Whooping Cough

Whooping cough is a highly contagious disease caused by the bacteria Bordatella pertussis. It is characterized by classic paroxysms (spasms) of uncontrollable coughing, followed by a sharp intake of air which creates the characteristic "whoop" of the disease name.

B. pertussis is uniquely a human pathogen, meaning that it neither causes disease in other animals, nor survives in humans without resulting in disease. It exists worldwide as a disease-causing agent, and causes epidemics cyclically in all locations.

B. pertussis causes its most severe symptoms by attacking specifically those cells in the respiratory tract which have cilia. Cilia are small, hair-like projections which beat constantly, and serve to constantly sweep the respiratory tract clean of such debris as mucus, bacteria, viruses, and dead cells. When B. pertussis interferes with this normal, janitorial function, mucus and cellular debris accumulate and cause constant irritation to the respiratory tract, triggering the cough reflex and increasing further mucus production.

Children under the age of two, particularly infants, are most at risk for serious infection, although the disease can occur at any age. However, once an individual has been exposed to B. pertussis, subsequent exposures result in mild illness similar to the common cold, and thus usually not identifiable as resulting from B. pertussis.