Whooping cough, medically known as pertussis, is a highly contagious respiratory illness characterized by severe, uncontrollable coughing fits. While its distinctive “whoop” sound and symptoms were recognized for centuries, the scientific journey to understand its cause and develop effective countermeasures is a more recent development.
Early Accounts and Recognition of Pertussis
Historical records indicate that symptoms consistent with whooping cough were recognized for hundreds of years before its specific cause was understood. The earliest documented European epidemic believed to be pertussis occurred in Paris in 1578, described by the French physician Guillaume de Baillou. He detailed the severe coughing that often led to apparent suffocation, and referred to the disease as “quintana.” Other historical names for the illness included “chin cough” or “kin cough” in England and the “100-day cough” in China, reflecting its prolonged and intense nature.
The term “pertussis” itself, derived from Latin meaning “intensive cough,” was introduced by English physician Thomas Sydenham in 1670. Despite these early descriptions and the recognition of its devastating impact, particularly on children, the medical community lacked an understanding of what caused the disease. Accounts from the 18th century highlight its increasing incidence in Europe, demonstrating its widespread presence.
Identification of the Causative Agent
The scientific breakthrough in understanding whooping cough occurred in the early 20th century with the identification of the bacterium responsible. In 1900, Jules Bordet, a Belgian scientist, and Octave Gengou, his assistant, first observed a small ovoid bacterium in the sputum of a 5-month-old child suffering from pertussis in Paris. Their initial observation, however, did not immediately lead to its isolation.
It took six more years for Bordet and Gengou to successfully isolate and cultivate the bacterium. This achievement, in 1906, was made possible by their development of a specialized culture medium, now known as Bordet-Gengou medium, which provided the specific nutrients for its growth. The isolated microorganism was a Gram-negative, aerobic coccobacillus, and it was subsequently named Bordetella pertussis in honor of Jules Bordet. This discovery provided the answer to the cause of whooping cough, shifting the understanding of the disease from symptomatic observation to a microbiological etiology.
Development of Prevention and Treatment
The isolation of Bordetella pertussis in 1906 opened the door for developing diagnostic tools and prevention strategies. Shortly after their discovery, Bordet and Gengou initiated efforts to create a vaccine, developing the first inactivated whole-cell vaccine in 1912. Other researchers followed, with early pertussis vaccines becoming available in Europe and the U.S. by 1914, though their effectiveness was initially limited.
By the 1930s, whole-cell pertussis vaccines were developed and refined, notably by bacteriologists Pearl Kendrick and Grace Eldering, who demonstrated their efficacy. In the 1940s, the pertussis vaccine was combined with diphtheria and tetanus toxoids to create the DTP (diphtheria, tetanus, pertussis) vaccine, which became widely available and significantly reduced disease incidence. Modern vaccines, such as acellular pertussis vaccines (DTaP and Tdap), were introduced later to reduce side effects while maintaining protection.