Infection Control and Safety
Domain 9 tests the chain of infection, standard and transmission-based precautions, sterilisation and disinfection, sharps safety, post-exposure management and environmental safety.
Standard precautions
- WHO five moments for hand hygiene. Use alcohol-based rub unless hands are visibly soiled or the patient has Clostridioides difficile or norovirus - then soap and water.
- Donning: gown, mask, goggles, gloves. Doffing: gloves first, then goggles, gown and mask, with hand hygiene last.
Spaulding classification
- Critical items (entering sterile tissue or the vascular system) require sterilisation - autoclave at 121 °C, 15 psi for 15–20 minutes, or 134 °C for 3–4 minutes.
- Semicritical items (contacting mucous membranes, e.g. laryngoscope blades) need high-level disinfection.
- Non-critical items (skin contact only) need low-level disinfection.
Transmission-based precautions
- Contact: MRSA, scabies, C. difficile - gown and gloves.
- Droplet: influenza, pertussis, meningococcal meningitis - surgical mask within 1–2 metres.
- Airborne: tuberculosis, measles, varicella - N95 respirator and negative-pressure room.
Worked example
A nurse sustains a hollow-bore needlestick from a patient of unknown HIV status. Reasoning: wash the site with soap and water; do not squeeze or suck it. Report immediately and attend the designated clinic. HIV post-exposure prophylaxis should begin as soon as possible, ideally within 2 hours and no later than 72 hours, continued for 28 days with baseline testing and counselling plus follow-up serology.
Traps
Recapping needles; using alcohol rub after C. difficile contact; sending a semicritical item for low-level disinfection; delaying PEP to finish the shift; storing sterile packs at floor level.