Campylobacteriosis is an infection by one of several species of Campylobacter bacteria, particularly Campylobacter jejuni (C. jejuni). This infection typically causes diarrhea. The infection also can cause fever and abdominal cramps.
Humans usually become infected with Campylobacter after eating poorly prepared meat, especially undercooked chicken. Campylobacter is currently the most common bacterial cause of food-borne illness in the United States, producing more infections than either Salmonella or Escherichia coli (E. coli).
Infants have an especially high rate of campylobacteriosis because of their immature immune defenses. Young adults also are at higher risk of infection, possibly because they have less experience cooking and handling raw meats. So, they may be exposed more often to potentially contaminated foods.
Most healthy people probably develop some degree of immunity against Campylobacter as they mature. This may account for the lower number of cases of Campylobacter infection in middle-aged and older adults.
Besides being transmitted to humans in tainted, undercooked meat, Campylobacter also can contaminate unpasteurized milk and untreated water. In addition, Campylobacter bacteria sometimes infect humans who have handled raw meat (especially poultry), touched a sick pet that has diarrhea, or traveled to undeveloped countries where sanitation is poor. Although it is possible to develop campylobacteriosis after direct contact with an infected person, this is not common.
People with weakened immune systems, such as those with HIV infection, are more likely to become infected with Campylobacter.They also tend to have symptoms that are more severe.