Healthcare acquired infections Flashcards
What is HAI?
- infections that were not present or in the pre-symptomatic phase at the time of admission to hospital - which arise > 48 hrs after admission or within 48 hrs of discharge
How many patients have HAI?
4.9% patients in Scotland in 2011
What are possible outcomes of HAI?
Extended length of stay, pain, discomfort, permanent disability, death
What are the most common sites of HAI?
- UTI (22.6% of all HAI) – mainly related to catheterisation - Surgical Site Infection (18.6%) - Respiratory Tract Infection (17.5%) – intubation accounted for about a quarter of these - Bloodstream infections (10.8%) – many Central Venous (CVC) Catheter related
What risk do microbes pose to humans?
EVERYONE and EVERYTHING harbours microbes that may pose a risk! - Patients in hospital are more vulnerable to microbial colonisation AND infection
What is the fundamental question in clinical microbiology?
Colonisation versus infection
Who discovered staph aureus?
Alexander Ogston
What is MSSA?
Meticillin sensitive staphylococcus aureus
How much of the population has staph aureus in their nose?
30%
How can a colonised strain of staph aureus cause infection?
- Break in skin e.g. surgical site infection - Vascular device e.g. PVC, CVC - Catheter associated urinary tract infection (CAUTI) - Ventilator associated pneumonia (VAP)
Which microbial factors tip the balance towards infection?
Increased: resistance, virulence, transmissibility, increased survival, ability to evade host defences
Which host factors tip the balance towards infeciton?
Devices: PVC, CVC, Urinary catheter Antibiotics Break in skin surface Foreign body Immunosuppression
What are some means of transmission for infection?
- Direct contact - Resp. droplet - Faecal oral - Penetrating injury
How can we break the chain of infection?
Risk awareness Standard Infection Prevention and Control Precautions (SICPs) Hand Hygiene Appropriate PPE Vaccination Post Exposure Prophylaxis Environment
How can cleaning break the chain of infection?
Physical removal of organic material and decrease in microbial load
How can disinfection break the chain of infection?
Large reduction in microbe numbers - spores may remain
How can sterilisation break the chain of infection?
Removal/Destruction of ALL microbes and spores
What is low, medium and high risk factors for infection transmission and how do we counter these?
Low: intact skin contact - cleaning will fix Medium: mucous membrane contact - disinfection will fix High: surgical instruments - sterilisation will fix
What is an important part of the cleaning process?
DRYING IS AN IMORTANT PART OF THE PROCESS
What are two methods of disinfection?
Heat: Pasteurisation + Boiling Chemical: Chemicals vary in their organism activity range Needs to be equipment compatible - alcohol
What are 4 methods of sterilisation?
Steam under pressure (autoclave) Hot Air Oven Gas (ethylene dioxide) Ionising Radiation
What is the definition of an outbreak?
infection is defined as 2 or more cases of a infection linked in time and place
How do we act when there is an outbreak?
Act on suspicion: Typing necessary to determine if the same strain present
What are some control measures during an outbreak?
- Single room isolation
- Cohorting of cases
- Clinical Area/Ward Closure
- Re-inforcement of IPC measures
- Staff exclusion (e.g. colonised staff in case of MRSA; non-immune staff in case of VZV, measles etc.)
- Staff decolonisation or other measures
