Section III. DETERMINATION OF POTENTIAL HEALTH HAZARDS
IN DAIRY PRODUCTS
Determine the existence of any potential health hazard, based upon the
deteriorative condition and the amount of product deterioration. A health hazard is
defined as any substance that could harm a person's health and/or well-being.
4-19. MICROBIAL PATHOGENS
Depending upon the microorganisms present in the product, microbial spoilage
certainly may be a potential health hazard. The following microorganisms may be a
health hazard in dairy products.
a. Clostridium botulinum. Dairy products are rarely involved in outbreaks of
botulism since most dairy products are consumed in a fresh state rather than canned.
b. Salmonella Species. Raw milk has been the carrier in outbreaks throughout
the world. One outbreak in the US was due to ingestion of pasteurized milk. Affected
ice cream was, in most cases, contaminated by infected shell eggs. The risk of
Salmonella organisms in dairy products is rather low.
c. Escherichia coli. Certain strains of E. coli may cause enteritis in humans. In
1971, an outbreak due to enteropathogenic E. coli in imported cheese resulted in
several hundred reported cases. In other countries, outbreaks have been associated
with consumption of dairy products. The symptoms of illness are diarrhea, fever,
nausea, and cramps.
d. Staphylococcus Species. These organisms, especially S. aureus, may be
present in the milk of cows suffering from acute mastitis. It is the most common
pathogenic organism found in raw milk, but most cases of infection may be traced to a
human carrier. Some organisms, especially the lactobacilli, inhibit the growth of
staphylococci. Staphylococcal food poisoning has occurred through consumption of
cheese which had not developed acidity in a normal manner. Evidently, the acid-
producing bacteria, such as the lactobacilli, had not developed and were thus not
available to inhibit the growth of contaminating staphylococci.
e. Mycobacterium bovis. Infected raw milk is the chief means by which milk-
borne tuberculosis is transmitted to man. The organism is one of the most heat-
resistant of the nonspore-forming pathogenic bacteria, but fortunately it is destroyed by
pasteurization. Milk-borne cases of tuberculosis are rare today. Such cases were more
common when milk was not pasteurized and when tubercular cows were not eliminated
from the herds.