Infection Prevention and Control
This domain tests how infections spread and the routine practices that stop them. Questions usually ask you to sequence a procedure or choose the right precaution.
The chain of infection
Six links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host. Breaking any one link prevents transmission - hand hygiene breaks the transmission link.
Standard precautions
Treat every patient's blood and body fluids as infectious. Apply hand hygiene, gloves, gown, mask and eye protection as indicated, safe sharps handling, spill management, linen handling and correct waste segregation.
Hand hygiene
WHO five moments: before touching a patient, before a clean or aseptic procedure, after body fluid exposure risk, after touching a patient, after touching patient surroundings. Six steps cover palms, backs of hands, between fingers, backs of fingers, thumbs and fingertips. Alcohol-based rub for 20–30 seconds when hands are visibly clean; soap and water for 40–60 seconds when soiled.
Sterilisation and disinfection
Sterilisation kills all microorganisms including spores; autoclaving is 121 °C at 15 psi for 15–20 minutes. High-level disinfection (glutaraldehyde, boiling) kills all but some spores. Sodium hypochlorite 1% available chlorine is used for blood spills and 0.5% for general surfaces. Transmission-based precautions: contact, droplet and airborne (N95 respirator plus negative-pressure room for TB, measles, chickenpox).
Worked example
You leave a TB patient's room wearing gloves, goggles, gown and N95. Reasoning: the correct doffing order is gloves, then goggles or face shield, then gown, then mask or respirator last, with hand hygiene after each step - the respirator is removed last because it protected the airway.
Traps that cost marks
Alcohol rub does not kill C. difficile spores or norovirus - use soap and water. Never recap needles. Gloves do not replace hand hygiene.