3. Hospital Acquired Infections

Question 1

What are examples of organisms that may cause HAI?

Answer 1

MRSA, C. difficile, E.coli, MSSA, R Gram negs, yeasts/Candida

Question 2

What are examples of HAI syndromes?

Answer 2

Catheter associated BSI, urinary catheter associated UTI, surgical site infection, vent associated pneumonia, antibiotic associated diarrhoea

Question 3

What is the prevalence of HAI in the UK?

Answer 3

8%. Varies depending on speciality. Prevalence ranges from 3.5-10.5% in industrialised countries.

Question 4

What is the incidence of HAI in Europe?

Answer 4

4 million per year

Question 5

What are the 5 commonest syndromes of HAI in order?

Answer 5

1. Hospital-acquired PNEUMOMIA, 2. SSI, 3. UTIs, 4. blood stream infections, 5. GI infections

Question 6

What is the Hospital Microbiome Project?

Answer 6

This tried to figure out where the organisms in the hospital came from. 1st day (before occupied) - bugs go from the environment onto the patient. 2+ days - bugs go from the patient outwards.

Question 7

What type of pathogen is C.difficile?

Answer 7

Gram-positive spore-forming anaerobe

Question 8

Why is the prevalence of E.coli bacteraemia increasing?

Answer 8

• There is an increase in cases during the summer which may be due to factors such as dehydration in elderly patients
• It’s possible that the drive to reduce antibiotic use in the community has led to increased rates of invasive disease (bacteraemia)
• The NHS has aimed to prevent Gram-negative bloodstream infections
• 3/4 of E. coli bacteraemia occurs before patients reach hospital

Question 9

What can be done to reduce E. coli bacteraemia?

Answer 9

1. Reducing the numbers of bugs is a good approach (e.g. cleaning the environment, washing hands regularly)
2. Reducing the number of resistant bugs - screen patients for certain organisms (e.g. MRSA, VRE). For some organisms, it is possible to reduce the carriage of those organisms with topical suppression
3. Prioritisation of side rooms - requires risk assessment and taking into account several factors
4. Reducing transmission of bugs: educating staff, cleaning the environment and equipment, reduce the use of broad-spectrum or unnecessary antibiotics, better surfaces to prevent adherence of bacteria.

Question 10

What are main contributors to SSIs?

Answer 10

Host defence, wound environment, pathogens

Question 11

Why is carbapenemase-producing Enterobacteriaceae a problem?

Answer 11

• This is a problem because carbapenems are our LAST RESORT antibiotic. It is difficult to treat so it has a HIGH MORTALITY.
• We do NOT know the optimal management for CPE bacteraemia or invasive infection
• We also don’t know the pharmacokinetics and pharmacodynamics (e.g. how long to give the drug for)
• There was a CPE outbreak in 2014-2015
• Areas that use a lot of carbapenems are at increased risk of CPE outbreaks

Question 12

Why are HAIs increasing?

Answer 12

We do more invasive procedures; prosthetic and implantable devices; obesity; diabetes; extremes of age; immunosuppression; emerging organisms and resistance

Question 13

How can we manage the hospital environment to reduce the risk of HAIs?

Answer 13

1. Environmental hygiene and cleaning
2. Control of environmental sources (e.g. water)
3. Building works (aspergillus)
4. Negative pressure isolation - protect others from an infectious patient with airborne infection
5. Positive pressure isolation - protection of transplant patients from organisms outside the room