Questions and Answers
- What is Campylobacter infection?
- What are the symptoms of Campylobacter?
- What kind of germ is Campylobacter?
- How does food and water get contaminated with Campylobacter?
- How do people get infected with Campylobacter bacteria?
- How is Campylobacter infection diagnosed and treated?
- Is Campylobacter infection serious?
- What are public health agencies doing to control Campylobacter and prevent infections?
Campylobacter infection, or campylobacteriosis, is an infectious disease caused by Campylobacter bacteria. It is one of the most common causes of diarrheal illness in the United States. The Foodborne Diseases Active Surveillance Network (FoodNet) indicates that about 14 cases are diagnosed each year for every 100,000 people. Many more cases go undiagnosed or unreported. CDC estimates Campylobacter infection affects more than 1.5 million people every year. Most cases are not part of recognized outbreaks, and more cases occur in summer than in winter.
People with Campylobacter infection usually have diarrhea (often bloody), fever, and abdominal cramps. The diarrhea may be accompanied by nausea and vomiting. These symptoms usually start within two to five days after exposure and last about a week. Some infected people do not have any symptoms. In people with weakened immune systems, such as people with the blood disorders thalassemia and hypogammaglobulinemia, AIDS, or people receiving some kinds of chemotherapy, Campylobacter occasionally spreads to the bloodstream and causes a life-threatening infection.
Campylobacter are bacteria that can make people and animals sick. Most human illness is caused by one species, called Campylobacter jejuni, but other species also can cause human illness.
Many chickens, cows, and other birds and animals that show no signs of illness carry Campylobacter. Campylobacter can be carried in the intestines, liver, and giblets of animals and can be transferred to other edible parts of an animal when it’s slaughtered. In 2014, National Antimicrobial Resistance Monitoring System (NARMS) testing found Campylobacter on 33% of raw chicken bought from retailers.
Milk can become contaminated when a cow has a Campylobacter infection in her udder or when milk is contaminated with manure. Other foods, such as fruits and vegetables, can be can become contaminated through contact with soil containing feces from cows, birds, or other animals. Animal feces can also contaminate lakes and streams. Pasteurization of milk, washing or scrubbing of fruits and vegetables, and disinfection of drinking water helps prevent illness.
It takes very few Campylobacter germs (fewer than 500) to make someone sick. That means a single drop of juice from raw chicken can have enough Campylobacter in it to infect someone.
Most Campylobacter infections are associated with eating raw or undercooked poultry or from contamination of other foods by these items. People can get infected when a cutting board that has been used to cut and prepare raw chicken isn’t washed before it is used to prepare foods that are served raw or lightly cooked, such as salad or fruit. People also can get infected through contact with the feces of a dog or cat. Campylobacter does not usually spread from one person to another.
Outbreaks of Campylobacter infections have been associated most often with poultry, raw (unpasteurized) dairy products, untreated water, and produce.
Campylobacter infection is common in the developing world, and people who travel abroad have a greater chance of becoming infected. About 1 in 5 Campylobacter infections reported to the Foodborne Diseases Active Surveillance Network (FoodNet) are associated with international travel.
Even more rarely, people may become infected through contaminated blood during a transfusion.
Campylobacter infection is diagnosed when a laboratory test detects Campylobacter bacteria in stool, body tissue, or fluids. The test could be a culture that isolates the bacteria or a rapid diagnostic test that detects genetic material of the bacteria.
Most people with Campylobacter infection recover without specific treatment. Patients should drink extra fluids as long as the diarrhea lasts. Antibiotics are needed only for patients who are very ill or at high risk for severe disease, such as people with severely weakened immune systems; the blood disorders thalassemia and hypogammaglobulinemia; or AIDS; and people receiving chemotherapy.
Most people with a Campylobacter infection recover completely within a week, although they may shed (get rid of) Campylobacter bacteria in their stool for several weeks after recovery, which might result in person-to-person transmission. Campylobacter infection rarely results in long-term consequences. Some studies have estimated that 5–20% of people with Campylobacter infection develop irritable bowel syndrome for a limited time and 1–5% develop arthritis.
About 1 in every 1,000 reported Campylobacter illnesses leads to Guillain-Barré syndrome (GBS). GBS happens when a person’s immune system is triggered by an earlier infection, such as Campylobacter infection. GBS can lead to muscle weakness and sometimes paralysis that can last for a few weeks to several years, and often requires intensive medical care. Most people recover fully, but some have permanent nerve damage, and some have died of GBS. As many as 40% of GBS cases in the United States may be triggered by Campylobacter infection.
CDC tracks all reported human Campylobacter infections and works to identify the source of infections transmitted by food and other routes. Through the surveillance systems listed below, CDC monitors cases, estimates the total number of people infected each year, targets prevention measures to meet food safety goals, and provides data and analyses that inform food safety action and policy.
- PulseNet, a national laboratory network that detects foodborne disease outbreaks, compares the DNA fingerprints of Campylobacter from patients to find clusters of illnesses that may represent an outbreak.
- FoodNet, a collaboration among CDC, 10 state health departments, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS), and the Food and Drug Administration (FDA), collects data on human infections caused by Campylobacter.
- National Antimicrobial Resistance Monitoring System (NARMS), a collaboration among state and local public health departments, CDC, the U.S. Food and Drug Administration, and the U.S. Department of Agriculture, tracks changes in antibiotic resistance among Campylobacter bacteria isolated from humans, retail meats, and food animals.
- National Outbreak Reporting System (NORS) collects data from state health departments for Campylobacter outbreaks.
- Laboratory Enteric Disease Surveillance (LEDS) collects data for laboratory-confirmed Campylobacter infections from state public health laboratories.
U.S. Department of Agriculture Food Safety and Inspection Service (USDA-FSIS)external icon regulates meat, poultry, and processed eggs. In 2011, USDA-FSIS established performance standards to limit Campylobacter contamination of whole broiler chickens, requiring contamination rates to be no more than 10.4% of samples in processing plants. In 2016, USDA-FSIS implemented further measures, requiring Campylobacter contamination rates to be no more than 1.9% in ground chicken and turkey products and 7.7% in raw chicken parts in processing plants. USDA-FSIS also is posting contamination testing results onlineexternal icon.
U.S. Food and Drug Administration (FDA)external icon regulates all foods other than those regulated by USDA-FSIS. FDA publishes the Food Codeexternal icon, a model for regulating retail and food service establishments, including restaurants, grocery stores, and institutions, such as nursing homes. The FDA Food Safety Modernization external iconAct, passed in 2011, aims to ensure the U.S. food supply is safe by shifting the focus to preventing contamination.