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Public Health - Seattle & King County

Fact sheet for patients with pertussis (Whooping Cough) and their close contacts

What is pertussis?

Pertussis (whooping cough) is a highly contagious bacterial infection. It causes a cough that can be severe and long-lasting. The illness usually starts with mild cold symptoms or cough, which can turn into severe coughing spells followed by gagging, or vomiting and sometimes a "whoop" sound when trying to catch the breath. Young infants, adolescents and adults with pertussis are less likely to make the "whoop" sound. Infants with pertussis may eat poorly, turn blue, or stop breathing. Infants are also at highest risk for severe pertussis complications that require hospitalization such as difficulty breathing, pneumonia, convulsions, and even death. Pertussis in older children, teens and adults sometimes is shorter and less severe, but is still contagious.

How does pertussis spread?

Pertussis spreads to close (face-to-face) contacts of an infected person through droplets produced while talking, coughing and sneezing. If untreated, an infected person can spread pertussis for several weeks.

My doctor told me I have pertussis. What should I do?

  • If your doctor prescribed medicine, take it as directed.

  • Don't spread pertussis: you are still contagious until you have taken 5 days of antibiotics.
    • Stay home from group activities including work and school.
    • Stay away from children under 1 year old, pregnant women, and others who have frequent contact with infants.

What should I tell people in my household and other people with whom I have had face-to face contact?

  • You should let them know you may have spread the infection to them.

  • These people should watch for symptoms for 21 days after the most recent exposure to the contagious person.

  • They should contact their health care provider:
    • If they become sick, they should stay away from children under 1 year old, pregnant women and anyone who has close contact with infants or pregnant women; antibiotic treatment may be necessary.
    • If they are not sick, they can discuss whether they should take antibiotics to prevent the disease.

  • They should also make sure their pertussis vaccinations are up to date.

  • Pregnant women, people with an infant under 1 year old in the household, and those who have close contact with infants or pregnant women should consult their healthcare provider about the need for preventive antibiotics.
Report all King County cases to Public Health by calling 206-296-4774.

For the general public:

For King County health care providers: