Epidemiology of Leprosy

In this chapter some aspects of the operational and descriptive epidemiology of leprosy are discussed, namely: the basic epidemiological indicators for monitoring leprosy, the geographical distribution of the disease, and its trends by World Health Organization (WHO) region and selected countries. Globally the new case detection (NCD) of leprosy excluding India sees a gradual decline since the years 2004/2005. India was an exception with a sharp decline from 2001 onward. In the past few years, the global annual detection figures show a slight, gradual decrease (2015, 210,740, and 2019, 202,185 new cases per year).

WHO September 2002: New cases of leprosy are decreasing, but not at the anticipated rate. In order to accelerate the annual decline, countries should screen contacts and treat eligible contacts with single-dose rifampicin, as recommended by the World Health Organization (WHO) in its guidelines.

It is pointed out that different operational factors and lack of completeness (and validity) of data make comparison between countries and, even within countries, between regions difficult. Before any interpretation of epidemiological data is done, one has to look how these data have been collected and its indicators calculated and if operational factors have been stable or changing over time.