Whooping cough, also called pertussis (per-TUH-sis), is a bacterial infection of the respiratory tract * that causes severe coughing.
Whooping cough is a respiratory disease found only in humans that is caused by the bacterium Bordetella pertussis. The first account of the infection was recorded in the 16th century, but it was not until the early 20th century that B. pertussis was identified as the cause.
The infection causes a violent series of coughing fits usually ending in a high-pitched intake of breath that sounds like a “whoop,” giving the disease its common name, whooping cough. These coughing fits can be so severe that patients may vomit, lose consciousness, break a rib, or turn blue from lack of oxygen.
Whooping cough occurs throughout the world in all age groups, with 16 million cases and 195,000 deaths reported each year. In the early 20th century, it was a common childhood disease and a leading cause of infant death. With the widespread use of a vaccine * starting in the mid-1940s, infection rates in children in the United States declined by 99 percent until the 1980s, when they began to rise again. In 2015, there were approximately 29,000 cases of whooping cough reported in the United States.
The increase in whooping cough cases in the United States is thought to be attributable to two main factors. Because previously deadly childhood diseases have been controlled by immunization, some parents feel less urgency to vaccinate their children. Still, the vaccination (vak-sih-NAY-shun) rate for children ages 19 to 35 months in the United States in 2014 was 90 percent for measles/mumps/rubella, polio, hepatitis B and varicella, though many states give exemptions to parents who do not wish their children to be vaccinated. In addition, vaccination, or even having the whooping cough, does not provide lifelong immunity * . Unless teens and adults have booster shots to renew their immunity, they can develop the disease and pass it on to children who have not been immunized or who are too young to have completed the required series of vaccinations.
Following exposure to the bacteria, an incubation * period begins and generally lasts 7 to 10 days but occasionally stretches to as long as a month. During this time, the bacteria settle in the lungs, where they produce toxins * that cause inflammation and make it difficult to clear out the mucus * that forms in the respiratory tract.
After the incubation period, there are three distinct stages of whooping cough infection: the catarrhal (kah-TAR-ul), paroxysmal (pair-ruck-SIZ-mul), and convalescent (kon-vuh-LEH-sent) stages. In the catarrhal stage, the first symptoms of the disease appear and often are mistaken for those of a common cold or the flu. They include runny nose, sneezing, mild fever, and a cough that gradually worsens. This stage typically lasts one to two weeks.
In the paroxysmal stage, the characteristic symptoms of whooping cough become obvious. The occasional cough develops into sudden violent attacks, or paroxysms, of rapid coughing ending with the whooping noise. Spasms of coughing are due to the buildup of mucus in the respiratory tract and occur frequently at night. Babies under six months of age may not have the strength to make the whooping sound that older children do, and the characteristic whoop may be absent in adults. It is difficult to breathe during these fits, and many patients turn blue from lack of oxygen. The severe coughing also can lead to vomiting and extreme tiredness. Between these bouts, patients look normal. The paroxysmal stage generally lasts from 1 to 6 weeks but can linger for up to 10 weeks.
In the final, convalescent stage, coughing slowly subsides over two to three weeks.
In some cases, the doctor can make the diagnosis of whooping cough based solely on hearing the cough. However, other infections (specifically with Chlamydophila pneumoniae) can produce a syndrome with a cough very much like the whoop in classic whooping cough, so careful examination of the offending bacteria is necessary. A definitive diagnosis requires an examination of fluid from the nose or throat. Samples of this fluid are checked for bacteria. Blood tests can look for the increased number of lymphocytes * commonly seen with this disease and for antibodies * to the bacterium. Experts suspect that many cases of adult whooping cough go undiagnosed.
Doctors commonly prescribe a two-week course of antibiotics to keep the disease from spreading to other people. Antibiotics can also be prescribed for other people living in the same household with the patient to prevent these people from contracting the infection. However, antibiotics can do little to improve the illness if they are not prescribed until after the characteristic whooping cough symptoms appear. Cough medicines do not ease the cough significantly, but using a cool-mist vaporizer and avoiding irritants such as smoke or fumes can help.
Children 18 months of age and younger who contract whooping cough need to be watched carefully because they may choke or stop breathing during a coughing spasm. Infants younger than six months of age usually are hospitalized and given oxygen and intravenous * fluids, and their mouth and nose may need to be suctioned to keep their breathing passages clear of mucus.
