The origin and development of leprosy in antiquity

Abstract

Through the ages leprosy has filled mankind with awe and horror. It still remains one of the unconquered infectious diseases, although the World Health Organisation reports a decrease in its prevalence (18 million to two million new cases annually over the past 20 years). For many, leprosy’s origins are to be traced back to the Hebrew Bible and the condition of zara’ath mentioned in Leviticus 13-14. This was a light-coloured scaly skin lesion which rendered the patient ritually unclean. Such a person was banned from society by a priest, and could only return on being pronounced clean. Zara’ath was almost certainly a benign skin lesion and not leprosy. When the Hebrew Bible was translated into Greek (the Septuagint) in the 3rd century BC, zara’ath was translated as lepros/lepra, possibly after an apparently comparable disease described in the Hippocratic Corpus (5th – 4th centuries BC). The Hippocratic disease was clearly a benign, scaly skin eruption, and not leprosy as we know it. The fact that leprosy, as a very chronic progressive disease with a characteristic clinical picture, was not described by Hippocrates, almost certainly means that it did not occur in the Greek community of the time. True leprosy is an infection caused by Mycobacterium leprae, and manifests initially as light-coloured skin macules. With prominent bodily immunity against the organism the skin lesions enlarge slowly, later become scaly with a numb surface, and are complicated by nervous infiltration and atrophic degeneration of the extremities (tuberculoid leprosy). With low immunity, progressive nodular infiltration of skin and underlying structures result in extensive deformities (e.g. the typical “leonine facies”), subcutaneous abscesses, destruction of nerves and other tissues, blindness, deafness and testicular atrophy (lepromatous leprosy). Medical writings of ancient civilisations show that a leprosy-like disease was recognised in Mesopotamia by the 2nd millennium BC, and possibly in India and China in the 1st millennium BC. It has been suggested that leprosy was brought to the Mediterranean region by Alexander the Great’s armies, 4th century BC.Leprosy produces pathognomonic bone lesions, and the earliest osteo-archaeological evidence of leprosy was found in Egyptian skulls dating back to the 2nd century BC. The first clinical description of a disease recognisable as classical leprosy, can be dated to Strato of Alexandria, 3rd century BC. This condition, which became known as elephantiasis or elephas, was subsequently described by numerous notable physicians of the time, and Aretaeus of Cappadocia in particular. It migrated to Greece and Italy; Pliny the Elder stating that it fi rst appeared in Rome at the end of the 1st century BC. Although it was considered incurable, complex therapeutic programmes including venesection, purges, enemas and perspirants were prescribed in order to rid the body of the presumed fluid retention. Elephantiasis spread through the Roman Empire, but only became a notable European epidemic during the Middle Ages. In time the zara’ath-associated lepra of the Septuagint and elephantiasis were considered related diseases, and by the 4th century they were seen as the same disease. The two names became interchangeable. The influence of the Christian Church was such that the ritualised banning of lepers became incorporated into the treatment of elephantiasis – against the advice of physicians like Caelius Aurelianus (4th/5th century AD). Gradually the name lepra (leprosy) replaced elephantiasis, which ensured the stigmatisation of leprosy as an “unclean disease” with divine punishment for previous sins – a tragic misconception which persisted up to modern times. Today elephantiasis refers to a tropical parasitic disease, fi lariasis, characterised by gross swelling and deformation of the lower body.