Transmission Routes & Control Of Infections Flashcards
Describe a chain of infection
Infectious agent e.g. virus ->
reservoir e.g. equipment/ ppl/ water ->
portal of exit e.g. excretions/ secretions/ droplets ->
mode of transmission e.g. droplet/ vectorborne ->
portal of entry e.g. respiratory/ GI tract/ mucous membrane/ skin -> susceptible host e.g. ppl chronic disease/ v young ->
infectious agent
Factors affecting transmission
Host agent interaction Pathogenicity and virulence Antigenicity Infectious dose Mechanism of disease production Mode of spread
What spreads by contact (direct or indirect) and what is required in a hospital setting?
Examples: MRSA, C. Difficile
Described as being 15 micrograms+
Requires isolation in a single room, door can be open
Infectious agents don’t stay in air for significant period
Contamination within 3 feet of bed
PPE - aprons
What spreads by droplets and what is required to prevent spread in a hospital setting?
Examples: SARS (severe acute respiratory syndrome), adenovirus
5-15micrograms
Requires isolation room with door closed, significant contamination within 6-10 feet of patient, small particles stay suspended in air
PPE - surgical face mask, eye protection, depending on task gloves & aprons
What spreads by airborne particles, how can this be controlled in a hospital environment?
Examples: TB, chickenpox, aspergillus
_<3micrograms
Stay suspended in air for significant period of time require specialist air handling/ filtration, negative pressure isolation room, 8-12air changes/ hour
PPE - filter masks (N95 respirator) , eye protection, head wear, gowns or aprons, depending on task double glove, washable/ disposable footwear
5 moments for hand hygiene
Before touching patient
Before clean/ aseptic procedure
After body fluid exposure risk
After touching patient
After touching patient surroundings
How to handrub?
See slide 24
