Standard and Transmission-Based Precautions in Hospital Infection Control
On this page
Direct answer
Hospital infection control is the set of practices that prevent transmission of pathogens between patients, staff and visitors, built on standard precautions applied to every patient plus transmission-based precautions for known or suspected infection. Hand hygiene is the single most effective measure in most facilities. Needle-stick injury management is the standard practical scenario for post-exposure prophylaxis.
What you must remember
- Standard precautions: Apply to every patient regardless of diagnosis, covering hand hygiene, gloves, masks and eye protection when splashes are expected, and safe sharps handling.
- Contact precautions: Used for MRSA, VRE, ESBL producers and Clostridioides difficile, with gown and gloves; soap and water is preferred for C difficile because alcohol rub is less effective against its spores.
- Droplet precautions: Used for meningococcal disease, influenza and pertussis, with a surgical mask worn within about one metre of the patient.
- Airborne precautions: Used for pulmonary tuberculosis, measles and varicella, with a fit-tested N95 respirator and a negative-pressure room.
- Hand hygiene moments: Before patient contact and aseptic tasks, after body-fluid exposure, and after patient or surrounding contact; alcohol rub suffices when hands are not visibly soiled.
- Needle-stick injury: Wash the site, report at once, test the source for HIV, hepatitis B and hepatitis C with consent, and start HIV post-exposure prophylaxis as early as possible.
A graded pathway: a deep needle-stick injury
A nurse sustains a deep needle-stick injury from a hollow-bore needle used on a patient whose HIV status is unknown. The steps below run from first aid to follow-up.
- Wash and report: wash the site with soap and water, then report to the occupational health unit so the exposure is recorded.
- Test the source: the source patient is counselled and tested for HIV, hepatitis B and hepatitis C with consent, and results are sought urgently.
- Start prophylaxis early: because the injury is deep and the source status is unknown, HIV post-exposure prophylaxis starts while testing continues, ideally within two hours and in any case within 72 hours.
- Check hepatitis B immunity: if the nurse is not immune, immunoglobulin and vaccination are given according to protocol.
- Follow up: baseline and follow-up blood tests are arranged at defined intervals, with advice on precautions during follow-up.
- Close the loop: sharps injuries are reported to the infection control committee, so the hospital can change practice when a pattern emerges, such as repeated injuries from one device.
Where the exam tries to catch you
Exam questions favour the distinction between cleaning, disinfection and sterilisation, and the needle-stick timeline.
- Trap: alcohol hand rub is enough after contact with Clostridioides difficile Correct: alcohol rub is not reliable against spores, so soap and water is the correct choice.
- Trap: a surgical mask suffices for tuberculosis or measles Correct: these need a fit-tested N95 respirator and a negative-pressure room, whereas a surgical mask suits droplet precautions.
- Trap: wait for source test results before starting PEP Correct: PEP starts as early as possible without waiting, and it is not useful after 72 hours.
Frequently asked questions
Which infections require airborne isolation in a hospital?
Pulmonary tuberculosis, measles and varicella require airborne precautions, with the patient in a negative-pressure room and staff wearing a fit-tested N95 respirator. These infections are the classic exam examples for airborne transmission.
How soon should HIV post-exposure prophylaxis start after a needle-stick injury?
HIV post-exposure prophylaxis should start as early as possible, ideally within two hours of exposure, and is generally not useful after 72 hours. Delays reduce its effectiveness, so the decision is made quickly while source testing proceeds.
Why is soap and water preferred for Clostridioides difficile?
Alcohol-based hand rub does not reliably kill Clostridioides difficile spores, so washing with soap and water is preferred when the organism is suspected or confirmed. This is why hospitals ask staff to wash rather than rub after contact with patients who have C difficile infection.
What is the difference between disinfection and sterilisation?
Sterilisation destroys all microorganisms including bacterial spores, for example by autoclaving, and it is required for surgical instruments. Disinfection reduces microbial load and is used for surfaces and heat-sensitive equipment, using agents such as glutaraldehyde or hypochlorite.