Introduction

The descriptions of leprosy in the Bible do not resemble any known infectious disease. Indeed, Leviticus identifies leprosy as a disease to be found in the walls of a house, rather than in people. Biblical Leprosy seems to most closely resemble a scaly, flaking skin condition described by Hippocrates, which he named Lepra and which he considered to be a curable condition. It is probable that almost any disfiguring skin complaint was classed as leprosy, even after the spread of bacterial leprosy, which we know today as Hansen’s Disease.

Hansen’s Disease

Causative Agent

Mycobacterium leprae

Primary Host

Exclusively a Human disease.

Spread by

Droplets and / or frequent contact. It is, however, not highly infectious.

Birthplace

Possibly ancient Egypt, although civilisations in what are now China and India recognised the disease.

Endemic Today

Less than two dozen, mainly tropical, countries. Twelve countries, Angola, Brazil, Central African Republic, Democratic Republic of the Congo, India, Indonesia, Guinea, Madagascar, Mozambique, Myanmar, Nepal and Niger had 90% of all cases recorded in 1999.

Earliest Known

First positively identified reference around 600BC.

First Significant in Europe

There was a sudden, dramatic increase during the 12th century. This spread has been linked to the Crusades, which may have introduced Hansen’s Disease into Europe. If so, this was when the change from Biblical Leprosy would have occurred.

Control Measures

Control was by isolation. The Third Lateran Council, of 1179, decreed that lepers should be identified and separated. A mass was held for the leper, who became ‘dead among the living’. From that time on, the leper had to carry a clapper or bell to announce his or her presence and to live outside the normal world. In some places the leper had to carry a long stick to use when reaching for goods or alms and had to wear clothes marked with a yellow cross.

Decline

In Europe, the disease declined rapidly in the fourteenth century. This has lead some observers to suggest that plague so decimated the sufferers that there were not enough to spread the infection. It may have been a factor. However, Lazar houses were, by design, well isolated from the general population. This should have provided some protection for the occupants and, if so, there should have been proportionately more lepers after a plague, not less. There is also no evidence that, even taking the worst figures for the effects of the Black Death, the population fell below the point at which Hansen’s Disease was viable.

Another, more probable, explanation is that Hansen’s Disease was controlled by the spread of tuberculosis. The two diseases are caused by closely related mycobacteria and people exposed to tuberculosis are known to have a very high resistance to Hansen’s Disease. Tuberculosis has been with us for at least 5,000 years, but it thrives best in crowded living conditions, which tends to link it to cities. Tuberculosis started to become significant in its own right from about the eighteenth century. However, one of its characteristics is that a very large percentage of the population (1 in 3 around the world today) can carry the disease and in most it will be dormant, waiting for other factors, such as malnutrition, to weaken the body's immune system. The numbers touched for King’s Evil show that it was widespread by the middle of the thirteenth century, which ties in quite well with both the growth of cities in Europe and the decline of Hansen’s Disease.

Situation Today

Hansen’s Disease is curable with drug therapy, which lasts from six to twelve months. It is easily diagnosed by people with minimum training and, if caught early enough, need not cause any disfigurement. In the past 15 years, the disease has been eradicated from nearly 100 countries.

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