Table 1.

Selected Presently Used Pertussis Case Definitions

Organization/Country, Year	Clinical Criteria	Laboratory and Epidemiologic Criteria	Comment
WHO, 2000	A case diagnosed as pertussis by a physician, or a person with a cough lasting ≥2 weeks with ≥1 of the following symptoms: paroxysms (ie, fits) of coughing inspiratory “whooping” posttussive vomiting (ie, vomiting immediately after coughing) without other apparent cause	Isolation of B. pertussis, or detection of genomic sequences by PCR, or positive paired serology	Case classification: clinical case: a case that meets the clinical case definition, but is not laboratory confirmed. laboratory-confirmed case: a case that meets the clinical case definition and is laboratory confirmed.
CSTE/CDC, 2010	A cough illness lasting ≥2 weeks with 1 of the following: paroxysms of coughing, inspiratory “whoop,” or posttussive vomiting, without other apparent cause (as reported by a health professional)	Isolation of B. pertussis from clinical specimen PCR positive for pertussis	Case classification: probable: in the absence of a more likely diagnosis, a cough illness lasting ≥2 weeks, with ≥1 of the following symptoms: paroxysms of coughing or inspiratory “whoop”or posttussive vomiting and absence of laboratory confirmation, and no epidemiologic linkage to a laboratory- confirmed case of pertussis confirmed: acute cough illness of any duration, with isolation of B. pertussis from a clinical specimen, or cough illness lasting ≥2 weeks, with ≥1 of the following symptoms: paroxysms of coughing or inspiratory “whoop” or posttussive vomiting and ≥1 of the following: PCR positive for pertussis or contact with a laboratory-confirmed case of pertussis
France, 2009	Patient coughing ≥14 days with 1 or more of the following: whoop vomiting cyanosis apnea	Patient coughing ≥14 days with: positive PCR/culture >100 IU/mL of anti-PT antibodies >3 year from vaccination or 100% change in the antibody titer between 2 serologies at 1-month interval	Epidemiologically confirmed: patient coughing ≥7 days and in contact in the past 20 days with a biologically confirmed case
Canada, 2009	Suspect case: one or more of the following, with no other known cause: paroxysmal cough of any duration cough with inspiratory “whoop” cough ending in vomiting or gagging, or associated with apnea Probable case: cough lasting 2 weeks or longer in the absence of appropriate laboratory tests and not epidemiologically linked to a laboratory – confirmed case AND ≥1 of the following, with no other known cause: Paroxysmal cough of any duration Cough with inspiratory “whoop” Cough ending in vomiting or gagging, or associated with apnea	Confirmed case: laboratory confirmation of infection: isolation of B. pertussis from an appropriate clinical specimen or detection of B. pertussis DNA from an appropriate clinical specimen and ≥1 of the following:  - cough lasting ≥2 weeks  - paroxysmal cough of any duration  - cough with inspiratory “whoop”  - cough ending with vomiting or gagging, or associated with apnea or epidemiologic link to a laboratory-  confirmed case and ≥1 of the following for which there is no other known cause:  - paroxysmal cough of any duration  - cough with inspiratory “whoop”  - cough ending in vomiting or gagging, or associated with apnea
Massachusetts, 2009	1989–1992: ≥1 week with paroxysms or posttussive vomiting From 1993: cough ≥2 weeks with 1 of the following: paroxysms, whoop, or posttussive vomiting (CDC definition)	Bacteriologic cases: positive culture (or + DFA until 1992), PCR added 2004  Serologic case: positive single-serum anti-pertussis toxin antibody (persons ≥11 years only) + clinical case definition Epidemiologically linked case: contact with a laboratory confirmed case + clinical case definition
EU, 2008	Cough ≥2 weeks with ≥1 of the following: paroxysms inspiratory “whooping” posttussive vomiting or any person diagnosed as pertussis by a physician or apnea episodes in infants	Isolation of B. pertussis Nucleic acids of B. pertussis B. pertussis–specific antibody response Epidemiologic link by human-to-human transmission	Possible case: any person with clinical criteria Probable case: person with clinical criteria and epidemiologic link Confirmed case: person meeting the clinical and laboratory criteria
Australia, 2004	Coughing ≥2 weeks or paroxysms of coughing or inspiratory whoop or posttussive vomiting	Culture of B. pertussis PCR for B. pertussis Seroconversion or significant increase of antibodies (without recent vaccination) Single IgA titer to whole cells Detection of B. pertussis by DFA	Probable case: Any person with clinical criteria Confirmed case: Person meeting the clinical and laboratory criteria or epidemiologic link

Abbreviations: CDC, Centers for Disease Control and Prevention; CSTE, Council of State and Territorial Epidemiologists; DFA, direct fluorescent antibody; EU, European Union; IgA, immunoglobin A; IU, international units; PCR, polymerase chain reaction; PT, pertussis toxin; WHO, World Health Organization.