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Year : 2015  |  Volume : 60  |  Issue : 3  |  Page : 219-221
Chronicles of Gerhard-Henrik Armauer Hansen's life and work

1 Department of Skin and VD, PGIMS, Rohtak, Haryana, India
2 Department of General Medicine, PGIMS, Rohtak, Haryana, India

Date of Web Publication6-May-2015

Correspondence Address:
Sangita Ghosh
42/136, New Ballygunge Road, Kolkata, West Bengal - 700 039
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0019-5154.156310

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Gerhard-Henrik Armauer Hansen, a Norwegian scientist, discovered Mycobacterium leprae as the causative organism for leprosy, defying the hereditary affliction theory of the disease. He was born in Bergen, Norway in 1841 in a Danish family. After acquiring his medical degree in 1866 from the University of Oslo, he joined as an assistant physician in a leprosy hospital in Bergen. In 1873, he published his report claiming leprosy to be an infectious disease with a description of the infectious material in leprous tissue. His conviction of belief and an unstinted devotion to a lifetime of scientific research changed the way leprosy was approached as a disease. It was the fruit of his untiring work that the amended act of 1885 was passed, which resulted in steady decline in leprosy burden in Norway. In February 1912 he breathed his last, leaving behind an inspirational story of a brave heart scientist who fought all odds to unveil the truth for the benefit of mankind.

Keywords: Discovery of M. Leprae, hansen, norway

How to cite this article:
Ghosh S, Chaudhuri S. Chronicles of Gerhard-Henrik Armauer Hansen's life and work. Indian J Dermatol 2015;60:219-21

How to cite this URL:
Ghosh S, Chaudhuri S. Chronicles of Gerhard-Henrik Armauer Hansen's life and work. Indian J Dermatol [serial online] 2015 [cited 2021 Sep 23];60:219-21. Available from:

What was known?
Hansen′s disease, another name for leprosy, is named after Gerhard-Henrik Armauer Hansen who discovered the Lepra bacilli, the causative organism for leprosy, thus disproving the hereditary affliction theory.

   Introduction Top

"Who discovered lepra bacilli?" Asked my professor as we gathered around a patient afflicted with leprosy, in our first clinical session on the disease in a leprosy ward. One of us pointed towards a big portrait on the wall and fumbled "Hansen". Pleased with the answer, the professor insisted on hearing a little more than just the name from his students. But as much as we struggled to connect a few disjointed words like Norway, leprosy and bacilli to this name, none of us really knew the history well enough for a narration. The rest of the lecture focused mainly on clinical skills and basics of leprosy knowledge. But the untold story of Hansen that day, kept lurking at the back of my mind and the large portrait on the wall was a like a bookmark that urged me to turn the pages of history, every time I walked past Dr. Hansen in the canvas. As I sought to know more, I found a fascinating story of a brave heart scientist who was very justifiably famous as the discoverer of the leprosy bacilli, and a man who dedicated a lifetime of scientific research towards transforming one of the great scourges of mankind to an understandable and treatable disease.

The story dates back to 1841 in Bergen, a small town in the west of Norway. In the summer that year, was born Gerhard Henrik Armauer Hansen, 8 th of fifteen children to Mrs. Elizabeth Concordia Schram and Mr. Claus Hansen, on the July 29 th . [1] After spending a mischievous childhood moderated by his strict father in a middle class household, this destiny's child went to the University of Christiania to study medicine in 1859. This exceptional research talent acquired his degree with honours in 1866. After completing his internship, he served as a community doctor in Lofoten, a small Norwegian fishing village in northern Norway, for a year. But as destiny had it planned, Hansen returned to his people in Bergen in the year 1868. [2]

Norway, which was already fighting its battle against leprosy, by the middle of nineteenth century, was probably the worst hit by leprosy in Europe and it was Bergen where the leprosy research centre was established with three other lepra hospitals. It was estimated that in the 1850s, roughly two individuals per thousand in Norway were afflicted with leprosy, but the prevalence in Bergen was as much as 25 per thousand. [2] On his return to his hometown, Hansen met Dr. Daniel Cornelius Danielssen and Dr. Carl Wilhelm Boeck, the two celebrated stalwarts of ancient leprosy research, who had the very famous "Om Spedalskhed" (On Leprosy) publication to their credit, along with a great deal of researched knowledge. [3] Dr. Danielssen was especially considered as the foremost authority in leprosy scientific research and the guiding force behind all public health efforts to combat leprosy, not only in Norway but entire Europe. He however was a staunch believer of the concept of hereditary affliction of leprosy, supported by the rest of the medical fraternity of his time. [1] An infectious etiology was not obvious because of the long incubation period that obscured the trail of contact. But as we all know today, history was yet to be written, and written differently.

