Leprosy is a chronic granulomatous infection. It is a major health problem in India which has 1/3 of total leprosy patients in the world. It is more prevalent among the lowest socio-economic strata. World Health Assembly in 1991 passed a resolution to eliminate leprosy as a public health problem by the year 2000. Elimination of leprosy as a public health problem is defined as a priority rate of less than one case per 10 000 persons; The target was achieved on time. The widespread use of MDT by WHO has reduced the disease burden dramatically; Over the past 20 years, more than 14 million leprosy patients have been cured about 4 million since 2000.
SUNITA MINZ *, MADHULIKA PRADHAN, UMESH MKUMAR, KUMUD CHANDRA KANDPAL, ANUSHA SHRIVASTAVA, A. SARAVANAKUMAR, K.KAMALAKANNAN, T.SIVAKUMAR.
NANDHA COLLEGE OF PHARMACY, TAMILNADU, INDIA.
Leprosy was recognized in the ancient civilizations of China, Egypt and India. The first known written mention of leprosy is dated 600 BC. The word leper comes from a Greek word meaning scaly. In India, leprosy is known since ancient times as kustha roga and attributed to punishment or curse from God. Leprosy is a chronic disease caused by a bacillus, Mycobacterium leprae; M. leprae multiplies very slowly and the incubation period of the disease is about five years.
Leprosy bacilli mainly affect the skin and peripheral nerves; if untreated, there can be progressive and permanent damage to the skin, nerves, limbs and eyes. Injuries to these insensitive parts may lead to disfigurement, the main consequence of this disease which generates fear and stigma.
Thus early detection and prompt treatment of leprosy with prescribed multi drug therapy (MDT) not only cures leprosy but also interrupts its transmissions to others. It is transmitted via droplets, from the nose and mouth, during close and frequent contacts with untreated cases.
This chronic infectious disease usually affects the skin and peripheral nerves but has a wide range of possible clinical manifestations. Patients are classified as having paucibacillary (few bacillus) or multibacillary Hansen's disease:
"Paucibacillary (PB) Hansen's disease is milder and characterized by one or more hypopigmented skin macules.
"Multibacillary (MB) Hansen's disease is associated with symmetric skin lesions, nodules, plaques, thickened dermis, and frequent involvment of the nasal mucosa resulting in nasal congestion and epistaxis.
MODE OF TRANSMISSION
Leprosy may be transmitted via aerosols containing M.leprae (droplet infection). Numerous studies indicate that it is tranmitted from person-to-person by close contact between an infectious patient and a healthy but suspect person. This contact may be direct (eg, skin-to-skin) or indirect (eg, contact with soil, and fomites such as contaminated clothes and linen). It may also be transmitted via breast milk from lepromatous mothers, by insect vectors, or by tattooing needles.
Leprosy is a curable disease and treatment provided in the early stages averts disability; with minimal training, leprosy can be easily diagnosed on clinical signs alone; A World Health Organization (WHO) Study Group recommended multidrug therapy (MDT) in 1981. MDT consistants of three drugs: dapsone, rifampicin and clofazimine.
This drug combination kills the pathogen and cures the patient; MDT is safe, effective and easily administrated under field conditions. MDT has been highly successful both in MB and PB. By april'94 a total of 5.6 million cases world over were cured by MDT. The estimated cases of leprosy fell from 10-12 million to 2.7 million.
MDT is available in convenient monthly calendar blister packs to all patients; 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.
EFFECTIVENESS OF MULTIDRUG THERAPY
PB patients treated with MDT are cured within six months; MB patients treated with MDT are cured within 12 months; Patients are no longer infectious to others after the first dose of MDT. In other words, transmission of leprosy is interrupted; There are virtually no relapses, ie recurrences of the disease after treatment is completed; No resistance of the bacillus to MDT has been detected; WHO estimates that early detection and treatment with MDT has preceded about four million people from being disabled. This suggests great cost-effectiveness of MDT as a health intervention, considering the economic and social loss averted.
CURRENT LEPROSY SITUATION
Leprosy was considered till 1980 as a perennial problem with no solution in sight, the introduction of multi-drug therapy (MDT) in the last twenty years has resulted in massive progress towards conquering the disease. The leadership provided by WHO together with the strong commitment of leprosy endemic countries and the support of Non-Govermental Organizations (NGO) and donor agencies have greatly contributed to the reduction of the global burden of leprosy by nearly 95% and the elimination of the disease as a public health problem in over 120 countries. Currently, only nine countries have major problems with leprosy with India topping the list.
The latest available information on the leprosy situation indicates that the bulk of the problem continues to be in Asia which with about 198,000 cases contributes to a share of 60% of the global burden, while the contribution of Africa and Americas is only 19% and 15 % respectively. In the Americas the only country yet to reach leprosy elimination is Brazil with a prevalence rate of 1.77 per 10,000. According to the latest available information, intensive efforts are still needed to reach the leprosy elimination target in five countries: Brazil, India, Madagascar, Mozambique, and Nepal.
CURRENT LEPROSY PREVALENCE IN INDIA
The prevalence rate in India, which traditionally accounted for the highest burden of leprosy, globally and regionally, has declined from 5.9 per 10,000 in 1996 to 0.8 per 10,000 population in 2006. The new case detection has declined from a peak of 89 / 100,000 in 1999 to 14.27 / 100,000 in the year 2006.
The leprosyivalence and annual new case detection rate / 10,000 population has shown a fundamental declination trend, as can be seen from the data given.
YEAR-WISE LEPROSY PREVALENCE RATE IN INDIA
Year / Prevalence rate per 10,000 population / Annual new case detection rate
1991 / 25.9 / 5.9
1992 / 20.0 / 6.2
1993 / 13.7 / 6.4
1994 / 10.9 / 5.7
1995 / 4.8.4 / 4.9
1996 / 5.9.9 4.6
1997/5/8 / 5.1
1999 / 5.3 / 8.9
2000 / 5.3 / 7.0
2001/3.7 / 5.5
2004 / 2.4 / 3.3
2005 / 1.3 / 2.3
2006 / 0.8 / 1.4
2007 / 0.7 / 1.2
While the member states should receive primary credit for the above achievements, WHO technical support and financial assistance to some critical activities has been a strong contributor factor, along with assistance from partner agencies like World Bank, The Nippon and Sasakawa Foundations of Japan and the International Federation of Anti-Leprosy Associations (ILEP).
Another major contributing factor has been the free supply of leprosy drugs to all endemic countries from 1995 to 2000 by The Nippon Foundation and from 2000 onwards by the Novartis Foundation for Sustainable Development. Novartis has assured free supply of leprosy drugs until 2010.
The goal is to achieve elimination of leprosy as a public health problem everywhere in the world including India. Elimination of leprosy aims at reducing the disease burden to very low levels so that after reaching such low levels the disease will slowly disappear over a period of time. This very low level has been defined by WHO as a level of prevalence of less than one case per 10,000 population. On 30th January, 2006, the Ministry of Health, Government of India formally announced that India achieved the elimination target (leprosyvalence was 0.8 per 10,000).
The strategy and implementation of leprosy elimination in India is proving to be a huge success story. However there are still some challenges to be addressed specifically in the area of rehabilitation of leprosy affected persons.