Pertussis Information


(Whooping Cough)

What is pertussis?

Pertussis, or whooping cough, is a contagious disease involving the lungs and airways. It is caused by a bacterium, Bordetella pertussis, that is found in the nose, mouth, and throat of an infected person. More than 100 cases are reported each year in Pennsylvania, mostly in children. Other cases of pertussis occur but are not diagnosed, especially in adults.

Who gets pertussis?

Pertussis can occur at any age.

How do you get pertussis?

People get pertussis by breathing in droplets from the nose and mouth of already infected persons. Older children and adults may have milder disease and may spread the disease to unimmunized infants and young children. An infected person is most contagious at the beginning of the disease. If untreated, an infected person can spread pertussis for up to 3 weeks after coughing starts. Antibiotic treatment limits contagiousness to five days after treatment is started.

How soon do symptoms start?

Symptoms usually start 5 to 10 days after exposure to another person with the disease, but may take as long as 20 days to start.

What are the symptoms of pertussis?

Pertussis begins as a mild illness like the common cold. Sneezing, runny nose, low-grade fever, and mild coughing progress to severe coughing. Some persons have episodes of rapid coughing followed by a high-pitched whoop as they take a deep breath. However, not everyone with pertussis has a whoop, especially very young infants. Severe cough may continue for many weeks despite proper treatment. Symptoms may be milder in older children and adults. However, pertussis can be a serious disease, especially in infants and young children. Complications can include pneumonia, dehydration, seizures, encephalopathy (a disorder of the brain), and death.

How is pertussis treated?

Antibiotics such as erythromycin may be useful early in the disease. Antibiotics are particularly helpful in reducing spread of the disease to other persons.

However, once severe symptoms begin, antibiotics may not have any effect on symptoms.

How can pertussis be prevented?

The single best control measure is adequate vaccination of children. The pertussis vaccine is usually given together with other vaccines such as diphtheria and tetanus (DTaP vaccine). Recent changes in the pertussis vaccine have improved its safety while keeping a high level of protection. Children should be routinely immunized at ages 2, 4, 6, and 15 months, and again at 4-6 years. 

Before 2005, the only booster available contained tetanus and diphtheria (Td), and was recommended for adolescents and adults every 10 years. Today, there are boosters for adolescents and adults that contain tetanus, diphtheria, and pertussis, Tdap. Pre-teens going to the doctor for their regular check-up at age 11 or 12 should get a dose of Tdap. Adults who didn’t get Tdap as a pre-teen should get one dose of Tdap instead of the Td booster.

When pertussis does occur, preventive antibiotic treatment is sometimes recommended for household and other close contacts of the person with pertussis.




Infectious Agent:

Bordetella pertussis, gram negative pleomorphic bacillus.

Mode of Transmission:

Airborne transmission primarily through contact with infected droplets.

Incubation Period:

Commonly 7-10 days with a range of 5-21 days.

Period of Communicability:

Early in catarrhal stage through three weeks after onset of paroxysmal cough. If treated with appropriate antibiotics, the period of communicability can be reduced to five days.


Clinical Case Definition:

A cough illness lasting at least two weeks with one of the following: paroxysms of cough, inspiratory “whoop”, or post-tussive vomiting and without other apparent cause (as reported by a health professional).

Outbreak Case Definition:

A cough illness lasting at least two weeks, as reported by a health professional. An outbreak of pertussis exists when there are several reported cases of pertussis epidemiologically linked and occurring in a common setting other then familial (i.e. school, day-care, community). 

Case Classification:


  • A case of acute cough illness of any duration with a positive culture for B. pertussis.
  • A case that meets the clinical case definition and is confirmed by PCR.
  • A case that meets the clinical definition and is epidemiologically linked directly to a case confirmed by either culture or PCR.

Positive serology is not acceptable for confirmation of pertussis disease.


A probable case meets the clinical case definition, is not laboratory confirmed, and is not epidemiologically linked to a laboratory confirmed case.



  • Posterior nasopharyngeal (NP) swab or aspirate within 2 weeks of cough onset-even if on antibiotic therapy.
  • Flexible dacron or calcium alginate swabs or catheter/trap.
  • Transport swab in ½ strength charcoal horse blood agar & aspirate in trap both at 4° Celsius.
  • Lab to use Regan-Lowe or Bordet-Gengou media.


  • NP swab or aspirate.
  • Validate with culture when possible.
  • Long term transport at equal to or less than negative 20° Celsius.



  • Usually 7-10 days with a range of 5-21 days.

Catarrhal stage

  • Onset of cold-like symptoms (coryza, sneezing, mild fever, occasional cough).
  • Lasts approximately 1-2 weeks with cough gradually becoming more severe.

Paroxysmal stage

  • Characterized by patient having bursts (paroxysms) of numerous rapid coughs, often resulting in characteristic high pitched “whoop”, cyanosis, apnea or vomiting.
  • Usually lasts 4-6 weeks, but may last up to 10 weeks.

Convalescent stage

  • Gradual recovery, with cough becoming less paroxysmal.
  • Generally, cough disappears after 2-3 weeks.


  • Pertussis is a disease that must be reported to the Division of Immunizations (DOI).
  • Determination of appropriate investigation and assignment for such will occur at the State Health Center or District Office level regardless of the source of the initial report.
  • Any cases reported directly to the DOI by an outside source will be forwarded to the District Office Immunization Consultant for assignment and investigation.
  • Disease investigation must be initiated within 24 to 48 hours of receipt of the initial referral. Consultation with DOI is required.
  • Status of case investigations must be communicated and submitted to the DOI. Time expectations for such are categorized as:

Immediate (same day)

Verbally communicated to DOI and must contain demographic, clinical and lab data, outbreak control measures and follow-up action plan.

Within 10 working days

The initial disease report date, case reports of VPD’s meeting clinical case definition are to be entered in NEDSS regardless of report status.

Within 30 working days

The case must be concluded and have a final interview date and be closed out in NEDSS.


At any time; for any reason; to determine clinical case definition/status; outbreak control measures; and follow-up action plan.

»»For all cases resulting in death, a copy of the patient’s medical records and death certificate are required««


Identify contacts and consider prophylaxis (antibiotics) as appropriate:

Contacts less than 7 years of age and are unimmunized or have received fewer than 4 doses of pertussis vaccine should have pertussis immunization initiated or continued according to the accelerated schedule. Those who have had 4 doses should receive a booster DTaP unless a dose has been given within the last 3 years or they are more than 7 years old. 10 - 64 year olds should receive a dose of Tdap, if they have not already received one. Inadequately immunized contacts less than 7 years of age should be excluded from school/daycare/public gatherings for 14 days after the last exposure or until they have received 5 days of appropriate antibiotic therapy. Exclude suspected cases from work/school/daycare until they have completed 5 days of appropriate antibiotic therapy. 

Appropriate Treatment or Prophylaxis Antibiotics

♦ 14 days of Erythromycin ♦ 7 days of Clarithromycin

♦ 5 days of Azithromycin ♦ 14 days of Trimethoprim/Sulfa


Perform a record review of the child-care/school.

Exposed children should be observed carefully for respiratory symptoms for 14 days after the last contact with the confirmed case. Immunization and chemoprophylaxis should be given the same as for household/close contacts. Symptomatic children and staff should be excluded from school pending physician evaluation. Confirmed cases may return to school after they have completed 5 days of appropriate antibiotic therapy.


Questions should be directed to the Division of Immunizations at 717-787-5681