Pertussis Fact Sheet

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Pertussis, or whooping cough, is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis

This bacterium is found in the nose, throat and mouth of an infected person, and can be easily spread. Pertussis can occur at any age, but often causes serious problems in babies, and is usually milder in older children and adults. Children who are too young to be fully vaccinated and those that have not received all their vaccinations are at highest risk for severe illness and complications. Complications of pertussis can include pneumonia (infection of the lungs), encephalitis (inflammation of the brain), seizures, and other physical and medical outcomes associated with a severe cough.

Pertussis is spread from person-to-person by airborne droplets and close contact with infected respiratory secretions.

Pertussis is spread to others by direct, close contact with secretions from the nose, throat and mouth of an infected person. Droplets from a cough or a sneeze can spread the disease to others. A person with pertussis may be contagious for as long as 2 weeks before to 3 weeks after symptoms begin. Anyone with pertussis should not attend childcare, school, work, or other public places until they have completed 5 days of an appropriate antibiotic treatment.

Symptoms to look for include:

  • Low fever
  • Runny nose
  • Cough that is mild at first, then severe with times of deep, rapid coughing and a crowing or high pitched “whoop”. The cough often worsens at night.
  • Vomiting after coughing

Symptoms occur within 4 to 21 days (usually 7 to 10 days) after someone has been exposed to an infected person.

Laboratory testing is needed to confirm a pertussis infection.

People who think they may have pertussis should see a doctor or their local health department immediately to be tested by swabbing the back of the nose. 

See a doctor for treatment.

Pertussis is treated with an antibiotic, and if treated soon enough, the antibiotic may decrease the contagiousness and severity of the disease.

A person in close contact with someone who has pertussis should be given an antibiotic and/or pertussis vaccination to prevent acquiring and spreading pertussis.

People in close contact may include:

  • Persons who live in the same house;
  • Persons who have contact with mouth or nose secretions, such as through a cough or sneeze, or sharing food and eating utensils;
  • Persons who have done medical treatments such as mouth-to-mouth resuscitation or intubation; or
  • Close contacts in child and daycare settings, schools, work, or extracurricular activities.

Pertussis disease can be prevented with a pertussis vaccine.

Every child should get pertussis vaccine at 2, 4, 6, and 15 to 18 months of age, and another dose at 4 to 6 years of age. Pertussis vaccine is also recommended for adolescents ages 11 to 18, pregnant women, healthcare workers, and adults in close contact with infants. Age-appropriate vaccination against pertussis is required for enrollment in Maryland childcare institutions and schools. For additional information about pertussis vaccine, please visit: