Campylobacteriosis

• Reporting criteria
• The disease and its epidemiology
• Case definitions

• Laboratory testing
• Case investigation
• Disease control measures

• References
• Contact

What and how to report to the Colorado Department of Public Health and Environment (CDPHE) or local public health agency  

• All specimens with a positive test for Campylobacter (regardless of specimen source) by culture, enzyme immunoassays (EIA), polymerase chain reaction (PCR), or other form of testing should be reported to public health within four (4) days of the positive test result.
  • All positive Campylobacter laboratory tests should be reported to public health, regardless of symptoms. Public health will make the determination of whether the case meets the case definition. 
• Cases should be reported using EpiTrax Reportal, fax or telephone to CDPHE or local health departments (telephone and fax numbers are listed at the end of this document).
• All potential foodborne, waterborne, and enteric disease outbreaks should be reported immediately to CDPHE or local health departments and entered into EpiTrax, even if the causative agent is not yet known. 
  • In general, an “outbreak” is defined as an increase in the number of illnesses above what is normally expected among a specific population, within a given area, over a certain period of time. 
  • Specifically, a foodborne disease outbreak occurs when two or more people get the same illness from the same contaminated food or drink.

Purpose of surveillance and reporting

• To identify cases for investigation and potential outbreaks
• To monitor trends in disease incidence

Back to top

Etiologic agent

Campylobacteriosis refers to disease caused by bacteria in the genus Campylobacter. C. jejuni and C. coli are the most common species isolated from patients with diarrhea. Other Campylobacter organisms, including C. lari, C. fetus and C. upsaliensis, have been associated with diarrhea in normal and immunocompromised hosts.

Clinical description

The most common symptoms of campylobacteriosis are diarrhea (often bloody), abdominal pain, and fever. Nausea and vomiting may accompany the diarrhea. Asymptomatic infections may occur. Symptoms usually resolve within a week, however some individuals may have prolonged symptoms and sometimes relapse. Rarely, patients develop long-term complications including reactive arthritis, irritable bowel syndrome, and Guillain-Barré syndrome, a rare disease that affects the nerves of the body beginning several weeks after the diarrheal illness. Guillain-Barré syndrome results in paralysis that lasts several weeks and usually requires intensive care. Extraintestinal infection, although rare, can occur in immunosuppressed patients, presenting as bacteremia, meningitis, or other focal infections. Gastrointestinal symptoms may be absent in these instances.

Reservoirs

Campylobacter bacteria are found in swine, sheep, and other animals and are very common in the gastrointestinal tracts of cattle and poultry. Pets such as birds, kittens, and puppies may be sources of human infection. A very large percentage of raw chicken is contaminated with C. jejuni.

Modes of transmission

Campylobacter bacteria are transmitted via the fecal-oral route. A small dose of Campylobacter (fewer than 500 organisms) can cause illness. The most common mode of transmission is ingestion of food or water that has been contaminated with animal or human feces. This includes raw and undercooked poultry, raw milk, and raw milk products. In particular, infections can occur through cross-contamination when cutting boards are used for both raw poultry and vegetables without adequate cleaning in between. However, any food contaminated with the bacteria can be a source of infection. The risk of transmission may be elevated during international travel, especially to regions where the bacteria is endemic. Person-to-person spread appears to be uncommon though may occur, especially among household contacts and in settings with diapered children.

Incubation period

The average incubation period is 2–5 days but can range from 1 to 10 days.

Infectious period

The disease is communicable for as long as the infected person excretes Campylobacter bacteria in their stool, which generally begins at the onset of symptoms and can last 2 to 7 weeks without antibiotic treatment. Antibiotics, when prescribed early in the infection, usually eradicate the organism from the stool within 2 to 3 days. As is the case with most enteric illnesses, people are most infectious when they have diarrhea and are usually more infectious than those who are asymptomatic.

Epidemiology

Campylobacter is the most common bacterial cause of diarrheal illness in Colorado and in the U.S. During 2023, 1,720 cases were reported in Colorado, with a five-year average of 1,229 cases per year (2019-2023). Cases are reported throughout the year, but are more common in the summer months. 