However absurd the theory of hereditary transmission of leprosy sounds today, one cannot deny Dr. Daniel Cornelius Danielssen's contribution in the fight against leprosy. It was to his credit that Bergen was made the epicenter of leprosy research. [1] While working under Dr. Danielssen, a young and inquisitive Hansen travelled with him all across Norway to study the disease, collect pathological samples from the lepers and research relentlessly to finally come to a revolutionary conclusion that challenged Dr. Danielssen's theory of hereditary transmission. He believed an organism carried the disease from person to person and emphasized the theory of contagion, ruling out hereditary etiology for this condition. [4] It was a daring speculation at a time when the concept of contagion was still poorly understood. By declaring this theory, Hansen ran into a professional conflict with his superior but continued to believe firmly in his observation. Despite all the negative criticism and resistance against such a challenging proposal, he continued to research further to prove his theory.

In 1869, in his first published work, he described the pathological alterations in leprous tissue. [5] But his technique of staining bacteria was exceedingly primitive and furthermore his poor equipment complicated his work and it would be unfair to expect him to have delivered more adequate description of the lepra bacilli than he did. It became clear to Hansen that he needed improved skills in pathologic anatomy and particularly in microscopy. In 1870, a grant allowed Dr. Hansen to travel to Vienna to for advanced training in staining and histopathology, which enabled him to strengthen his research technique [6] and a more determined Hansen launched his search for that infectious substance, a culprit yet to be captured and produced in front of the world. He would sit unceasingly for days on end, focusing through the microscope and looking at stained tissue slides of leprous tissue. Finally in the year 1873, when he was merely 32 years old, he concluded his successful attempt at identifying the infectious substance in leprous material and published his historic work. [5] This incidentally was also the year when he married his Chief Dr. Danielssen's daughter Stephanie Marie. In 1875, he was made physician-in-chief for all the lepers in Norway. [2]

In tissues taken from nodules of leprosy patients he described rod shaped bodies, resembling bacteria and claimed that these bacteria were indeed the causative agent for leprosy and leprosy was neither a hereditary disease nor a curse given by God that the lepers must suffer for their sins. Dr. Hansen was in fact the first investigator to suggest that microorganisms can cause human diseases. The rest of the medical fraternity worldwide still laughed at this revelation and his daring proposal, and thought of it as a figment of Hansen's imagination. Some of the investigators though were convinced about the existence of such a substance in the experimented material, but rejected its role in causing leprosy. [7] However; his attempts at inoculation of the organism into other animals made it more difficult for him to prove his stand. He was unable to satisfy Koch's postulates, which required any putative pathogen to be first isolated and then shown to cause the same disease when re-introduced into another animal. A desperate Hansen even tried to inoculate the eye of a woman with material drawn from leprosy patient without her consent. [5],[8] It was undoubtedly a reckless attempt at human experimentation and to nobody's surprise this unethical attempt landed him in a medico legal quagmire, which later proved to be a major setback in his medical career. He also suffered a stroke at the young age of 36 in 1877, but continued his untiring work unfettered and uninhibited.

In 1879, a young German bacteriologist caller Albert Neisser (who later gained fame for discovering the causative organism of gonorrheoa), a pupil of Robert Koch, on his research trip to Norway to study leprosy, had the opportunity to meet Dr. Hansen and have a look at his research work. From Hansen he received preparations made from lepra nodes. [9] On his return to Germany, Neisser made all attempts to stain them better to yield more convincing results and equipped with his advanced staining methods and by virtue of being a bacteriologist himself, he succeeded. A very excited Dr. Neisser went ahead to publish his scientific find in 1880, without giving the due credit to Dr. Hansen, and claimed the honour of discovering the organism that caused the disease. [7],[9] Soon the term Neisser's bacterium was in use while Hansen was busy in Bergen fighting his court case for violating medical ethics for human experimentation. The court found him guilty for failing to obtain consent from the subject and he was removed from his post as resident physician of the Bergen leprosy hospital in 1880. [5] But once the news of Albert's claim reached Bergen, the entire medical fraternity of Norway defended Hansen's stand and it was none other than Dr. Danielssen who encouraged Hansen to respond strongly to Neisser's deliberate attempt at plagiarism. [9] Fortunately the truth was unveiled and the conflict was officially addressed in a lepra congress held in Berlin where Hansen [Figure 1] was recognized as the true discoverer of the lepra bacilli. [8],[9] This also marks the world's awakening and acceptance of the contagion theory and changed the way leprosy as a disease was approached. It was the fruit of his untiring work that the amended act of 1885 was passed, which ordered health authorities to allow lepers to live in precautionary isolation, away from the unaffected section of the community, which led to quick and steady decline in the leprosy disease burden in Norway. [4]
Figure 1: Henrik Armauer Hansen: The discoverer of M. Leprae

