Which of the following are types of transmission-based precautions?

• A. Contact precautions
• B. Droplet precautions
• C. Airborne precautions
• D. All of the above

Answer: (D)

Transmission-based precautions come in three main forms, each targeting a different path your patient’s infection might take. These are contact precautions, droplet precautions, and airborne precautions. Because infections can spread by direct or indirect contact, by larger respiratory droplets, or by smaller airborne particles, you apply the specific precaution that matches the transmission route. If a pathogen spreads by contact, you use contact precautions (gloves and gown). If it spreads by droplets, you use droplet precautions (mask within close range, plus eye protection as needed). If it spreads by airborne particles, you use airborne precautions (N95 respirator or higher, and a negative-pressure room). Since all three categories exist, the correct choice is all of the above.