Whooping cough, otherwise known as pertussis, after the causative bacillus Bordetella pertussis, is an acute infectious disease of childhood. Affecting the respiratory tract, it is characterized by paroxysms of coughing, culminating in the prolonged inspiration which gives the disease its name. Before the present century, the popular name was generally spelled without the initial “w,” and did not come into general use until the end of the eighteenth century. Until the early nineteenth century, the commonest appellation was chincough. The term pertussis was first used by Thomas Sydenham in the latter part of the seventeenth century.

Distribution and Incidence

The distribution of whooping cough is now worldwide. It is generally an endemic disease that erupts in sporadic epidemics, but in most developed countries it has been controlled by immunization programs. Of clinical cases, 80 percent occur in the under-10 age group, and unlike most other communicable diseases, whooping cough develops more often in females than in males.

Etiology and Epidemiology

Although included among the more important diseases of childhood, whooping cough has been relatively neglected, and various aspects of its epidemiology are not yet fully understood. Transmission seems to be mainly airborne, apparently by droplet infection. Human beings are the only reservoir of the disease; B. pertussis cannot survive long outside the host, and quickly succumbs to drying, ultraviolet light, and temperatures above 120° to 130°F. It spreads primarily through household and schoolroom contact, although mild subclinical cases, perhaps in adolescents and adults, may play a further (undemonstrated) role in transmission.