How to Investigate an Outbreak.ppt

7/29/2019 How to Investigate an Outbreak.ppt

1/18

1

Disease Detectives 102:

How to Investigate an Outbreak

Science Olympiad

Eleventh Annual Coaches Clinic

October 3-4, 2003


2/18

Investigating an Outbreak---a

Challenge for the Disease Detective

What Is an Outbreak?

Uncovering Outbreaks

Why Investigate an Outbreak?

Interactive exercise at:

www.cdc.gov/excite/classroom/outbreak.htm
http://www.cdc.gov/excite/classroom/outbreak.htmhttp://www.cdc.gov/excite/classroom/outbreak.htm


3/18

What Is an Outbreak?

An outbreak, or an epidemic, exists when

there are more cases of a particular disease:

in an area,

among a specific group of people, or

over a particular period of time


4/18

Uncovering Outbreaks

Health departments learn about most

outbreaks in one of two ways:

Calls from a physician or other healthcareprovider.

Public heath surveillance


5/18

Why Initiate an Investigation?

Describe the problem

Control and prevention based on

scientific evidence Political and public concerns

Training of epidemiologists

Research--answer scientific questions


6/18

Guidelines for Epidemiologic

Field Investigations

Prepare for field work

Verify diagnosis

Confirm epidemic

Identify and count cases

create case definition

develop line listing


7/18

Guidelines for Epidemiologic

Field Investigations

Tabulate and orient data: time, place, andperson

Take immediate control measures Formulate and test hypothesis

Plan additional studies

Implement and evaluate control measures

Initiate surveillance

Communicate findings


8/18

Field Investigation:

Time

Epidemic curve: # of cases by time of onset

Shape of the curve gives you clues:

agent known: use incubation period to look back

at exposure

agent unknown, but common event likely:

postulate agent by determining the incubation

period


9/18

Number of bioterrorism-related anthrax cases, bydate of onset and work location District of

Columbia (DC), Florida (FL), New Jersey (NJ), and

New York City (NYC)September 16-October 25, 2001

MMWR, November 2, 200l/Vol. 50/No. 43


10/18

Salmonellosis in passengers on a flight from

London to the United States,

by time of onset, March 13--14, 1984


11/18

Legionnaires' Disease

By date of onset, Philadelphia, July 1-August 18,

1976


12/18


Place

Orient to:

place of residence

place of work activity sites (church, reunions, weddings, etc.)

Spot map: specific residence and/or exposure

within buildings

city blocks or neighborhoods

county or state level


13/18

Distribution of cholera cases and implicated water

well - Golden Square area of London, August-

September, 1848


14/18

Culture-positive cases of shigellosis, by sites along the

Mississippi River where each case swam within three days of

onset of illness - Dubuque, Iowa, September 1974


15/18


Person

Thoroughly describe the case group (things

such as age, sex, race)

Identify things shared in common (events,behaviors, etc.)

Get information on people who are NOT

cases as well - the population! Compare groups


16/18

Deaths associated with tractor injuries, by age

group, Georgia 1971-1981


17/18

Student resources

for outbreak investigation Introduction to epidemiology

www.cdc.gov/excite/classroom/intro_epi.htm

How to investigate an outbreak www.cdc.gov/excite/classroom/outbreak.htm

Disease Detectives

www.cdc.gov/excite/disease_detectives/index.htm
http://www.cdc.gov/excite/classroom/intro_epi.htmhttp://www.cdc.gov/excite/classroom/outbreak.htmhttp://www.cdc.gov/excite/disease_detectives/index.htmhttp://www.cdc.gov/excite/disease_detectives/index.htmhttp://www.cdc.gov/excite/classroom/outbreak.htmhttp://www.cdc.gov/excite/classroom/intro_epi.htm


18/18

Questions?

Paul Garbe

[email protected]

404-498-1305
mailto:[email protected]:[email protected]

Documents

How to Investigate an Outbreak.ppt