Healthcare Acquired Infection Flashcards
Define Healthcare Acquired Infections (HAI)
Infections that were not present or in pre-symptomatic phase at the time of admission to hospital, which arise >= 48 hours after admission or within 48 hours of discharge
What is the difference between colonisation and infection?
Colonisation refers to the presence of an organism in or on the body without causing harm/symptoms, whereas infection refers to the breaching of immune barriers by an organism, resulting in symptomatic illness
What are the microbial factors leading to an increased risk of infection? (5)
- Resistance
- Virulence
- Transmissability
- Increased survival ability
- Ability to evade host defences
What are the host factors leading to an increased risk of infection? (9)
- Devices (PVC, CVC, urinary catheter, ventilation)
- Antibiotics
- Break in skin surface
- Foreign body
- Immunosuppression
- Gastric acid suppression
- Age extremes
- Overcrowding
- Increased opportunity for transmission (e.g. interventions, inadequate hand hygiene)
What is the Chain of Infection?
Source of microbe»_space; Transmission»_space; Host
What are the main modes of transmission of microbes? Give examples of organisms which spread by each method. (4)
- Direct contact (S. aureus, coliforms)
- Respiratory/droplet (Neisseria meningitidis, mycobacteria tuberculosis)
- Faecal-oral (C. difficile, Salmonella)
- Penetrating injury (Group A strep, blood-borne viruses)
Methods of breaking the chain of infection (7)
- Risk awareness
- Standard infection prevention and control precautions (SICPs)
- Hand hygiene
- Appropriate PPE
- Vaccination
- Post-exposure prophylaxis
- Environment
Define cleaning
Physical removal of organic material and decrease in microbial load
Define disinfection
Large reduction in microbe numbers - spores may remain
Define sterilisation
Removal/destruction of all microbes and spores
What is an appropriate method of cleaning?
- Following manufacturer’s instructions (usually detergent and water) -
drying is important
(Essential prior to disinfection and sterilisation, if required)
What are appropriate methods of disinfection? (2)
Heat (pasteurisation or boiling)
Chemical (e.g. alcohol, hydrogen peroxide)
What are appropriate methods of sterilisation? (4)
- Steam under pressure (autoclave)
- Hot air oven
- Gas (ethylene dioxide)
- Ionising radiation
Define an outbreak
2 or more cases of an infection linked in time and place
What are appropriate control measures for an outbreak? (6)
- Single room isolation
- Cohorting of cases
- Clinical area/ward closure
- Re-inforcement of infection prevention and control measures
- Staff exclusion (depending on outbreak - colonised staff, non-immune staff)
- Staff decolonisation or other measures
