MICRO: Healthcare associated infections Flashcards
What are HAI?
Healthcare associated infections; they are categorised by organism (1) or by syndrome (2).
(used to be hospital acquired infections)
How common are HAIs in the UK?
- 8%
- 22%
- 40%
- 55%
8% - approximately 8% of patient have a HAI at any one time
List some syndromes of HAI.
List some organisms causing HAI.
How many people die as a result of HAI each year in Europe?
37,000
Which syndromes are these infections associated with?
- MRSA
- C diff
- E coli
- MSSA
- R gram -ve
- Yeast/candida
What are the 3 most common HAI syndromes?
HAP > surgical site infections> UTI > BSI > GI
NB: this may vary with locations/wards.
What % of HAI are made up by C diff and MRSA?
15% of all HAI
Which is the most common syndrome of HAI?
- Bloodstream infections
- Norovirus gastroenteritis
- Hospital acquired pneumonia
- Urinary tract infection with catheter
- Clostridium difficile
HAP
What was the purpose of the Hospital Microbiome Project? What was the result?
Determine where the organisms in hospital were originating - collected samples from surfaces, air, staff and patients. Aimed to determine which parameters were most important.
- 1st day - from surfaces in room to patient
- 2+ days - from the patient to the room, patient’s microbiome takes over patient’s space
Where do organisms in a hospital come from?
Mainly the environment
C. difficile is?
- Gram positive anaerobe
- Gram negative aerobe
- Gram variable coccobacillus
- Gram positive spore-forming anaerobe
- Other not listed
C. difficile is a Gram-positive spore-forming anaerobe that colonises the gut. It produces toxins to have its effect and cause disease.
What causes diarrhoea/colitis in C diff infection?
- Toxinotype III/ Toxins A and B
- Pro-inflammatory
- Cytotoxic
- Enterotoxic
What is the range of symptoms in C difficile?
Mild diarrhoea/asymptomatic –> severe colitis with dehydration, pseudomembraneous colitis and perforation
What is the assessment for antibiotics for C diff infection?
Severe C difficile - oral vancomycin (used to be metronidazole)
What is the use of fidaxomysin?
What is a non-drug management for C difficile?
Faecal transfer
What is the most common UTI in the community and in hospital?
Community - E coli (82%)
Hospital - E coli(55%) but more due to other causes too.
What % of catheters causing UTI become colonised within the first 96 hours?
60%
What 3 groups of factors influence risk for surgical site infection (SSI)?
- Staff, ward, category, day of week
- Host defence, host gender, surgeon gender
- Host defence, wound environment, pathogens
- Virulence of pathogens, antibiotics used, type of suture
- Experience of surgeon closing wound, mask used by theatre staff, music played in theatre
Host defence, wound environment, pathogens
What are the main resistance mechanisms in resistant gram negatives?
- Chromosomal
- Plasmid mediated
(E coli< Klebsiella < Enterobacter etc)
Which 4 infection control strategies are used to reduce HAI?
- Reduce number of bugs (i.e. sterilise, washing, etc.)
- Reduce number of resistance bugs (i.e. screen patients)
- Prioritise side rooms + reduce transmission of bugs (i.e. for fever + rash in ED; for homeless man with cough and abnormal CXR)
- Medical education (i.e. hand cleaning technique)
Key strategies:
- measure infection
- analyse for trends
- feedback and alter practice
- improve infection control and reduce infection
What does this gram stain show?
Gram +ve cocci in clusters = MRSA
What are the implications of MRSA infection?
