Leprosy bacillus (Mycobacterium leprae)
Bacilo de la lepra (Mycobacterium leprae)
- Date
- 1873 · confidence high
- Place
- Bergen, Vestland, Norway
- Credited to
- Gerhard Armauer Hansen
- Field
- Life & health
⚠️ Disputed: the sources disagree.
What was discovered
In 1873 Hansen observed bacilli in tissue of leprosy patients in Bergen, the first microbe identified as the cause of a chronic human disease. He showed leprosy was infectious and not hereditary.
Neisser, who received samples from Hansen, tried to claim the discovery (1879) through staining; Hansen did not fulfil Koch's postulates because the bacillus cannot be cultured in vitro. Today Hansen is recognised as the discoverer.
What it led to
- Norway's leprosy isolation and register policy (1877)
- treatment with dapsone (1940s) and multidrug therapy (1981)
- use of the term 'Hansen's disease' to avoid stigma