Campylobacter spp. is the second most common cause of domestically acquired foodborne illnesses in the U.S. In 2022, there were 66,613 campylobacteriosis cases reported in the United States, with a five-year average of 64,699 cases per year (2018-2022). During this time period, 20% of campylobacteriosis cases in the FoodNet catchment area were hospitalized and < 1% of cases died. Fewer than 1% of cases were outbreak-associated, and approximately 10% were acquired internationally.

While Campylobacter outbreaks are generally less frequent than other enteric pathogens, notable outbreaks in the United States include outbreaks attributed to contact with pet store puppies, raw milk, and undercooked chicken livers.

For more data, see Colorado reportable disease data (Colorado data), CDC WONDER and CDC BEAM Dashboard (national data), and CDC FoodNet Fast (FoodNet catchment area data).

Back to top

Clinical criteria

An illness of variable severity commonly manifested by diarrhea, abdominal pain, nausea and sometimes vomiting. The organism may also rarely cause extra-intestinal infections such as bacteremia, meningitis or other focal infections.

Laboratory criteria for diagnosis

• Confirmed
  • Isolation of Campylobacter spp. from a clinical specimen
• Probable
  • Detection of Campylobacter spp. in a clinical specimen using a culture independent diagnostic test (CIDT)

Epidemiologic linkage

A clinically compatible case that is epidemiologically linked to a case that meets the probable or confirmed laboratory criteria for diagnosis.

Criteria to distinguish a new case from an existing case

A case should not be counted as a new case if laboratory results were reported within 30 days of a previously reported infection in the same individual.

Case classification

Confirmed

• A case that meets the confirmed laboratory criteria for diagnosis
• Probable
• A case that meets the probable laboratory criteria for diagnosis OR 
• A clinically compatible case that is epidemiologically linked to a probable or confirmed case of campylobacteriosis.

Interpretation note: Epi-linked probable cases can be epi-linked to either a confirmed or probable case, as long as the index case has a positive test result (see laboratory criteria above). Additionally, confirmed or laboratory-confirmed probable cases can include asymptomatic infections and infections at sites other than the gastrointestinal tract that are laboratory-confirmed (rare).

Back to top

• The Colorado State Public Health Laboratory (“State Lab”) provides testing services to support public health investigations. 
• The State Lab may test clinical and/or environmental samples when determined to be necessary for public health investigations. These services vary by pathogen but may include:
  • Testing for individuals who have been restricted or excluded from work or child care by public health
  • Testing for outbreak investigations, with prior approval from CDPHE
  • Other testing services as discussed with CDPHE
• The State Lab maintains a test directory, guidance for submitting samples, and other helpful resources on their webpage.
  • Additional questions can be directed to the Lab Coordinators by email (cdphe_labcoordinators@state.co.us; preferred method) or phone 303-692-3069.

Back to top

Interview all confirmed and probable (including epi-linked probable) cases of campylobacteriosis to determine:

• Potential source of infection, and implement disease control measures as appropriate 
• If others are ill (i.e., could this be an outbreak?) 
• If the case may be a source of infection for others (e.g., a high-risk worker or a diapered child); and if so, prevent further transmission

Local health departments have primary responsibility for interviews of sporadic cases in their jurisdictions. CDPHE is available to assist with case investigations upon request through CDPHE’s Enteric Disease Interview Team (EDIT). Interviews should be conducted and appropriate disease control measures implemented as soon as reasonably possible after the case is reported.

Forms 

For single cases, use the CDPHE Campylobacteriosis case investigation form for the interview, and enter the information into the case’s morbidity record (CMR) in EpiTrax. Interview all cases, regardless of specimen source (stool, blood, wound, urine, etc.).

