Clinical meaning
Isolation precautions are infection prevention strategies designed to interrupt the chain of infection by targeting the mode of transmission. The chain of infection requires six links: (1) Infectious agent (pathogen), (2) Reservoir (where the organism lives and multiplies), (3) Portal of exit (how it leaves the reservoir), (4) Mode of transmission (how it travels to a new host), (5) Portal of entry (how it enters the new host), and (6) Susceptible host. Isolation precautions target the MODE OF TRANSMISSION link. There are two tiers of precautions: STANDARD PRECAUTIONS apply to ALL patients regardless of known or suspected infection status and include hand hygiene, PPE based on anticipated exposure, respiratory hygiene/cough etiquette, safe injection practices, and proper handling of contaminated equipment and surfaces. TRANSMISSION-BASED PRECAUTIONS are used IN ADDITION to standard precautions when the route of transmission is not completely interrupted by standard precautions alone. There are three categories: AIRBORNE (particles <5 microns that remain suspended: TB, measles, varicella), DROPLET (particles >5 microns that fall within 3-6 feet: influenza, pertussis, meningococcal meningitis), and CONTACT (direct or indirect physical transfer: MRSA, C.diff, scabies, VRE). A patient may require more than one type of transmission-based precaution simultaneously.