Whooping cough (pertussis) is a highly contagious infection of the upper respiratory tract that causes inflammation of the breathing passages and episodes of intense coughing. During the first two weeks of this infection, symptoms may resemble those of a cold, asthma or allergy (e.g., coughing, sneezing). During a pertussis-related coughing fit, coughing can become so intense, and breathing so difficult, that a person ends up gasping for breath after it finally subsides. The effort to get air in quickly through narrowed airway passages produces the characteristic “whooping” sound that gives the infection its distinctive name.

Whooping cough primarily affects children, but also can afflict teens and adults. Since the 1940s, infants born in the United States have had access to the DTP vaccine, which immunizes them against whooping cough (as well as tetanus and diphtheria). As a result, the spread of whooping cough has been largely contained in recent decades, according to the U.S. Centers for Disease Control and Prevention (CDC). However, the 1980s and 1990s saw a rise in the number of new infections. Many of those becoming infected are infants younger than 6 months old, when most children are still not fully vaccinated against whooping cough in the United States. Whooping cough is more common in females than males.