Hansen's disease is caused by which organism?

Hansen's disease is caused by which organism?

• A. Mycobacterium kansasii
• B. Mycobacterium avium
• C. Mycobacterium tuberculosis
• D. Mycobacterium leprae

Answer: (D)

Hansen's disease, or leprosy, is caused by Mycobacterium leprae, a slow-growing acid-fast bacillus that prefers cooler temperatures found in the skin and peripheral nerves. This explains why the illness classically presents with skin lesions and nerve involvement leading to sensory loss. The other mycobacteria listed cause different diseases: Mycobacterium tuberculosis causes tuberculosis, while Mycobacterium kansasii and Mycobacterium avium complex cause pulmonary or disseminated infections, especially in people with weakened immunity. They are not responsible for Hansen's disease.

Hansen's disease, or leprosy, is caused by Mycobacterium leprae, a slow-growing acid-fast bacillus that prefers cooler temperatures found in the skin and peripheral nerves. This explains why the illness classically presents with skin lesions and nerve involvement leading to sensory loss. The other mycobacteria listed cause different diseases: Mycobacterium tuberculosis causes tuberculosis, while Mycobacterium kansasii and Mycobacterium avium complex cause pulmonary or disseminated infections, especially in people with weakened immunity. They are not responsible for Hansen's disease.