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If one looks at his personal life, he did have his share of ups and downs. In his seventies, he penned his autobiography "The Memories and Reflections of Dr. Gerhard Armauer Hansen." [10] Coming from a humble middle class background, pursuing medical education itself was a challenge which he took upon himself, serving as a school teacher in a girls school and later as a prosector in anatomy, in order to meet the expenses of medical school. [1],[6] Hansen was also an accomplished biologist and an ardent follower of Darwin's theory of evolution and propagated it for wider acceptance. [1] He is described as a radical in his time who doubted the benefit of visiting the church, which earned him a lot of criticism and displeasure from the clergy. Hansen sometimes was considered unflinching in his views and was not known to be amenable to debate. He was critical of women's freedom and even doubted women's credential to become doctors. [6] But Hansen was well respected by his colleagues who described him as a humble, hardworking, warm-hearted and entertaining person with a great sense of humour. He married Dr. Danielssen's daughter Stephanie Marie in 1873, but lost her to tuberculosis within a year of their marriage. [2] Two years later, he remarried and had a son with his second wife. He named his son Daniel Cornelius Armauer Hansen, after his previous father in law Dr. Daniel Cornelius Danielssen. He encouraged his son to pursue medical education, which rightfully carried his legacy forward and later went on to become the chief of the tuberculosis hospital in Bergen. [2],[6]

After an episode of a brain stroke at a very early age, Hansen started experiencing symptoms of heart disease in his fifties, which nearly confined him to bed. Undaunted, he continued to travel around the country on official inspection tours. In February 12, 1912 in Florψ, a little town on the western coast, he breathed his last. [2] He was given a funeral at state expense; he had been the president of the Bergen Museum and the ceremony took place from its hall. It was much later that the cause of his illness was revealed and history tells us that he actually suffered from syphilis and probably his stroke and subsequent heart disease was in fact due to syphilis. It is also rumored that he might have contracted the disease from a seamstress in Christiana during his student years in 1860s. [11]

   Conclusion Top

The real significance of Hansen's contribution to medicine in general, and to bacteriology in particular, can be fully grasped only when one recalls the position investigative medicine had reached in 1873, when the leprae bacillum was discovered. He shared the fate of other great minds that labored in advance of their time and was met with opposition, scathing criticism and a lack of recognition. It was his misfortune to have fought a battle against a bacterium which even today defies most attempts at artificial cultivation. But his numerous contributions to leprosy with his discovery of the causative organism will always be held in reverent esteem in the history of medicine.

   References Top

Hansen W, Freney J. Armauer Hansen (1841-1912), portrait of a Nordic pioneer. Hist Sci Med 2002;36:75-81.  Back to cited text no. 1
Vogelsang TM. Gerhard Henrik Armauer Hansen 1841-1912. The discoverer of the leprosy bacillus. His life and his work. Int J Lepr Other Mycobact Dis 1978;46:257-332.  Back to cited text no. 2
Vogelsang TM. The Hansen-Neisser Controversy, 1879-1880. Intl J Leprosy 1963;31:74-80.  Back to cited text no. 3
Melson R. Armauer Hansen 1841-1912. Arch Dermatol 1942;45:388-9.  Back to cited text no. 4
Jay V. The legacy of Armauer Hansen. Arch Pathol Lab Med 2000;124:496-7.  Back to cited text no. 5
Mange PF. Gerhard Henrik Armauer Hansen and his discovery of Mycobacterium leprae. Nihon Rai Gakkai Zasshi. 1994;63:17-29.  Back to cited text no. 6
Getz B. Leprosy research in Norway, 1850-1900. Med Hist 1958;2:65-7.  Back to cited text no. 7
Harboe M. Armauer Hansen--the man and his work. Int J Lepr Other Mycobact Dis 1973;41:417-24.  Back to cited text no. 8
Kobro I. Gerhard Henrik Armauer Hansen. Annals of Med History 1925;7:127-32.  Back to cited text no. 9
Harboe M. Gerhard Henrik Armauer Hansen--still of current interest. Tidsskr Nor Laegeforen 1992;112:3795-8.  Back to cited text no. 10
Whonamedit? A dictionary of medical eponyms. [Internet]. Norway. Gerhard Henrik Armauer Hansen. Inc.; 1994-2012. Available from:[Last accessed on 2012 Aug 13].  Back to cited text no. 11

What is new?
This article encapsulates the unyielding determination and astute scientific acumen that Gerhard-Henrik Armauer Hansen exhibited in his lifetime and gives us a glimpse into the life of a legend in the field of Leprology.


  [Figure 1]


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