Airborne precautions are infection prevention and control interventions designed to stop the spread of very small, germ-carrying particles through the air. These measures are used in addition to standard infection control practices. They prevent the transmission of infectious agents that can travel long distances and remain suspended in the environment. These precautions are implemented to protect individuals from inhaling pathogens that linger in the air.
Understanding Airborne Transmission
Certain infectious agents spread through the air when an infected person breathes, talks, coughs, or sneezes. These activities release tiny, lightweight particles, known as aerosols or droplet nuclei, into the air. Unlike larger respiratory droplets that fall quickly, these smaller particles, typically less than 5 micrometers in diameter, can remain suspended for extended periods, sometimes for hours.
Air currents can disperse these suspended particles over significant distances, allowing them to infect individuals not in close proximity to the source. This means a person can become infected even if they were not in the same room as the infected individual at the time of particle expulsion. Understanding this distinct mode of transmission is foundational to implementing specific precautions.
Specific Measures for Airborne Precautions
Implementing airborne precautions involves several specific measures to contain and filter infectious particles. One measure is the use of specialized respiratory protection, such as N95 respirators. These respirators filter out at least 95% of airborne particles as small as 0.3 micrometers from the air the wearer breathes.
For an N95 respirator to be effective, it must form a tight seal around the wearer’s face. This requires an initial fit-testing process to determine the correct make, model, and size for each individual. A user seal check must be performed every time the respirator is worn, as an improper fit reduces protection.
Another measure involves placing patients with suspected or confirmed airborne infections in specialized rooms called Airborne Infection Isolation Rooms (AIIRs), also known as negative pressure rooms. These rooms maintain a lower air pressure inside than in adjacent areas. This pressure difference ensures that when a door is opened, air flows into the room, preventing contaminated air from escaping. The air from these rooms is typically exhausted directly to the outside or passed through high-efficiency particulate air (HEPA) filters before recirculation. These rooms often have a minimum of 6 to 12 air exchanges per hour.
Limiting patient movement outside of the isolation room is standard practice to minimize pathogen spread. If movement is medically necessary, the patient should wear a surgical mask to help contain respiratory secretions. Entry to these rooms is often restricted to essential personnel, and visitors must adhere to strict protective measures, including wearing an N95 respirator.
Diseases Requiring Airborne Precautions
Tuberculosis (TB) is a bacterial infection that spreads when tiny bacteria are carried by air currents. Patients with active TB are typically placed in airborne isolation until they are no longer considered infectious.
Measles is a highly contagious viral disease. The virus can remain suspended in the air for up to two hours after an infected person has left an area. Its ability to travel long distances and linger makes airborne controls important to prevent widespread transmission.
Chickenpox, caused by the varicella-zoster virus, spreads through the air via inhalation of aerosols from respiratory secretions or fluid from skin lesions. This virus is highly contagious and can be transmitted even before the characteristic rash appears. Airborne precautions are applied until all lesions have crusted over, or in vaccinated individuals, until no new lesions have appeared for 24 hours.
Why Adherence Matters
Strict adherence to airborne precautions is important for preventing the spread of infectious agents within healthcare facilities and the wider community. These measures protect healthcare workers, other patients, and visitors from exposure to airborne pathogens. Following these protocols helps prevent disease transmission.
Failure to follow airborne precautions increases the risk of disease transmission. This risk extends to vulnerable individuals, such as immunocompromised patients, who may experience severe illness if infected. Consistent application of these precautions maintains a safer environment for everyone and reduces the potential for outbreaks.