World Leprosy Day

World Leprosy Day is an international observance held annually on the last Sunday of January to raise public awareness about leprosy. The establishment of this day aims to combat social ignorance regarding the disease, enhance measures to prevent its spread, and prevent deformities and disabilities that may arise in untreated individuals. World Leprosy Day holds global significance due to the continued occurrence of the disease in many countries and its long-standing association with social stigma. The condition referred to in society as “leprosy” is medically defined as leprosy or Hansen’s disease.

History

The causative agent of leprosy, Mycobacterium leprae, was identified in 1873 by Gerhard Armauer Hansen, after which the disease was also named Hansen’s disease. The origin of World Leprosy Day dates back to 1954, when it was proposed by French activist Raoul Follereau to counter the widespread misconception that leprosy had been eradicated and to highlight its continued presence worldwide.

World Leprosy Day is observed annually on the last Sunday of January globally. In India, however, it is commemorated on January 30, the anniversary of Mahatma Gandhi’s death, and carries special historical and social significance within the country’s context. In 2025, World Leprosy Day was observed on January 26, with the theme “Unite. Act. Eliminate” (Birleşin, Harekete Geçin, Ortadan Kaldırın) chosen for the year.

Objective

The primary objective of World Leprosy Day is to reduce misconceptions and fears stemming from ignorance about leprosy. The day emphasizes that the disease is bacterial in origin, transmitted through prolonged and close contact, and treatable today with multidrug therapy. It highlights that disabilities can be prevented through early diagnosis and seeks to reduce the discrimination and stigma faced by those affected by the disease.

Additionally, World Leprosy Day is recognized as a global awareness and education initiative that underscores leprosy’s status as a neglected tropical disease, its persistence in socioeconomically disadvantaged regions, and the critical importance of access to healthcare services.

Symptoms

The symptoms of leprosy can vary depending on the type and progression of the disease. They typically appear after a long incubation period. Patients may develop sudden, non-scaly, non-round patches on any part of the body, which may sometimes be itchy. In some cases, copper-red, shiny lesions may appear on the skin.

As the disease affects the nervous system, pain may develop in the nerves of the arms and legs, and inward bending or flexion of the fingers may occur. Facial paralysis, leading to immobility of the lower eyelids and inability to close them, is also a recognized symptom.

Involvement of the upper respiratory tract may cause recurrent nosebleeds and nasal congestion. In advanced stages, swelling of the face may develop, raised nodules may appear on the skin, and in some cases, a characteristic “lion face” appearance may emerge. Nerve damage can lead to deformities, muscle paralysis, and loss of function in the hands and feet.

Transmission

Leprosy is transmitted through droplets from the nose and mouth of untreated patients during close and prolonged contact. Daily brief interactions are not considered sufficient for transmission. Due to the slow replication rate of Mycobacterium leprae, symptoms typically appear only after a long period.

Classification of Leprosy

Leprosy is classified into two main types and two borderline types, based on the body’s immune response to the disease. The main types are lepromatous and tuberculoid; the borderline types are borderline and indeterminate leprosy.

Lepromatous Leprosy

This form occurs when the body’s resistance is significantly compromised. The causative bacteria are numerous and highly active. Numerous small, symmetrical, poorly defined, shiny copper-red patches appear on the skin, particularly on the trunk. Over time, loss of sensation develops in these areas. Hard nodules called lepromas form on the face, neck, nipples, and genital organs. Although nerve damage is relatively less common in this type, internal organ involvement is more prominent.

Tuberculoid Leprosy

This type primarily affects the peripheral nervous system. Facial paralysis may occur. Nerve damage to certain hand muscles can result in a “claw hand” appearance. Due to involvement of sensory nerves, the ability to perceive heat, touch, and pain may be lost. Reduced function of sweat glands leads to increased skin dryness and scaling.

Borderline Leprosy

Borderline leprosy is an intermediate form between lepromatous and tuberculoid types. During its progression, it tends to evolve toward one of the two main types, and its features become more dominant accordingly.

Indeterminate Leprosy

This type typically presents as a single skin lesion that may include sensory loss. Over time, the lesion may spread outward or resolve in the center.

Treatment

Leprosy is a curable disease when diagnosed early. Treatment duration typically ranges from 6 to 12 months, depending on the type of leprosy. Infectiousness is eliminated shortly after treatment begins. In Türkiye, treatment is provided free of charge. If diagnosis is delayed or treatment is not received, deformities and physical disabilities may develop within 10 to 20 years.

Disability Resulting from Leprosy (Anadolu Agency)

Global Prevalence

Leprosy is one of the tropical diseases currently present in more than 120 countries.^【1】 According to World Health Organization data, 128,375 new cases were reported worldwide in 2020, and this number increased by approximately 10 percent in 2021, exceeding 140,500. In 2021, India recorded 75,394 new cases, making it the country with the highest burden of the disease. Leprosy was least common in Europe, with only 14 cases reported in 2021. According to data released by the Turkish Ministry of Health, three new cases were detected in Türkiye in 2021, with a total of 485 leprosy patients reported in the country.^【2】

In December 2025, new leprosy cases were detected in Croatia and Romania. Authorities confirmed that these cases were imported and posed no risk of widespread transmission.^【3】

Disclaimer: The content provided in this article is for general encyclopedic informational purposes only. The information herein should not be used for diagnosis, treatment, or medical advice. Always consult a physician or qualified healthcare professional before making any decisions regarding health. Neither the author of this article nor KÜRE Encyclopedia assumes any responsibility for consequences arising from the use of this information for diagnostic or therapeutic purposes.