Risk factors in the development of E. coli enteritis include young and old age, immunocompromised status, pregnancy, recent ingestion of uncooked or poorly handled vegetables, meat (e.g. hamburgers), poultry, raw milk, or poorly stored foods that require refrigeration (e.g. mayonnaise), drinking from untreated water, recent travel to developing countries, exposure to infected individuals, daycare, and healthcare settings, and recent sexual history of receptive anal or oral–anal contact.

Risk factors in the development of E. coli enteritis include the following:

• Young age (children < 5 years) or old age
• Immunocompromised status
• Pregnancy
• Recent ingestion of uncooked or poorly handled vegetables, meat, poultry, raw milk, or poorly stored foods that require refrigeration (e.g. mayonnaise)

• Enterohemorrhagic E. coli O157:H7 is commonly associated with ingestion of ground beef (e.g. in hamburgers) or alfalfa sprouts

• Recent drinking from untreated water (e.g. stream or well)
• Recent travel to developing countries

• Enterotoxigenic E. coli is the most common cause of traveler’s diarrhea

• Exposure to daycare
• Exposure to healthcare settings (e.g. nursing homes or hospitals)
• Exposure to infected individuals
• Recent sexual history of receptive anal or oral–anal contact