Infection Prevention and Control
What to master
Start with the chain of infection (infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host) and link every intervention to breaking one of those links. Hand hygiene is the single most effective measure; know the WHO five moments.
Distinguish standard precautions (apply to everyone, every time: gloves, gown, eye protection based on splash risk) from transmission-based precautions:
- Contact: MRSA, VRE, C. difficile, scabies, RSV in infants. Gown and gloves; dedicated equipment.
- Droplet: influenza, pertussis, meningococcal meningitis, mumps, rubella. Surgical mask within about 1 metre; patient in a single room if possible.
- Airborne: tuberculosis, measles, varicella, disseminated zoster. N95 (fit-tested) respirator plus negative-pressure room.
Know sterilisation versus disinfection, safe sharps handling, and care bundles that prevent device infection: CLABSI (chlorhexidine, maximal barrier, daily line review), CAUTI (closed system, dependent drainage, early removal), VAP (head of bed 30–45°, oral care, sedation holidays).
Traps in questions
- Hand sanitiser for C. difficile. Alcohol does not kill spores - wash with soap and water.
- Order of PPE doffing - gloves first, then goggles, gown, mask last; perform hand hygiene after.
- Putting an airborne patient in a shared room.
- Recapping needles versus immediate sharps disposal.
Worked example
A patient with suspected pulmonary TB is admitted. Options: standard precautions only, droplet precautions with a surgical mask, airborne precautions with an N95 in a negative-pressure room, contact precautions with gown and gloves. Choose airborne precautions - TB requires a fit-tested N95, negative pressure, and the door kept closed.
Rule of thumb
Ask "how does this organism travel?" and match the precaution to the route - alcohol rub for most, soap and water for spores.