Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae. It primarily affects the skin, peripheral nerves, upper respiratory tract, and eyes. Leprosy has been known to humanity since ancient times and has historically been associated with significant social stigma.
The exact mode of transmission of leprosy is not fully understood. However, it is believed to spread through respiratory droplets from an infected person to a susceptible individual. Prolonged and close contact with untreated cases is typically required for transmission. The incubation period of leprosy can range from a few months to several years, which complicates epidemiological tracking.
Leprosy presents with a range of
symptoms depending on the type. Common symptoms include skin lesions that may be lighter than the normal skin tone, numbness in affected areas, muscle weakness, and eye problems. Nerve damage can lead to loss of sensation and muscle atrophy, which, if untreated, can result in disability.
Diagnosis of leprosy is based on clinical signs and symptoms, skin smears, and biopsies. The
World Health Organization (WHO) has established clinical criteria for diagnosing leprosy, which includes the presence of hypopigmented or reddish skin lesions with sensory loss, thickened peripheral nerves, and positive skin smears for Mycobacterium leprae.
Leprosy is endemic in several countries, particularly in tropical and subtropical regions. According to WHO, the global prevalence of leprosy has significantly decreased due to effective
multidrug therapy (MDT). However, pockets of high endemicity remain. India, Brazil, and Indonesia account for the majority of new cases. Surveillance and monitoring are crucial for controlling the disease.
Risk factors for leprosy include living in endemic areas, close contact with untreated individuals, genetic susceptibility, and immunosuppression. Socioeconomic factors such as poverty, overcrowding, and poor hygiene also contribute to the spread of the disease.
Leprosy is treated with a combination of antibiotics known as
multidrug therapy (MDT), which is provided free of charge by WHO. The standard MDT regimen includes dapsone, rifampicin, and clofazimine, and the duration of treatment ranges from 6 to 12 months depending on the type of leprosy. Early diagnosis and treatment are essential to prevent complications and transmission.
Despite advancements in treatment, several challenges remain in
leprosy control. These include delayed diagnosis, stigma and discrimination, lack of awareness, and insufficient healthcare infrastructure in endemic regions. Additionally, the long incubation period and potential for asymptomatic carriers complicate control efforts.
The WHO aims to eliminate leprosy as a public health problem through early detection, effective treatment, and reducing stigma. Strategies include strengthening surveillance systems, providing training for healthcare workers, promoting community awareness, and ensuring the availability of MDT. Integration of leprosy services into general health systems is also crucial for sustainable control.
