The degree of infectiousness of a patient with tuberculosis correlates with

The infectiousness oftuberculosis (TB)is directly related to thenumber of Mycobacterium tuberculosis organisms expelled into the airby an infected patient.

Step-by-Step Justification:

TB Transmission Mechanism:

TB spreads throughairborne droplet nuclei, which remain suspended for long periods​.

Factors Affecting Infectiousness:

High bacterial load in sputum:Smear-positive patients are much more infectious​.

Coughing and sneezing frequency:More expelled droplets increase exposure risk.

Environmental factors:Poor ventilation increases transmission​.

Why Other Options Are Incorrect:

A. Hand hygiene habits:TB is airborne,not transmitted via hands.

B. Presence of acid-fast bacilli (AFB) in blood:TB isnot typically hematogenous, and blood AFB does not correlate with infectiousness.

C. Tuberculin skin test (TST) >20 mm:TST indicates prior exposure,not infectiousness.

CBIC Infection Control References:

APIC Text, "Tuberculosis Transmission and Control Measures"​.