Healthcare-Assocoated Infections

Question 0

Pseudomonas

Answer 0

Not normally dangerous

A danger for burn victims

Question 1

Iatrogenic infection

Answer 1

Directly caused by medical intervention

Eg: surgery, inserting catheter, drip

Question 2

Antibiotic-associated disease

Answer 2

Diarrhea - clostridium difficile

Colonization by antimicrobial-resistant microbes

Question 3

Staph epidermis

Answer 3

Not normally dangerous
Dangerous is enters bloodstream,
Attaches to an artificial heart valve
This leads to endocarditis

Question 4

Why does staph epidermis attach to artificial heart valves?

Answer 4

Has an adhesin that can link to plastic

Question 6

Example of how trauma can lead to infection

Answer 6

A car accident victim has fomites from the road embedded in their flesh
Fomites have clostridium perfringens on them
Leads to gas gangrene

Question 7

Why are patients encouraged to cough and move around after surgery?

Answer 7

Anaesthetic inhibits mucocilliary elevator.

Move mucus out of airways

Question 8

Nosocomial infection

Answer 8

An infection acquired in associated with a healthcare environment

Question 9

Prevalence of nosocomial infections

Answer 9

Around 5% of Australians have a nosocomial infection at any one time
In Australia, ~150,000 cases/year, ~7000 deaths/year

Question 10

Microbes associated with contaminated air-conditioning systems

Answer 10

Aspergillus (a type of mould)

Mycobacterium

Question 11

Bacteria associated with contaminated water systems

Answer 11

Pseudomonas
Serratia
Legionella
Mycobacteria

Question 12

Bacteria associated with contaminated food

Answer 12

Campylobacter

Salmonella

Question 13

Chain of infection
1) 
2)
3)
4)
5)

Answer 13

1) Pathogen
2) Source
3) Transmission
4) Entry
5) Host

Question 14

Common sources of infection

Answer 14

Patients, staff, visitors, fomites

Endogenous flora, infectious pathogens

Question 15

Methods of transmisison

Answer 15

Vehicle transmission - Contaminated food, water, drugs, blood, body fluids

Vector transmission - Mosquitoes, flies, rats, vermin

DIrect transmission - Direct person-person transmission

Indirect transmission - Surgical instruments, needles, blood transfusions, fomites

Airborne transmission

Question 16

Examples of endogenous pathogens

Answer 16

Gram-negative bacteria colonise URT - EG: Klebsiella

Vancomycin-resistant enterococci endogenous to gut

Question 17

Common viral epidemics in hospitals

Answer 17

Rotavirus
Norovirus
Varicella zoster
Influenza

Question 18

Least serious HCAIs

Answer 18

Urinary tract infections

Question 19

Most serious HCAIs

Answer 19

Surgical wound infections

Question 20

Serious HCAIs

Answer 20

Lower respiratory tract infections, skin infections, blood infections

Question 21

Bacteria associated with urinary tract HPAIs

Answer 21

Gram negative

Question 22

Bacteria associated with surgical wound HPAIs

Answer 22

Gram positive

Question 23

Bacteria associated with HPAIs of LRT, skin, blood

Answer 23

Both Gram positive and negative

Question 24

Most common HPAIs

Answer 24

Urinary tract infections

Question 25

Second most common HPAIs

Answer 25

Surgical wound infections

Question 26

Hospital-associated VRE

Answer 26

Enterococcus faecalis, Enterococcus faecium

Question 27

Spore-forming bacterial HCAI

Answer 27

Clostridium difficile

Question 28

Features of Clostridium dificile

Answer 28

Spore-forming Anaerobic Gram-positive rod Resistant to alcohol hand wash - need to be washed off with soap and water

Question 29

Normal adult carriage rate in gut of Clostridium dificile

Answer 29

~3%

Question 30

How does Clostridium dificile colonise the gut?

Answer 30

Broad spectrum antibiotic treatment disrupts normal gut flora C. dificile overgrows Results in a spectrum of conditions from diarrhoea to pseudomembranous colitis

Question 31

Exotoxins that cause damage in C. dificile infection

Answer 31

Toxin A - Enterotoxin - Fluid production and mucosal damage | Toxin B - Cytopathic toxin - Ulceration

Question 32

Symptoms of C. dificile infection

Answer 32

Abdominal cramps, watery or bloody diarrhoea

Question 33

Risk factors contributing to C. dificile infection

Answer 33

Advanced age, admission to ICU, severe underlying disease, prolonged hospital stay, use of antacids, recent surgery, placement of a naso-gastric tube

Question 34

Features of staphylococcaceae

Answer 34

Gram positive cocci Facultative anareobes Non-motile Normal flora of URT, nose, skin, vagina, intestine

Question 35

Pathogenesis of S. aureus

Answer 35

``` Can multiply and spread rapidly in tissues Exfoliative toxins Enterotoxins Haemolysins Lipases Proteases DNAses Leukocidins Protein A Beta-lactamase ```

Question 36

Features of S. aureus that facilitate infection

Answer 36

Survives well in the environment (drying, etc) Produces adhesins allowing colonisation Forms biofilms

Question 37

Important conditions caused by S. aureus

Answer 37

Osteomyelitis Endocarditis Haematogenous spread

Question 38

Main antibiotic used to treat MRSA

Answer 38

Vancomycin

Question 39

Features of enterococci

Answer 39

Gram positive cocci Commensal organisms found in the GIT Survive well in the environment

Question 40

Enterococcal nosocomial infections

Answer 40

E. faecalis, E. faecium

Question 41

Enterococcal innate antimicrobial resistances

Answer 41

Penicillins Cephalosporins Aminoglycosides

Question 42

Enterococcal acquired antimicrobial resistances

Answer 42

Glycopeptides (EG: Vancomysin) - common