Infection Control and Safety
Infection control questions reward precise knowledge of the chain of infection, standard precautions, and the difference between sterilization, disinfection, and antisepsis.
Core concepts
- Chain of infection: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host. Breaking any link prevents transmission.
- Standard precautions apply to all patients regardless of diagnosis-hand hygiene, gloves, masks, eye protection, gowns as needed. Hand hygiene is the single most important measure.
- Spatter vs. aerosol: spatter consists of large droplets that settle quickly; aerosols are small particles that remain airborne. Both require barriers; aerosols also warrant ventilation and evacuation.
- Sterilization destroys all microorganisms including spores (autoclave, chemical vapor, dry heat). Disinfection reduces pathogens on surfaces (low-, intermediate-, high-level). Antisepsis applies to living tissue.
- Spore testing verifies sterilizer function; biological indicators are the gold standard. Chemical indicators show exposure, not sterility.
- Sharps safety: never recap by hand-use the one-handed scoop or a recapping device; dispose in puncture-resistant containers.
Traps
Questions love to blur "disinfect" and "sterilize," or ask whether a chemical indicator proves sterility (it does not). Another trap: assuming gloves replace hand hygiene-they do not.
Rule of thumb
If the item penetrates tissue or contacts sterile areas, it must be sterilized; if it only touches intact mucosa or skin, high-level disinfection or barriers may suffice.