This Day in Tech 1882

Robert Koch isolated the tuberculosis bacillus only five years after proving that bacillus anthracis is the infectious microorganism that transmits anthrax.
Courtesy Karolinska Institutet Library

1882: German physician Robert Koch announces his discovery of the tuberculosis bacillus, isolating the cause of a scourge responsible for one in seven deaths during the mid-19th century.

Koch turned to the study of infectious diseases while still in medical school at the University of Gottingen. There, he was influenced by anatomist Jakob Henle, an advocate of the germ theory, which posited that communicable disease was transmitted through microorganisms.

Despite the work of other prominent microbiologists, including Joseph Lister and Louis Pasteur, the prevailing view for much of the 19th century was that diseases arose spontaneously within an individual. Koch, piggybacking on the work of his predecessors and making huge contributions of his own, played a key role in finally debunking that theory.

Besides discovering the TB germ, Robert Koch also isolated the infectious bacillus for both anthrax and cholera.

Koch volunteered for medical service during the Franco-Prussian War and carried out much of his groundbreaking research on anthrax — including the discovery of the bacillus anthracis — while serving as district medical officer in the rural Wollstein, a farming region in the Rhineland.

He began serious research into tuberculosis after moving in 1880 to the Imperial Health Bureau in Berlin, which offered better laboratory facilities. By 1882, Koch had isolated the bacillus and published his definitive paper on the subject.

The German Cholera Commission sent Koch overseas in 1883, first to Egypt and then to India, to study the rising tide of that disease in those countries. His work led to the identification of the bacillus that causes cholera and eventually to a worldwide convention on the handling of cholera, which remains relevant to this day.

That work took him away from tuberculosis for a few years, but he returned to it after becoming professor of hygiene at the University of Berlin. Koch developed tuberculin, which he believed would result in a cure of tuberculosis, but his claims proved to be exaggerated, which damaged his reputation for a time.

The damage was not lasting, however, owing to Koch's many achievements that changed attitudes and approaches to the treatment of infectious diseases. Tuberculin also proved effective, not as a cure for the disease, but as a test for presymptomatic tuberculosis.

An immunization for tuberculosis, BCG, was produced in 1906, although it wasn't tried on humans until the early 1920s and didn't see widespread use until after World War II.

Koch, who was awarded a Nobel Prize in 1905 for his work in tuberculosis, also laid down the conditions, known as Koch's postulates, that must be met before a specific bacteria can be said to have caused a specific disease.