Global practices in regard to implementation of preventive measures for leprosy

The global incidence of leprosy is declining slowly, but it is not known why this is happening. Suggested reasons include the gradually increasing global standard of living, increasing coverage with Bacillus Calmette–Guérin (BCG) vaccination of infants over the last 90 years or so, and specific measures to find and treat patients with leprosy over the last 60 years or so. None of these has a large effect and there is interest in finding other ways to speed up the decline in incidence by developing more targeted measures to interrupt the transmission of leprosy in the community. The number of patients on treatment for leprosy (the registered prevalence) has declined steadily over the last three decades, largely in parallel with the decreasing duration of treatment. The number of new cases detected each year has shown a much smaller, but variable decline in different countries [1], and is strongly influenced by policies relating to case finding. In fact, with the integration of health services, active case-finding activities have been reduced and it is likely that a significant number of incident cases are not being detected [2]. The continuing incidence of leprosy in children in approximately 100 countries suggests that transmission of the disease continues and indicates the need for a global strategy of prevention. Rising living standards and the gradually improving coverage of BCG vaccine in infants are two general changes that may have exerted downward pressure on the incidence of leprosy, although the effect is difficult to quantify [3]. Treatment with powerful bactericidal drugs does not seem to have had a major impact on incidence [3], probably because most transmission occurs before initiating treatment. The Global Leprosy Programme (GLP), based in the WHO Regional Office for South-East Asia (SEARO) in New Delhi, plans to issue new guidelines on the treatment and prevention of leprosy. To date, guidance on leprosy management has come from meeting reports, such as those of the Expert Committee or strategy documents and operational guidelines. Neither the 2010 Expert Committee Report [4], nor the 2009 Operational Guidelines [5], written as a guide to the implementation of the Global Leprosy Strategy 2011–2015 [6], recommended any specific preventive measures, although they did call for further research into the logistics and feasibility of prophylaxis for contacts of new cases. Two possible strategies to reduce incidence are being studied. Firstly, if cases could be detected and started on treatment much earlier, there may be an effect on the transmission of Mycobacterium leprae, the causative organism of leprosy. Active case-finding, especially through (extended) contact surveys, may help, but this is still dependent on overt signs of