within 1-6 hours of consumption, distinguishing it from other foodborne pathogens. 5, 6 The enterotoxins are:
- Highly heat-stable and can survive retort temperatures, meaning cooking contaminated food will not eliminate the toxin 7, 8
- Produced when S. aureus proliferates in foods held between 40°F-140°F (4°C-60°C) 1
- Active at very low doses (100-200 ng can cause illness) 7
Prevention Strategies
The three most critical prevention factors for staphylococcal food poisoning are: preventing colonized persons from handling cooked foods, ensuring proper cooling, and minimizing time between preparation and consumption. 2
For Immunocompromised Patients
Immunosuppressed individuals should reheat all ready-to-eat foods, including hot dogs and deli meats, until steaming hot (165°F/74°C) before consumption to eliminate any bacterial contamination, though this will not destroy preformed enterotoxin. 4, 3
Cross-Contamination Prevention
Uncooked meats and their juices must never contact other foods, and all surfaces, utensils, and hands must be thoroughly washed after contact with raw products. 3, 9
Common Pitfalls
- Visual inspection cannot detect enterotoxin contamination - foods may appear, smell, and taste normal yet contain sufficient toxin to cause illness 1
- Reheating contaminated food will kill bacteria but not destroy the heat-stable enterotoxin already produced 7, 8
- Refrigeration slows but does not prevent S. aureus growth - improper cooling in large containers allows the organism to multiply even under refrigeration 2