Which of the following is not a transmission-based precaution?

• A. Contact precautions
• B. Droplet precautions
• C. Standard precautions
• D. Airborne precautions

Answer: (C)

The main idea here is understanding how precautions are applied in infection prevention. Standard precautions are the universal measures used with every patient—they form the baseline for all patient care, regardless of illness or diagnosis. They include practices like hand hygiene, proper use of gloves and other PPE as needed, safe injection practices, respiratory hygiene, and safe handling of equipment and the environment.

Transmission-based precautions are added on top of standard precautions when there’s a known or suspected mode of transmission for a particular infection. These are more targeted: contact precautions for infections spread by direct or indirect contact, droplet precautions for infections spread by larger respiratory droplets, and airborne precautions for infections spread by small particles that can stay suspended in the air.

Since standard precautions are not tied to a specific transmission route and are applied universally, they are not considered a transmission-based precaution. The other options—contact, droplet, and airborne—are all examples of transmission-based precautions. Even when these additional precautions are used, standard precautions continue to be in effect.