W6 - Hospital acquired infections

Question 1

What are HAI?

Answer 1

Hospital acquired infections

Question 2

how common are HAI in the UK?

Answer 2

about 8% of all hospital admissions

Question 3

What is the most common syndrome of HAI?

A) Bloodstream infections
B) Norovirus gastroenteritis
C) HAP
D) UTI with catheter
E) Clostridium difficile

Answer 3

C - HAP (25%)

D - UTI (17%)
A - bloodstream (14%)
B - gastrointestinal (8%)

Question 4

antibiotic associated diarrhoea is usually due to which organism?

Answer 4

clostridium difficile

Question 5

Where do organisms in a hospital come from?

Answer 5

Before occupied – environmental
Once occupied – come from people (patients
and staff)* and things (fomites) in the hospital

Typically from human-associated microbes, especially skin-associated ones

Question 6

How do organisms move with a new patient admitted to the room?

Answer 6

1st day => from surfaces to the patient
2nd day onwards => from patient to the room

Net result => increased microbial diversity of the surfaces in the room

Question 7

C diff:

• Gram stain
• Transmission
• Route of transmission
• Toxin production and end result

Answer 7

C diff:

• G+ spore-forming anaerobe
• spores transmissible, contaminate environment, persist for long periods
• person-to-person faecal-oral route
• ingested spores germinate in the gut
• Toxins A and toxins B => diarrhoea, colitis

Question 8

How severe are symptoms of C diff infection?

Answer 8

range from mild diarrhoea => severe colitis
- dehydration, pseudomembranous colitis, perforation

Question 9

In what populations is c diff attack rates higher?

Answer 9

1. older
2. debilitated
3. antibiotic-treated

Question 10

Describe 1st line, 2nd line, and non-pharmacological treatment for c diff infection

Answer 10

oral vancomycin (1st line for all c diff)

fidaxomicin (2nd line for all c diff, good for recurrent c diff – lowers recurrence)

non drug approaches: faecal transfer

Question 11

What bacteria is most responsible for community acquired UTI? How does that compare to hospital acquired UTIs?

Answer 11

Community => E coli (82%)
Hospital => E coli (55%), Klebsiella (13%), Proteus (12%)

Question 12

What 3 groups of factors influence surgical site infection (SSI) risk?

Answer 12

1. Wound environment
2. Host defence
3. Pathogens

Question 13

The pathogens that tend to cause the most HAI tend to be G+ OR G- pathogens? Name 3 and their relative frequencies of infection?

Why are they more so implicated in HAI?

Answer 13

G-

E coli < Klebsiella < Enterobacter, etc.

b/c they have the most resistance mechanisms