About Campylobacter infection

Key points

  • Campylobacter bacteria are a common cause of diarrheal illness. The illness is called campylobacteriosis.
  • People most commonly get Campylobacter infection by eating raw or undercooked poultry.
  • Eating other contaminated foods, drinking untreated water, and touching animals that carry Campylobacter can also cause infection.
A three-dimensional computer-generated image of a cluster of curly-cue shaped Campylobacter bacteria.


Campylobacter are bacteria that can make people ill with diarrhea. The illness is called campylobacteriosis.

Campylobacter cause the most bacterial diarrheal illnesses in the United States. CDC estimates that 1.5 million people in the United States get ill from Campylobacter every year.

Fast facts

  • Many Campylobacter infections are not diagnosed or reported.
  • Most infections are not part of recognized outbreaks.
  • Infections are more common in summer than in winter.

People at risk

Anyone can get Campylobacter infection. But some groups of people are at increased risk for infection or serious illness. These groups include

  • Children younger than 5
  • Adults 65 and older
  • People with a weakened immune system
  • People who work with animals
  • International travelers

How it spreads

Campylobacter can spread from animals to people.

Campylobacter can live in the intestines, liver, and other organs of animals. Many chickens, cows, and other animals carry Campylobacter without becoming sick.

Campylobacter can spread from these animals to people.

People can get infected in many ways.

It takes very few Campylobacter to make someone sick. For example, a single drop of juice from raw chicken can contain enough Campylobacter to cause an infection.

Common ways people get infected include:

  • Eating raw or undercooked poultry or other foods, including seafood, meat, and produce
  • Preparing raw or lightly cooked foods, including salad and fruits, with knives or on cutting boards that were used with raw poultry, seafood, or meat
  • Touching animals or their food, water, poop, belongings (such as toys and bowls), or habitats (such as beds, cages, tanks, coops, stalls, and barns)
  • Drinking untreated water

Some outbreaks linked to Campylobacter

Outbreaks of Campylobacter infections among people have been linked to many sources. Some of these sources include: