Leprosy

Leprosy, caused by Mycobacterium leprae infection, is a chronic infectious disease. The source of infection is untreated leprosy patients, especially those with multibacillary leprosy. The primary mode of transmission is through respiratory droplets and prolonged close contact. About 95 percent of people have natural immunity to Mycobacterium leprae, and even if infected, they may not develop the disease. Only a small percentage of individuals with immunodeficiency are prone to the disease. Mycobacterium leprae primarily affects the skin, mucous membranes and peripheral nerves.

The incubation period is generally two to five years. Most leprosy patients have a slow and insidious progression of the disease, with early symptoms often being inconspicuous.

Due to differences in the host's specific immune response to Mycobacterium leprae, the symptoms and signs of leprosy are diverse. Symptoms and signs involving the skin and peripheral nerves appear earliest and are most common. The typical clinical presentation includes skin lesions accompanied by decreased or loss of sensation, local anhidrosis, hair loss, often associated with thickening, tenderness, and pain in the affected peripheral nerves.

Without timely and standardized treatment, permanent deformities may occur, including eyebrow loss, facial palsy, saddle nose, leonine facies, and deformities of the eyes, hands and feet.

Early detection, diagnosis and treatment are crucial to promptly interrupt leprosy transmission and prevent deformities. Symptom monitoring for leprosy and regular surveillance in endemic areas can help identify hidden leprosy cases early, eliminating sources of transmission. It is recommended to enhance health education, follow-up, and chemoprophylactic interventions for close contacts of leprosy patients.