Paper short abstract:

This paper discusses evidence for leprosy at Indus Civilization sites in light of hypotheses that M. leprae migrated to urban settlements in South Asia from Africa during the third millennium B.C. with regular long distance exchange among the two continents.

Paper long abstract:

Leprosy is a disease caused by infection with Mycobacterium leprae. It has long been associated with outcaste people suffering on the edge of civilization. Prior to successful eradication in many countries, the disease was considered interwoven with civilization itself. Currently one-quarter of a million people still suffer from the disease. Despite its long history of interaction with humans and our strong concern with understanding the natural history of this disease, technical difficulties with culturing M. leprae have severely limited our understanding of the origins, evolution, and transmission of this disease. Recent genomics research suggests the disease originated in Africa 40,000 years ago and recent archaeological evidence suggested it was present at an Indus outpost in Rajasthan, India by 2000 B.C. This paper will discuss new skeletal and molecular evidence from Harappa in light of hypotheses about the origin and early migration of M. leprae, one of the largest cities in the Indus Civilization. Results of our analysis demonstrate the role of urbanization and exchange in the evolution of this pathogen in human populations.