Epidemiology of Campylobacter Jejuni Infection
C. jejuni frequently contaminates raw chicken. Surveys show that 20 to 100% of retail chickens are contaminated. This is not surprising since many healthy chickens carry these bacteria in their GI tract. Raw milk is also a source of infection. The bacteria are often carried by healthy cattle and by flies on the farms. Children under 5 and young adults are more frequently afflicted than other age groups.
Isolation of C. jejuni from food is difficult because the bacteria are usually present in very low numbers. A microaerophiliac atmosphere is required with antibiotic-containing selective media.