Transmission-based precautions are a set of infection control measures used in healthcare settings. These precautions are employed in addition to standard precautions when those are insufficient to prevent the spread of specific infectious agents. They serve as a second tier of protection, designed for patients known or suspected to be infected or colonized with microorganisms that can transmit easily. The primary goal of these additional measures is to safeguard both patients and healthcare personnel from potential infection.
How Infections Spread
Infectious agents can spread through various mechanisms, necessitating different precautions to interrupt their transmission. One common mode is direct contact, involving physical touch between an infected person and a susceptible individual, such as skin-to-skin contact. Indirect contact transmission occurs when an individual touches contaminated objects or surfaces that an infected person has previously contacted. Another pathway for infection involves respiratory droplets, which are larger particles generated when an infected person coughs, sneezes, or talks. These droplets typically travel short distances, generally no more than three to six feet, before falling out of the air. In contrast, airborne transmission involves much smaller particles, known as droplet nuclei, which can remain suspended in the air for extended periods and travel over longer distances.
Contact Precautions
Contact precautions are specifically applied for infections that spread through direct physical contact or indirect contact with contaminated surfaces or patient care items. Healthcare workers caring for patients under contact precautions must wear personal protective equipment (PPE), including a gown and gloves, upon entering the patient’s room, creating a barrier to prevent the transfer of microorganisms to the healthcare worker’s clothing or hands. Strict adherence to hand hygiene is also important, requiring thorough handwashing or the use of alcohol-based hand rub after removing PPE and exiting the patient’s environment. Environmental controls are also part of contact precautions, often involving the use of dedicated patient-care equipment to avoid cross-contamination. Common infections requiring contact precautions include Clostridioides difficile (C. diff), Methicillin-resistant Staphylococcus aureus (MRSA), and Vancomycin-resistant Enterococci (VRE).
Droplet Precautions
Droplet precautions are implemented for pathogens transmitted through respiratory droplets, which are relatively large particles produced during coughing, sneezing, or talking. Healthcare personnel entering the room of a patient on droplet precautions are required to wear a surgical mask. Patient placement considerations for droplet precautions often include placing the patient in a private room to limit exposure to others. If a private room is unavailable, maintaining a spatial separation of at least three feet from other patients is recommended. Patients who need to be transported outside their room should wear a mask if they can tolerate it, helping to contain the spread of their respiratory secretions. Infections necessitating droplet precautions commonly include influenza, pertussis (whooping cough), and some types of bacterial meningitis.
Airborne Precautions
Airborne precautions are the most stringent transmission-based precaution, used for infections caused by microorganisms that remain suspended in the air over long distances. These tiny particles, called droplet nuclei, are widely dispersed by air currents and inhaled by susceptible individuals even without close proximity. Healthcare workers providing care for patients under airborne precautions must wear a specialized respirator (e.g., N95 or higher-level) designed to filter very small airborne particles. Proper fit-testing ensures a tight seal and effective protection. A defining feature is the use of Airborne Infection Isolation Rooms (AIIRs), also known as negative pressure rooms. These specialized rooms are engineered to maintain lower air pressure inside the room compared to the adjacent hallway, ensuring that air flows into, rather than out of, the room. Air from AIIRs is typically exhausted directly to the outside or passed through high-efficiency particulate air (HEPA) filters before being recirculated, preventing the escape of infectious particles into other areas of the facility. Examples of diseases requiring airborne precautions include tuberculosis, measles, and varicella (chickenpox).
The Importance of Transmission-Based Precautions
Adhering to transmission-based precautions is important for maintaining a safe healthcare environment. These measures prevent healthcare-associated infections (HAIs), which patients acquire during their stay. By limiting the spread of infectious agents, these precautions protect vulnerable patients who may have weakened immune systems or are recovering from procedures. Furthermore, transmission-based precautions are important for safeguarding healthcare workers, reducing their risk of exposure to infectious diseases. Implementing these evidence-based practices ultimately helps to control the spread of infections within healthcare facilities and into the broader community. This approach to infection control fosters a safer environment for everyone in healthcare.