LEPROSY

LEPROSY

Leprosy, also called Hansen's disease, is a chronic infectious disease that primarily affects the skin, the peripheral nerves, the mucosa of the upper respiratory tract, and the eyes. Leprosy can lead to progressive permanent damage of these structures, and the resulting devastating disfigurement and disability has led to the historical social stigma and isolation (leper colonies) of those affected by the disease.

Leprosy Causes

Leprosy is an acquired infectious disease that can affect individuals of all ages. It is caused by the acid-fast, rod-shaped bacteria Mycobacterium leprae, which was discovered in 1873 by G.A. Hansen.

v  Because the bacterium multiplies very slowly, the signs and symptoms of leprosy may not develop until much later after exposure to M. leprae (ranging from several weeks to 20 years or more).

v  Though humans are the major reservoir and host for infection with M. leprae, other animals such as armadillos, chimpanzees, and mangabey monkeys also serve as reservoirs of infection.

v  Leprosy is thought to be transmitted via droplets from the nose and mouth during close prolonged contact with affected individuals, though the exact route of transmission has yet to be proven definitively.

v  Not all individuals infected with M. leprae will go on to develop leprosy, because only 5%-10% of the population is thought to be susceptible to the infection because of immunological reasons.

SIGNS AND SYMPTOMS

The signs and symptoms of leprosy can vary depending on the individual's immune response to M. leprae. The WHO classification system uses clinical manifestations (the number of skin lesions and nerve involvement) as well as skin smear results to distinguish between forms of the disease. The two major WHO classifications are paucibacillary (PB) leprosy and multibacillary (MB) leprosy. However, within the WHO's simplified classification there can be a fairly wide range of patient presentations.

• Paucibacillary leprosy
• Two to five skin lesions with negative skin smear results at all sites
• Paucibacillary single lesion leprosy
• One skin lesion with negative skin smear results at all sites
• Multibacillary leprosy
• More than five skin lesions or positive skin smear results at any site

The Ridley-Jopling classification is another classification system that is used globally in evaluating patients in clinical studies and contains five different classifications of leprosy that further define the patient's severity of symptoms and disease progression. The five different categories, in order of increasing severity of disease, include indeterminate leprosy, tuberculoid leprosy, borderline tuberculoid leprosy, mid-borderline leprosy, borderline lepromatous leprosy, and lepromatous leprosy.

In general, the signs and symptoms of leprosy may vary with the form of the disease and include the following:

• Flat or raised skin lesions or nodules, often less pigmented than the surrounding skin, though they may reddish or copper colored
• Single or multiple skin lesions that are often found on cooler parts of the body such as the face, buttocks, and extremities
• Thickening of the skin and peripheral nerves
• Ulcerations of the skin
• Peripheral nerve involvement leading to loss of sensation
• Peripheral nerve involvement leading to muscle weakness (for example, clawed hand deformities, contractures, and foot drop)
• Hoarseness
• Testicular involvement leading to sexual dysfunction or sterility
• Eye involvement including eye pain, eye redness, inability to close the eyelids, corneal ulcers, and blindness
• Loss of eyebrows and eyelashes
• Destruction of the nasal cartilage

PREVENTION

The prevention of leprosy ultimately lies in the early diagnosis and treatment of those individuals suspected or diagnosed as having leprosy, thereby preventing further transmission of the disease to others.

v  Public education and community awareness are crucial to encourage individuals with leprosy and their families to undergo evaluation and treatment with MDT.

v  Household contacts of patients with leprosy should be monitored closely for the development of leprosy signs and symptoms.

v  A study demonstrated that prophylaxis with a single dose of rifampicin was 57% effective in preventing leprosy for the first two years in individuals who have close contact with newly diagnosed patients with leprosy.

v  There is currently no widely used standard for using medications for the prevention of leprosy.

v  Currently, there is no single commercial vaccine that confers complete immunity against leprosy in all individuals.

v  Several vaccines, including the BCG vaccine, provide variable levels of protection against leprosy in certain populations.

        

     REFERENCE : LEPROSY 

SYMPTOM