Healthcare Acquired Infections

Question 1

Define a healthcare acquired infection?

Answer 1

One that arises >48hrs post admission or <48 hours post-discharge
A bit arbitrary

Question 2

What are the msot common sites for HAIs and what causes them?

Answer 2

UTIs - Catheters
Surgical Sites
Resp Infection - A lot associated with intubation
Bloodstream - Related to central lines
GI
Skin/soft tissue

Question 3

What methods do we have to kill off pathogens?

Answer 3

1) Cleaning
2) Disinfection
3) Sterilisation

Question 4

How does cleaning work?

Answer 4

Physical removal of organic material with detergent and water (then allowed to dry)
Used for low risk objects that make intact skin contact like stethoscopes and mattresses

Question 5

How does Disinfection work?

Answer 5

Either by heat (Pasteurisation or boiling) OR Chemical (e.g. alcohol & Chlorhexidine).

Used for medium risk items that make mucous membrane contact e.g. vaginal speculae, endoscopes an bedpans

Question 6

How does sterilisation work?

Answer 6

Destroys all microbes an spores, several methods:

• Hot air Oven
• Autoclave (high pressure steam)
• Gas (Ethylene Dioxide)
• Ionising Radiation

Used for high risk items like surgical instruments

Question 7

Define an outbreak?

Answer 7

2 or more cases linked in time and place. Important to confirm that its the same strain with typing e.g. serotyping for viruses

Question 8

What control measures can we use to prevent spread of an outbreak?

Answer 8

• Single rooms
• Cohorting infected patients
• Ward Closure
• Reinforce IPC measures
• Staff exclusion
• Staff decolonisation

Question 9

When would we exclude certain staff from patients?

Answer 9

if they’re not immune e,g. a VZV outbreak

If they’re colonised e.g. with MRSA

Question 10

What is the major HAI?

Answer 10

CLostridium Difficile. The most common type of Antibiotic Associated Diarrhoea (AAD)

Question 11

How do you catch C. Diff?

Answer 11

Can be endogenous (commensal in the patients gut) or exogenous (picked up from the environment).

Usually infection is triggered by antibiotic use that kills off the commensal gut flora, especially:

• Cephalosporins
• Co-amoxiclav
• Ceftriaxone & other quinalones
• Clindamycin

Question 12

How does a C.Diff infection present?

Answer 12

• Diarrhoea
• Special Odour of their faeces
• Abdo pain, pyrexia & Leucocytosis
• Pseudomembranous colitis

Question 13

How do we treat a C. Diff infection?

Answer 13

Stop predisposing Abx if possible
Only treat symptomatic patients:
- Oral Metronidazole
- Oral Vancomycin if severe or metro fails
- Oral Fidaxomicin for relapses

Question 14

Give some examples of other HAIs and mode of transmission?

Answer 14

Droplet - TB or Neisseria Meningitidis
Direct - Staph Aureus
Faecal-Oral - Salmonella or C. Diff
Penetrating injury - Group A Strep & Viruses