Gerhard Armauer Hansen

Gerhard Henrik Armauer Hansen (1841 to 1912) was a Norwegian physician from Bergen, remembered for identifying Mycobacterium leprae in 1873 as the cause of leprosy. He studied medicine at the University of Christiania, graduating with honors in 1866, worked at Rikshospitalet and as a doctor in Lofoten, and in 1868 returned to Bergen to study leprosy at Lungegård Hospital beside the noted expert Daniel Cornelius Danielssen. At a time when leprosy was widely regarded as hereditary or miasmic, Hansen concluded from epidemiological studies that it was a communicable disease with a specific cause, and in 1873 he announced the bacterium in the tissues of people with the condition. His claim was weakened because he could not produce a pure culture, and a priority dispute followed with Albert Neisser, who stained the bacteria in 1880. An experiment in which he tried to infect a patient without consent ended in court and cost him his hospital post, a case that helped introduce informed consent for medical research in Norway. As medical officer for leprosy he was behind the leprosy acts of 1877 and 1885, and known cases in Norway fell from 1,800 in 1875 to 575 in 1901.