Healthcare associated infections

Question 1

What is an infection?

Answer 1

deposition and multiplication of bacteria and other micro-organsisms in tissue or on surfaces of the body with an associated tissue reaction

Question 2

When does colonisation occur?

Answer 2

if the response of the host is slight or absent

Question 3

What are the different sources of infection?

Answer 3

endogenous = caused by hosts own resident organisms

exogenous = caused by organisms foreign to the host

Question 4

What are the different modes of transmission of an infection?

Answer 4

airborne 
faecal -oral
contact
blood borne 
injection / inoculation 
sexual

Question 5

What are some examples of host vulnerability?

Answer 5

extremes of ages 
immunocompromised
drug therapy 
invasive devices
pregnancy 
underlying disease 
nutritional state 
trauma

Question 6

What are some local signs of infection?

Answer 6

erythema 
swelling 
pain 
oedema 
purulent discharge 
heat

Question 7

What are systemic signs of infection?

Answer 7

sepsis

• fever or hypothermia
• rigor
• hypotension
• tachycardia
• raised WCC and CRP
• increased serum lactate

Question 8

What are healthcare associated infections?

Answer 8

any infection acquires as a result of accessing healthcare

- could include acute hospital, rehabilitation facility, nursing or residential home

Question 9

How common are healthcare associated infections?

Answer 9

at any one time 10% of patients will have them
risks vary according to the kind of setting e.g. ICU, type of patient

costs the NHS £1 billion

Question 10

What are some different types of infections?

Answer 10

pneumonia
urinary infection 
surgical site infection 
gastroenteritis
bloodstream infection

Question 11

Are HCAI preventable?

Answer 11

studies suggest 15% are preventable
predominantly exogenous
predominantly device associated

Question 12

Why are HCAI a particular problem now?

Answer 12

vulnerable patients:

• extremes of life
• complex high tech treatments

use of antibiotics
- resistance means we are starting to run out

Question 13

What does the health and social act of 2008 state?

Answer 13

all NHS trusts must register with care quality commission
- meet legal requirements, NHS trusts must ensure that patients, workers and others are protected agains the identifiable risks of acquiring an HCAI
CQC conduct unannounced inspections

Question 14

What are the major current organisms of concern?

Answer 14

MRSA
c diff
MDR acinetobacter
vancomycin resistant enterococci 
multiply resistance enterobacteriaceae 
pseudomonas aeruginosa from water sources 
mycobacterium tb

Question 15

What is MRSA?

Answer 15

Meticillin resistant staphylococcus aureus

• common bacteria carriedby approx 30% pop
• resistant to flucloxacillin
• causes range of infections - some trivial, some serious
• often colonises without causing infection

Question 16

What can MRSA cause?

Answer 16

skin infections 
chest infections 
endocarditis 
bone infection 
bacteraemia
death

Question 17

Why does MRSA cause an infection?

Answer 17

about 30% of people carry MRSA
Cross infection in community and hospitals
antibiotic misuse
patients not screened

Question 18

What can be done to prevent MRSA infections occurring?

Answer 18

nasal swab
groin swab
wounds, urine, line sites, sputum

investigations of acquisitions to extract learning
targets set locally on number of blood stream infections

Question 19

What is C. diff?

Answer 19

anaerobic gram +ve bacilli 
lives in the gut 
produces spores
resists drying 
resists abx 
produces toxins 
toxins produce diarrhoea

Question 20

What does C.diff cause?

Answer 20

watery diarrhoea
abdominal pain 
pseudomembranous colitis
dehydration 
bowel perforation 
death

Question 21

Why is C. diff important?

Answer 21

human costs:

• morbidity and mortality
• 16/17 12840 cases
• costs healthcare an estimated £4500-9000

Question 22

Why does C. diff occur?

Answer 22

antimicrobials prescribed for infection
colonisation due to cross infection
overgrowth of the bacteria in the gut
toxin causes bowel damage

Question 23

What is the protocol for patients with C.diff?

Answer 23

1) stop abx if possible
2) start treatment
3) monitor fluids
4) specialist review
5) terminal clean when better
6) ensure discharge info given

Question 24

What are the treatments for c.diff?

Answer 24

mainly focussed on drugs which kill c. diff

• metronidazole
• oral vancomycin
• fidaxomicin

Question 25

What is a new treatment for c.diff?

Answer 25

donor faecal transplant

Question 26

What is enterobacteriaceae?

Answer 26

large fam of bacteria
live harmlessly in the bowel of healthy individuals
can be pathogens and cause disease

Question 27

What bacteria are part of the enterobacteriaceae family?

Answer 27

common bacteria isolated in a healthcare setting:

• e.coli
• klebsiella
• enterobacter
• proteus
• salmonella
• serratia
• citrobacter

Question 28

What infections can be caused by enterobacteriaceae?

Answer 28

wide range of infections:

• UTI (70-90%)
• intraabdominal infections
• pneumonia
• bacterial meningitis
• septic arthritis
• osteomyelitis
• endocarditis
• bacteraemia

Question 29

How was penicillin discovered?

Answer 29

it was noted that it inhibits the growth of staphylococcus

Question 30

What are carbapenems used for?

Answer 30

meropenem, ertapenem, imipenem, doripenem

often used as a last resort for treating infections caused by antibodies resistant enterobacteriaceae

Question 31

What are carbapenemases?

Answer 31

enzymes produced by bacteria that destroy carbapenem abx

made by small but growing number of enterobacteriaceae strains

Question 32

What are the different type carbapenemases?

Answer 32

KPC, OXA-48, NDM, VIM enzymes

Question 33

What are examples of carbapenem producing organisms?

Answer 33

acinetobacter baumannii
pseudomonas aeruginosa
stenotrophomonas maltophilia

Question 34

What are carbapenem producing enterobacteriaceae?

Answer 34

klebsiella pneumoniae
escherichia coli
enterobacter cloacae

Question 35

What is colistin resistance in china?

Answer 35

emergence of plasmid-mediated colistin resistance mechanism MCR-1 in animals and humans in china
- highest users of colistin in agriculture

Question 36

What are the principles for controlling multi drug resistant gram negative bacteria?

Answer 36

screening - complex need to screen stool/rectal swabs, culture versus molecular 
isolation 
hand hygiene
decontamination of the environment 
antibiotic restriction

Question 37

What does CPE stand for?

Answer 37

carbapenemase-producing Enterobacteriaceae

Question 38

What is acinetobacter baumannii?

Answer 38

gram negative bacillus
multi-drug resistant
- colistin and tigecycline as reserve agents
- moving towards pan -resistance
adapted to hospital environment
- forms biofilms on equipment and wounds
- able to withstand desiccation
associated with
- wound colonisation and ventilator associated pneumonia
- returning military personnel from iraq and afghanistan

Question 39

Why is the value of screening for MDR acinetobacter controversial?

Answer 39

environmental screening can be useful to detect persistent environmental contamination
cleaning and decontamination - some evidence for hydrogen peroxide vapour

Question 40

What cleaning control measures are there for MDR acinetobacter?

Answer 40

environmental screening
enhanced cleaning
decant and deep clean
use of hydrogen peroxide
implement rapid cleaning team
commence inter-theatre trip terminal cleaning
embed an assurance framework for cleaning theatres

Question 41

What is pseudomonas aeruginosa?

Answer 41

widespread in the environment - soil, water, moist environment

• usually colonises hosp and domestic sink taps, traps and drains
• humans may be colonised at moist sites
• highly opportunistic pathogen
• outbreaks in burns are freq reported from water sources
• water transmission has become a matter of urgent concern