## Causes of MDT Failure and Relapse in Leprosy **Key Point:** Treatment failure in leprosy is predominantly due to **poor compliance and irregular drug intake**, not primary drug resistance or dosing errors. Non-adherence is the leading preventable cause of relapse. ## Epidemiology of Relapse **High-Yield:** In India and other endemic regions, 80–90% of relapses are attributable to: - Irregular or incomplete MDT (most common) - Premature cessation of therapy - Poor patient education and follow-up - Socioeconomic barriers to accessing supervised therapy ## Why Adherence Matters in Leprosy MDT | Factor | Impact | |--------|--------| | **Irregular rifampicin intake** | Allows surviving bacilli to develop resistance; breaks the bactericidal effect | | **Incomplete dapsone course** | Permits relapse; dapsone is essential for preventing resistance | | **Clofazimine interruption** | Reduces post-treatment immunity; increases relapse risk | | **Premature cessation** | Inadequate sterilization of lesions; clinical and bacteriological relapse | **Clinical Pearl:** Supervised directly observed therapy (DOT) for rifampicin (monthly) and regular home visits for dapsone compliance significantly reduce relapse rates. India's NLEP emphasizes monthly supervised doses and community health worker follow-up. **Mnemonic:** **IRIS** (Immune Reconstitution Inflammatory Syndrome) is a **reaction** (Type 2 lepra reaction) that occurs *during* or *after* MDT in some patients, not a cause of treatment failure per se — it is managed with corticosteroids while continuing MDT. [cite:Park 26e Ch 9]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.