Define "virus."
Viruses are the smallest of the foodborne microbial contaminants. They
are packets of infectious genetic material wrapped with an outer layer
of protein. Most experts believe that viruses are the most common cause
of foodborne illness in the U.S.
Viral agents commonly associated with foodborne illness
|
Viral agent
|
Symptoms
|
Incubation
|
Duration of Illness
|
Source
|
Food Involved
|
|
Hepatitis A
|
Sudden onset of fever; fatigue, nausea; loss of appetite, vomiting,
abdominal pain, and jaundice after several days; children often
exhibit no symptoms
|
10-50 days, average is 28-30 days
|
1-2 weeks
|
Human intestinal tract; feces-contaminated water
|
Shellfish, salads, cross-contaminated deli meats and sandwiches;
fruit and fruit juices, milk and milk products; vegetables; any food
that will not receive a further heat treatment; water and ice
|
|
Norovirus
|
Nausea, vomiting (more common in children), watery diarrhea with
abdominal cramps, mild fever
|
1-2 days
|
1-3 days
|
Human intestinal tract; feces-contaminated water
|
Ready-to-eat food including salads, sandwiches, and bakery products;
liquid items such as salad dressing or cake icing; oysters from
contaminated waters; contaminated raspberries; contaminated well
water
|
|
Rotavirus
|
Vomiting, watery diarrhea, abdominal pain, and mild fever (illness
is more common in children than in adults)
|
1-3 days
|
4-6 days
|
Human intestinal tract; feces-contaminated water
|
Water and ice, raw and ready-to-eat food (salads, fruit)
contaminated water
|
Viruses also cause other life-threatening diseases, such as smallpox,
polio, influenza, and AIDS.
Unlike bacteria, viruses cannot multiply outside of their specific host
- human, animal, or plant. Although inert in the environment, viruses
transmitted by food are quite hardy and remain infectious while stored
in the refrigerator or the freezer. Therefore, maintaining foods at
proper temperatures does not reduce the presence of viral agents.
Viruses can also withstand the low pH of the stomach and the harsh
detergent conditions of the upper small intestine.
SOURCE: FDA/CFSAN Bad Bug Book located at: http://vm.cfsan.fda.gov/~mow/intro.html
Cromeans,
T.L. 1997. Understanding and Preventing Virus Transmission via Foods. Food
Technology. 51(4):20.
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