For surveillance purposes, collect exposure histories for the seven days before symptom onset. Determining the exposure period can be difficult for cases who do not have an acute onset of gastrointestinal symptoms. It’s important to do a complete assessment for GI illness, even when the specimen was collected from a source other than stool, to determine if any GI symptoms were present, even if mild. Use the following criteria to determine the case’s exposure period:

1. If the case reports diarrhea or vomiting, then use the onset date of diarrhea/vomiting to determine exposure period.
2. If the case does not report diarrhea or vomiting but reports other clinically relevant symptoms (see Clinical description section above), then use the onset date of other symptoms to determine exposure period.
3. If the case does not report onset of any clinically relevant symptoms (see Clinical description section above), then use the specimen collection date to determine exposure period.*

*Do not enter specimen collection date as “onset date” in EpiTrax (clinical tab); use this date to determine exposure period only. “Onset date” in EpiTrax only applies if the case experienced symptoms of illness. Otherwise, leave this field blank.

If the case reports international travel for even one day during their exposure period, it is fine to complete the travel section, then skip to the “School, work, and volunteer information” section. No other additional exposure information needs to be collected.

After completing the case interview, enter the information into the case’s morbidity record (CMR) in EpiTrax, including the investigation form, and conduct any necessary disease control activities. If an outbreak is suspected, create a new outbreak in EpiTrax, and contact CDPHE if assistance is needed; this includes requests for additional testing at the State Lab.

Identify and evaluate contacts

Symptomatic contacts

• Contacts of a case with a positive lab test who have clinically compatible symptoms are epi-linked probable cases and are treated the same as cases with a positive lab test for disease control purposes. See Disease control measures below. 
  • Complete a case interview with all epidemiologically linked probable cases.
  • Epi-linked probable cases who have been interviewed should be entered into EpiTrax as a new, probable campylobacteriosis morbidity record (CMR). Link this newly created CMR to the laboratory-confirmed case’s CMR under the “contacts” tab in EpiTrax.
• Refer symptomatic individuals who have not previously been tested (especially if they are high-risk workers) to their health care provider for stool testing and appropriate medical care.
• If a common source of exposure is suspected (e.g., a shared meal or social event), create an outbreak record in EpiTrax, and notify CDPHE as soon as possible.  

Asymptomatic contacts 

• Ask about high-risk occupations, including food handling, health care, community residential programs, and child care/school attendance. 
• Provide information on symptom monitoring and next steps if symptoms develop.
  • Stress the importance of good hand washing, personal hygiene, excluding themselves from work, and notifying their supervisor whenever they have a diarrheal illness.  
  • If an asymptomatic contact develops diarrhea, follow the steps outlined above under Symptomatic contacts. If the contact works in a high-risk setting, exclude them from work per the Managing special situations section below, even in the absence of a positive lab test.

Reported incidence is higher than usual/outbreak suspected

If the number of reported cases of campylobacteriosis in your jurisdiction is higher than usual, or if an outbreak is suspected, investigate the situation to determine the source of infection and mode of transmission. Notify CDPHE as soon as possible to discuss potential stool testing of untested, symptomatic contacts, and enter the outbreak into EpiTrax. CDPHE staff can assist local public health agencies to investigate outbreaks and determine disease control recommendations to prevent further cases, as well as coordinate surveillance of cases that cross county lines.

Back to top

Campylobacter (Campylobacteriosis) | CDC

Treatment

Most persons infected with Campylobacter do not require antimicrobial therapy. In more severe cases, antibiotics can be used. Antibiotics can shorten the duration of symptoms if they are given early in the illness and will eradicate the organism from the stool. Because antimicrobial resistance to Campylobacter is increasing, health care providers should check the antimicrobial susceptibility pattern of the isolate before prescribing antibiotics.

In general, individuals experiencing diarrhea are at risk of dehydration due to loss of fluids. If symptoms persist, worsen, or are severe, cases should promptly seek medical care.

Prophylaxis

No prophylactic treatment of close contacts is recommended.

