Leprosy (Hansen’s disease): interrupting transmission and achieving zero autochthonous cases
The World Health Organization (WHO) has unveiled its new strategy to achieve interruption of transmission and zero new cases for leprosy in more than 100 countries by 2030. The strategy also aims to significantly reduce the disease burden in remaining countries.
Following remarkable progress over the past 4 decades, Towards zero leprosy – Global Leprosy (Hansen’s disease) Strategy 2021–2030 moves beyond “elimination as a public health problem”,1 to motivating high-burden countries and stimulating work in other countries to complete the unfinished task of ending the disease.
“The strategy promotes innovative approaches such as the use of targeted active case detection and the potential introduction of a safe and effective vaccine” said Dr Poonam Khetrapal Singh, Regional Director, WHO South-East Asia Region. “The implementation of the Global Leprosy Strategy 2021–2030 will drive rapid and sustained progress in all leprosy-endemic countries, advancing progress on the WHO Roadmap for Neglected Tropical Diseases 2021–2030 and the Sustainable Development Goal targets.”
Developed amid the new reality of COVID-19, this strategy looks beyond traditional service delivery, to methods such as e-learning, telemedicine, mobile health and other innovative approaches, to drive improvements towards achieving the new leprosy targets. These new tools and approaches can also greatly contribute to combatting stigma and ensuring that the human rights of people affected are respected.
The strategy, aligned with broader global health trends, moves towards multi-disease service integration, digitalization and accountability, while also addressing key challenges, including human resource capacity, surveillance and antimicrobial resistance.
The strategy calls for the development of “zero-leprosy road maps” in all endemic countries, to benefit from the integrated, cross-cutting approaches of the new road map for NTDs to accelerate progress. Key targets include:
The strategy is built on 4 pillars, which include interventions to:
Contact tracing is being prioritized, along with strategic active case-finding activities, in known or presumed hotspots and also in “silent” areas. Chemoprophylaxis is recommended for all contact cases.
Research holds a prominent place in the new strategy. Partners and academia are encouraged to collaborate on basic and operational research, working with people affected by leprosy, to build the evidence base for better policies, strategies and programmes.
In 2019, just over 200 000 cases of leprosy were detected in 118 countries globally.
These included around 5% of cases with visible deformities at the time of diagnosis, equating to 1.4 per million population – a 40% reduction on the 2014 figure. Globally, the new child case detection rate was 7.9 per million children – also a significant improvement on the 2014 rate of 10.1 per million children.
The strategy presents the basic direction, goals, challenges and strategic pillars at the global level. It is up to national NTD and leprosy programmes in both high- and low-incidence settings to adapt these strategic pillars to the country context, and to select targets and indicators appropriate to the particular country.
Leprosy is caused by infection with the bacillus Mycobacterium leprae, which multiplies very slowly in the human body. The bacterium has a long incubation period (on average 5 years or longer). The disease affects nerve endings and destroys the body’s ability to feel pain and injury.
Leprosy is curable. Treatment provided in the early stages of infection averts disability. Multidrug therapy is available free of charge through WHO. This therapy has been donated by The Nippon Foundation in the past (1995–2000), and by Novartis since 2000, with an agreement to continue until at least 2025.
Continued discrimination has deterred people from coming forward for diagnosis and treatment – thus encouraging cases to remain hidden and indirectly contributing to transmission.
Social stigma also facilitates transmission among vulnerable groups, including migrant populations, displaced communities, and very poor and hard-to-reach populations. Combating stigma and achieving early diagnosis through active, early case-finding are critical to interrupting transmission.
Defined as less than 1 case on treatment per 10 000 population. This was achieved globally in 2000; however, pockets of endemicity have continued in many countries. India and Brazil report the highest numbers of cases annually.