Robert Koch announces discovery of the tuberculosis bacillus in Berlin

Background. Robert Koch, a German physician and microbiologist, was appointed as a government advisor at the Imperial Health Office in 1880 and worked there until 1885. His earlier work on anthrax in 1876 is considered the birth of modern bacteriology. Koch utilized agar for pure culture isolation, a method suggested by his assistant Walther Hesse in 1881, which facilitated his study of pathogenic organisms.

The Announcement. On 24 March 1882, Koch presented his findings on tuberculosis to the German Physiological Society in Berlin. He reported that the causative agent was the slow-growing Mycobacterium tuberculosis, also known as Koch's bacillus. The presentation was titled 'Die Ätiologie der Tuberkulose' (The Etiology of Tuberculosis). This event is commemorated annually as World Tuberculosis Day.

Immediate Aftermath. Following the discovery, Koch was promoted to Geheimer Regierungsrat, a senior executive position, in June 1882. At the time of his 1882 discovery, Koch believed that human and cattle tuberculosis bacilli were different pathogens. His report was expanded into a booklet in 1884, in which Koch concluded that the bacilli caused the disease, fulfilling principles that were formulated by his assistant Friedrich Loeffler in 1883 and later known as Koch's postulates.