Leprosy - An Overview of Current Public Health Burden

Hansen's disease (also known as leprosy) is a long-lasting infection caused by bacteria. The disease was once feared as a highly contagious and devastating disease. Now, however, the disease is relatively rare and easily treated. Early diagnosis and treatment usually prevents disability related to the disease.

Introduction

Although leprosy was managed differently in the past, with the duration of treatment lasting many years, often a lifetime, making it difficult for patients to adhere to it; current use of multiple drugs (multidrug therapy, or MDT) has significantly shortened duration and increased effectiveness of treatment.

MDT treatment has been made available by WHO free of charge to all patients worldwide since 1995. It provides a simple yet highly effective cure for all types of leprosy.

Elimination of leprosy as a public health problem (with a prevalence less than 1 case per 10 000 persons) was achieved globally in the year 2000. More than 16 million leprosy patients have been treated with MDT over the past 20 years.

According to official reports received from 121 countries from all WHO regions except for Europe, the global registered prevalence of leprosy at the end of 2014 was 175 554 cases (0.24 cases per 10 000 people). The number of new cases reported globally in 2014 was 213 899 (0.3 new cases per 10 000 people). In 2013, 215 656 new cases were reported, and in 2012, 232 857 new cases.

The number of new cases indicate the degree of continued transmission of infection. Global statistics show that 200 808 (94%) of new leprosy cases were reported from 13 countries reporting more than 1000 new cases each and only 6% of new cases were reported from the rest of the world.

Pockets of high endemicity still remain in some areas of many countries, including countries reporting less than 1000 new cases. Some of these areas show very high notification rates for new cases and may still witness intense transmission.

Leprosy today

Leprosy control has improved significantly due to national and subnational campaigns in most endemic countries. Integration of basic leprosy services into general health services has made diagnosis and treatment of the disease more accessible.

Detection of all cases in a community and completion of MDT treatment were the basic tenets of the “Enhanced Global Strategy for Further Reducing Disease Burden Due to Leprosy” (2011–2015).

In 2016 WHO launched a new global strategy – “The Global Leprosy Strategy 2016–2020: Accelerating towards a leprosy-free world” – which aims to reinvigorate efforts for leprosy control and to avoid disabilities, especially among children affected by the disease in endemic countries.

Global Leprosy Strategy 2016-2020

This strategy emphasizes the need to sustain expertise and increase the number of skilled leprosy staff, to improve the participation of affected persons in leprosy services, and to reduce visible deformities – also called grade-2 disabilities (G2D) – as well as stigma associated with the disease. The strategy also calls for renewed political commitment and enhanced coordination between partners, and highlights the importance of research and improved data collection and analysis.

For complete details, please see Global Leprosy Strategy 2016-2020.

Elimination of leprosy as a public health problem

In 1991 the World Health Assembly passed a resolution to “eliminate” leprosy as a public health problem by the year 2000. Elimination of leprosy is defined as a registered prevalence rate of less than 1 case per 10 000 persons. The target was achieved on time.

The widespread use of MDT and the reduction in duration of treatment dramatically contributed to this reduction:

Over the past 20 years, more than 16 million leprosy patients have been treated.
The prevalence rate of the disease has dropped by 99%: from 21.1 per 10 000 in 1983 to persons to 0.24 per 10 000 in 2014.
A dramatic decrease has been achieved in the global disease burden: from 5.2 million people with leprosy in 1985 to 805 000 in 1995, 753 000 in 1999 and 175 554 people with leprosy at the end of 2014.
With the exception of few small countries (with populations of less than 1 million), leprosy has been eliminated from all countries.
So far, there has been no resistance to anti-leprosy treatment when used as MDT, even if sporadic cases of resistance to a single drug are observed. Vigilance is maintained though a global sentinel surveillance mechanism.
Efforts currently focus on promoting early detection of cases to reduce disease burden (in particular disabilities) and to interrupt transmission. This will ultimately contribute to eliminating leprosy at sub-national levels.

Actions and resources required

In order to reach all patients, leprosy treatment needs to be optimally integrated into general health services. Moreover, political commitment needs to be sustained in all countries even after reaching elimination. Partners in leprosy elimination also need to ensure that human and financial resources continue to be available.

The age-old stigma associated with the disease remains an obstacle to self-reporting and early treatment. The image of leprosy must be changed at the global, national and local levels. A new environment, in which patients will not hesitate to come forward for diagnosis and treatment at any health facility, must be created ensuring no discrimination and promoting inclusion.

WHO response

In order to reinvigorate efforts for leprosy control WHO developed the “Global Leprosy Strategy 2016‒2020”, which is structured around the following 3 core pillars:

Pillar I: Strengthen government ownership, coordination and partnership
Pillar II: Stop leprosy and its complications
Pillar III: Stop discrimination and promote inclusion

Targets of the strategy

The targets of the new global strategy to be met by 2020 are:

Zero disabilities among new paediatric patients.
A grade-2 disability rate of less than 1 per 1 million people.
Zero countries with legislation allowing discrimination on basis of leprosy.

Sustained and committed efforts by the national programmes along with continued support from national and international partners have led to a decline in the global burden of leprosy. Increased empowerment of people affected by the disease, together with their greater involvement in services and the community, will bring us closer to a world without leprosy.

Key facts

Leprosy is a chronic disease which can be highly contagious and devastating.
Leprosy is curable with multidrug therapy (MDT).
The disease has largely been reduced worldwide, and thus by definition, eliminated. The widespread use of MDT and the reduction in duration of treatment dramatically contributed to this reduction.
Official figures from 121 countries from 5 WHO regions show the global registered prevalence of leprosy to be at 175 554 cases at the end of 2014. During the same year, 213 899 new cases were reported.

Also read: Leprosy - symptoms, treatment and key facts

Resource(s)
1). World Health Organization (WHO): Leprosy - Media centre. Accessed 16 September 2016. Available here: http://www.who.int/mediacentre/factsheets/fs101/en/
2). Centers for Disease Control (CDC): Hansen's disease (Leprosy). Accessed 17 September 2016. Available here: http://www.cdc.gov/leprosy/