Prepared salads and public health

Area of Science:

• Food Safety
• Microbiology
• Public Health

Background:

• Prepared salads have been increasingly recognized as vehicles for foodborne illnesses.
• Numerous large-scale outbreaks have occurred nationally and internationally.
• Infectious intestinal disease outbreaks linked to prepared salads represent a significant public health concern.

Purpose of the Study:

• To analyze the types of prepared salads and pathogens involved in outbreaks.
• To discuss the attribution of prepared salad types and pathogens in associated outbreaks.
• To highlight the public health impact of contaminated prepared salads.

Main Methods:

• Analysis of reported foodborne general outbreaks of infectious intestinal disease in England and Wales (1992–2006).
• Review of UK studies on salad vegetables, fruit, and mixed salads (1995–2007).
• Examination of outbreak data associated with specific prepared salad types and pathogens.

Main Results:

• 4% of 2274 foodborne outbreaks were linked to prepared salads, affecting 3434 people.
• 66 hospitalizations and one death were reported.
• While 98.6% of samples were of satisfactory quality, outbreaks of salmonellosis were linked to bagged salad leaves and fresh herbs.

Conclusions:

• Contaminated prepared salads, particularly those containing bagged leaves and fresh herbs, can cause significant gastrointestinal illness.
• Environmental contamination of fresh produce is a known factor.
• Breakdowns in hygiene practices during preparation are critical in preventing recurrent foodborne illness outbreaks from non-animal-origin foods.