The pathogenic mechanisms of C. jejuni are still not completely understood, but it does produce a heat-labile toxin that may cause diarrhea. C. jejuni may also be an invasive organism. However, most clinical laboratories are equipped to isolate Campylobacter spp. C. jejuni frequently contaminates raw chicken. This is not overly surprising since many healthy chickens carry these bacteria in their intestinal tracts.
Raw milk is also a source of infections.
The bacteria are often carried by healthy cattle and by flies on farms. Non-chlorinated water may also be a source of infections. However, properly cooking chicken, pasteurizing milk, and chlorinating drinking water will kill the bacteria. Complications are relatively rare, but infections have been associated with reactive arthritis, hemolytic uremic syndrome , and following septicemia, infections of nearly any organ. Fatalities are rare in healthy individuals and usually occur in cancer patients or in the otherwise debilitated.