Infection Prevention and Control
The chain of infection
Six links must all be present for infection to spread: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host. Break any link and transmission stops. Standard precautions apply to every patient, every time, because many carriers are asymptomatic.
Standard precautions
- Hand hygiene before and after every contact.
- Gloves for blood, body fluids, secretions, excretions and non-intact skin.
- Apron or gown when splashing is likely; mask, eye protection as needed.
- Safe sharps handling: never recap by hand, never pass a needle hand to hand.
- Clean and disinfect shared equipment; segregate linen and waste at source.
- Cover your own cuts; keep immunisations (especially hepatitis B) up to date.
Transmission-based precautions
- Contact: MRSA, scabies, C. difficile – gloves and gown, dedicated equipment.
- Droplet: influenza, mumps, pertussis – surgical mask within about one metre.
- Airborne: pulmonary TB, measles, varicella – N95 respirator, negative-pressure room, door closed.
Cleaning, disinfection, sterilisation
Cleaning removes soil; disinfection kills most organisms; sterilisation destroys all, including spores. An autoclave at 121 °C, 15 psi for about 15–20 minutes is standard for reusable instruments; CSSD manages this cycle.
Worked example
A patient with suspected pulmonary TB is admitted to your ward. Reasoning: TB spreads by airborne droplet nuclei, so standard precautions alone are not enough. Place the patient in a separate, well-ventilated room with the door closed, wear a fit-checked N95 before entering, keep the patient's mask on during transport, and limit visitors. Report to the nurse and infection control link nurse.
Traps
- Wearing gloves instead of doing hand hygiene.
- Reusing gloves between patients.
- Sending a TB patient to the general X-ray queue without a mask.
- Assuming antibiotics remove the need for isolation.