Lecture 7 - Infection control Flashcards
Define:
1) carrier
2) colonisation
3) infection
1) person who has microbes with no sign of disease
2) presence and multiplication of microbes without tissue invasion or damage
3) entry and multiplication into tissue causing damage
Define:
1) contamination
2) reservoir
1) soiling of objects with potential infectious material
2) place where micro-organism lives and reproduces
What is the difference between exogenous and endogenous infection with examples of both
- exogenous means from another person or environment: e.g. airborne, contact or percutaneous
- endogenous means self infection e.g. surgical wound
Give examples of Airborne transmission
droplets - TB flu.
fluids - nebulisers.
dust - aspergillius.
Give examples of contact transmission
hands - MRSA
body fluids - HIV Hep
equipment - pseudo TB
food - salmonella campylobac
Give examples of percutaneous infection
Insect vectors - malaria
intravascular lines - s aureus
contaminated IV fluid - gram neg bacilli
sharps injuries - Hep B HIV
Give an example of self infection
picking at a wound - s aureus
Name some host factors which increase susceptibility to infection
- any compromises in normal defences e..g break in skin
- diabetes
- immunosuppression
- iv or urinary catheters
- prolonged hospital stay
- recurrent admissions
- intensive care
- prolonged broad spec ABs (pre disposed to infection MDR)
define a nosocomial infection
more than 48h post admission
under 10 days of discharge (30 for surgical wound )
within 72h of outpatient procedure
name the 5 most common type of nosocomial infection
UTI Resp infections post op surgical wound line infections / other devices diarrhoea (viral GE or C diff)
What indicates a line infection
phlebitis, painful venflon site and pus on removal
Common causes of line infections
Gram negative bac (MDR) MRSA C diff Haemtolytic strep VRE
1) Which antimicrobials are coliforms showing increased resistance of
2) give 2 examples of coliforms
3) how does this resistance occur
1) beta lactams
2) klebsiella or e.coli
3) enzymes with beta lactam resistance e.g. ESBA ampC
Which Abx was usually last line however recently has huge worldwide concern of emerging MDR + which to ABs may work
carbapenems
tigecycline and IV colistin
Name two ways hospital can prevent multi drug resistance
1 -remove exogenous sources (sterile equipment and good hygine etc)
2 -block transmission ( protective clothing and hand washing and isolation)
When does Group A streptococcus cause hosp acquired infections? How is it spread?
1) post op infection or post natal sepsis.
2) staff or visitors may introduce usually contact transmission though droplets may aerosolise
List 6 ways infection control can improve host resistance to bacteria following surgery
good nutrition immunisation good surgical technique minimise use of invasive devices appropriate use of antibiotics education
Name 3 occasions where antibiotics shouldn’t be prescribed following positive culture results
- asymptomatic bacteruria (unless pregs)
- long term catheter almost always colonised only treat if evidence systemic
- wounds often colonised only treat if evidence infection (cellulitis worsening pain)
What other infec control methods can be put in place if a MDR strain is found?
isolation in single room and microbiological screening, no unneccessary movement of patient, terminal cleaning,
