***Consider reporting suspect pertussis cases in our NEW Online Case Report Form so we can exchange information in a confidential format more quickly (supported by IDPH portal REDCap survey). See more reporting instructions to the below.


Pertussis is a highly contagious respiratory disease caused by the bacteria Bordetella pertussis. Pertussis lives in the nose, mouth, and throat of infected individuals. 

The bacteria are shed in nasopharyngeal secretions and can be spread through coughing, sneezing, or direct contact with fluids from the nose, mouth, or throat of an infected person. If untreated, infected individuals can spread the pertussis bacteria to others from 1 week before cough onset to 21 days after cough onset. Untreated infants (<1 year) remain infectious for up to 42 days from cough onset. When treated with antibiotics, the infectious period is reduced to 5 days after the initiation of treatment. Severe infections can result in complications such as pneumonia among all age groups. Seizures and encephalopathy generally occur only among infants. The average incubation period for pertussis is 7-10 days with a range of 4-21 days.

Case Definition

A cough illness lasting ≥ 2 weeks with at least 1 of the following signs or symptoms:

  • Paroxysms of coughing, OR

  • Inspiratory “whoop,” OR

  • Post-tussive vomiting, OR

  • Apnea (with or without cyanosis) (for infants <1 year of age only)

Diagnostics Testing

1APHL Pertussis Brochure

2CDC Pertussis

  • Locally available FDA approved PCR tests for B. pertussis
    • Multiplex assay: Biofire FilmArray Respiratory Panel, bioMérieux
      • Targets the pertussis toxin promoter (ptxP): highly specific
  • Other locally available PCR tests for B. Pertussis
  • Singleplex assay: Typically, an in-house laboratory developed PCR method
    • Targets the insertion sequence IS481: highly sensitive
  • It is important to note research has found that PCR can detect pertussis in infants less than 6 months of age up to 3 weeks following pertussis treatment initiation. Pertussis positive PCR results may correspond to the presence of antibiotic-damaged bacteria. As a result, the clinical significance of pertussis detected by PCR after initiation of antibiotic treatment is unclear. For more information, see Real-Time PCR Measurement of Persistence of Bordetella pertussis DNA.

Bordetella pertussis Commercial Lab Reference Table


Specimen Collection

Collect nasopharyngeal (NP) swabs as soon as pertussis is suspected, within 21 days of cough onset.

  • Carefully insert swab through the nares straight back (not upwards) until reaching the posterior wall of the nasopharynx.
  • Gently roll and rub the swab.
  • Leave the swab in place for several seconds before slowly removing the swab.
  • For Specimen Handling, see CDC Specimen Collection Guidelines.

Prenatal Care To Prevent Pertussis

It is recommended pregnant women receive the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during each pregnancy. To maximize the maternal antibody response and passive antibody transfer to the infant, pregnant women should receive the vaccine between 27 through 36 weeks gestation. For more information, see Pregnancy and Whooping Cough.

Pertussis Reporting

To report suspect  Cases, use the Online Case Reporting Form

OR  Contact the CDPH Disease Reporting Hotline at 312-743-9000. 

*After hours, weekends, and holidays, call 311 and ask for the communicable disease physician on-call (or 312-744-5000 if outside the City of Chicago)

Schools:  please click here for reporting and  management

Cases should be reported within 24 hours.

Asset Publisher

Pertussis Contact

Complete the Online Case Report Form (*preferred) or

Fax paper Case Report Form to:
(312) 746-6388 or
Call Provider Reporting Hotline:
(312) 743-9000

Sign up for electronic reporting through the Illinois National Electronic Disease & Surveillance System (I-NEDSS)

For questions during non-business hours call 311.
(312-744-5000 if outside the City of Chicago.)