ABSTRACT
Since in many outbreak investigations the food vehicle no longer exists, having been either eaten up or destroyed, it is not always possible to link the pathogen found in feces to the food source. Keeping samples of hazardous food from all meals served in institutions for a period of 7 days has been recommended (46, 73). This practice would prove useful in an outbreak situation, but too much valuable freezer space may be wasted. Although an outbreak may not be evident for 5 days or more after meal service, keeping samples for 5 days offers the best compro mise.