Whooping cough usually lasts between six weeks and two months, but it can take even longer for a patient to recover completely. The coughing spasms may continue on and off for several months.
Complications of whooping cough include bacterial infections such as ear infections or pneumonia * ; dehydration * due to poor fluid intake and vomiting after coughing; broken blood vessels in the eyes, nose, and brain from forceful coughing; and problems associated with lack of oxygen such as seizures * or, rarely, brain damage and, particularly among young infants, death. Adults may cough hard enough to break a rib.
Vaccination is the best way to prevent whooping cough in children. The vaccine for pertussis is given in a combined vaccine, including those for diphtheria * and tetanus * . The DTaP vaccine (made with acellular pertussis, which contains only parts of the pertussis bacterium and does not cause as many side effects as the vaccine made with the whole bacterium) is given in five doses: at two, four, and six months, between 15 and 18 months, and between four and six years or age. At least three doses are required to stimulate immunity, and four or all five doses are preferred.
Teens and adults who have completed the childhood series of vaccinations for whooping cough can receive a booster shot to renew their immunity. This is especially important for people who work with young children and those who travel to parts of the world where whooping cough is common. Adults can also reduce their chances of spreading the disease by practicing good hygiene, such as regularly washing their hands; not sharing food, silverware, or drinking glasses; and covering their mouth when they sneeze or cough.
See also Croup • Diphtheria • Pneumonia • Vaccines and Immunization
Bakalar, Nicholas. “Symptom-Free Carriers May Be Spreading Whooping Cough.” Well (blog), New York Times, June 29, 2015. http://well.blogs.nytimes.com/2015/06/29/symptom-free-carriers-may-bespreading-whooping-cough/ (accessed November 3, 2015).
MedlinePlus. “Whooping Cough.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/whoopingcough.html (accessed November 3, 2015).
Texas Department of State Health Services. “Pertussis.” https://www.dshs.state.tx.us/idcu/disease/pertussis/ (accessed November 3, 2015).
Centers for Disease Control and Prevention. 1600 Clifton Rd., Atlanta, GA 30329-4027. Toll-free: 800-232-4636. Website: http://www.cdc.gov (accessed November 3, 2015).
World Health Organization. Ave. Appia 20, 1211 Geneva 27, Switzerland. Telephone: 41 22 791 21 11. Website: http://www.who.int/en/ (accessed November 3, 2015).
* respiratory tract includes the nose, mouth, throat, and lungs. It is the pathway through which air and gases are transported down into the lungs and back out of the body.
* vaccine (vak-SEEN) is a preparation of killed or weakened germs, or a part of a germ or product it produces, given to prevent or lessen the severity of the disease that can result if a person is exposed to the germ itself. Use of vaccines for this purpose is called immunization.
* immunity (ih-MYOON-uh-tee) is the condition of being protected against an infectious disease. Immunity often develops after a germ has entered the body.
* incubation (ing-kyoo-BAY-shun) is the period of time between infection by a germ and when symptoms first appear. Depending on the germ, this period can be from hours to months.
* toxins are substances that cause harm to the body. mucus (MYOO-kus) is a thick, slippery substance that lines the insides of many body parts.
* lymphocytes (LIM-fuh-sites) are white blood cells, which play a part in the body's immune system, particularly the production of antibodies and other substances to fight infection.
* antibodies (AN-tih-bah-deez) are protein molecules produced by the body's immune system to help fight specific infections caused by microorganisms, such as bacteria and viruses.
* intravenous (in-tra-VEE-nus), or IV, means within or through a vein. For example, medications, fluid, or other substances can be given through a needle or soft tube inserted through the skin's surface directly into a vein.
* pneumonia (nu-MO-nyah) is inflammation of the lungs.
* dehydration (dee-hi-DRAY-shun) is a condition in which the body is depleted of water, usually caused by excessive and unreplaced loss of body fluids, such as through sweating, vomiting, or diarrhea.
* seizures (SEE-zhurs) are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.
* diphtheria (dif-THEER-e-uh) is an infection of the lining of the upper respiratory tract (the nose and throat). It is a disease that can cause breathing difficulty and other complications, including death.
* tetanus (TET-nus) is a serious bacterial infection that affects the body's central nervous system.