Diphtheria

Diphtheria, an acute and highly infectious disease, affecting children particularly, characterized by the formation of a false membrane in the passages of the upper respiratory system. The cause of the disease is Corynebacterium diphtheria, a bacillus discovered in 1883.

The diphtheria bacilli enter the body through the mouth and nose and attack the mucous membranes, where they multiply and secrete a powerful toxin. The toxin damages the heart and central nervous system, and can lead to death. Beginning about five days after exposure to diphtheria, a gray-white exudate is formed where the bacteria attack the walls of the nose and throat. This exudate increases in size and thickness, becoming a grayish false membrane, and it may block the air passages. Surgery may be necessary to prevent asphyxiation.

Before the development of diphtheria antitoxin in 1894 by French bacteriologist Pierre Roux and German physician Emil von Behring, the mortality rate from the disease averaged 35 percent and was as high as 90 percent in cases of diphtheria of the larynx. The universal use of antitoxin in treatment has cut the mortality rate to approximately 5 percent. Even more effective has been the development of harmless forms of diphtheria toxin, called toxoids. Given to infants during the first year of life as part of a combined injection, these toxoids immunize the children against serious infection and have drastically reduced the incidence of diphtheria in most parts of the world. In the United States in 1985, only two cases were reported.

The Schick test, used to determine whether an individual is immune or susceptible to diphtheria, was developed by the Hungarian-American pediatrician Béla Schick in 1913.