Leprosy is caused by—

RML PRE 2025

Applied Microbiology & Infection control

Easy

Appeared in: RML PRE 2025

Explanation

Leprosy, also known as Hansen's disease, is a chronic infectious disease caused by the bacterium Mycobacterium leprae.
This was confirmed by Gerhard Armauer Hansen in 1873, which is why the disease is named after him.
M. leprae is an acid-fast bacillus that has a strong affinity for skin cells and peripheral nerve cells (Schwann cells).
The disease primarily manifests with lesions on the skin and neurological damage in the limbs, eyes, and face.
Unlike other mycobacteria, M. leprae cannot be grown in artificial laboratory media, which has made it difficult to study.

Option B: Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), not leprosy. While both are mycobacterial diseases, they are caused by distinct species with different clinical presentations.
Option C: Rotavirus is a virus that causes severe gastroenteritis, characterized by diarrhea and vomiting, particularly in young children. It is unrelated to the bacterial infection that causes leprosy.
Option D: A mosquito is an insect vector that transmits various pathogens but is not a causative organism itself. Leprosy is transmitted primarily through respiratory droplets, not by insect bites.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Leprosy as background academic context rather than a clinical decision trigger.
Identifying the correct causative agent is the first step in diagnosis and management. Leprosy is treatable with a multi-drug therapy (MDT) regimen.
Early diagnosis and treatment are crucial to prevent nerve damage, permanent disability, and disfigurement associated with advanced leprosy.
Nurses play a key role in case finding, administering MDT, managing leprosy reactions, educating patients to prevent injuries, and reducing the social stigma associated with the disease.

How to Approach the Question

First, identify the key term in the question, which is 'Leprosy'.
The question asks for the 'cause' of the disease, implying you need to identify the specific pathogen.
Scan the options to evaluate each one based on your knowledge of microbiology and infectious diseases.
Recall that leprosy is a bacterial infection. This helps eliminate options like viruses (Rotavirus) and vectors (Mosquito).
Differentiate between the two bacterial options. Mycobacterium leprae is specifically associated with leprosy, while Mycobacterium tuberculosis is known to cause tuberculosis.
Select the option that correctly links the pathogen to the disease.

Concept Tested & Keywords

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