Which of the following is an example of a transmission-based precaution?

• A. N95 respirator for suspected TB.
• B. Gloves for cosmetic contact.
• C. Hand hygiene before touching patient.
• D. Public space discussion.

Answer: (A)

Transmission-based precautions target the specific route by which an infection spreads, added to standard precautions to break transmission in high-risk situations. Tuberculosis spreads through airborne particles that can linger in the air, so protecting healthcare workers requires a respirator that can filter these small droplets and a setting arranged to minimize airborne spread. An N95 respirator worn by staff caring for someone with suspected TB is the clearest example of applying an airborne transmission precaution because it directly addresses the route of transmission and uses specialized protective equipment to block inhalation of infectious particles. Other options illustrate general barrier protection or standard precautions—gloves for cosmetic contact addresses protecting surfaces from touch but not the airborne route, hand hygiene before touching a patient is a routine standard precaution, and a public space discussion has no clinical infection-control relevance.