Gerhard Hansen: discoverer of the organism of leprosy.

This year marks the hundredth anniversary of the death, on 12 February 1912, of the Norwegian leprologist, Gerhard Hansen, who was the first to describe the Mycobacterium leprae (Hansen's bacillus). It was, in fact, only the second specific disease-causing organism to be discovered, the first being the bacillus of anthrax.