Domain 3: Preventing/Controlling the Transmission of Infectious Agents
Preventing/Controlling the Transmission of Infectious Agents tests Standard Precautions, transmission-based precautions, hand hygiene, PPE, environmental cleaning, and device bundles. The emphasis is selecting the correct precaution immediately and sustaining it.
Core rules and concepts
- Standard Precautions apply to all patients: hand hygiene, gloves for contact with blood/body fluids, gown and eye/mouth protection when splash is anticipated, and safe injection practices.
- Contact precautions for C. difficile, norovirus, MRSA, VRE, and scabies; use soap and water for C. difficile and norovirus because alcohol does not reliably kill spores.
- Droplet precautions for influenza, pertussis, meningococcus, and mumps; airborne precautions for pulmonary TB, measles, varicella, and disseminated zoster, with an AIIR and N95 respirator.
- Clean environmental surfaces and shared equipment; use sporicidal bleach for C. difficile and norovirus according to policy.
Worked example
A long-term care resident develops vomiting and diarrhea. Norovirus is suspected. Place the resident on contact precautions, use gown and gloves, perform hand hygiene with soap and water, and clean contaminated surfaces with bleach. The reasoning is that norovirus is non-enveloped, spreads by contact and droplets, and resists alcohol; excluding ill staff until 48 hours after symptoms resolve reduces transmission.
Traps
Using alcohol rub for C. difficile or norovirus, applying droplet instead of airborne precautions for TB or measles, relying on PPE without hand hygiene, and continuing contact precautions beyond the locally defined duration without criteria are common errors.