Campylobacteriosis is one of the most common causes of foodborne bacterial enteritis worldwide. Campylobacter species are curved gram-negative bacilli. At least 11 species of Campylobacter are considered pathogenic to humans, with Campylobacter jejuni and Campylobacter coli being the most common. Campylobacteriosis is a zoonosis, the natural reservoir being the gastrointestinal (GI) tract of livestock, birds, dogs, cats, rodents, and even household pets. Transmission to humans occurs by ingestion of contaminated food or water, including unpasteurized milk and undercooked meat, or by direct contact with fecal material from infected animals or persons. Infection with Campylobacter can be asymptomatic, cause acute enteritis or colitis, or cause bacteremia with seeding of distant organs.

Surveillance studies estimate that 1.3 million symptomatic enteric Campylobacter infections occur in the United States annually (14 cases per 100 000 persons). The vast majority of cases go undiagnosed or unreported and occur as isolated, sporadic events, not as part of recognized outbreaks. Death is uncommon, occurring in only 0.2% of reported cases. The organism is isolated more frequently from males than females. No clear racial predominance is evident. Campylobacteriosis is a global disease with a higher incidence in developing countries, particularly in tropical and subtropical regions.

After an incubation period of 3 days (range 1-7 days), infection is established, usually in the jejunum and ileum and occasionally the colon. The mucosal inflammatory changes are indistinguishable from those seen in salmonellosis and shigellosis. The clinical manifestations are of variable severity and include abdominal pain and diarrhea.

Patients may initially have a prodrome of high fever, rigors, generalized aches, and dizziness lasting for 1-2 days prior to the GI symptoms. Abdominal pain can be relatively severe compared with other bacterial enteritides. It is usually colicky and peri-umbilical; however, it may become sharper and radiate to right lower quadrant, mimicking acute appendicitis. Diarrhea can be profuse, frequent (more than 10 stools per day), and mixed with frank blood. Acute enteritis is often self-limiting and subsides within several days. Acute colitis may result in diarrhea lasting for a week or longer. Mild weight loss (less than 5 kg [11 lbs]) during this period of time is not uncommon. If bacteremia occurs, it is usually transient and is seldom detected (1.5 per 1000 cases).

Several conditions can increase risk for Campylobacter bacteremia, including HIV infection, other causes of immunodeficiency, malignancy, diabetes, alcohol use disorder, pregnancy, and extremes of age.

Campylobacter infection has been associated with acute extra-intestinal complications that may occur with or without preceding diarrhea: cholecystitis, hepatitis, pancreatitis, and peritonitis in patients with peritoneal dialysis; hemolytic-uremic syndrome; glomerulonephritis; myopericarditis; and massive GI bleeding.

Campylobacter infection is also associated with late-onset complications including reactive arthritis and Guillain-Barré syndrome.

Pediatric patient considerations: Campylobacter fetus and occasionally C jejuni are associated with perinatal infection. Amnionitis may develop due to bacteremia or by ascending infection. Premature labor, stillbirth, and septic abortion have been reported. Infants may develop sepsis, respiratory distress, diarrhea, vomiting, jaundice, and convulsions. Meningitis is a serious complication with increased morbidity and mortality.

In developed countries, incidence is highest in children younger than 1 year and in those aged 15-30 years. In developing countries, disease mainly occurs in children younger than 5 years.

Immunocompromised patient considerations: Immunocompromised patients may have a prolonged course of the infection and may have recurrent diarrhea. The risks for bacteremia, extra-intestinal complications, and development of antibiotic-resistant strains are increased.