Education

Encourage the case to:

• Avoid preparing food for other individuals until diarrhea has resolved. 
• Always wash hands thoroughly with soap and water for at least 20 seconds before eating or preparing food, after using the toilet, after changing diapers, and after touching pets or other animals (especially puppies and kittens with diarrhea). 
• After changing diapers, wash your hands and the child’s hands for at least 20 seconds. Clean and sanitize diaper changing stations/areas often.
  • In child care and other institutional settings, dispose of stool and soiled diapers/linens in a sanitary manner.
• Keep food that will be eaten raw, such as fruits and vegetables, from becoming contaminated by raw, animal-derived food products (e.g., raw meat, fish, poultry) by cleaning or using different knives and cutting boards during preparation. Store raw, animal-derived foods away from other foods that will be eaten raw while in the refrigerator.
• Thoroughly cook all food products from animals, especially poultry, and avoid consuming unpasteurized milk, or other unpasteurized products.

Managing special situations

Food handlers 

• Food handlers with campylobacteriosis must be excluded from work until at least 24 hours after diarrhea has resolved without the use of anti-diarrheal medications and adequate hygiene can be maintained, ideally as verified by environmental health. "Exclude" means to prevent a person from working as an employee in a food establishment or entering a food establishment as an employee. 
  • While individual circumstances may vary, cases are generally not required to provide two consecutive negative stool tests to return to work. 
  • If a case has questionable hygienic practices or there are other concerns, consider excluding the case from work until the case has obtained two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• In an outbreak situation, longer exclusion and/or return to work testing may be required to return to food handling.
• The Colorado Retail Food Establishment Regulations may require additional restrictions or disease control measures for the case, their close contacts, and/or their employer. 
  • Please consult with environmental health to determine if the case’s place of employment should enact additional disease control measures to be in compliance with the regulations. 

Child care centers/preschools

Refer child care providers to the CDPHE Infectious Disease in Child Care and School Settings for an overview of Campylobacter infections.

• Children or staff with campylobacteriosis should be excluded until at least 24 hours after diarrhea has resolved without the use of anti-diarrheal medications. 
  • Parents of cases should be counseled not to take their children to another child care center during this period of exclusion in order to avoid possible transmission of campylobacteriosis at a new location.
  • Since many child care center staff assist with food preparation and/or feeding children, it is very important that staff with Campylobacter infection follow this exclusion guidance. See Disease control measures section (Food handlers) above.
  • If there are concerns about hygienic practices at the child care center, consider excluding the case from care until the case has obtained two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.
• Determine whether additional children or staff are (or have recently been) ill with diarrheal illness.
  • Other children or staff with diarrhea should be excluded and referred to their health care provider for stool testing and appropriate medical care. 
  • If other cases in the center are identified, initiate an outbreak investigation and consider sending a letter home to parents.
    • In an outbreak situation, longer exclusion and/or return to work/child care testing may be required. Contact CDPHE for assistance.
  • If the case is the only person in the classroom or facility who has been ill, no further action is indicated for other children/staff in that classroom or center.
• Reinforce the importance of meticulous hand washing, proper sanitizing and disinfection, and proper diaper changing technique with child care center staff. If possible, this should be verified by environmental health.
• Consult with CDPHE for instances in which children attend drop in style care at gyms, churches, etc.

Schools 

Refer school personnel to the CDPHE Infectious Disease in Child Care and School Settings for an overview of Campylobacter infections. 

• Students or staff with campylobacteriosis should be excluded until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications.
• If there are concerns about the case’s hygiene (e.g., the case has developmental disabilities and wears diapers) consider obtaining two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given, before a case returns to school.
• Students or staff who handle food for others must not prepare food until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. See Disease control measures section (Food handlers) above. 
• In an outbreak situation, longer exclusion and/or return to work/school testing may be required.

Community residential programs (including facilities serving the developmentally disabled)

Actions taken in response to a case of campylobacteriosis in a community residential program will depend on the type of program and the level of functioning of the residents. In general: 

• Staff members with campylobacteriosis should be excluded from work until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. 
• For staff members who provide direct patient care (e.g., feed patients, give mouth or denture care, or give medications), follow guidelines for staff in health care facilities below. 
• While individual circumstances may vary, in general, staff members are not required to provide two negative stool tests to return to work. 
• Residents with campylobacteriosis should be placed on contact precautions until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications.
• If the resident has questionable hygiene, is incontinent, or there are other concerns, the resident should remain on contact precautions until they have obtained two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given. 
• Residents and staff with campylobacteriosis must be excluded from handling or preparing food for others until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. See Disease control measures section (Food handlers) above. 
• In an outbreak situation, longer exclusion and/or return to work testing may be required.

