Infection Prevention and Control
The chain of infection
Six links: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry and susceptible host. Infection control breaks any one link. Transmission is contact (direct, indirect, faecal-oral), droplet (influenza, pertussis), airborne (tuberculosis, measles, varicella) or vector-borne.
Standard precautions apply to every patient
Treat all blood and body fluids as infectious. Core elements: hand hygiene, gloves and other PPE chosen by risk, respiratory hygiene and cough etiquette, safe injection and sharps practice, spill management, linen handled without shaking or placing on the floor, waste segregation, and cleaning of shared equipment between patients.
Transmission-based precautions
- Contact: gown and gloves, dedicated equipment; MRSA, scabies, C. difficile.
- Droplet: surgical mask, single room, distance above one metre; influenza, mumps.
- Airborne: fit-tested N95, negative-pressure or well-ventilated room with the door closed; TB, measles, chickenpox.
Cleaning, disinfection and sterilisation
Cleaning removes soil; disinfection kills most organisms on inanimate objects; sterilisation kills all organisms including spores, usually by autoclave at 121 degrees Celsius and 15 psi for 15 minutes. For blood spills, wear gloves, absorb the spill, then apply 1% sodium hypochlorite for 10-20 minutes; general surfaces use 0.5%.
Needle-stick injury
Wash with soap and running water, do not squeeze or suck the site, apply antiseptic, report immediately to the infection control nurse, and start post-exposure prophylaxis as early as possible, ideally within two hours. Baseline testing covers HIV, hepatitis B and hepatitis C.
Worked example
A patient with sputum-positive TB is admitted. The GDA wears an N95, ensures the door stays closed, teaches the patient to cover his cough, and does not place him in a general bay.
Traps
Gloves never replace hand hygiene; do not recap needles; alcohol is not the correct agent for a blood spill.