Identify the three modes of disease transmission used in infection control.

• A. Contact, Droplet, and Airborne transmission
• B. Direct, Indirect, and Mechanical
• C. Bloodborne, Waterborne, Foodborne
• D. Vector-borne only

Answer: (A)

Transmission in infection control is described using three broad modes: contact, droplet, and airborne. Understanding these helps explain why certain precautions are chosen in healthcare settings.

Contact transmission covers direct touch with an infected person and indirect contact via contaminated surfaces or instruments. Interrupting this route relies on thorough hand hygiene and the proper use of gloves and gowns, along with diligent environmental cleaning.

Droplet transmission involves larger respiratory droplets expelled when someone talks, coughs, or sneezes. These droplets travel only short distances, typically within about a meter. Protection focuses on wearing masks for close contacts, eye protection when there’s a splash risk, and placing the patient in appropriate isolation to limit exposure.

Airborne transmission is about tiny particles that can linger in the air and travel longer distances. Diseases such as tuberculosis, measles, and varicella illustrate this route. Preventing it requires airborne precautions: a well-fitting N95 respirator (or higher), and a negative-pressure isolation room with proper ventilation.

Other classifications, like direct versus indirect or routes such as bloodborne or vector-borne, either describe subtypes or describe specific routes that don’t form the standard three-category framework used in many infection-control programs.