6. History, Hygeine and Hospital Infection Flashcards
How did Koch’s postulates determine if an infectious agent was the cause of a disease?
The organism occurs in every case of the disease, it occurs in no other disease and removal of the agent from the body and growth in a pure culture induces the disease.
What are problems with the three rules of Koch’s Postulate?
Every case of the disease - hard to define the disease and isolate the microbe.
No other disease - commendable can be pathogens, endogenous infection or colonisation without symptomatic disease common.
Removal from the body and reinduction - no model nor pure culture.
What are the four general stages of transmission of infection?
Reservoir to immediate source to mode of transmission to susceptible host.
How can transmission of infection be prevent?
Eliminate microbes from the reservoir or from the immediate source. Or protect the susceptible host from the immediate source. The mode of transmission could also be stopped.
What is the average increased number of days as an in patient with a hospital squired infection?
11 days.
How many deaths do hospital acquired infection cause a year?
5000.
What is the excess cost to the NHS every year from hospital acquired infections?
£1 billion.
What does the rate of spread of infection depend on?
Time period of infectivity, rate of mixing infectious and susceptible individuals, capacity for transmission to take place, capacity for transmission to take place and number of infectious individuals contacted by infectious individual during infective period.
How can the basic reproductive rate of an infection be calculated?
R0 = BXD
Basic rate = capacity for transmission x number of infectious individual contacted x time period of infectivity.
What happens with the following scenarios?
a. R0 > 1
b. R0
a. Infection propagates.
b. Infection dies out.
What can reduce the rate of infection spread?
Hand washing, cohorting of staff and antibiotic use.
