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Leprosy

Etiology


Leprosy is most prevalent for those under-served and marginalized communities, often the poorest of the poor. Leprosy is caused by a bacillus, Mycobacterium leprae, and transmitted via droplets, from the nose and mouth, during close and frequent contacts with untreated cases. Untreated, leprosy can cause progressive and permanent damage to the skin, nerves, limbs and eyes.

Signs and Symptoms


Mycobacterium leprae, the bacterium causing Leprosy, multiplies very slowly and the incubation period of the disease is about five years. Symptoms can take as long as 20 years to appear. Initital symptoms are that of patchy skin discoloration, then turning into skin lesions that are lighter than normal skin color. Other symptoms include muscle weakness and numbness. Leprosy mainly affects the skin, the peripheral nerves, mucosa of the upper respiratory tract and also the eyes, apart from some other structures. Early diagnosis and treatment with multidrug therapy (MDT) are the key elements in eliminating the disease as a public health concern.

Diagnosis


Globally, according to the official reports of 130 countries and territories during 2011 the number of new cases was of 192,246, while the number of new cases detected during 2010 was of 228,474, which implied a reduction of approximately 8% with respect to 2008. By 2011 all the countries of the Region had reached the national goal of elimination (<1 case per 10,000 inhabitants), with the exception of Brazil (1.51), while at first subnational administrative level five countries had still not reached the goal (Argentina, Bolivia, Dominican Republic, Paraguay and Venezuela). Between 2010 and 2011, 18 countries and territories have not reported cases of leprosy, 17 countries and territories reported less than 100 new cases and 10 countries reported 100 or more new cases. Brazil has renewed its commitment to reduce the prevalence of leprosy as a priority within its National Plan for the Elimination of Neglected Infectious Diseases, and has initiated a process of evaluation and monitoring of leprosy elimination. 

Treatment


In the early 1960s, Rifampicin and clofazimine, the other two components of MDT, were discovered due to in the 1960s, M. leprae starting to develop resistance to dapsone, the world’s only known anti-leprosy drug at that time. In 1981, a World Health Organization (WHO) Study Group recommended multidrug therapy (MDT). MDT consists of 3 drugs: dapsone, rifampicin and clofazimine and this drug combination kills the pathogen and cures the patient.

In the Region of the Americas, MDT implementation began in 1985. Its coverage in 1990 reached 42%; and by 2001, coverage was almost universally available. Its impact on reducing the disease burden could be observed over the period between 1992 and 1999. Leprosy prevalence dropped by 80%, resulting in a reduction in incidence from 8.1 per 10,000 inhabitants in 1992 to 1.4 in 1999. Continued efforts are being made to consolidate elimination and arrive at the interruption of the disease where as since 1995, WHO provides free MDT for all patients in the world, initially through the drug fund provided by the Nippon Foundation and since 2000, through the MDT donation provided by Novartis and the Novartis Foundation for Sustainable Development.

Prevention and Control


In 1991 WHO's governing body, the World Health Assembly (WHA) passed a resolution to eliminate leprosy by the year 2000. Elimination of leprosy is defined as a prevalence rate of less than 1 case per 10 000 persons. The target was achieved on time and the widespread use of MDT reduced the disease burden dramatically. Efforts currently focus on eliminating leprosy at a national level in the remaining endemic countries and at a sub-national level from the others. Over the past 20 years, more than 14 million leprosy patients have been cured, about 4 million since 2000.

In order to reach all patients, leprosy treatment needs to be fully integrated into general health services. Moreover, political commitment needs to be sustained in countries where leprosy remains a public health problem. Partners in leprosy elimination also need to continue to ensure that human and financial resources are available. The age-old stigma associated with the disease remains an obstacle to self-reporting and early treatment. The image of leprosy has to 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.

Elimination and Eradication


With the Regional Plan of Action for the Elimination of Leprosy in the Americas promoted by PAHO in 1992, the coverage with multidrug therapy (MDT) in 1990 reached 42%, and since 2001 until present time the coverage is practically universal.  Since 1995, PAHO through WHO provides MDT free of charge to all the people that need it, initially through the funds for medications from The Nippon Foundation and since the year 2000 through the donations of MDT provided by Novartis and currently by the Novartis Foundation for Sustainable Development.

In Resolution CD49.R19, adopted on October 2, 2009 by PAHO´s member states, leprosy was included as one of the neglected infectious diseases, for which the goal of elimination of leprosy at first subnational level by 2015 was defined. Principles and Directives for the Elimination of Discrimination Against People Affected by Leprosy and their Family Members were approved by the United Nations Human Right Council in June 2010. The Resolution A/RES/65/215 for the Elimination of Discrimination Against People Affected by Leprosy and their Family Members, was adopted by the United Nations General Assembly in December 2010 for the purpose of promoting the formulation and application of policies and measures to prevent the discrimination of people affected by leprosy and their family members.

The Guides for the Community-based Rehabilitation, published in 2010 by the World Health Organization-WHO/OPS, the International Labour Organization (ILO) and the United Nations For Education, Scientific and Cultural Organization (UNESCO), and the International Disability and Development Consortium (IDDC) has a chapter devoted exclusively to leprosy. Guidelines to Strengthen the Participation of People Affected by Leprosy in the Leprosy Health Care Services were prepared by WHO in 2011 with the participation of allies, partners, and people affected by leprosy. In 2012 PAHO formulated a "Plan of Action in order to Accelerate the Achievement of the Elimination of Leprosy in Latin America and the Caribbean," that presents the lines of action in order to meet the goals and sustain the regional achievements from  2012-2015, with the objective of maintaining the achievements reached in the elimination of leprosy in the Region and to reach prevalence reduction at first sub-national political-administrative level (less than 1 case per 10,000 inhabitants) by 2015.

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