Infection Prevention and Control: Standard and Transmission-Based Precautions
The chain of infection
Infection prevention and control rests on breaking the chain of infection: infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. Know the modes of transmission: contact (direct and indirect), droplet, airborne, and vector-borne. In health settings, contaminated hands and equipment are the most common vehicles.
Standard precautions
Standard precautions apply to all clients at all times, regardless of diagnosis:
- Hand hygiene using the WHO five moments and the correct technique; alcohol-based rub for visibly clean hands, soap and water when hands are visibly soiled or for organisms such as Clostridioides difficile.
- Personal protective equipment: gloves, gowns, masks, eye protection; sequence for donning and doffing, with hand hygiene before and after.
- Safe handling of sharps and correct disposal in a sharps container; never recap a used needle.
- Respiratory hygiene and cough etiquette, cleaning and disinfection of equipment and surfaces, and safe waste and linen management.
- Aseptic technique for invasive procedures and correct reprocessing of reusable equipment.
Transmission-based precautions
Used in addition to standard precautions: contact precautions (e.g., gown and gloves, dedicated equipment), droplet precautions (surgical mask within a set distance), and airborne precautions (fit-checked P2/N95 respirator, negative pressure room).
Traps
Questions often test whether gloves replace hand hygiene: they do not. Another trap is assuming standard precautions apply only to clients with a known infection; they apply to everyone. Watch for the correct sequence in doffing and for when alcohol rub is insufficient.
Rule of thumb
If a question involves body fluids, non-intact skin, or a sharps injury, the answer almost always begins with standard precautions and hand hygiene.
Worked example
After removing gloves following a dressing change, the assistant performs hand hygiene immediately; gloves are not a substitute for hand hygiene, and hands may be contaminated during removal.