Chile becomes second country to receive WHO verification for eliminating leprosy

• Chile became the first country in the Americas — and the second globally — to be officially verified as having eliminated leprosy disease.

• The verification by the World Health Organisation (WHO), together with the Pan American Health Organisation (PAHO), recognises more than three decades of sustained public health action, robust surveillance, long-term political commitment, and a health system that has remained vigilant even in the absence of local transmission.

• In September 2024, Jordan became the first country in the world to be officially verified as having eliminated leprosy. 

How Chile achieved this milestone?

• Leprosy (Hansen disease) was historically recorded in Chile at the end of the 19th century on Rapa Nui (Easter Island). 

• The disease was limited in mainland Chile, with sporadic introductions, contained through isolation and treatment measures in the Island, where the last secondary cases were managed by the late 1990s.

• Since then, Chile has not reported any locally acquired case of leprosy for more than 30 years, with the last locally acquired case detected in 1993. 

• However, the disease was never removed from the country’s public health agenda. It remained a notifiable condition, monitored through mandatory reporting, integrated surveillance, and continuous clinical readiness across the health system.

• At the request of Chile’s Ministry of Health, PAHO and WHO convened an independent expert panel in 2025 to assess whether elimination had been achieved and could be sustained over time.

• Its findings confirmed the absence of local transmission and validated Chile’s capacity to detect and respond to future cases occurring among the non-autochthonous population.

• Chile’s accomplishment paves the way for other nations, illustrating the impact of political will, cross-sector collaboration, and adaptive planning in low-incidence settings.

Leprosy

• 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. 

• Leprosy is curable and treatment in the early stages can prevent disability.

• Left untreated, leprosy can cause permanent damage to the skin, nerves, limbs and eyes. 

• Leprosy is a neglected tropical disease (NTD) which still occurs in more than 120 countries. More than 200,000 new cases are reported every year.

Transmission

The disease is transmitted through droplets from the nose and mouth. Prolonged, close contact over months with someone with untreated leprosy is needed to catch the disease. The disease is not spread through casual contact with a person who has leprosy like shaking hands or hugging, sharing meals or sitting next to each other. Moreover, the patient stops transmitting the disease when they begin treatment.

Diagnosis

Leprosy is diagnosed by finding at least one of the following cardinal signs: 

i) Definite loss of sensation in a pale (hypopigmented) or reddish skin patch.

ii) Thickened or enlarged peripheral nerve, with loss of sensation and/or weakness of the muscles supplied by that nerve.

iii) Microscopic detection of bacilli in a slit-skin smear.

• The cases are classified into two types for treatment purposes: Paucibacillary (PB) case and Multibacillary (MB) case.

• PB case: A case of leprosy with one to five skin lesions, without demonstrated presence of bacilli in a skin smear.

• MB case: A case of leprosy with more than five skin lesions; or with nerve involvement (pure neuritis, or any number of skin lesions and neuritis); or with the demonstrated presence of bacilli in a slit-skin smear, irrespective of the number of skin lesions.

Treatment

The current recommended treatment regimen consists of three drugs: dapsone, rifampicin and clofazimine. The combination is referred to as multi-drug therapy (MDT). The duration of treatment is six months for PB and 12 months for MB cases. MDT kills the pathogen and cures the patient.

What is the scenario in India?

• National Leprosy Control Programme (NLCP) was launched in 1955, with the primary objective of controlling leprosy transmission. 

• In 1983, the programme was renamed as the National Leprosy Eradication Programme (NLEP) with the introduction of a more effective and globally accepted treatment regimen called Multi-Drug Therapy. 

• This led to India achieving the status of eliminating leprosy at the national level, defined as Prevalence Rate (PR) of less than one leprosy case per 10,000 population, in 2005.

• After achieving elimination status at national level, National Leprosy Eradication Programme (NLEP) has taken a number of initiatives to encourage early case detection of leprosy patients to prevent Grade 2 Disabilities, and to ensure free of cost treatment of leprosy patients. 

• NLEP is a Centrally Sponsored Scheme operating under the umbrella of the National Health Mission (NHM).

• Over the years, India’s leprosy prevalence rate has reduced from 57.2 per 10,000 in 1981 to 0.57 in 2024–25.

• On January 30, 2023, the government of India launched National Strategic Plan (NSP) & Roadmap for Leprosy (2023-27) to achieve zero transmission of leprosy by 2027, which is three years ahead of the Sustainable Development Goal (SDG) 3.3. 

• The NSP and Roadmap contains implementation strategies, year-wise targets, public health approaches and overall technical guidance for the programme. 

• The strategy and roadmap focuses on awareness for zero stigma & discrimination, promotion of early case detection, prevention of disease transmission by prophylaxis (Leprosy Post Exposure Prophylaxis) and roll out of web-based information portal (Nikusth 2.0) for reporting of leprosy cases.

Major challenges for eradication programme:

i) Stigma and discrimination: Leprosy has been historically associated with deep-rooted social stigma, leading to delayed diagnosis and treatment-seeking behavior due to fear of societal rejection.

ii) Drug resistance: Prolonged and inconsistent use of Multi-Drug Therapy (MDT) may lead to drug resistance, making treatment more challenging. 

iii) High-risk populations: Certain vulnerable populations, such as migrants and homeless individuals, are at higher risk due to limited access to healthcare and poor living conditions and limited health seeking behaviour.

iv) Monitoring and follow-up: Ensuring that the patients complete their treatment regimen and receive appropriate follow-up, especially in areas with poor healthcare infrastructure and low literacy rates.

v) Co-infections: Leprosy can occur alongside other diseases, such as tuberculosis, complicating diagnosis and treatment strategies.