Skip to textbook content
Doctor’s PassportTextbook
TopicsAll topics

Loading topic navigation…

Textbook navigation
TopicsAll topics

Loading topic navigation…
← Infectious diseases, microbiology and sexual health indexChapter sections
Role and principlesAssessment and patient selectionBaseline assessmentInterventionsTargets, monitoring and follow-upSpecial situationsCommon pitfallsQuestionsSources
Full textbook9 sectionsOpen only what you need
Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.

Healthcare-associated infection and isolation

Infectious diseases, microbiology and sexual health · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

RapidFull
!
Time-critical presentation

Isolate promptly and contact infection prevention for suspected high-consequence infection, uncontrolled diarrhoea or vomiting, airborne infection, unexplained cluster, carbapenemase-producing organism or severe respiratory illness with transmission risk. Do not delay resuscitation; use appropriate PPE and minimise exposed staff.

Role and principles

Recognise transmission risk and healthcare-associated infection early, choose proportionate isolation and personal protective equipment, and preserve essential clinical care while preventing spread.

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

Assessment and patient selection

Likely healthcare acquisition

New infection follows admission, procedure, device or recent healthcare exposure and involves a plausible site or organism rather than simple temporal coincidence.

Contact-spread syndromeRed flag

Acute diarrhoea, draining wounds, uncontrolled secretions or resistant-organism carriage creates hand and environmental contamination risk requiring prompt contact measures.

Airborne concernRed flag

Possible pulmonary tuberculosis, measles, varicella or another nationally designated airborne disease requires rapid room, mask and staff-exposure planning.

Possible outbreakRed flag

Two or more epidemiologically linked cases, unusual resistance or staff illness suggests transmission beyond an isolated event and requires infection-prevention investigation.

Baseline assessment

  1. 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.
  2. 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.
  3. 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.
  4. 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.

Interventions

01New transmission riskInstitute proportionate precautionsFirst stepSymptoms, exposure or microbiology suggests contact, droplet or airborne spread.+
  1. 1Perform immediate risk assessment, place the patient appropriately, display clear precautions, provide required PPE and inform infection prevention without delaying urgent care.
  2. 2Obtain targeted diagnostic samples, document onset and movement history and identify high-risk roommates, staff procedures or visitors.
  3. 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.+
  1. 1Assess whether the device is still essential, examine the site and obtain paired or source samples according to the syndrome.

Targets, monitoring and follow-up

  • 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.

Special situations

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.

Common pitfalls

  1. 01

    Using antibiotics to treat a colonisation result without an invasive syndrome.

  2. 02

    Entering isolation without the task-specific PPE or hand-hygiene plan.

  3. 03

    Leaving precautions indefinitely because no one owns the review decision.

  4. 04

    Delaying imaging, resuscitation or mental-health care solely because a patient is isolated.

  5. 05

    Failing to recognise linked cases across ward moves and staff contacts.

Practice

Two practice questions

Your practice draft is saved in this browser.

Question 1 of 2
0 correct
Infectious diseases, microbiology and sexual healthOriginal SBA

C difficile precautions

An inpatient develops new profuse diarrhoea after broad-spectrum antibiotics and C difficile is suspected. Which immediate infection-control action is most appropriate?

Choose one answer, then submit
← Rapid synopsisBack to overviewAll Infectious diseases, microbiology and sexual health topics →
Sources and review status4 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NHS England national infection prevention and control manualStandard and transmission-based precautions for NHS care.
  • UKHSA C difficile guidanceDiagnosis, isolation, hand hygiene and outbreak control recommendations.
  • UKHSA CPE toolkitCarbapenemase-producer screening, precautions and control.
  • NICE NG125 surgical site infectionsNational prevention and treatment principles for healthcare-associated surgical infection.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem · Content changes

Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
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.
    • 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.
    2
    Start 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.+
    1. 1Notify infection prevention, construct a case definition and line list, preserve isolates and clarify shared locations, staff, equipment and procedures.
    2. 2Strengthen hand hygiene, cleaning, cohorting, ventilation or admissions controls according to route while maintaining essential patient care.
    3. 3Coordinate communication, UKHSA notification where indicated, staff advice and criteria for declaring the outbreak controlled.