Merck Manual

Please confirm that you are not located inside the Russian Federation


Campylobacter Infections


Larry M. Bush

, MD, FACP, Charles E. Schmidt College of Medicine, Florida Atlantic University

Last full review/revision Feb 2020| Content last modified Feb 2020
Click here for the Professional Version
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version

Several species of the gram-negative bacteriaCampylobacter (most commonly Campylobacter jejuni) can infect the digestive tract, often causing diarrhea.

  • People can be infected when they consume contaminated food or drink or have contact with infected people or animals.

  • These infections cause diarrhea, abdominal pain, and fever.

  • Identifying the bacteria in a stool sample confirms the diagnosis.

  • For some people, replacing lost fluids is all that is needed, but if symptoms are severe, antibiotics are also needed.

(See also Overview of Bacteria.)

Campylobacter bacteria normally inhabit the digestive tract of many farm animals (including cattle, sheep, pigs, and fowl). The feces of these animals may contaminate water in lakes and streams. Meat (usually poultry) and unpasteurized milk may also be contaminated. People may be infected in several ways:

  • Eating or drinking contaminated (untreated) water, unpasteurized milk, undercooked meat (usually poultry), or food prepared on kitchen surfaces touched by contaminated meat

  • Contact with contaminated food or water (for example, when handling contaminated food)

  • Contact with an infected person (particularly oral-anal sexual contact)

  • Contact with an infected animal

Campylobacter bacteria, usually Campylobacter jejuni, cause inflammation of the colon (colitis) that results in fever and diarrhea. These bacteria are a common cause of infectious diarrhea in the United States and among people who travel to countries where food or water may be contaminated.

Campylobacter jejuni affects healthy and ill people and causes diarrhea in all age groups. It seems to mostly affect children 1 to 5 years of age.


Campylobacter symptoms usually develop 2 to 5 days after exposure and continue for about 1 week. Symptoms of Campylobacter colitis include diarrhea, abdominal pain, and cramps, which may be severe. The diarrhea may be watery and sometimes bloody and can be accompanied by nausea, vomiting, headache, muscle aches, and fever ranging from 100 to 104° F (38 to 40° C).


Complications of Campylobacter infection can include

Bacteremia occurs temporarily in some people with colitis. This infection usually causes no symptoms or complications. However, the bloodstream is repeatedly or continuously infected in a few people, usually those with a disorder that weakens the immune system, such as AIDS, diabetes, or cancer. This infection causes a long-lasting or recurring fever.

Other symptoms develop as the bloodstream carries the infection to other structures, such as the following:

Guillain-Barré syndrome (a nerve disorder) develops in about 1 of 2,000 of people with Campylobacter colitis because antibodies that the body makes to fight off the infection sometimes also attack the nerves. Guillain-Barré syndrome causes weakness or paralysis. Most people recover, but muscles may be greatly weakened. People may have difficulty breathing and need to use a mechanical ventilator. Weakness does not always completely resolve. About 25 to 40% of people who develop Guillain-Barré syndrome have had a previous Campylobacter infection

Reactive arthritis may develop days to weeks after the diarrhea resolves. Usually, the disorder causes inflammation and pain in the knees, hips, and Achilles tendon.

Inflammation of the eyes (uveitis) and the urethra (causing painful urination) may also occur.


  • Culture of a stool sample

  • Sometimes culture of a blood sample

Doctors may take a sample of stool and send it to a laboratory to grow (culture) and identify the bacteria. However, stool is not always tested. Stool cultures take days to complete, and doctors do not usually need to know which bacteria caused the diarrhea to effectively treat it. However, if people have bloody diarrhea or appear seriously ill, the stool is usually tested. A test that identifies genetic material of the bacteria in stool, called the polymerase chain reaction (PCR) technique, may be used so that the bacteria can be detected more quickly. The PCR technique increases the amount of the bacteria's DNA to make it easier to detect. Other tests may rapidly identify the bacteria (antigen) in the stool.

If the bacteria are identified, they are tested to see which antibiotics are effective (a process called susceptibility testing).

If doctors suspect that the bloodstream or other organs are infected, they take a sample of blood to be cultured.


  • Usually no specific treatment

  • Sometimes an antibiotic such as azithromycin

Many people get better in a week or so without specific treatment.

Some people require extra fluids by vein (intravenously) or by mouth.

People who have a high fever, bloody or severe diarrhea, or worsening symptoms may need to take azithromycin for 3 days by mouth. Ciprofloxacin is an alternative but is used with caution because resistance to this antibiotic is increasing.

If the bloodstream is infected, antibiotics such as imipenem or gentamicin are required for 2 to 4 weeks. The antibiotics used first may be adjusted based on results of the susceptibility tests.

More Information

Drugs Mentioned In This Article

Generic Name Select Brand Names
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Also of Interest


View All
Overview of Tuberculosis (TB)
Overview of Tuberculosis (TB)
3D Models
View All
COVID-19 Virus
3D Model
COVID-19 Virus