Guidelines for the Diagnosis, Treatment and Prevention of Leprosy

Introduction

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by Mycobacterium leprae. It primarily affects the skin, peripheral nerves, mucosal surfaces of the upper respiratory tract, and eyes. Though feared for centuries due to historical stigma and misconceptions, leprosy is curable with multidrug therapy (MDT) and early treatment can prevent disability.

These guidelines provide current evidence-based recommendations for the diagnosis, treatment, and prevention of leprosy, aiming to reduce disease transmission, prevent disabilities, and improve the quality of life for affected individuals.

Diagnosis of Leprosy

Clinical Diagnosis

Leprosy diagnosis is primarily clinical, based on characteristic signs and symptoms:

• Hypopigmented or reddish skin lesions with definite loss of sensation
• Thickened or enlarged peripheral nerves
• Weakness of muscles supplied by affected nerves
• Presence of acid-fast bacilli in skin smears (though not all patients have positive smears)

Classification of Leprosy

Leprosy is classified based on clinical manifestations, bacteriological index, and immunological response:

1. Paucibacillary (PB) or Tuberculoid Leprosy: 1-5 skin lesions, negative skin smear results
2. Multibacillary (MB) or Lepromatous Leprosy: More than 5 skin lesions, positive skin smear results

Diagnostic Procedures

• Clinical examination: Thorough examination of skin, nerves, eyes, and limbs
• Skin smears: Examination for acid-fast bacilli using slit-skin smears
• Histopathology: Biopsy of suspicious skin lesions
• Serological tests: Anti-PGL-I antibodies (primarily for research)
• Molecular tests: PCR detection of M. leprae DNA (available in specialized centers)

Treatment of Leprosy

Introduction to Multidrug Therapy

Since 1981, the World Health Organization (WHO) has recommended multidrug therapy (MDT) as the standard treatment for leprosy. MDT combines antibiotics that effectively kill the bacteria and prevent the development of drug resistance.

Recommended Regimens

For Paucibacillary (PB) Leprosy:

• Rifampicin: 600 mg once monthly (supervised)
• Dapsone: 100 mg daily (self-administered)
• Duration: 6 months

For Multibacillary (MB) Leprosy:

• Rifampicin: 600 mg once monthly (supervised)
• Clofazimine: 300 mg once monthly (supervised) + 50 mg daily (self-administered)
• Dapsone: 100 mg daily (self-administered)
• Duration: 12 months

Treatment of Special Cases

• Pregnant women: Standard MDT can be safely administered
• Children: Adjusted dosages based on body weight
• Patients with pre-existing liver disease: Close monitoring required, alternative regimens may be considered
• Rifampicin-resistant leprosy: Alternative regimens including fluoroquinolones, minocycline, and clarithromycin under specialist supervision

Management of Reactions

Leprosy reactions (type 1 or reversal reactions and type 2 or erythema nodosum leprosum) can occur before, during, or after treatment. Management includes:

• Type 1 reactions: Prednisolone 40-60 mg/day, tapered over weeks to months
• Type 2 reactions: Prednisolone, thalidomide (with strict precautions), or clofazimine at higher doses
• Antibiotics for MDT should be continued during reaction treatment

Prevention of Leprosy

Chemoprophylaxis

Single-dose rifampicin (SDR) as post-exposure prophylaxis is recommended for contacts of leprosy patients:

• Contacts of MB patients: Single dose of rifampicin (600 mg for adults, adjusted for children)
• Contacts of PB patients: Currently not routinely recommended unless other risk factors present
• Effectiveness: Approximately 50-60% reduction in risk of developing leprosy within 2 years

Immunoprophylaxis

• BCG vaccination: Offers partial protection against leprosy (approximately 20-60% efficacy)
• More effective against MB than PB leprosy
• Often recommended in endemic areas for contacts of leprosy patients
• Booster vaccinations may increase protection

Public Health Measures

• Case detection: Early identification through active surveillance and contact examination
• Accessible treatment: Ensuring availability of free MDT at primary healthcare levels
• Contact tracing and examination: Regular screening of household and close contacts
• Health education: Community awareness to reduce stigma and promote early care-seeking
• Disability prevention: Prompt treatment and rehabilitation services

Prevention of Disability

The following measures can prevent or minimize disability in leprosy patients:

• Educating patients about self-examination and care of insensitive limbs
• Prompt treatment of reactions to prevent nerve damage
• Regular monitoring of nerve function during and after treatment
• Provision of protective footwear and devices
• Reconstructive surgery for established deformities when indicated
• Occupational therapy and vocational rehabilitation

Conclusion

Leprosy remains a public health challenge in several countries, but with proper implementation of these guidelines for diagnosis, treatment, and prevention, new cases and associated disabilities can be significantly reduced. Early case detection, prompt completion of MDT, appropriate management of reactions, and effective prevention strategies are key components of leprosy control programs.

Healthcare providers should maintain a high index of suspicion for leprosy to ensure early diagnosis and treatment. Continued education for healthcare workers, patients, and communities is essential to dispel myths, reduce stigma, and promote timely care-seeking behavior.

These guidelines will be periodically updated as new evidence emerges regarding leprosy diagnosis, treatment, and prevention.