This ppt on outbreak management will give an idea on the definition, history and management of an outbreak.

1. OUTBREAK – MANAGEMENT
DR.M.JANE ESTHER
II YR MD(Micro) POST GRADUATE
CMCHRC, Trichy
Tamilnadu

2. Contents
• Definition of an outbreak
• History of worst outbreaks
• Investigations
• Management
• Institutional outbreak

3. OUTBREAK - DEFINITION
• The occurrence in a community or region
of cases of an illness with a frequency
clearly in excess of normal expectancy.

4. Worst outbreaks - history
• Ebola – 2014-2015

5. Plague – black death
400 BC

6. Small pox – 1492 to 1900

7. Yellow fever epidemic
• 1793

8. Cholera pandemic
• 1817-1823

9. Influenza
• 1918

10. Typhus
• 1918-1922

11. Malaria
• 2800 children – die each day

12. AIDS
• From 1981

13. INVESTIGATIONS
• Regardless of the communicable disease, the
procedure for the investigation of a
suspected outbreak is the same
• 10 Steps

15. 1.Establish the existence of an outbreak
• Compare current information with previous
incidence in the community during the same
time of year to determine if the observed
number of cases exceeds the expected.
• Compare available information about new
cases with a predetermined definition of an
outbreak.

16. 1.Establish the existence of an outbreak
• Public health surveillance.
• Gather reports of illnessess
• Doctors and microbiologists – notify
• Public health officials – look at reports
• Astute clinician
• Specimens collected – organism identified
• Serotyping / DNA fingerprinting/ PFGE

17. 2.Confirm the diagnosis
• Analyze clinical histories of cases
• Have standard laboratory tests performed to confirm or
reject the suspected diagnosis
• To determinethe type of agent associated with the illness
(e.g.,bacterial, viral, other).

18. 3.Establish the case definition and count
cases
Case definition
• Features of the illness
• The pathogen or toxin, if known
• Certain typical symptoms
• Time range
• Geographic range,

19. Case count
• The number of cases that meet the case
definition is called the case count.

20. 4.Relate the outbreak to time, place and
person
• Characterize the outbreak
according to person, place or time
by interviewing known or selected
cases
• When they became ill (time)
• Where they became infected
(place)
• Who they are (person).

21. 5.Formulate a tentative hypothesis
To explain the most likely
• Cause
• Source – Mode of transmission
• Distribution – Location, age
• Example : Food borne illness 
what they ate? Where ? – before
they became ill
• Time after intake
• Challenge : Memory

22. 6.Testing the hypothesis
• Analytical studies – compare ill with healthy
• H/O sickness – particular food – association
• Frequencies of exposure to a specific food
item
• Strength of the statistical association
• The food’s production, preparation and service
• The food’s distribution

23. Testing a hypothesis
• Food studies (in food borne outbreak)
• Finding bacteria with the same DNA fingerprint in an
unopened package of food and in the stool samples of
people in the outbreak can be convincing evidence of a
source of illness

24. 7.Finding the Point of Contamination
• Environmental assessment
• Who cooked?
• Ingredients
• Steps followed
• Temperature
• Health status of workers

25. 8.Epidemiologic investigations & Report
writing
• Summarize and interpret all of the
information that has been
collected
• Examine the results of laboratory
tests that have been conducted.
• Construct epidemic curves, tables
and charts.
• On the basis of the available data
and the appropriate calculations-
accept or reject the hypothesis.

26. 9.Controlling an Outbreak
• Once the source of illness is found – control
measures
• Isolating the source (patient)
• Discarding the food
• Temporary closure of restaurant
• Disinfection of the room/ ward
• Inform public

27. 10.Deciding an Outbreak is Over
• An outbreak ends when the number
of new illnesses reported drops back
to the number normally expected.
• The epidemic curve helps
investigators see that illnesses are
declining.
• Public health officials - continue
surveillance for a few weeks
• Continue or restart
their investigation – if cases start
occuring again

29. Practical Considerations
• Regional Health Authority (RHA)- routine surveillance –
early identification of outbreaks
• A plan for the investigation of outbreaks
• Each RHA- establish direct contact with Laboratory
• A line-listing of cases and contacts – should be maintained
electronically
• Outbreaks be reported to the Director of Communicable
Disease Control

30. Management of Outbreaks in Institutions
• Each facility should have a plan in place for routine
surveillance and for outbreak investigation – RHA
should be aware of it
• Team approach by the facility staff and Regional
Health Authority (usually the Medical Officer of
Health or delegate)
• Provincial Infection Control Nurse should be informed
of and involved in the outbreak investigation.

31. • It may be difficult to recognize an outbreak in a health-
care facility
• The Regional Health Authority - should establish
circumstances under which they are to be notified.
• Those where public health intervention or expertise may
be required (e.g., foodborne illness, influenza).

32. • Food-borne outbreaks  potential to spread
• Early consultation with a public health inspector/
Provincial Infection Control Nurse responsible for
communicable diseases is strongly recommended

33. summary
• Definition
• Recent and remote outbreaks
• 10 steps of management
• Investigations to be carried out
• Management of institutional
outbreaks

34. References
• Epidemiological investigation of an outbreak –
communicable disease management protocol
manual
• Outbreak management – CDC guidelines