Which statement best describes tuberculosis transmission?

• A. It is spread by contaminated surfaces
• B. It is spread through droplets when coughing
• C. It is spread through blood contact
• D. It is airborne and highly contagious; if coughing, assume TB

Answer: (D)

Tuberculosis spreads primarily through airborne particles produced when an infected person with active TB coughs, speaks, or sneezes. These tiny droplet nuclei can linger in the air and be inhaled by others, especially in enclosed or poorly ventilated spaces. Because of this mode of transmission, the best description is that TB is airborne and can be highly contagious in settings where coughing is present, so clinicians and responders should assume TB in coughing patients and use airborne precautions (such as an N95 respirator and appropriate isolation) to protect themselves.

The other options don’t fit because TB is not spread mainly by touching contaminated surfaces (fomites), nor through direct blood contact, and it is transmitted via small airborne particles rather than larger droplets that fall to the ground quickly.