Hospital Aquired Infetcions + Infection Prevention Flashcards
What is a hospital acquired infection?
An infection acquired in a hospital with onset at least 48hrs after admission- inc staff and visitors
Why are hospital aquired infections important?
- frequent
- impact health
- costly (longer hospital stays)
- preventable
What are most common types of HAI?
UTI, Gi, pneumonia, surgical wounds
what pts are at highest risk of HAI?
- elderly and very young
- obese/ malnourished
- cancer
- diabetes
- immunosurpressed
- smoker
- surgical pts
- emergency admission
How can pts risk factors for HAI be reduced?
- stop smoking, feed properly
- skin prep
- antibiotic prophylaxis
- hand hygiene
- MRSA screens
- disinfectant body wash
How can Pt- pt transmission be reduced?
Isolation rooms
Rooms with two doors and negative pressure
Herd immunity
How can healthcare worker- pt transmission be reduced?
Vaccinations Hand washing PPE Surgical technique Prescribe antibiotics carefully
how can environment- pt transmission be reduced?
Good cleaning (H2O2 vapour) Ensuites Single use devices Sterilisation of equipment Sterile food Irradiation of vector breeding sites
What organisms most likley to cause infection of pig heart valve or prosthetic that’s been in longer than a year?
Viridands strep
Staph aureus
Candidiasis
Enterococcus faecialis
What organisms most likely to cause infection of prosthetic heart valve put in less than a year ago?
Coagulase negative staph (staph epididermis)
What bacteria most likely to cause prosthetic joint and cardiac pacing wire infections?
Coagulase -ve staph and staph aureus
Describe the process of infection at a surface
- Adehesion to host cells or prosthetic surface by pili
- 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
- bacteria multiply and spread
- Host responds (in pyogenic bacteria pus is produced, in granulomatous your get granulomatous inflammation)
How can infections on central lines be cultured?
Take sample from central line and new line. Infective bacteria on central line will grow much faster than on new line.
How can surface infections be prevented?
Maintain surface integrity (no cuts) and prevent colonisation/ contamination and remove colonising bacteria (sterilise)
What does endemic vs epidemic mean?
Endemic is usual background rate
Epidemic is rate of infection than usual background rate for that time/ place
What do outbreak and pandemic mean?
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.
What is the basic reproductive number?
the avg number of cases each case generates over the course of its infective period in an otherwise uninflected, non immune population
What reasons are there for outbreaks/ epidemics/ pandemics?
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)
What is the infectious dose? What does it depend on?
The number of microorganisms needed to cause an infection Varies by: - microorganism - presentation of microorganism - immunity of host
What negative consequences are there to infection prevention?
Reduced exposure means reduced antibodies and so were more susceptible to outbreaks
Later age of exposure means more severe outcomes
