Campylobacteriosis (Campylobacter spp.)
2026 Case Definition

Background

Campylobacteriosis is a bacterial illness that generally causes a self-limited clinical illness typically characterized by diarrhea (bloody or non-bloody), abdominal cramps, fever, and nausea, sometimes with vomiting; asymptomatic infection also occurs frequently. Severe symptoms and invasive infections can also occur, and persons with Campylobacter infections are at increased risk for three post-infectious complications: Guillain-Barre syndrome (GBS), reactive arthritis, and irritable bowel syndrome. Campylobacter infection is transmitted by the fecal-oral route, usually through ingestion of contaminated food or water or through direct contact with infected animals. Person-to-person transmission is uncommon.

Clinical Criteria

• In the absence of an alternative etiology, a person with clinically compatible illness. Common presentations of illness include diarrhea (bloody or non-bloody), abdominal cramps, or vomiting.*

* Post-infectious, immune-mediated syndromes such as GBS, reactive arthritis, and irritable bowel syndrome are not directly caused by the infection and are not included as part of the clinical criteria. Common symptoms including fever and nausea, as well as extra-intestinal infections such as bacteremia, meningitis, or other localized infections may occur but are not included to classify a case without laboratory evidence.

Laboratory Criteria

Confirmatory Laboratory Evidence:

• Isolation of any Campylobacter spp. by culture in a clinical specimen from any source

Presumptive Laboratory Evidence:

• Detection of any Campylobacter spp. using a culture-independent diagnostic test (CIDT) in clinical specimen from any source.

Note: The categorical labels used here to stratify laboratory evidence are intended to support the standardization of case classifications for public health surveillance. The categorical labels should not be used to interpret the utility or validity of any laboratory test methodology.

Epidemiologic Linkage

• A person who shares an exposure with a confirmed or probable case of campylobacteriosis, OR 
• A person who is exposed to a confirmed case of campylobacteriosis, OR 
• A person who is exposed to a probable case with presumptive laboratory evidence of campylobacteriosis.

Criteria to Distinguish a New Case from an Existing Case

• A repeat positive culture or CIDT test result on a specimen collected more than 90 days since previous specimen collection date should be enumerated as a new case for surveillance.
• When two or more Campylobacter species are identified or detected from one or more specimens from the same individual, each identified infection with a unique species should be enumerated as a separate case.

Probable

• Meets the presumptive laboratory evidence, OR
• Meets the clinical criteria AND epidemiologic linkage criteria.

Confirmed

• Meets the confirmatory laboratory evidence.

• Campylobacteriosis (Campylobacter spp.) | 2015 Case Definition
• Campylobacteriosis (Campylobacter spp.) | 2012 Case Definition
• Campylobacteriosis (Campylobacter spp.) | 1990 Case Definition