Hospital Aquired Infetcions + Infection Prevention

Question 1

What is a hospital acquired infection?

Answer 1

An infection acquired in a hospital with onset at least 48hrs after admission- inc staff and visitors

Question 2

Why are hospital aquired infections important?

Answer 2

• frequent
• impact health
• costly (longer hospital stays)
• preventable

Question 3

What are most common types of HAI?

Answer 3

UTI, Gi, pneumonia, surgical wounds

Question 4

what pts are at highest risk of HAI?

Answer 4

• elderly and very young
• obese/ malnourished
• cancer
• diabetes
• immunosurpressed
• smoker
• surgical pts
• emergency admission

Question 5

How can pts risk factors for HAI be reduced?

Answer 5

• stop smoking, feed properly
• skin prep
• antibiotic prophylaxis
• hand hygiene
• MRSA screens
• disinfectant body wash

Question 6

How can Pt- pt transmission be reduced?

Answer 6

Isolation rooms
Rooms with two doors and negative pressure
Herd immunity

Question 7

How can healthcare worker- pt transmission be reduced?

Answer 7

Vaccinations 
Hand washing 
PPE
Surgical technique
Prescribe antibiotics carefully

Question 8

how can environment- pt transmission be reduced?

Answer 8

Good cleaning (H2O2 vapour)
Ensuites
Single use devices 
Sterilisation of equipment 
Sterile food
Irradiation of vector breeding sites

Question 9

What organisms most likley to cause infection of pig heart valve or prosthetic that’s been in longer than a year?

Answer 9

Viridands strep
Staph aureus
Candidiasis
Enterococcus faecialis

Question 10

What organisms most likely to cause infection of prosthetic heart valve put in less than a year ago?

Answer 10

Coagulase negative staph (staph epididermis)

Question 11

What bacteria most likely to cause prosthetic joint and cardiac pacing wire infections?

Answer 11

Coagulase -ve staph and staph aureus

Question 12

Describe the process of infection at a surface

Answer 12

1. Adehesion to host cells or prosthetic surface by pili
2. Creation of biofilm- bacteria produce quorum sensing materials which reduce metabolic rate of bacteria (reduces susceptibility to antibiotics) and cause them to produce a slime which helps with adhesion and keeps WBCs away
3. bacteria multiply and spread
4. Host responds (in pyogenic bacteria pus is produced, in granulomatous your get granulomatous inflammation)

Question 13

How can infections on central lines be cultured?

Answer 13

Take sample from central line and new line. Infective bacteria on central line will grow much faster than on new line.

Question 14

How can surface infections be prevented?

Answer 14

Maintain surface integrity (no cuts) and prevent colonisation/ contamination and remove colonising bacteria (sterilise)

Question 15

What does endemic vs epidemic mean?

Answer 15

Endemic is usual background rate

Epidemic is rate of infection than usual background rate for that time/ place

Question 16

What do outbreak and pandemic mean?

Answer 16

Outbreak is two or more cases linked in time or place

Pandemic is very high rate of spread across many countries. Usually due to new strains.

Question 17

What is the basic reproductive number?

Answer 17

the avg number of cases each case generates over the course of its infective period in an otherwise uninflected, non immune population

Question 18

What reasons are there for outbreaks/ epidemics/ pandemics?

Answer 18

New pathogens/ strains (antigenic drift/ shift, new virulence factors, antibacterial ressistance)
New hosts (non immune people (forgein, HIV+ ect)
New practices (more tattoos, sex, equipment, procedures ect)

Question 19

What is the infectious dose? What does it depend on?

Answer 19

The number of microorganisms needed to cause an infection
Varies by:
- microorganism
- presentation of microorganism
- immunity of host

Question 20

What negative consequences are there to infection prevention?

Answer 20

Reduced exposure means reduced antibodies and so were more susceptible to outbreaks
Later age of exposure means more severe outcomes