Mode of spread of TB infection is?

ESIC Nursing Officer 2016 (Shift -2)

Applied Microbiology & Infection control

Easy

Appeared in: ESIC Nursing Officer 2016 (Shift -2)

Explanation

Tuberculosis (TB) is an infectious disease caused by the bacterium Mycobacterium tuberculosis.
It spreads through the air when a person with active pulmonary TB coughs, sneezes, speaks, or sings, releasing infectious particles.
These particles, known as droplet nuclei, are the dried residue of droplets and are small enough (1-5 microns) to remain suspended in the air for long periods.
A new infection occurs when a susceptible individual inhales these airborne droplet nuclei.
Among the choices, 'Droplet' is the best description of the origin of these infectious particles, representing the respiratory route of transmission.

Option B: This is incorrect. Water-borne transmission involves ingesting water contaminated with pathogens.
Option C: This is incorrect. Fomite transmission involves contact with contaminated inanimate objects. While M. tuberculosis can survive on surfaces, this is not the primary or common mode of spread.
Option D: This is incorrect. This mode of transmission, also known as vector-borne, involves an insect (like a mosquito or tick) carrying the pathogen from one host to another.

Clinical Relevance

Nursing practice connection: Knowing Mode of transmission for communicable diseases, specifically Tuberculosis (TB) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Understanding that TB is airborne is critical for implementing correct infection control measures, known as Airborne Precautions.
Nursing interventions include placing the patient in a negative-pressure isolation room, ensuring 6-12 air changes per hour, and venting air to the outside.
All healthcare personnel must wear a fit-tested N95 respirator mask before entering the patient's room to prevent inhalation of droplet nuclei.

How to Approach the Question

First, identify the core subject of the question, which is the mode of transmission for Tuberculosis (TB).
This is a factual recall question. Access your knowledge about common infectious diseases and their transmission routes.
Recall that TB is a respiratory infection spread through the air.
Evaluate the given options: 'Water borne', 'Fomite', and 'Insect bite' are distinct transmission routes for other types of diseases (gastrointestinal, contact, and vector-borne, respectively).
The option 'Droplet' relates to respiratory secretions. Although TB is technically 'airborne' (spread by droplet nuclei), these nuclei originate from droplets. Therefore, 'Droplet' is the most plausible answer among the choices.
Confirm the choice by eliminating the other options as clearly incorrect for TB.

Concept Tested & Keywords

Concept Tested: Mode of transmission for communicable diseases, specifically Tuberculosis (TB).
Stem keywords: TB infection, spread, mode
Lead-in keywords: is

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 90-92