Transmission-based precautions are infection control measures used in healthcare settings. They supplement standard precautions when patients are known or suspected to be infected with pathogens that spread through specific routes. Their purpose is to interrupt the transmission of infectious agents, protecting patients, healthcare workers, and visitors. These measures are necessary when standard practices alone cannot contain the spread of particular infections.
Airborne Precautions
Airborne precautions prevent the spread of infectious agents that remain suspended in the air over long distances. These agents are very small particles, less than 5 micrometers in diameter, and can stay viable and infectious for extended periods. When an infected individual coughs, sneezes, or talks, these tiny particles can be released and inhaled by others.
Pathogens like Mycobacterium tuberculosis (tuberculosis), measles, and varicella (chickenpox) require airborne precautions. These microorganisms can travel on air currents, potentially infecting individuals in different areas of a facility.
Patients needing airborne precautions are placed in an Airborne Infection Isolation Room (AIIR) with negative pressure. This ventilation system ensures air flows into the room but not out, containing infectious particles. Healthcare personnel entering these rooms must wear a fit-tested N95 respirator or higher respiratory protection to filter out small airborne particles.
Droplet Precautions
Droplet precautions prevent the transmission of infectious agents that spread through larger respiratory droplets. These droplets are greater than 5 micrometers in size and are generated when an infected person coughs, sneezes, or talks. Unlike airborne particles, these larger droplets travel only short distances, about three to six feet, before falling out of the air.
Common infections requiring droplet precautions include influenza, mumps, rubella, and pertussis (whooping cough). These pathogens transmit when droplets from an infected individual’s respiratory tract land on another person’s mucous membranes, such as the eyes, nose, or mouth.
Healthcare personnel and visitors entering a patient’s room on droplet precautions must wear a surgical mask. N95 respirators are not generally required, but maintaining a safe physical distance from the infected individual is important to prevent direct droplet exposure. Patient transport outside the room should be limited; if necessary, the patient should wear a surgical mask to contain their respiratory secretions.
Contact Precautions
Contact precautions prevent the spread of infectious agents transmitted through direct or indirect contact. Direct contact involves physical contact between an infected and a susceptible person, such as touching a patient’s skin or wound. Indirect contact occurs when a susceptible person touches a contaminated object or surface in the patient’s environment, like a doorknob or medical equipment, before touching their mucous membranes.
Common infections requiring contact precautions include methicillin-resistant Staphylococcus aureus (MRSA), Clostridioides difficile (C. difficile), and vancomycin-resistant enterococci (VRE). Scabies, a parasitic infestation, also requires contact precautions due to its direct transmission. These pathogens can persist on surfaces and hands, making environmental cleanliness and hand hygiene important.
Healthcare personnel must wear a gown and gloves upon entering the patient’s room or care area. These items should be removed and discarded before leaving the room to prevent contamination. Hand hygiene, with soap and water or an alcohol-based hand rub, immediately after removing personal protective equipment and leaving the room, helps prevent transmission.