The BIG 5 is a group of highly infectious foodborne pathogens. These BIG 5 pathogens have a low infectious dose, contaminate the gastrointestinal systems after ingestion, and are shed in feces. These pathogens shed in high numbers. A food employee infected with a BIG 5 pathogen will typically shed hundreds of thousands of pathogens in their feces that can easily be transmitted to food even when good hand washing practices are used. Consequently, the illness experienced by the consumer can be very severe. The BIG 5 include:
- Norovirus
- Salmonella Typhi (typhoid-like fever)
- E. Coli O157:H7, Enterohemorrhagic or Shiga toxin-producing E Coli
- Shigella spp. (causes shigellosis)
- Hepatitis A virus