LEPROSY (Syllabus: GS Paper 3 – Sci and Tech)

News-CRUX-10     6th May 2024        

Context: Evidence from archaeological sites in the medieval English city of Winchester shows that English red squirrels once served as an important host for Mycobacterium leprae strains that caused leprosy in people according to a study.


  • About: It is a chronic infectious disease caused by Mycobacterium leprae. 
  • Known as: Hansen’s disease
  • Affects: Skin, the peripheral nerves, mucosal surfaces of the upper respiratory tract and the eyes. Leprosy is known to occur at all ages ranging from early childhood to old age. 
  • Transmitted: Via droplets, from the nose and mouth, during close and frequent contact with untreated cases.
  • Symptoms: Discolored patches of skin, Growths (nodules) on the skin, Thick, stiff or dry skin, Painless ulcers on the soles of feet.
  • Treatment: Hansen’s disease is treated with a combination of antibiotics.

  • World Leprosy Day: It is observed on the last Sunday of January each year.
  • National Leprosy Eradication Programme (NLEP): It is a centrally sponsored Health Scheme under the National Health Mission of the Ministry of Health and Family Welfare.
  • Vision: “Leprosy-free India”.

Key Points of Study

  • The study reveals that the medieval strain of M. leprae found in squirrels shares closer genetic ties with medieval human strains from Winchester than with modern squirrel strains in England.
  • This genetic connection suggests that during the Middle Ages, M. leprae circulated between humans and animals in a manner previously undocumented.
  • These findings challenge prior notions and suggest that M. leprae circulates in a wider array of wild animals than previously thought.
  • The discovery hints at the potential contribution of zoonotic infections to the ongoing epidemic of leprosy, expanding our understanding of its transmission dynamics.
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