Pertussis

Pertussis, or whooping cough, is an acute respiratory infection caused by Bordetella pertussis. It may begin with an ordinary runny nose and mild cough, yet the person is already highly infectious. Over the following days, coughing can become repetitive and forceful, with vomiting, exhaustion, cyanosis, or an inspiratory whoop. The pattern changes with age. An infant may stop breathing, turn blue, gag, or feed poorly without producing a dramatic cough. An adolescent or adult may have only a cough that has continued for 2 weeks or longer. A whoop is helpful when present, but its absence does not exclude pertussis. For nursing decisions, connect three findings: a prolonged or paroxysmal cough, exposure to a susceptible household or community, and a vulnerable patient—especially an infant younger than 1 year. Antibiotics reduce transmission most effectively when started early; they may not promptly reverse a cough once airway injury and paroxysms are established. Droplet precautions, public-health notification, and protection of high-risk contacts therefore begin before the classic whoop appears.