situations where the disease results from poisonous products produced by the
microorganisms (refer to Section III).
b. There are three basic varieties of foodborne infections:
(1) Those caused by bacteria.
(2) Those caused by viruses.
(3) Those caused by parasites.
FOODBORNE INFECTIONS CAUSED BY BACTERIA
a. There are many infections caused by bacterial contamination of food. This
subcourse discusses only the most common infections: salmonellosis and shigellosis.
(1) Salmonellosis is an infection caused by bacteria of the salmonella family.
There are more than 1,200 different varieties of salmonella. Salmonella can
contaminate food at any time from the handling or processing stage until it is served to
(2) A wide variety of foods may contain salmonella bacteria, including poultry
products, meat and meat products, eggs and egg products, shellfish, and unpasteurized
milk and dairy products. In particular, poultry products are a source of salmonelIa.
Even infected persons who show no outward signs of the disease (carriers) can
(3) It is difficult for a food service facility to eliminate salmonella completely.
However, certain basic countermeasures can be taken. Employees should observe
strict personal hygiene, particularly hard-washing practices. This is done to prevent
fecal contamination. Food preparation procedures should avoid cross-contamination as
much as possible, particularly in the preparation of poultry. For example, the same
utensils should not be used on raw poultry and cooked foods. Foods should come from
reliable sources, and milk and milk products should be pasteurized. Finally, all foods
should be cooked for an adequate time and at an adequate temperature and then
chilled quickly. There are a wide variety of salmonella symptoms. The more common
ones are fever, abdominal pain, diarrhea, frequent vomiting, and chills. Although
salmonellosis is rarely fatal, it is a special hazard to those who are in poor physical
condition, to the very young, or to the aged.
c. Shigellosis (bacillary dysentery). Shigellosis or bacillary dysentery is caused
by bacteria of the shigella family. Shigella tend to contaminate moist prepared foods,
such as ham and egg salad and milk or dairy products. Usually the food has been
contaminated by the feces of an infected person. Rodents, roaches, flies, and other