Is Whooping Cough (Pertussis) Contagious?

Whooping cough (also termed pertussis) is a respiratory disease that is caused by the bacterium Bordetella pertussis. It results in characteristic fits of coughing (the characteristic noise on inhalation produces a whooping sound) and mild to moderate difficulty with breathing (most noticeable during coughing fits). These symptoms are caused by the release of toxins produced by Bordetella pertussis bacteria that damage the lining of throat cells and cause inflammation and swelling of the throat.

Early in the disease patients may have cold-like symptoms (mild cough and/or fever), but after about a week or so, severe coughing can begin.

The Stages of Whooping Cough

• Stage one: The cold-like symptoms comprise stage one of whooping cough and last about one to two weeks; stage one is termed the catarrhal stage.
• Stage two: Termed the paroxysmal stage, this stage can last from about one to six weeks and consists of fits of rapid coughing (coughing fits) and the characteristic whooping sounds.
• Stage three: Also called the convalescent stage, stage three lasts about two to three weeks with a gradual reduction of the coughing fits.

How Long Do Whooping Cough Symptoms Last?

The length of time coughing fits last is variable; for example, some individuals will still experience some coughing for as long as about three and a half months. The coughing fits can cause intermittent shortness of breath, vomiting, and fatigue.

Unfortunately, a person is usually not diagnosed with whooping cough until stage two, but the person can be contagious during stage one. Individuals with whooping cough are highly contagious during the first two weeks of stage two, but they still can be contagious for about three weeks. Some experts suggest antibiotic therapy reduces contagiousness in individuals with the disease.

Not every person who gets pertussis develops the characteristic coughing fits. If a person, especially an infant or young child, develops a persistent relatively severe cough for a week or more, a physician should be consulted to perform blood tests and cultures for Bordetella pertussis bacteria.

Coughing, sneezing, or direct personal contact with an infected individual easily spreads whooping cough from person to person. It is not spread to pets (dogs and cats, for example), but it can be spread to other adults and even to vaccinated individuals whose vaccine immunity has waned. It can be spread before the characteristic coughing fits begin.

The incubation period is variable, and symptoms develop usually five to 10 days after exposure to the bacteria; occasionally, the incubation period can be up to three weeks. It is possible to be contagious during the incubation period, but the highly contagious time for spread to others is in the beginning weeks of stage two (coughing fits, whooping sounds produced).

After about three weeks of symptoms, the body usually develops an immune response that effectively limits and/or kills the bacteria. However, symptoms can still be present for some period of time (weeks to months) because of the damage done by the infection.

Early treatment with antibiotics is thought to reduce the time of contagiousness and importantly, may reduce the severity of symptoms. However, antibiotics may not help reduce any symptoms if started later (a few weeks) in the disease process.

The U.S. Centers for Disease Control and Prevention (CDC) states that giving cough medicine for pertussis usually will not help and is not recommended for children under 4 years of age; parents and/or caregivers should check with their child's pediatrician if they aren't sure what to do.

Call your child's physician or your physician or consider going to an emergency department if coughing spells cause the following:

• Pauses in breathing
• Struggling to breathe
• Face turning blue or red during coughing fits
• Vomiting during and/or after coughing fits
• Inhalation that produces a whooping sound

Perhaps the best way to avoid pertussis is to contact your child's pediatrician to make sure that your child is up to date with their childhood vaccinations since these include vaccinations for pertussis. For adults, the same thing is true; they should get routine booster shots for pertussis, diphtheria, and tetanus every 10 years or when their physician recommends it.