37 Infection control Flashcards
HAI
Which organisms are most commonly implicated?
UTI - e. coli K penumoniae Staph saprophyticus Enterococcus
SSTI -
Staphylococci - MRSA
Enterococci
E. coli
Pneumonia -
Staph aureus
Pseudomonas
GI -
C. difficile
What are sources of HAI?
Route of spread same as community - airborne, droplet, direct, fomite
Staff
Visitors
Fomites
IV lines
Catheter
Surgical prosthesis
Wound infections
Why might certain patients be at higher risk for HAI?
Lacking immunity - unvaccinated
Underlying diseases - e.g diabetes, HIV
Medications - antibiotic disrupt flora, steroids lower host defences
Trauma - disturbance to natural host barrier
What increases risk of post-operative infection?
Length of pre-operative stay
Presence of intercurrent infection
Length of operation
Nature of operation
Presence foreign bodies e.g shunts/ protheses
State of tissue - vascular supply/ drainage of tissues
What are general principles for reducing HAI?
Reduce risk from environment - sterile equipment etc
Interruption of infection chain - ventilation systems, isolate patient, hand washing
Ensure host ability to resist infection - care of catheters/ IV lines, immunisation, prophylactic antibiotics
What is role of infection control team?
Surveillance of hospital infection
Establish monitoring of polices e.g disinfectant policy, catheter care policy
Investigation of outbreaks
Environmental cleaning/ disinfection/ disposal of waste
What information is used for surveillance?
Lab reports - key organisms e.g MRSA
Ward rounds - regular review of certain patients e.g C. DIff
Investigation of outbreak requires combination of microbiological and epidemiological information.
What do we need to know?
Who is infected/ how many
When were they admitted
Where were they admitted - all on same ward?
When did they develop infection
What is common exposure/ treatment?
Identify pathogen - depends on patient symptoms
What are steps in outbreak investigation?
Identify outbreak -
- two or more cases linked in time/ place
- single case of rare disease e.g VHF
- greater infection rate compared to usual background rate
Identify organism - should have common strain. Perform typing
Declare outbreak
- agree case definition
- hypothesis generation
Contain outbreak and prevent further spread
Identify cause/ source of outbreak
Review investigation at conclusion - identify if could be prevented
Identifying organism is important for epidemiological purposes.
What are methods of identifying?
Antibiotic susceptibility pattern - e.g VRE
DNA whole genome sequencing
DNA plasmid sequencing
Restriction fragment length polymorphism analysis - RFLP. Ribosome sequences highly conserved in species, can be used to identify bacteria by ribosome analyisis e.g 16S RNA
Decontamination
Physical cleaning must first be performed to remove dirt, and reduce bacterial load. Dirt can also protect microbes from sterilisation/ disinfection.
What is sterilisation?
What is disinfection?
Sterilisation - kill/ remove all viable organisms
Disinfection - removes most pathogens. Chemicals kill pathogens, but may not kill viruses/ spores. Boiling may not kill every bacteria, but will reduce bacterial load significantly - pasteurisation
Pasteurisation heats fluids to levels to kill most viable microbes, without affecting taste e.g 65 deg for 30 mins
What are techniques for sterilisation?
Heat - autoclave (with steam)
Radiation - gamma/ ultraviolet
Filtration
Chemicals - liquid/ gas
Freezing/ ultrasound/ electricity are techniques employed, with variable evidence of efficacy
Prions are extremely resistant to all sterilisation techniques. Requires high heat/ pressure, which living tissue would not survive
Most devices are not inert, and induce local immune response.
How does this increase risk of infection?
Local immune response can deplete complement/ neutrophils, and cause minor tissue damage.
Increasing risk of infection
Devices do not have blood supply, so bacteria can multiply on device, and difficult for immune system to clear them. Means device may need removed
Patient has long term TPN through CVC.
Which has minimal role in prevention of CVC-associated infection?
Antibiotic-impregnated CVC Antimicrobial CVC locks CVC fixation CVC hub disinfection policy CVC sub-cutaneous tunnelled line
Antibiotic impregnated CVC - do not retain antimicrobial activity beyond a few weeks.
So can be useful in ITU, but no use in long term CVC line in this case
How does Staphylococcus aureus gain resistance to methicillin?
Acquisition of mec A gene
mec A encodes for penicillin-binding protein PBP2a, which has low affinity for penicillins
What is infection control procedure for positive MRSA?
Isolation
Hand hygiene
Disposable gloves/ aprons
Cleaning/ decontamination - terminal clean
If for operation, operate at end of list
What is treatment for MRSA deocolonisation?
Bactroban - 2% muipirocin TDS for 5 days
Octenisan body wash/ shampoo - OD for 5 days
Who should be screened for Carbapenemase-producing Enterobacteriaceae CPE?
How many swabs are required?
Inpatient in hospital abroad in last 12 months
Inpatient in UK with hospitals with known outbreak
Previously colonised with CPE
Stool/ rectal/ wound swabs
Require three sets of swabs 48 hours apart, before can be declared CPE free
How to manage patient with CPE infection?
