01Role and principlesWho benefits and the main preventive aims.
Healthcare-associated infection arises from interaction between vulnerable hosts, invasive devices, antimicrobial pressure, staff and visitor contact and the care environment. Prevention depends on reliable everyday practice, not isolation alone. Device necessity, aseptic technique, hand hygiene, cleaning and antimicrobial stewardship interrupt different parts of the chain.
Transmission-based precautions add controls for the route. Contact precautions address hands and contaminated surfaces; droplet precautions address larger respiratory particles at close range; airborne precautions require appropriate rooms and respiratory protective equipment for designated pathogens or aerosol-generating procedures. Local infection-prevention teams translate current national guidance into available facilities.
Isolation decisions require daily review. Delay can expose others, but unnecessary isolation reduces observation, rehabilitation and communication. Explain the reason and likely duration, ensure diagnostic and emergency care continue, and provide accessible information to relatives and staff. Colonisation status should follow the patient across transitions without becoming a substitute for clinical diagnosis.
Key points
- Standard infection-control precautions apply to every patient: hand hygiene, respiratory etiquette, sharps safety, environmental cleaning and risk-based protective equipment.
- Add contact, droplet or airborne precautions from the suspected route and procedure, then refine when the diagnosis and infectious period are clearer.
- A single room is a clinical intervention with communication, mobility and psychological harms; review the indication and stop isolation when national and local criteria are no longer met.
- Diarrhoea after antibiotics or healthcare exposure raises Clostridioides difficile: isolate, use soap and water after contact and obtain the appropriate unformed stool sample.
- Screening results may represent colonisation rather than infection. Colonisation may require organism- and setting-specific transmission precautions, but it does not justify antibiotics unless an invasive syndrome exists.
- Investigate clusters through infection prevention and UKHSA channels, preserving patient confidentiality while recording exposures, movement and staff or visitor links.
02Assessment and patient selectionRisk features, eligibility and important cautions.
New infection follows admission, procedure, device or recent healthcare exposure and involves a plausible site or organism rather than simple temporal coincidence.
Acute diarrhoea, draining wounds, uncontrolled secretions or resistant-organism carriage creates hand and environmental contamination risk requiring prompt contact measures.
Possible pulmonary tuberculosis, measles, varicella or another nationally designated airborne disease requires rapid room, mask and staff-exposure planning.
Two or more epidemiologically linked cases, unusual resistance or staff illness suggests transmission beyond an isolated event and requires infection-prevention investigation.
03Baseline assessmentMeasurements that guide the plan and track progress.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Clinical syndrome and exposure timelineFirst step - Why
- Determine whether infection is present, where it began and which contacts or procedures are relevant.
- Interpretation and limitations
- Colonisation and contamination must be separated from symptomatic infection. Device days, ward moves, procedures and antimicrobial exposure improve attribution.
- 02
Site-specific microbiology - Why
- Identify pathogen and resistance and support cohort or contact decisions.
- Interpretation and limitations
- Collect only clinically appropriate specimens with good technique. Screening swabs answer carriage questions and should not be interpreted as invasive infection.
- 03
Clostridioides difficile stool testing - Why
- Assess compatible new unformed diarrhoea after healthcare or antimicrobial exposure.
- Interpretation and limitations
- Test only an appropriate diarrhoeal specimen and interpret multi-step toxin or molecular algorithms with symptoms; carriage without toxin-mediated disease can occur.
- 04
Respiratory molecular testing - Why
- Identify transmissible respiratory viruses when the result changes isolation, treatment or outbreak action.
- Interpretation and limitations
- Sampling timing affects sensitivity, and a negative result may not immediately remove precautions when epidemiology and symptoms remain highly suggestive.
- 05
Typing and epidemiological linkage - Why
- Determine whether isolates and cases form a transmission cluster.
- Interpretation and limitations
- Whole-genome or other typing supports but does not replace person-place-time investigation, since genetically related organisms may circulate widely.
04InterventionsLifestyle, treatment and escalation options.
01New transmission riskInstitute proportionate precautionsFirst stepSymptoms, exposure or microbiology suggests contact, droplet or airborne spread.+
- 1Perform immediate risk assessment, place the patient appropriately, display clear precautions, provide required PPE and inform infection prevention without delaying urgent care.
- 2Obtain targeted diagnostic samples, document onset and movement history and identify high-risk roommates, staff procedures or visitors.
- 3Review precautions when results and clinical course clarify pathogen, infectious period and control criteria; communicate status at every transfer.
02Device-associated infectionRemove avoidable risk and investigate sourceA vascular, urinary, respiratory or surgical device is linked to new infection.+
- 1Assess whether the device is still essential, examine the site and obtain paired or source samples according to the syndrome.
- 2Start clinically indicated treatment and arrange removal, exchange or procedural source control when biofilm or obstruction makes retention unsafe.
- 3Record device days, insertion practice and learning through the appropriate surveillance and governance route.
03Possible outbreakMove from individual to population controlLinked cases or an unusual organism suggest transmission within a care setting.+
- 1Notify infection prevention, construct a case definition and line list, preserve isolates and clarify shared locations, staff, equipment and procedures.
- 2Strengthen hand hygiene, cleaning, cohorting, ventilation or admissions controls according to route while maintaining essential patient care.
- 3Coordinate communication, UKHSA notification where indicated, staff advice and criteria for declaring the outbreak controlled.
05Targets, monitoring and follow-upResponse, safety and longer-term review.
- Review isolation indication, transmission route, symptom onset and planned discontinuation criteria every day on the ward round.
- Audit hand hygiene, PPE use, environmental cleaning, device necessity and antimicrobial review as separate controls rather than assuming a closed door is sufficient.
- Track new linked cases, ward movement, staff illness and laboratory typing through a protected outbreak line list.
- Monitor hydration, delirium, mobility, pressure risk, communication and emotional wellbeing because isolation can itself cause preventable harm.
- Ensure discharge and transfer documents state colonisation or infection status, required precautions and pending public-health or laboratory actions accurately.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
Colonisation is not infection
A resistant organism on screening affects transmission precautions and future empirical risk but does not itself justify antimicrobial treatment.
Soap matters for spores
Alcohol hand rub does not reliably remove C difficile spores; use soap and water after caring for a patient with suspected or confirmed infection.
PPE follows the task
The same patient may require different protection for routine contact and an aerosol-generating procedure; risk is determined by route and activity.
Isolation has side effects
Reduced contact and mobility can worsen delirium, pressure injury and deconditioning, so teams must deliberately preserve observation and rehabilitation.
07Common pitfallsFrequent interpretation and management errors.
- 01
Using antibiotics to treat a colonisation result without an invasive syndrome.
- 02
Entering isolation without the task-specific PPE or hand-hygiene plan.
- 03
Leaving precautions indefinitely because no one owns the review decision.
- 04
Delaying imaging, resuscitation or mental-health care solely because a patient is isolated.
- 05
Failing to recognise linked cases across ward moves and staff contacts.