Differentiating Between Major Types
of Foodborne Diseases
Microbiological hazards cause most foodborne diseases in the U.S. The three
microbiological hazards of concern are bacteria, viruses, and parasites. These
microorganisms can cause one of three types of illness –infection, intoxication, or
toxin-mediated infection.
Type of Illness
Infection
Intoxication
Toxin-Mediated
Infection
Causes
Forms
Happens when a person
eats food containing
harmful microorganisms,
which then grow in the
intestinal tract and cause
illness.
Happens when a person
eats food containing toxins
that cause illness.

Usually a result of chemical
contamination




Happens when a person

eats food containing
harmful bacteria; while in

the intestinal tract, the
bacteria produce toxins that
cause illness.
Some bacteria
(Salmonella, Listeria,
Vibrio Vulnificus)
All Viruses
All Parasites
Some bacteria
(Botulism, Staph, Bacillus
Cereus, and Clostridium
perfringens)
No viruses or parasites
Some bacteria (shigella,
and e. coli)
No viruses or parasites