Leprosy has been a major public health problem in India for centuries. In India, between 2001 and 2005, the prevalence of leprosy was reduced by 80%. This sharp decline in the prevalence of leprosy alongside the cessation of active surveillance for detection of leprosy cases has raised a sense of alarm in the scientific community.

This is a total population survey aiming to estimate the prevalence of undetected active cases of leprosy in the community in defined rural (Panvel Taluka, Raigad District) and urban (M-East Ward, Mumbai) areas by health workers from Kushth Nivaran Samiti (Panvel) and Lok Seva Sangam (Mumbai). Those provisionally diagnosed with leprosy were subjected to an independent verification using clinical, bacteriological and histopathological investigations at the Foundation for Medical Research.

A population of 196,694 and 600,247 was covered in defined rural and urban areas respectively. In the rural area on examining 178,646 individuals, 120 provisionally diagnosed leprosy cases were detected, of which 65 were paucibacillary (PB) and 55 were multibacillary (MB) based on the WHO operational classification used by health workers at field level. In the urban area, of the 512,434 individuals who were examined, 134 provisionally diagnosed leprosy cases were detected with 92 PB and 42 MB cases. Among the clinically confirmed cases, 35.6% (32/90) and 34.9% (36/109) in rural and urban areas respectively were children.

There are large numbers of undetected leprosy cases in the community with a high proportion of MB patients and children among them. This indicates active transmission pointing to the need for a paradigm shift in leprosy care services and control programme.