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Symptoms and Signs of Whooping Cough (Pertussis)

Doctor's Notes on Whooping Cough (Pertussis)

Whooping cough, or pertussis, is an airway infection with the bacteria Bordetella pertussis. The infection is extremely contagious and causes symptoms that occur in three stages. Early symptoms of whooping cough are similar to those of a cold and include sneezing, runny nose, and a mild fever. The characteristic cough that produces the “whoop” sound occurs during the second, or paroxysmal, stage of infection. The third stage is the recovery stage in which the coughing symptoms lessen and improve over time.

Symptoms are most severe during the second stage. In addition to the characteristic cough that comes in bursts, other associated symptoms can include bluish skin during a coughing attack, vomiting (following a cough attack), and exhaustion. Ypung infants are at greatest risk of complications from whooping cough.

Medical Author:
Medically Reviewed on 3/11/2019

Whooping Cough (Pertussis) Symptoms

The course of whooping cough follows three stages.

  • The first stage of whooping cough is the catarrhal (runny nose) stage. This phase typically lasts for one to two weeks. Symptoms during this phase resemble that of an upper respiratory illness or common cold: runny nose, nasal congestion, sneezing, and occasional cough. A low-grade fever may be present in some cases. It is only during this stage that antibiotics can halt the progression of whooping cough.
  • The second stage of whooping cough is the paroxysmal stage. The duration of this phase is highly variable, lasting from one to 10 weeks. Intense and drawn out bouts of coughing characterize this phase. The attacks tend to be more frequent at night, with an average of 15 attacks in a 24-hour period. Often people can hear a high-pitched "whoop" caused by the gasping person inhaling between coughs. (Barking coughs usually indicate a viral infection and are not indicative of whooping cough). Newborn babies and infants, in particular, may appear to stop breathing and perhaps turn blue during the coughing spasms. Vomiting or choking is also common during this stage as well.
  • The third stage of whooping cough is the convalescent stage. This can last for weeks or months and a chronic cough that becomes less paroxysmal (fewer sudden outbursts of coughing) in nature characterizes this stage.

Whooping Cough (Pertussis) Causes

The bacteria Bordetella pertussis causes whooping cough. Humans are the only known reservoir for these bacteria. (That means it can only thrive and multiply in humans.)

  • Whooping cough spreads by contact with droplets coughed out by someone with the disease or by contact with recently contaminated hard surfaces upon which the droplets landed. The B. pertussis bacteria thrive in the respiratory passages where they produce toxins that damage the tiny hairs (cilia) needed to remove particulate matter and cellular debris normally introduced into the airways with each breath. This results in an increased inflammation of the respiratory passages and the typical dry cough that is the hallmark of the infection. Whooping cough is contagious from seven days after exposure to the bacteria and up to three weeks after the onset of coughing spasms. The most contagious time is during the first stage of the illness.
  • Initially thought to be a disease of childhood, studies have shown that adults are susceptible to whooping cough and account for up to 25% of cases. The disease tends to be milder in adults and adolescents -- a persistent cough much like an upper respiratory infection or common cold. Because of this fine distinction, physicians frequently miss a diagnosis of whooping cough in that population and thus allows the bacteria to spread to more susceptible infants and children.
  • Whooping cough is highly contagious. Between 75%-100% of unimmunized household contacts of a person with pertussis will develop the disease. Even among fully immunized and naturally immunized people living in the same household, there have been reports of undetectable infection following extreme exposure.
  • Risk factors for getting whooping cough include exposure to an infected person's cough or sneeze or touching surfaces used by an infected person. Both frequent hand washing and the use of masks will help lessen the likelihood that the bacteria will spread to other members of a household where someone has whooping cough. Also avoid touching your nose or mouth and introducing the bacteria you may have picked up during outbreaks.
  • A related bacterium Bordetella parapertussis causes a similar but less severe cold-like infection called parapertussis.

Whooping Cough (Pertussis) Symptoms, Vaccine Facts Slideshow

Whooping Cough (Pertussis) Symptoms, Vaccine Facts Slideshow

A bacterium known as Bordetella pertussis causes “whooping cough”. The name refers to the whooping sound made upon breathing in during a prolonged coughing spell. This vaccine-preventable illness can be life-threatening to young children and even the elderly. In its early stages, it looks like the common cold, but then it develops into unrelenting coughing spells that often interfere with breathing. Whooping cough is also termed pertussis.

Whooping cough is also known as the “100 day cough” because coughing fits can last up to 10 weeks. Whooping cough symptoms may not present themselves until 5 to 21 days after exposure to someone with whooping cough.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.