kusta

Kusta, also known as Hansen's disease, is a chronic infectious disease caused by the bacteria Mycobacterium leprae or, less commonly, Mycobacterium lepromatosis. The condition mainly affects the skin and peripheral nerves and can involve the eyes and mucous membranes.

Transmission occurs through prolonged close contact and exposure to droplets from the nose or mouth of an untreated person. The disease is not highly contagious, and incubation can be months to many years, allowing symptoms to appear long after exposure.

Clinical forms range from paucibacillary (tuberculoid) to multibacillary (lepromatous), with varying amounts of bacteria and symptoms. Early signs include one or more pale or reddish skin patches with reduced sensation, numbness in affected areas, and thickened peripheral nerves. As nerve damage progresses, weakness and deformities may occur; eye involvement can lead to vision problems.

Diagnosis relies on clinical signs, skin smears or biopsies to detect bacteria, and nerve testing. Classification into paucibacillary or multibacillary guides treatment and prognosis.

Treatment uses multidrug therapy (MDT) recommended by the World Health Organization: rifampicin, dapsone, and clofazimine, given for 6 months (paucibacillary) or 12 months (multibacillary). MDT stops transmission and cures the disease in most cases; treatment is provided free of charge in many settings. Early treatment reduces the risk of disability and deformity.

Prevention includes early case detection and contact tracing. A single-dose rifampicin prophylaxis for close contacts can reduce risk; BCG vaccination offers partial protection. Stigma and discrimination remain persistent challenges in many communities.

Prognosis depends on the extent of nerve involvement; with timely MDT, most patients recover, though some nerve damage may be permanent. Leprosy is curable, and public health efforts continue to reduce incidence and improve outcomes.