outbreak investigation Flashcards
steps in outbreak investigation
Verify if outbreak exists
case definition
substantiate dx
case finding
epidemic curves
form hypothesis
an outbreak might be detected
through a rise in routine laboratory reports.
true
The main aims of epidemic/outbreak investigation are to:
identify the causative agent;
● define the route of transmission;
● establish the risk factors;
● develop and implement control and prevention strategies; and
● advise on preventing similar events in the future.
expert needed to know the target pathogens
microbiologists
limitations of case definition
time, place, person
people with signs and symptoms and an incubation
period clinically compatible with the suspected infection, but in whom
the diagnosis is negative, awaited or incomplete.
suspected cases
people with signs and symptoms compatible
with the suspected infection but in whom diagnostic information is
incomplete.
presumptive cases
people with signs and symptoms compatible with
the suspected infection and in whom a diagnosis has been confirmed.
This may be by either isolation of the pathogen from an appropriate
clinical sample or by demonstration of a fourfold rise in antibody titre
serologically.
confirmed cases
criteria of case definiton
temporal, geographical, personal
Data from cases are usually
documented in a __
questionnaire
usually shows a sharp rise to a peak and a fairly rapid tailing off
A point-
source epidemic curve,
the shape of the curve is
flatter and cases persist over a much longer period of time
propagated epidemic curve
how often is epidemic curve updated
everyday
similar to continuous but exposure is intermittent; multiple peaks – length: no relation to the incubation period (reflects intermittent times of exposure) e.g., contaminated food product sold over period of time
intermittent epicurve
is the first case that comes to
medical attention.
index case