Patients and staff in health care facilities (including hospitals, medical and dental clinics, skilled nursing and long-term care facilities)

Hospitals and skilled nursing/long-term care facilities generally have written infection control policies and procedures for handling cases of communicable disease among patients and staff members. 

If a facility does not have such policies in place, provide the following recommendations: 

• Health care workers with campylobacteriosis who provide direct patient care or handle medications (e.g., pharmacists) should be excluded from work until at least 24 hours after diarrhea has resolved without the use of anti-diarrheal medications.
  • While individual circumstances may vary, in general, health care workers are not required to provide two negative stool tests to return to work. 
• Patients with campylobacteriosis should be placed on contact precautions until at least 24 hours after their diarrhea has resolved without the use of anti-diarrheal medications. 
  • If the patient has questionable hygiene, is incontinent, or there are other concerns, the patient should remain on contact precautions until they have obtained two consecutive negative stool tests collected at least 24 hours apart and at least 48 hours after completion of antibiotics, if antibiotics are given.  
• In an outbreak situation, longer exclusion and/or return to work testing may be required.

Environmental measures

• Implicated food items and food prepared by cases must be removed from the environment. 
• A decision about testing suspect/implicated food items must be made in consultation with CDPHE. 
  • The general policy of the State Lab and the Communicable Disease Branch is only to test food samples associated with outbreaks, not in single cases.
• If a commercial product is suspected, CDPHE Communicable Disease Branch will coordinate follow-up with the CDPHE Division of Environmental Health and Sustainability and relevant outside agencies.

Back to top

American Academy of Pediatrics. Red Book: 2024-2027 Report of the Committee on Infectious Diseases, 33rd Edition. Illinois, Academy of Pediatrics, 2024.  

Campylobacteriosis (Campylobacter spp.) 2015 Case Definition | CDC. (n.d.). https://ndc.services.cdc.gov/case-definitions/campylobacteriosis-2015/

CDC Website “Diseases and Conditions”) 

Centers for Disease Control and Prevention (CDC). BEAM (Bacteria, Enterics, Ameba, and Mycotics) Dashboard. Atlanta, Georgia: U.S. Department of Health and Human Services. www.cdc.gov/ncezid/dfwed/BEAM-dashboard.html. Accessed 05/21/2025.

Centers for Disease Control and Prevention (CDC). FoodNet Fast: Pathogen Surveillance Tool. Atlanta, Georgia: U.S. Department of Health and Human Services. Available from URL: http://wwwn.cdc.gov/foodnetfast. Accessed 05/16/2025.

Heymann DL, ed. Control of Communicable Diseases Manual, 21st Edition. Washington, DC, American Public Health Association, 2022.

National Notifiable Diseases Surveillance System. Annual Summary Data 2018-2022 Request. (n.d.). https://wonder.cdc.gov/nndss-annual-summary.html

Zhao, C., Ge, B., De Villena, J., Sudler, R., Yeh, E., Zhao, S., White, D. G., Wagner, D., & Meng, J. (2001). Prevalence of Campylobacter spp., Escherichia coli, and Salmonella Serovars in Retail Chicken, Turkey, Pork, and Beef from the Greater Washington, D.C., Area. Applied and Environmental Microbiology, 67(12), 5431–5436. https://doi.org/10.1128/aem.67.12.5431-5436.2001

Back to top

CDPHE Communicable Disease Branch

• Phone: 303-692-2700 or 800-866-2759
• Fax: 303-782-0338
• After hours: 303-370-9395

CDPHE Laboratory Coordinators

• cdphe_labcoordinators@state.co.us (preferred method)
• Phone 303-692-3069

Back to top