Pertussis General Information Pertussis General Information



Pertussis  (Whooping Cough)

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)


Diagnostic Testing Diagnostic 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.
Specimen Collection 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.



Nov 2018 Pertussis Outbreak Nov 2018 Pertussis Outbreak

Breaking News:  November 2018

Pertussis Outbreak in Childcare Center: Provider Recommendations



  • Healthcare providers may see an increase in the number of patients seeking evaluation, testing, prophylaxis or treatment for pertussis due to an ongoing outbreak at a Chicago area childcare center.
  • Providers should ask for recent exposure to pertussis in patients presenting with cough for over 14 days.
  • Pertussis vaccination history should not alter decision making to test or prescribe post-exposure prophylaxis

Please see Nov 9, 2018 HAN for more information.

Prenatal Care to Prevent Pertussis 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 Contact Us Pertussis Contact Us

For Clinical Questions Contact:

Dr. Marielle Fricchione, Medical Director


 For Surveillance Questions Contact:

Enrique Ramirez, Epidemiologist


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