Isolate
Enviromental cleaning/ decontamination
Treatment with polymyxin (colistin) with either tigecycline or an aminoglycoside
Blood agar incubated aerobically, has large flat colonised, with sweet caramel odour, and serrated edges. Pale yellow colonies seen on MacConkey agar. Isolate is oxidase positive.
What is the organism?
Pseudomonas
For organisms to spread, it requires chain of infection to be in tact. What are the six links?
Causative agent
Infectious reservoir
Path of exit - how it leaves reservoir
Mode of transmission
Path of entry
Susceptible host
What are five moments of hand hygiene?
Before touching patients
Before aseptic procedures
After body fluid exposure
After touching patient
After touching patient surroundings
Patient with neck stiffness, photophobia, fever, non-purpuric blanching rash.
What is infection control procedure?
Standard precaution, admit to open bay
Standard precaution, isolate patient in positive pressure ventilated room with HEPA filtered air flow
Standard precautions, isolated patient in negative pressure ventilated room, all healthcare workers should wear respirator while nursing patient
Standard precautions, isolated patient in single room, all healthcare workers should wear surgical mask while nursing patient
Standard precautions, isolated patient in single room, all healthcare workers should wear surgical mask while nursing patient
Likely Neisseria meningitides - droplet transmission
26 year old man from India presents with fever, cough, haemoptysis, weight loss.
What is infection control procedure?
Standard precaution, admit to open bay
Standard precaution, isolate patient in positive pressure ventilated room with HEPA filtered air flow
Standard precautions, isolated patient in negative pressure ventilated room, all healthcare workers should wear respirator while nursing patient
Standard precautions, isolated patient in single room, all healthcare workers should wear surgical mask while nursing patient
Standard precautions, isolated patient in negative pressure ventilated room, all healthcare workers should wear respirator while nursing patient
likely pulmonary TB - airborne transmission
Wear FFP2/FFP3 mask capable of filtering particles 1-5 microns
50 year old oncology patient with cellulitis. Admitted for antibiotics and GSCF. Finished chemotherapy 1 week ago.
What is infection control procedure?
Standard precaution, admit to open bay
Standard precaution, isolate patient in positive pressure ventilated room with HEPA filtered air flow
Standard precautions, isolated patient in negative pressure ventilated room, all healthcare workers should wear respirator while nursing patient
Standard precautions, isolated patient in single room, all healthcare workers should wear surgical mask while nursing patient
Standard precaution, isolate patient in positive pressure ventilated room with HEPA filtered air flow
Likely neutropenic sepsis
Airflow directed away from room, to prevents infections entering room
What is antimicrobial stewardship?
Using right antibiotic, at right time, via right route, for right duration
Give optimal treatment to patient, as well as preserving antibiotics for future.
What are components of antimicrobial stewardship?
Can be restrictive - to prevent clinicians using antimicrobials
Can be persuasive - nudges to help clinicians use correct antimicrobial
AMS dedicated team required - microbiologist/ pharmacist
Antimicrobial guidelines - formulary restrictions, and compulsory order forms for restricted antimicrobials
AMS ward rounds
Monitor of antimicrobial resistance
Monitoring of antimicrobial use
Liaison between AMS team and clinical governance committee
What legal acts provides legal requirements for NHS trusts to ensure safety of healthcare workers?
Who ensures that infection prevention and control meets standards?
The Health Act 2008 Prevention and Control of Infections
2015 Hygiene Code by CQC introduced to reduce HAI
CQC regulate and inspect services, and trusts must demonstrate compliance
What is a care bundle?
3-5 interventions, which combined together, can help improve patient outcome
e.g catheter care
MRSA bacteraemia and death would be deemed a serious untoward incident (SUI)
What should be performed to identify why it occurred?
root cause analysis to identify why it happened, and what can be learned.
what happened who it happened to when it happened where it happened how it happened - what when wrong why it happened - what contributed to this
Outcomes can help guide immediate improvement
Surgical team contact you to say rust on instruments, and no other sets available. What is best option?
Cancel operation
Continue procedure
Return set to sterile service for reprocessing
Wipe rust off with disinfectant and use
Return set to sterile service for reprocessing
Surgical tools are coated to prevent rusting. If rust present, then means protective layer damaged, and may not be sterilised correctly.
Patient colonised with CPE discharged from side room.
What type of clean would you recommend?
deep clean Deep clean with additional technology - steam/ UV/ HPV Discharge clean Increase frequency clean routine clean
Deep clean with additional technology - steam/ UV/ HPV
Testing rinse water in endocscopy shows 12 CFUs of mycobacterium species.
What is next action?
Change filters and decontaminate
Change filters and retest next quarter
Nothing
Wait for next quarterly results before acting
Take machine out of service, sanitise pipework and retest
Take machine out of service, sanitise pipework and retest
Environmental mycobacterium can cause opportunistic infection
