Health Care Acquired Infections (HAI) Flashcards
(30 cards)
Definition of Healthcare acquired infections (HAI)
Infections that were not present or in the pre-symptomatic phase at the time of admissions to hospital, which arises >_48 hours after admission or within 48 hours of discharge
Possible outcomes of HAI
extended length of stay Pain discomfort permanent disability death increased cost litigation (process of taking legal action) loss of public confidence + decreased staff morale
What are patients in hospital more vulnerable to?
Microbial colonisation
infection
A strain of staph aureus which is COLONISED can also cause INFECTION through
Break in the skin e.g. surgical site infection
Vascular device e.g. PVC, CVC
Catheter associated UTI (CAUTI)
Ventilator associated pneumonia (VAP)
What disturbance leads to HAI?
Disturbance in balance-host equilibrium
Microbial factors tipping the balance towards infection
Increased
- resistance
- virulence
- transmissibility
- increased survival ability
- ability to evade host defences
Host factors tipping the balance towards infection
Devices (PVC, CVC, catheter, ventilation) Antibiotics Break in skin surface Foreign body Immunosuppression Gastric acid suppression Age extremes overcrowding Increased opportunity for transmission - interventions - hand
Proportion of HAIs due to different infections
UTI 22.6% (catheterisation mainly) Surgical site infections 18.6% RTI 17.5% (intubation 1/4) Bloodstream infections 10.8% (CVC) GI infection 15.4% Skin and soft tissue infection 4%
Means of transmission
Direct contact (s. aureus, colioforms)
Respiratory/droplet (Neisseria meningidits, mycobacterium tuberculosis)
Faecal-oral (C. diff, salmonella)
Penetrating injury (Group A strep, bloodborne virus)
Presentation of C. diff infection
Diarrhoea Faeces have characteristic odour Abdominal pain Pyrexia Raised WCC Pseudomembraneous colitis
Carriage rate of C. diff increases with….
age
Which toxins of C. diff DO NOT cause disease?
Toxin negative strains
Diagnosis of C. diff by ….
Lab tests (+ve toxin does not always mean disease) Clinical interpretation Diarrhoeal symptoms MUST be present
Treatment of C diff infection
Stop predisposing antibiotics if possible
DO NOT TREAT THE SYMPTOM FREE
Avoid the 4Cs
If symptomatic
- oral metronidazole
- oral vancomycin if severe or failure to improve on metronidazole
- oral fidaxomicin if 2nd episode
4Cs to avoid to reduce C.diff
Ceftrixazone
Co-amomxiclav
Clindamycin
Ciprofloxacin + other quinolones
You break the chain of infection by….
Risk awareness Standard infection prevention and control precautions (SICPs) Hand hygiene Appropriate PPE Vaccination Post exposure prophylaxis Environment
Methods of disinfection
Heat
- pasteurisation (bedpans, linen, dishwashers)
- boiling (vaginal specula, ear synringes)
Chemical
- e.g. alcohol, hydrogen peroxide
Cleaning effect on microbes
Physical removal of organic material and decrease in microbial load
Sterilisation effect on microbes
removal/destruction of ALL microbes and spores
Disinfection effects on microbes
Large reduction in microbe numbers, spores may remain
Methods of sterilisation
Steam under pressure (autoclave)
Hot air oven
Gas (ethylene dioxide)
Ionising radiation
Low risk for HAIs
Intact skin contact
- stethescopes, cots, matresses
- cleaning by manufacturers instructions
Medium risk for HAIs
Mucous membrane contact e.g.
- bedpans, vaginal speculum, endoscopes
Disinfection or sterilisation as appropriate
High risk for HAIs
Surgical instruments
Sterilisation needed
