Hospital Acquired Infection and Surgical Site infection

Question 1

What is a hospital associated infection?

Answer 1

1. Direct result of treatment or contact in a hospital or healthcare settin
2. As a result of healthcare delivered in community
3. Outside a healthcare setting but are brought in by patients, staff, or visitors and transmitted to others

Question 2

How common are hospital acquired infections?

Answer 2

7-25% of hospital admission are complicated by a noscoiomal infection

Question 3

What can make people at risk of hospital acquired infections?

Answer 3

1. Has been given broad-spectrum antibiotics (e.g. antibiotic resistant organisms, C.diff colitis)
2. Is unwell/immunocompromised (opportunistic infection)
3. Has compromised barriers (indwelling catheter/line, ventilation, surgery)

Question 4

What is the most common associated HAI?

Answer 4

catheter associated UTI (19%)

Question 5

What is another route of infection route in HAI?

Answer 5

• Infections associated with the use of intravascular access devices:
• Includes peripheral, central venous and arterial catheters
• > 60% of bloodstream infections are associated with intravascular devices

Question 6

What organisms are related to intravascular access devices?

Answer 6

1. Staphyloccous epidermis
2. Staphylococcus aureus and MRSA
3. Candidia species
4. Enterococci

Question 7

How common is ventilator associated pneumonia (VAP)?

Answer 7

up to 20% of patients admitted to ICU

Question 8

Why does VAP happen?

Answer 8

occurs as endotracheal tube interferes with protective upper airway reflexes and facilitates micro aspiration

Question 9

What organisms are involved in VAP?

Answer 9

1. Pseudomonas aeruginosa
2. Enterobacterieacia
3. Staph aureus

Question 10

When should you suspect VAP?

Answer 10

if new/persistent infiltrates of CXR plus two or more of purulent sputum, leucocytosis, leukopenia and temperature

Question 11

How can you prevent VAP?

Answer 11

1. reducing colonization (mouthwash, sliver lined endotracheal tubes)
2. nurses at 45 degrees to decrease aspiration risk 3. wean off vent asap

Question 12

How common and lethal are surgical site infections?

Answer 12

• Affects 5% of patients undergoing surgical procedures

- Contributes to >1/3 of post-op deaths

Question 13

What are the common organisms in surgical site infection?

Answer 13

1. Staph aureus
2. Strep pyogenes
3. Enterobacteriaceacae when surgery involves entry to hollow viscera

Question 14

What are the preventative methods for surgical site infection?

Answer 14

1. Hand hygiene
2. Strict asepsis
3. MRSA screening and decolonization
4. Hair removal
5. Peri-operative normothermia
6. Minimally disturbed low adherence/transparent dressings

Question 15

What is c.diff?

Answer 15

Gram positive anaerobic bacillus and most common healthcare-associated pathogen

Question 16

How common is C diff?

Answer 16

Part of colonic flora in 2-5% of healthy adults and 20-40% of hospitalised adults

Question 17

What does c.diff cause disease?

Answer 17

when it converts to a vegetative growth state with production of enterotoxins A and B causing colitis

Question 18

how do antibiotics cause c.diff?

Answer 18

Happens when inhibition by competing colonic flora is lost due to antibiotics exposure

Question 19

What is the presentation for c.diff?

Answer 19

1. Watery diarrhoea
2. Mild to fulminant colitis (pseudomembranous colitis)
3. Ileus
4. Toxic megacolon

Question 20

When do you need to consider c.diff?

Answer 20

in all diarrhoea associated with antibiotic use, esp in marked neutrophilia

Question 21

What is needed for diagnosis of c.diff?

Answer 21

1. Immunoassay for glutamate dehydrogenase (common antigen) detects all strains of C.diff
2. Detection of toxin (toxin immunoassay, toxic gene nucleic acid amplification) distinguishes infection for carriage

Question 22

How do you check for c.diff eradicated?

Answer 22

urea breath test

Question 23

What is the conservative management for c.diff?

Answer 23

SIGHT 
Suspect
Isolate
Gloves and aprons 
Hand wash with soap
Test immediately

Question 24

How do you medicate mild/moderate c.diff?

Answer 24

metronidazole PO

Question 25

How do you medicate severe c.diff WCC>15x10^9/L, or AKI or colitis or temp>38.5) ?

Answer 25

vancomycin PO or fidaxomicin

Question 26

How do you treat non repsonders for c.diff?

Answer 26

high dose vancomycin PO + IV metronidazole, fidaxomicin, IV immunoglobulin (no RCT data)

Question 27

How do you treat reccurent c diff?

Answer 27

1. (weaning) vancomycin
2. fidaxomicin
3. faecal transplantation