Cause and Risk Factors for Whooping Cough

Whooping cough is caused by bacteria called Bordetella pertussis (also called B. pertussis). Several types of Bordetella bacteria have been identified. Some types cause illness in humans (e.g., B. pertussis, B. parapertussis) and others affect animals (e.g., B. bronchiseptica causes kennel cough in dogs and respiratory infections and pneumonia in cats and pigs).

Bordetella pertussis bacteria are transmitted though the air when an infected person coughs or sneezes. This usually is how whooping cough spreads. When the bacteria are inhaled, they multiply in the respiratory tract (e.g., nose, mouth, throat), produce substances that prevent the body from eliminating germs, and cause inflammation that damages the lining of the airways.

Children and adults who have not been vaccinated, infants who have not yet completed the immunization series, and adults and adolescents whose immunity to the disease has diminished are at increased risk for developing whooping cough and also for spreading the disease. Pertussis can be transmitted to others before symptoms of the disease develop.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 01 Sep 2009

Last Modified: 23 Jun 2014