Standard and Transmission-Based Precautions and Isolation Practices
Standard and transmission-based precautions questions test whether you apply the right precaution at the right time, including empiric use before results return. Know what standard precautions require for every patient and when to add contact, droplet, or airborne precautions.
Core rules
- Standard precautions apply to all patients, all body fluids except sweat, nonintact skin, and mucous membranes. They include hand hygiene, gloves, gown, mask/eye protection when splashing, safe injection, respiratory hygiene, and clean equipment.
- Perform hand hygiene before and after patient contact and after glove removal. Gloves do not replace hand hygiene.
- Contact precautions: gown and gloves; dedicated equipment; single room when possible. Use for MRSA, VRE, CRE, ESBL, C. difficile, norovirus, and scabies.
- Droplet precautions: surgical mask; private room or cohort; use for influenza, pertussis, meningococcus, mumps, and rubella. Large droplets travel short distances, so mask on entering the room.
- Airborne precautions: N95 or higher respirator, negative-pressure AIIR, door closed; use for pulmonary TB, measles, varicella, and disseminated zoster. Only immune staff should care for varicella.
- Initiate empiric precautions based on the syndrome (diarrhea, rash, respiratory symptoms) and travel/exposure history; do not wait for test results.
- Discontinuation follows organism-specific rules. Contact precautions for MRSA/VRE often continue until cultures are negative or per policy; C. difficile until diarrhea resolves; airborne until effective therapy and criteria are met.
- Visitors and transport: visitors follow precautions; mask the patient during transport for droplet/airborne, and notify receiving areas.
Worked example
A patient arrives with fever, cough, and a recent flight from a country with endemic measles. Before diagnosis, use a surgical mask on the patient, place in an AIIR if available, and use airborne precautions with N95 for staff. If measles is confirmed, maintain airborne precautions; if varicella is suspected, only immune staff enter. If TB is suspected, airborne precautions until effective therapy and criteria are met-not until the patient feels better.
Traps
Do not use alcohol hand rub for C. difficile. Do not use droplet precautions for TB. Do not stop airborne precautions based on a single negative test when clinical suspicion is high. Do not forget that standard precautions apply even when transmission-based precautions are in place.