Fact Sheet N°
Campylobacters are bacteria that are a major cause of
diarrhoeal illness in humans and are generally regarded as the most common
bacterial cause of gastroenteritis worldwide. In developed and developing
countries, they cause more cases of diarrhoea than, for example, foodborne
Salmonella bacteria. In developing countries, Campylobacter
infections in children under the age of two years are especially frequent,
sometimes resulting in death. In almost all developed countries, the
incidence of human campylobacter infections has been steadily increasing
for several years. The reasons for this are unknown.
Campylobacters are mainly spiral-shaped, S-shaped or
curved, rod-shaped bacteria. There are 16 species and six subspecies
assigned to the genus Campylobacter, of which the most frequently
reported in human disease are C. jejuni (subspecies jejuni) and C.
coli. C. laridis and C. upsaliensis are also regarded as primary
pathogens, but are generally reported far less frequently in cases of
human disease. Most species prefer a micro-aerobic
(containing 3-10% oxygen) atmosphere for growth.
A few species tend to favour an anaerobic environment, although they will
grow under micro-aerobic conditions also.
- Campylobacteriosis is the disease caused by the presence of
campylobacters. The onset of disease symptoms usually occurs two to
five days after infection, but can range from one to ten days.
- The most common clinical symptoms of campylobacter infections
include diarrhoea (frequently with blood in the faeces), abdominal
pain, fever, headache, nausea, and/or vomiting. The symptoms typically
last three to six days.
- A fatal outcome is rare and is usually confined to very young or
elderly patients, or to those already suffering from another serious
disease such as AIDS.
- Complications such as bacteremia, hepatitis, pancreatitis
(infections of the blood, liver and pancreas respectively), and
abortion have all been reported with various degrees of frequency.
Post-infection complications may include reactive arthritis (painful
inflammation of the joints which can last for several months) and
neurological disorders such as Guillain-Barré syndrome, a polio-like
form of paralysis that can result in respiratory and severe
neurological dysfunction or death in a small, but significant, number
- The high incidence of campylobacter diarrhoea, as well as its
duration and possible sequelae, makes it highly important from a
Sources and Transmission
- Campylobacters are widely distributed and occur in most warm-blooded
domestic, production and wild animals. They are prevalent in food
animals such as poultry, cattle, pigs, sheep, ostriches and shellfish;
and in pets, including cats and dogs.
- The main route of transmission is generally believed to be foodborne,
via undercooked meats and meat products, as well as raw or
contaminated milk. The ingestion of contaminated water or ice is also
a recognized source of infection.
- Campylobacteriosis is considered to be a zoonosis, a disease
transmitted to humans from animals or animal products. In animals,
campylobacters seldom cause disease.
- One of the major gaps in our knowledge at present is the relative
contribution of each of the above sources to the overall burden of
disease. Since common-source outbreaks account for a rather small
proportion of cases, the vast majority of reports are made
sporadically, with no easily discernible pattern. Estimation of the
importance of all known sources is therefore extremely difficult. In
addition, the wide occurrence of campylobacters also hinders the
development of strategies to control campylobacters in the food supply
"from farm to fork".
Control and Prevention Methods
- Treatment is not generally indicated, except electrolyte replacement
and rehydration. Antimicrobial treatment (erythromycin, tetracycline,
quinolones) is indicated in invasive cases or to eliminate the carrier
- The prevention of infection requires control measures at all
stages of the food chain, from agricultural production on the farm,
to processing, manufacturing and preparation of foods in both
commercial establishments and the domestic environment.
- Specific intervention methods on the farm have been shown to
reduce the incidence of campylobacter in poultry. Measures include
enhanced biosecurity to avoid horizontal transmission of
campylobacter from the environment to the flock of birds. This
control option is feasible only where birds are kept in closed
- There are no proven intervention methods to reduce campylobacter
in cattle farms. Prevention of the contamination of raw milk on the
farm is not consistently possible; therefore, consumption of raw
milk should be avoided.
- Good hygienic slaughtering practices will reduce contamination of
carcasses by faeces, but will not guarantee the absence of
campylobacter from meat and meat products. Education in hygienic
handling of foods for abattoir workers and those involved in the
production of raw meat is essential to keep microbiological
contamination to a minimum.
- The only effective method of eliminating campylobacter from
contaminated foods is to introduce a bactericidal treatment, such as
heating (e.g. cooking or pasteurization) or irradiation.
- Preventive measures for campylobacter infection in the household
kitchen are similar to those used against other foodborne bacterial
- In countries without adequate sewage disposal systems, faeces and
articles soiled with faeces may need to be disinfected before
Recommendations for the Public and Travellers
- Make sure your food is properly cooked and still hot when served.
- Avoid raw milk and products made from raw milk. Drink only
pasteurized or boiled milk.
- Avoid ice unless you are sure it is made from safe water.
- When the safety of drinking water is doubtful, boil it or if this is
not possible, disinfect it with a reliable, slow-release disinfectant
agent. These are usually available at pharmacies.
- Wash hands thoroughly and frequently using soap, in particular after
contact with pets or farm animals, or after having been to the toilet.
- Wash fruits and vegetables carefully, particularly if they are eaten
raw. If possible, vegetables and fruits should be peeled.
- WHO's brochure A Guide on Safe Food for Travellers gives
practical advice for safeguarding health when travelling*.
Recommendations for Food Handlers
- Both professional and domestic food handlers should be vigilant
during the preparation of food and should observe hygienic rules of
food preparation. (WHO's rules for safe food preparation can be
found at the following URL:http://www.who.int/fsf/gldnrls.htm
- Professional food handlers who suffer from fever, diarrhoea,
vomiting or visible infected skin lesions should report to their
- More information for food handlers is given in the WHO Guide on
Hygiene in Food Service and Mass Catering Establishments (Document
Journalists can contact the Spokesperson's Office, WHO, Geneva: Telephone:
(+41 22) 791 2599; Fax: (+41 22) 791 4858; E-mail: email@example.com
All WHO Press Releases, Fact Sheets and Features as well as other
information on this subject can be obtained on Internet on the WHO web
* A Guide on Safe Food
for Travellers is available from the Marketing and Distribution
office, WHO, Tel.: +41 22 791 2476; Fax: +41 22 791 4857; E-mail: firstname.lastname@example.org
The order number is 1910012 and the code is WHO/FOS/97.4.