Whooping Cough or Pertussis

A Deadly Coughing Diseases for Unvaccinated Infants

Whooping cough, also known as Pertussis, is a very contagious bacterial infection that can be deadly to small infants who have not been vaccinated. Despite the availability of an effective vaccine since the 1940s, the number of cases of whooping cough have been increasing over the past two decade, particularly among teenagers and adults, in whom diagnosis can be difficult. Whooping cough outbreaks occur every 3 to 5 years in the United States.

Cases in teenagers and adults tend to be less severe because of partial immunity from childhood vaccinations, but even mild infections can be spread to infants who are more susceptible to serious complications.

Species Name: Bordatella pertussis or Bordatella parapertussis

Type of Microbe: Gram-negative Bacteria

How it causes disease: After breathing in of droplets from a contagious person, the bacteria bind to hair-like structures (called cilia) on cells of the respiratory tract. They release several different toxins which disrupt cell function, paralyze movement of cilia, interfere with the immune response, and cause cell death, leading to a sloughing off of dead cells in the throat.

How it spreads: Whooping cough is spread through droplets that are produced by coughing or sneezing. The infection is very contagious even before symptoms appear and can remain contagious for weeks or months following initial infection.

Who’s at risk? Before introduction of the pertussis vaccine, most children got infected between the ages of 1 and 5 years. Among immunized children, infants less than 1 year of age are at highest risk for serious illness and complications. Teenagers and adults are increasingly at risk if their vaccine-induced immunity wears off.

Pertussis is still a major cause of death and disease in malnourished children. Infections occur more in the late winter and spring. Girls are more likely to get infected than boys.

Symptoms: Seven to 14 days following exposure to the bacteria, an infected person will develop cold symptoms (low grade temperature, body aches, red eyes, runny nose, mild cough, and sneezing). After a week, the cough will become more severe with repeated coughing. Coughing bouts consist of violent and rapid coughing that continues until air is gone from the lungs. Inhalation of new air makes a loud “whooping” sound, which gives the disease its name. Following bouts of coughing, children may vomit and feel exhausted. Coughing bouts can in some cases lead to a loss of oxygen, with sometimes fatal consequences. The severe coughing stage can last one week to over a month. Symptoms are often milder in adults or teenagers who have partial immunity from childhood vaccinations.

Diagnosis: Diagnosis is usually made based on physical examination, patient’s history, and lab tests.

Laboratory tests including cultures or DNA tests of samples from a patient's throat, or blood tests for antibodies can be used for analysis. Some medical facilities may also have rapid diagnostic tests.

Treatment: In addition to taking in lots of fluids and keeping well-nourished, antibiotics can reduce the severity or duration of whooping cough. The macrolide antibiotics (such as erythromycin, azithromycin, and clarithromycin) are the most commonly prescribed. Trimethoprim-sulfamethoxazole is the alternative for patients who cannot take macrolides or have drug-resistant infections. Infants may be treated with corticosteroids in addition to antibiotics in some cases. The infection can persist for a long time and many don't seek out a doctor until after coughing for weeks or months. Antibiotics have to be taken early in the course to have much of an effect, but they may still reduce infectiousness later on.

Prevention: A pertussis vaccine is available as part of a combination vaccine called DTaP that protects against pertussis, diphtheria, and tetanus. The vaccine is given at 2, 4, and 6 months of age, and a 4th shot is given at 15 to 18 months. A fifth shot is given at 4 to 6 years, prior to entry into kindergarten. Because immunity from the vaccine can fade over time, a booster shot (“Tdap”), consisting of vaccines for tetanus, diptheria, and pertussis, is recommended by the CDC. The tetanus and diptheria booster is recommended every 10 years, and Tdap is recommended once during adulthood to supplement the tetanus and diptheria boosters.

Complications: Babies can get really sick. The most common complications associated with whooping cough are secondary infections, such as pneumonia, convulsions, and ear infections. Secondary infections are the most common cause of whooping cough-related deaths. Other physical complications affecting the eyes (subconjunctival hemorrhage) or hernias can occur following coughing bouts. A small percentage of individuals can develop potentially fatal neurological diseases such as encephalopathy following coughing bouts that result in loss of oxygen to the brain. Whooping cough in adults can lead to pneumonia and rib fractures from coughing bouts.


Centers for Disease Control and Prevention. Vaccines & Immunizations. Pertussis (Whooping Cough) Vaccine. http://cdc.gov/vaccines/vpd-vac/pertussis/default.htm

Centers for Disease Control and Prevention. Adult Booster Vaccination Guidelines. http://www.cdc.gov/mmwr/PDF/wk/mm5753-Immunization.pdf

Cohen J, Powderly WG, et al. Infectious Diseases, 2nd ed. ©2004 Mosby, An Imprint of Elsevier.

Immunization Action Coalition. Vaccine Information for the public and health professionals. Pertussis. http://www.vaccineinformation.org/pertuss/

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