The prevalence rate is defined as the number of cases registered for MDT treatment among the population in which the cases have occurred, again at a given point in time. History
Historical distribution
Using comparative genomics, in 2005, geneticists traced the origins and worldwide distribution of leprosy from East Africa or the Near East along human migration routes. They found four strains of M. leprae with specific regional locations. Strain 1 occurs predominantly in Asia, the Pacific region, and East Africa; strain 4, in West Africa and the Caribbean; strain 3 in Europe, North Africa, and the Americas; and strain 2 only in Ethiopia, Malawi, Nepal, north India, and New Caledonia. This confirms the spread of the disease along the migration, colonisation, and slave trade routes taken from East Africa to India, West Africa to the New World, and from Africa into Europe and vice versa.Skeletal remains discovered in 2009 represent the oldest documented evidence for leprosy, dating to the 2nd millennium BC. Located at Balathal, Rajasthan, in northwest India, the discoverers suggest that, if the disease did migrate from Africa to India during the 3rd millennium BC "at a time when there was substantial interaction among the Indus Civilization, Mesopotamia, and Egypt, there needs to be additional skeletal and molecular evidence of leprosy in India and Africa to confirm the African origin of the disease."
Inguinal lymphadenopathy causes swollen lymph nodes in the groin area. It can be a symptom of infective or neoplastic processes. Infective aetiologies include Tuberculosis, HIV, non-specific or reactive lymphadenopathy to recent lower limb infection or groin infections. Another notable infectious cause is Lymphogranuloma venereum, which is a sexually transmitted infection of the lymphatic system. Neoplastic aetiologies include lymphoma, leukaemia and metastatic disease from primary tumours in the lower limb, external genitalia or perianal region and melanoma. References
Ferrer R (October 1998). "Lymphadenopathy: differential diagnosis and evaluation". Am Fam Physician. 58 (6): 1313–20. PMID 9803196. Further reading
Principles and Practice of Infectious Diseases. Elsevier Health Sciences. 2014. ISBN 9781455748013. Retrieved 21 December 2017.