Whooping cough (pertussis) is an infection of the respiratory system caused by the bacterium Bordetella pertussis (or B. pertussis). It mainly affects babies younger than 6 months old who aren't yet protected by immunizations, and kids 11 to 18 years old whose immunity has started to fade.
Whooping cough causes severe coughing spells, which can sometimes end in a "whooping" sound when the child breathes in.
Before a vaccine was available, pertussis killed about 9,000 people in the United States each year. Now, the pertussis vaccine has reduced the annual number of deaths to less than 30. But in recent years, the number of cases has started to rise. In 2004, the number of whooping cough cases spiked past 25,000, the highest level since the 1950s.
Signs & Symptoms
The first symptoms of whooping cough are similar to those of a common cold:
- runny nose
- mild cough
- low-grade fever
After about 1 to 2 weeks, the dry, irritating cough evolves into coughing spells. During a coughing spell, which can last for more than a minute, a child may turn red or purple. At the end of a spell, the child may make the characteristic whooping sound when breathing in or may vomit. Between spells, the child usually feels well.
While many infants and younger kids with whooping cough develop the coughing fits and accompanying whoop, not all do. And sometimes babies don't cough or whoop as older kids do. Infants may look as if they're gasping for air with a reddened face and may actually stop breathing (this is called apnea) for a few seconds during very bad spells.
Adults and teens may have milder or different symptoms, such as a prolonged cough (rather than coughing spells) or coughing without the whoop.
Pertussis is highly contagious. The bacteria spread from person to person through tiny drops of fluid from an infected person's nose or mouth. These may become airborne when the person sneezes, coughs, or laughs. Others then can become infected by inhaling the drops or getting the drops on their hands and then touching their mouths or noses.
Infected people are most contagious during the earliest stages of the illness for up to about 2 weeks after the cough begins. Antibiotics shorten the period of contagiousness to 5 days following the start of antibiotic treatment.
Whooping cough can be prevented with the pertussis vaccine, which is part of the DTaP (diphtheria, tetanus, acellular pertussis) immunization.
DTaP immunizations are routinely given in five doses before a child's sixth birthday. For additional protection in case immunity fades, experts recommend that kids ages 11-18 get a booster shot of the new combination vaccine (called Tdap), ideally when they're 11 or 12 years old.
The Tdap vaccine is similar to DTaP but with lower concentrations of diphtheria and tetanus toxoid. It also should be given to adults who did not receive it as preteens or teens. The vaccine is also recommended for all pregnant women during the second half of each pregnancy, regardless of whether or not they had the vaccine before, or when it was last given.
Getting the vaccine is especially important for people who are in close contact with infants, because babies can develop severe and potentially life-threatening complications from whooping cough. An adult's immunity to whooping cough lessens over time, so getting vaccinated and protecting yourself against the infection also helps protect your infant or child from getting it.
As is the case with all immunization schedules, there are important exceptions and special circumstances. Your doctor will have the most current information.
People who live with or come into close contact with someone who has pertussis should receive antibiotics to prevent the spread of the disease, even if they've already been vaccinated against it. Young kids who have not received all five doses of the vaccine may need a booster dose if exposed to an infected family member.
The incubation period (the time between infection and the start of symptoms) for whooping cough is usually 7 to 10 days, but can be as long as 21 days.
Pertussis usually causes prolonged symptoms — 1 to 2 weeks of common cold symptoms, followed by up to 3 months of severe coughing.
The last stage consists of another few weeks of recovery with gradual clearing of symptoms. In some children, the recovery period can last for months.
Call the doctor if you suspect that your child has whooping cough. To make a diagnosis, the doctor will take a medical history, do a thorough physical exam, and may take nose and throat mucus samples to be checked in a lab. Blood tests and a chest X-ray also might be done.
Whooping cough is treated with antibiotics. Many experts believe that antibiotics are most effective in shortening the length of the infection when they're given in the first stage of the illness, before coughing spells begin. But even if antibiotics are started later, they're still important because they can stop the spread of the pertussis infection to others. Ask your doctor whether preventive antibiotics or vaccine boosters for other family members are needed.
Some kids with whooping cough need to be treated in a hospital. Babies and younger children are more likely to be hospitalized because they're at greater risk for problems like pneumonia. Whooping cough can be life-threatening for infants younger than 6 months, so they almost always need hospital treatment.
Other potential complications include difficulty breathing, periods of apnea, needing oxygen (particularly during a coughing spell), and dehydration.
While in the hospital, a child may need suctioning to clear the airways. Breathing will be watched closely, and oxygen given if needed. Intravenous (IV) fluids might be needed if a child shows signs of dehydration or has difficulty eating. Precautions will be taken to prevent the infection from spreading to other patients, hospital staff, and visitors.
If your child is being treated for pertussis at home, follow the schedule for giving antibiotics exactly as your doctor prescribed. Giving cough medicine probably will not help, as even the strongest usually can't relieve the coughing spells of whooping cough. The cough is actually the body's way of trying to clear the airways. (Due to potential side effects, cough medicines are never recommended for children under age 6.)
During recovery, let your child rest in bed and use a cool-mist vaporizer to help soothe irritated lungs and breathing passages. (Be sure to follow directions for keeping it clean and mold-free.) And keep your home free of irritants that can trigger coughing spells, such as aerosol sprays; tobacco smoke; and smoke from cooking, fireplaces, and wood-burning stoves.
Kids with whooping cough may vomit or not eat or drink much because of the coughing. So offer smaller, more frequent meals and encourage your child to drink lots of fluids. Watch for signs of dehydration, including thirst, irritability, restlessness, lethargy, sunken eyes, a dry mouth and tongue, dry skin, crying without tears, and fewer trips to the bathroom to pee (or in infants, fewer wet diapers).
When to Call the Doctor
Call the doctor if you think that your child has whooping cough or has been exposed to someone with whooping cough, even if your child has already had all scheduled pertussis immunizations.
This is especially important if your child has long coughing spells and:
- the coughing make your child's skin or lips turn red, purple, or blue
- your child vomits after coughing
- there's a whooping sound after the cough
- your child has trouble breathing or seems to have brief periods of not breathing (apnea)
- your child seems very sluggish
If your child has been diagnosed with whooping cough and is being treated at home, get immediate medical care if he or she develops difficulty breathing or shows signs of dehydration.
Reviewed by: Rupal Christine Gupta, MD
Date reviewed: February 2015