TB is transmitted primarily by which route?

• A. Airborne
• B. Waterborne
• C. Touching shared objects
• D. Foodborne

Answer: (A)

TB is transmitted through the air. When someone with active pulmonary TB coughs, sneezes, speaks, or sings, they release tiny particles called droplet nuclei. These particles are so small that they can stay suspended in the air for a long time and travel beyond just a short distance. If another person inhales enough of these aerosols, the bacteria can reach the lungs and establish infection. This is why ventilation, proper isolation of people with suspected TB, and respiratory protection are crucial in preventing spread.

The other routes aren’t how TB typically spreads. Waterborne transmission would require ingesting contaminated water, which isn’t how TB is usually transmitted. Touching shared objects or surfaces (fomites) isn’t an efficient route for TB, since the bacteria don’t infect through skin contact. Foodborne transmission is not a normal route for TB either. In practice, the key concept is that TB spread is primarily airborne because of the small aerosol particles produced by an infected person.