11. Nosocomial infection

Question 1

what % of hospitalised patient acquire infection whilst being there

Answer 1

5-10%

Question 2

what % of hospital acquired infections (HAI) are bacterial and viral

Answer 2

95% bacterial

5% viral and parasites

Question 3

what proportion of COVID-19 patients contracted the disease from hospital in the first wave

Answer 3

1/10

Question 4

what is the most common HAI

Answer 4

surgical site infection

Question 5

what % of HAIs does sepsis make up

Answer 5

3-5%

Question 6

what are the 2 sources of infection

Answer 6

exogenous

endogenous

Question 7

what is an exogenous source of infection

Answer 7

• direct inoculation of organism into patient without colonisation

Question 8

what is an endogenous source of infection

Answer 8

• infections that are caused by already colonising microorganisms

Question 9

describe and give an example of early endogenous infection

Answer 9

s. pneumoniae -> host already had this flora present prior to hospitalisation

Question 10

describe and give an example of late endogenous infection

Answer 10

MRSA - hospital flora which first colonise the patients body and then cause infection

Question 11

what surgical device is responsible for the highest cases and mortality of pateitns

Answer 11

respiratory therapy = respirators

Question 12

define comorbidities

Answer 12

another disease that may compromise the treatment of another

Question 13

give an example of a comoribidity

Answer 13

necrotising fasciitis and diabetes

Question 14

explain necrotising fasciitis

Answer 14

necrotic flesh dies
symptoms: excessive pain, hard skin, swelling

bullae are formed and bleeding into the skin occurs

risk factors for necrotising fascitis include diabetes - impaired vascular and immune function

Question 15

what type of necrotising fasciitis are most cases

Answer 15

type 1

caused by mix of gram neg and gram pos bacteria

Question 16

describe necrotising fasciitis as a result of clostridial infection

Answer 16

produces 2 deadly toxins that cause platelet aggregation and RBC destruction

bacteria ferment in the wound and result in gas-gangrene

Question 17

what do other types of necrotising fasciitis affect

Answer 17

extremities in young, healthy adults with history of injury

Question 18

in burn units, what % of deaths are caused by infection

Answer 18

61%

Question 19

why are burn victims predisposed to complications

Answer 19

burn wounds induce metabolic and inflammatory alterations

Question 20

what pathogen become prominent following the invention of air conditioning systems

Answer 20

legionella

Question 21

how can infections be transmitted in hospitals

Answer 21

poor hand hygeine
lack of properly sterilised instruments
air conditioning
indirect contact 
environment/ food

Question 22

study: Semmelweis

- mortality caused by post partum infection decreased from what to what following hand washing

Answer 22

decreased from 13.1%

to 2.4%

Question 23

Why does having diabetes affect necrotising fasciitis

Answer 23

Diabetes = reduced blood flow to extremities
Harder to mobilise the immune system = reduced function
More difficult to combat other infections such as necrotising fasciitis