Infection Control
Infection Control tests the chain of infection, standard precautions and safe waste handling - the knowledge that prevents the most common health-care-associated infections.
Core rules
- Chain of infection: infectious agent → reservoir → portal of exit → mode of transmission → portal of entry → susceptible host. Breaking any one link stops transmission.
- Hand hygiene is the single most effective measure. Wash with soap and water for 40–60 seconds when hands are visibly soiled; alcohol rub for 20–30 seconds when they are not. WHO five moments: before touching a patient, before a clean procedure, after body fluid exposure risk, after touching a patient, after touching surroundings.
- Standard precautions apply to every patient: treat all blood and body fluids as infectious, use gloves, apron, mask and eye protection as indicated.
- Donning order: gown, mask, goggles, gloves. Doffing: gloves, goggles, gown, mask, then hand hygiene.
- Biomedical waste segregation: yellow bag for human anatomical waste and heavily soiled items, red bag for contaminated recyclable plastic, white translucent puncture-proof container for sharps, blue for glass and metallic implants, green for general waste. Fill sharps containers only to three-quarters.
- Sterilisation kills spores (autoclave 121 °C at 15 psi for 15–20 minutes); disinfection does not.
Worked example
A staff nurse sustains a needle-stick injury. Reasoning: the immediate risk is transmission of blood-borne viruses through the portal of entry. Correct sequence: wash the site with soap and running water without squeezing or scrubbing, do not apply spirit or bleach, cover it, report immediately, fill the incident form and start post-exposure prophylaxis as advised, with baseline serology.
Traps that cost marks
- Recapping needles or bending them by hand.
- Using alcohol rub on visibly soiled hands.
- Putting sharps in a yellow bag.
- Removing gloves last instead of first when doffing.