Week 8 - Infection prevention and microbial stewardship Flashcards
What is an outbreak?
-Two or more cases linked in time and place
What id Epidemic?
-Infection rate greater than usual background rate
What is pandemic?
-Very high rate of infection spreading across many regions, countries and continent
What is direct spread?
-One person gives the infection to 1 or more people directly
What is indirect spread?
-The use of a vector is needed to spread the infection
What is the basic reproduction number?
-Average number of cases one case generates over the course of its infectious period in an otherwise uninfected, non-immune population
What host factors can lead to a new outbreak?
- New patients eg number of non-immunes increases (neonates)
- Increased susceptility eg incidence of co morbidity increases eg malignancy, DM
Discuss some pathogen factors which can lead to an outbreak
- New pathogen eg new antigens in antigenic shift
- New virulence factors eg c.diff strain producing more toxin -> increased diarrhoea = increased spread
- Antimicrobial resistance developing eg MRSA
Discuss practice factors which can lead to an outbreak
- New practice in social context eg HIV due to changes in sexual practice and injection
- New healthcare practice eg increasing bed occupancy increases c diff spread
Discuss some place causes of outbreaks
-Migration moves different strains of pathogen around the world
What factors determine the transmissibility of an infection?
- Infectious dose
- Host immunity and response
- Virulence factors
- Mechanism of transmission
What pathogen interventions can be put in place to prevent infection?
- Antibacterials to reduce bioburden
- Eradication by destroying habitat
What patient interventions can be put in place to prevent infection?
- Improved health via housing and sanitation
- Immunity via vaccinations and herd immunity
What practice interventions can be put in place to prevent infection?
- Promote health behaviour ie healthy eating, exercise, safe sex, food prep etc
- PPE for HCP
What place interventions can be put in place to prevent infection?
- Isolation rooms
- Environmental engineering -> safe water, air etc
What are the dangers with herd immunity?
-If not enough people are vaccinated then may just delay the age of onset of a particular infection which can increase the consequence severity eg polio in children doesnt develop to myelitis but in adults it does
What are the consequences of poor infection control?
- Decrease exposure to pathogen can decrease immunity and thus overall the population has an increased susceptibility
- Delay age of onset
What are the consequences of antimicrobial resistance?
- Treatment failure
- Economic burden
- Prophylaxis failure
- Increased incidence of death/illness
What is MDR defined as?
-Resistant to one agent in 3 or more classes of antimicrobiald
What is XDR defined as?
-Resistant to at least one agent in all but two or less classes
What is antimicrobial stewardship?
-Interventions designed to improve and measure appropriate use of antibiotics whilst optimising clinical outcomes
What are the benefits of antimicrobial stweardship?
- Decreased resistance to drugs
- Decreased cost of healthcare
- Minimise toxicity and ADRs due to shortened course
What are the three groups of antimicrobial stewardship interventions?
- Persuasive (education)
- Restrictive (formulary restriction)
- Structural (rapid lab tests)
What is a disadvantage of antimicrobial stewardship?
-Potential for readmission of patient as infection has not cleared
What is endemic disease?
-Usual background rate
Give an example of an infection which is not communicable between humans
-Legionella pneumophilia
