Campylobacteriosis

What Is It?

In humans, infection by one of several species of Campylobacter bacteria, particularly Campylobacter jejuni (C. jejuni) and Campylobacter fetus (C. fetus) typically results in diarrhea. In addition to diarrhea, the infection can cause fever and abdominal cramps. Humans usually become infected with Campylobacter bacteria after eating poorly prepared meat, especially undercooked chicken. According to government statistics, 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). Although infants have an especially high rate of campylobacteriosis because of their immature immune defenses, young adults are also at higher risk of infection. The higher rate of Campylobacter infection among young adults may be to the result of lifestyle factors, especially inexperience in cooking and handling raw meats, that may increase their exposure to potentially contaminated foods. Because most healthy people probably develop some degree of immunity against Campylobacter as they mature, the number of cases of Campylobacter infection in middle-aged and older adults is fairly low.

Besides being transmitted to humans in tainted, undercooked meat, Campylobacter bacteria also can contaminate unpasteurized milk and untreated water. In addition, Campylobacter bacteria sometimes infect humans who have handled raw meat (especially poultry), who have touched a sick pet that has diarrhea, or who have traveled to undeveloped countries where sanitation is poor. Although it is also possible to develop campylobacteriosis after direct contact with an infected person, direct person-to-person spread is not common.

Among people with weakened immune defenses — especially those with HIV, cancer, liver disease or diabetes — Campylobacter bacteria can produce a pattern of recurrent infections. In these people, Campylobacter also can spread through the blood and attack other organs. In pregnant women, C. fetus bacteria can spread to the unborn child, sometimes causing fetal death.

Symptoms

Some people who have a Campylobacter infection never develop significant symptoms, and some have only a mild case of the illness that resolves on its own. When full-blown symptoms occur, they usually begin one to seven days after exposure to Campylobacter, with an average of two to five days. Initially, you may have a 12- to 48-hour period of fever, headache, muscle aches and malaise (a general feeling of sickness). These early symptoms are followed by crampy abdominal pain and diarrhea, sometimes with nausea and vomiting. In some cases, the diarrhea is fairly mild, with only a few loose stools each day. In other cases, there are more than 10 stools daily, and the diarrhea contains obvious blood.