Transmission-based precautions are infection control measures used in healthcare to prevent the spread of infectious diseases. They are implemented when standard infection control practices are insufficient to contain highly transmissible infections.
Understanding Standard Versus Transmission-Based Precautions
Standard precautions represent the fundamental level of infection prevention, applied universally to all patients in healthcare settings, regardless of their diagnosis or presumed infection status. These practices assume that all blood, body fluids, non-intact skin, and mucous membranes may contain infectious agents. Standard precautions encompass hand hygiene, the use of personal protective equipment (PPE), respiratory hygiene, safe injection practices, and environmental cleaning.
Transmission-based precautions are additional measures that supplement standard precautions. They are employed when standard precautions are insufficient to prevent the spread of particular infectious agents. These supplementary precautions are necessary for pathogens that are highly contagious or spread through distinct routes, such as through the air, by droplets, or through direct or indirect contact. Their application is often based on a patient’s clinical symptoms, even before a definitive diagnosis is confirmed, to immediately reduce transmission risks.
Categories of Transmission-Based Precautions
Airborne Precautions
Airborne precautions are designed for diseases spread through small airborne particles, known as droplet nuclei, which can remain suspended in the air for extended periods and travel over long distances. These particles are typically less than 5 micrometers in size. Healthcare personnel must wear a fit-tested N95 or higher-level respirator to filter these tiny particles.
Patients requiring airborne precautions are typically placed in an Airborne Infection Isolation Room (AIIR), also known as a negative pressure room. These specialized rooms maintain lower air pressure inside compared to adjacent areas, ensuring that air flows into the room and contaminated air is exhausted outside through a dedicated ventilation system, often with HEPA filtration. Common conditions necessitating airborne precautions include tuberculosis, measles, and chickenpox.
Droplet Precautions
Droplet precautions are implemented for diseases transmitted through larger respiratory droplets generated when an infected person coughs, sneezes, or talks. These droplets are generally larger than 5 micrometers and travel short distances (3 to 6 feet) before falling onto surfaces or mucous membranes. Special air handling or ventilation systems are not required for droplet precautions because the droplets do not remain suspended in the air over long distances.
Healthcare personnel and visitors within the specified distance of the patient should wear a surgical mask. Eye protection may also be advised if there is a potential for splashes or sprays. Examples of infections that warrant droplet precautions include influenza, pertussis (whooping cough), mumps, and certain types of meningitis.
Contact Precautions
Contact precautions are used for infections that spread through direct physical contact with an infected patient or indirect contact with contaminated surfaces or equipment in the patient’s environment. Direct contact involves skin-to-skin contact, while indirect contact occurs when touching contaminated items.
Healthcare personnel entering the patient’s room for contact precautions must don a gown and gloves upon entry and remove them before exiting the room to contain pathogens. Dedicated or disposable patient-care equipment should be used to prevent transmission between patients. Conditions requiring contact precautions include Methicillin-resistant Staphylococcus aureus (MRSA), Clostridioides difficile (C. difficile), Vancomycin-resistant Enterococci (VRE), and scabies.
Implementing Transmission-Based Precautions
Effective implementation of transmission-based precautions involves several practical measures within healthcare settings. Placing patients in single rooms is often preferred to contain infectious agents, or patients with the same infection may be cohorted in a shared space. Clear signage indicating the required precautions is posted outside the patient’s room to inform staff and visitors.
Proper donning and doffing (putting on and removing) of personal protective equipment (PPE) is important to prevent self-contamination and the spread of pathogens. Healthcare workers receive training on the correct sequence for applying and removing gowns, gloves, and masks. Hand hygiene, through thorough handwashing or the use of alcohol-based hand rubs, is always performed before and after patient contact and after removing PPE.
Environmental cleaning is heightened in rooms where transmission-based precautions are in effect, focusing on thorough disinfection of frequently touched surfaces and shared equipment. Limiting patient transport outside the room to medically necessary purposes also helps contain the spread. Visitors are informed and instructed on the necessary precautions, including hand hygiene and the appropriate use of PPE, to protect themselves and others. These combined efforts aim to prevent healthcare-associated infections and support public health.