Infection Prevention and Control
Core concepts
Master the chain of infection - infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host - and know that breaking any link prevents transmission. Standard precautions apply to all patients regardless of diagnosis: hand hygiene, gloves, gown, mask/eye protection based on exposure risk, safe sharps handling, and respiratory hygiene.
Hand hygiene is the single most effective measure. Know the WHO five moments and that alcohol-based rub is preferred for routine decontamination except when hands are visibly soiled or with spore-formers such as C. difficile, where soap and water is required. Transmission-based precautions: contact (MRSA, C. diff, scabies), droplet (influenza, pertussis, meningococcus - mask within ~1 meter), and airborne (TB, measles, varicella - N95 respirator and negative-pressure room).
Understand sterilization versus disinfection, Spaulding classification (critical, semicritical, noncritical items), and the importance of cleaning before disinfection. Know sharps injury first aid and post-exposure reporting.
Traps in questions
- Using alcohol rub for C. difficile or visibly soiled hands.
- Ordering airborne precautions for droplet diseases (or vice versa).
- Removing PPE in the wrong sequence - gloves and gown first, then hand hygiene.
- Assuming standard precautions can be skipped for "clean" patients.
Worked example / rule of thumb
A patient with suspected pulmonary TB: place in an airborne infection isolation room with negative pressure, wear an N95, and keep the door closed. Rule of thumb: airborne = N95 + negative pressure; droplet = surgical mask + distance; contact = gown and gloves.