Why has the prevalence rate been selected as the yardstick for elimination?
Prevalence at the end of the year is a simple and easily understandable indicator, which gives the balance of the patients under active treatment, after excluding those cured and released from treatment during the year. The main thrust of the elimination strategy is to reduce the burden of the disease to very low levels. In view of the long incubation period of leprosy, it is difficult to differentiate new or incident cases, i.e., those who developed the disease within one year from those who developed earlier (backlog cases). Hence it was decided to use prevalence rate as the yardstick for elimination. WHO is fully aware of the limitations of using registered prevalence as an indicator of progress towards elimination. However, in the absence of practicable alternatives, prevalence was considered the best indicator available. Now that most countries have achieved the goal of elimination of leprosy as a public health problem, using the prevalence indicator, WHO is recommending a shift t
