Food is the most common vehicle for the spread of Campylobacter. Poultry is the most common food implicated. Some case-control studies indicate that up to 70% of sporadic cases of campylobacteriosis are associated with eating chicken.
Surveys by the USDA demonstrated that up to 88% of the broiler chicken carcasses in the USA are contaminated with Campylobacter while a recent Consumer Reports study identified Campylobacter in 63% of more then 1000 chickens obtained in grocery stores. Other identified food vehicles include unpasteurized milk, undercooked meats, mushrooms, hamburger, cheese, pork, shellfish, and eggs.
Most cases of campylobacteriosis are sporadic or involve small family groups, although some common-source outbreaks involving many people have been traced to contaminated water or milk.
Other sources of Campylobacter, in addition to food and water, that have been reported include children prior to toilet-training, especially in child care settings,2 and intimate contact with other infected individuals. C. jejuni is commonly present in the gastrointestinal tract of healthy cattle, pigs, chickens, turkeys, duck, and geese, and direct animal exposure can lead to infection. Pets that may carry Campylobacter include Birds, cats, dogs, hamsters, and turtles.3 The organism is also occasionally isolated from streams, lakes and ponds.
Campylobacter jejuni is a gram-negative, microaerophilic, thermophilic rod, growing best at 42 degrees C and low oxygen concentrations. These characteristics are adaptations for growth in its normal habitat-the intestine of warm-blooded birds and mammals. Food becomes contaminated from intestinal material during processing, but Campylobacter jejuni grows poorly on properly refrigerated foods. It does, however, survive refrigeration and will grow if contaminated foods are left out at room temperature. Campylobacter is sensitive to heat and other common disinfection procedures. Pasteurization of milk, adequate cooking of meat and poultry, and chlorination or ozonation of water will destroy this organism. Several closely related species with similar characteristics, C. coli, C. fetus, and C. upsalienis, may also cause disease in man.