Leprosy, also known as Hansen’s disease, is a long-term infection caused by the Mycobacterium leprae bacteria. This disease can impact the skin, nerves in the hands and feet, eyes, and the lining inside the nose.
After being exposed to leprosy, it might take 5-7 years for symptoms to appear. The initial sign is usually a patch on the skin that could be reddish or lighter than usual. As it progresses, leprosy can damage nerves, resulting in numbness, muscle weakness, disfigurement, and even blindness.
Fortunately, leprosy can be cured with a multi-drug antibiotic regimen taken over one to two years. Annually, more than 200,000 people around the globe are diagnosed with leprosy, though it’s rare in the U.S. with only about 250 cases each year.
Identifying and treating leprosy early can prevent severe outcomes and stop it from spreading. Leprosy can be classified in various ways, and knowing the type helps determine the best treatment approach. Traditionally, it’s classified based on immune response and the amount of bacteria present. The World Health Organization (WHO) uses a simpler system, dividing it into paucibacillary (PB) and multibacillary (MB) types, based on the number of skin lesions and nerves impacted.
Signs of leprosy might appear within one year after infection but could take up to 20 years. Typically, symptoms show up about five years after initial exposure. It mainly affects the skin and nerves in the hands and feet, as well as the upper respiratory tract mucous membranes.
Leprosy spreads through respiratory droplets, typically requiring prolonged, close contact with an untreated individual to be contagious. Thankfully, about 95% of people naturally resist the disease. Once leprosy enters the body, the immune system significantly influences the disease’s nature and severity. Some individuals have strong immunity that limits the infection, resulting in milder cases, while others might face more severe manifestations due to weaker immunity.
For those without natural protection, certain risk factors can increase the risk of developing leprosy. Diagnosis involves a physical examination, reviewing medical history and symptoms, and conducting diagnostic tests to confirm the presence of Mycobacterium leprae and determine the type.
Once diagnosed, a lepromin skin test might be conducted. This involves injecting a small amount of leprosy protein into the skin and observing for reactions such as redness or swelling, which helps confirm the diagnosis and type.
Leprosy treatment is typically effective and cures the disease, especially when initiated early to prevent complications. It often involves a combination of three antibiotics over one to two years, depending on the leprosy type. Individuals with paucibacillary leprosy typically require treatment for six months to a year, while those with multibacillary leprosy might need two years.
Besides antibiotics, treatments may be needed for nerve damage and other complications. People can reduce their leprosy risk through various measures. While leprosy complications can be serious if left untreated, early treatment helps manage the disease effectively.
Although leprosy still exists, it’s far less common now. Around 200,000 new cases are reported annually worldwide, including 150 to 250 in the U.S. Given that it spreads only through prolonged close contact and because most people are resistant, it’s not highly contagious.
Vaccinations like the Bacille Calmette-Guérin (BCG) vaccine, initially designed to fight tuberculosis, might help lower leprosy risk, though its effectiveness varies and decreases over time. Research is ongoing for a new vaccine, LepVax, which shows promise in clinical trials.
Leprosy doesn’t resolve without treatment. Without antibiotics, it can progress, leading to severe issues like nerve damage and deformities, so medical intervention is necessary.
