Guidelines for the Diagnosis, Treatment and Prevention of Leprosy
As a disease which mainly impacts the skin and the peripheral nerves, leprosy results in “neuropathy and associated long-term consequences, including deformities and disabilities.” Leprosy was eradicated as a public health problem in most countries by the year 2005 – which meant that the prevalence of the disease was lower than one case per 10,000 people. However, over 200,000 new cases of leprosy were reported in 2016. Knowing that an early diagnosis and treatment is vital for reducing the burden of leprosy, the World Health Organization (WHO) published these guidelines on October 6, 2018.
The previous WHO guidelines on leprosy were released in 1998 and 2010. The 2018 guidelines “incorporate new evidence and address areas of clinical uncertainty.” They employ the GRADE (Grading of Recommendation, Assessment, Development and Evaluation) method which assesses the quality of evidence, weighs the overall benefits and damage, and considers the preferences of both patients and health workers. The guidelines also keep in mind feasibility of measures in regions with limited resources and limited access to laboratories and specialised tests.
The primary audience for this report include policy makers in national health ministries, medical professionals working in low- and middle-income countries, non-governmental organisations providing services to leprosy patients, and researchers working in the area.The 106-page guidelines are divided into three parts: Guideline development process (Part I); Recommendations (Part II); and Research Priorities (Part III). The report also contains four annexes covering a review of conflicts of interest, evidence-to-recommendation tables, guides for discussions to identify preferences of people affected by leprosy, GRADE tables and a literature review report.
Leprosy used to be commonly found in regions with temperate climates, the guidelines note. Nowadays, it is primarily confined to tropical and subtropical areas. Knowledge on how leprosy is transmitted continues to be limited, but it is commonly believed to spread through the inhalation of droplets containing a bacteria named Mycobacterium leprae.
Around 95 per cent of people exposed to the bacteria do not develop leprosy, the guidelines state. However, the incubation period for the disease (the time between exposure and appearance of symptoms) can stretch from 2-20 years, or even longer.
The diagnosis of leprosy is based on one of three signs: “(i) definite loss of sensation in a pale (hypopigmented) or reddish patch; (ii) thickened or enlarged peripheral nerve with loss of sensation and/or weakness of the muscles supplied by that nerve; or (iii) presence of acid-fast bacilli [a class of bacteria] in a slit skin smear.” A ‘slit skin smear’ is a common diagnostic technique used for the detection of leprosy.
There are two broad classifications of leprosy. Paucibacillary (PB) cases show 1-5 skin lesions, but the skin smears have no demonstrated presence of bacilli. Multibacillary (MB) cases show more than five skin lesions and/or neuritis (inflammation of nerves). Cases in which slit-skin smears have a demonstrated presence of bacilli are also defined as multibacillary regardless of the number of skin lesions present.
The key elements to tackling leprosy are an early diagnosis and a full treatment of multidrug therapy (MDT). A multidrug therapy usually includes two or three drugs administered (varying in duration and dosage) depending on the age of the patient and the type of leprosy detected. The guidelines state that the World Health Organization provides MDT to countries for free by working with national leprosy programmes.
Leprosy prevention uses BCG vaccines or antibiotics employed as prophylactics (preventive measures). The antibiotic treatment is used in case of contact with leprosy patients.
The guidelines suggest a treatment made up of three drugs – rifampicin, dapsone and clofazimine. The treatment is recommended for six months in paucibacillary cases and for 12 months in multibacillary cases. The use of same drugs in both kinds of cases is expected to simplify the treatment and provide adequate care even if a MB leprosy case is misclassified as PB leprosy.
In case the leprosy is resistant to rifampicin or ofloxacin, the guidelines recommend combinations (with specific dosage and duration) of certain ‘second-line’ drugs – clarithromycin, minocycline and clofazimine.
For people who have been in contact with leprosy patients, the guidelines recommend a preventive treatment of single-dose rifampicin for adults and children aged two years and above.
Focus and Factoids by Devanshi Parekh.
PARI Library's health archive project is part of an initiative supported by the Azim Premji University to develop a free-access repository of health-related reports relevant to rural India.
World Health Organization
World Health Organization
06 Oct, 2018