Foodborne Outbreak Reporting Instructions

Revised: November, 2005
Guidelines for Completing the Form: “Investigation of a Foodborne Outbreak”
Foodborne and Diarrheal Diseases Branch
Centers for Disease Control and Prevention
I. Report Type
Indicate if this is a final report and if the data does not support a foodborne outbreak but
you are nevertheless reporting this outbreak to CDC.
II. Number of Cases
Provide number of laboratory-confirmed cases and number of presumptive cases. If
applicable, also provide an estimate of the total number of ill persons if you suspect that
this number exceeds the sum of the laboratory-confirmed and presumptive cases.
III. Dates
Indicate dates that the first and last known case patients became ill, and the dates that the
first and last known exposure took place. If available, please attach a copy of the
epidemic curve along with this report form.
IV. Location of Exposure
Provide the two-letter state abbreviation and select the full name of the county in which
exposure took place. If multiple states or counties were involved, list them in the “other
states” or “other counties” section.
V. Approximate Percentage of Cases in Each Age Group
This item seeks to identify unique patterns of age distribution for the outbreak, as well as
to identify age groups most affected. Indicate the approximate percentage of all cases
(lab-confirmed and presumptive) in the various age groups listed.
VI. Sex
Estimate the percentage of males and females, using all cases (laboratory-confirmed and
presumptive combined).
VII. Investigation Methods
Check off all boxes that describe the methods used to investigate this outbreak.
VIII. Implicated Food(s)
List the food item(s) implicated as a result of the investigation. Please be as specific as
possible, and if known include main ingredient(s), contaminated ingredients, reasons
suspected and method of preparation.
a. The name of the implicated food alone does not provide sufficient detail when
one ingredient of many is the actual source of contamination. Identification of an
implicated ingredient(s) provides a basis for identifying ingredients that may be
involved in other outbreaks. The contaminated ingredient(s) is the ingredient
that actually was contaminated with the agent, when such a distinction can be
made.
b. Reasons suspected should be chosen from the list below the table.

Revised: November, 2005
c. Method of preparation refers to common food preparation processes. By
identifying the food safety hazards associated with each method and the
frequency with which they occur, appropriate interventions and priorities can be
set for whole categories rather than just for a specific food. A list of codes to be
used for the method of preparation is found on page 6 of the form.
IX. Etiology
a. Identify the bacterium, virus, parasite, or toxin responsible for the outbreak, using
the criteria set forth in MMWR 1996 / Vol. 45 / ss-5 / Appendix B. The name
should follow standard taxonomy. Give as much detail as you have about the
organism or toxin.
b. If more than one etiology was identified, please include all of them in the
“Etiology” section
c. Check off all boxes that correspond to the specimen(s) from which the etiologic
agent was isolated or identified.
X. Isolate Subtype
If known, include the PFGE pattern designation for first and second enzyme as confirmed
by PulseNet, CDC. The state laboratory assigns a unique identification number to each
isolate and this number should go under the “State Lab ID” section.
XI. Contributing Factors
a. Factors that contribute to the occurrence of outbreaks are classified according to
contamination, survival, and proliferation. A factor should be checked only if the
investigator has strong evidence that it actually occurred in this outbreak; just
because a factor has been cited in similar outbreaks in the past does not mean it
was involved in this outbreak. Contamination factors relate to how the agent got
onto or into the food vehicle. Proliferation factors relate to how microbial agents
were able to increase in numbers and/or produce toxic products prior to the
vehicle being ingested. Survival factors refer to processes or steps that should
have eliminated or reduced the agent but did not because of one of these factors.
Explanations and examples of the codes are provided on page 6 of the form. If
the choice of “other” is made for any of the factors, please describe in the
“Remarks” section.
b. If one or more food workers are implicated as the source of contamination,
please indicate what evidence was used to support this conclusion. The choice of
“prior experience makes this the likely source” is provided for situations when
conclusive laboratory and epidemiologic evidence is absent, but other factors may
prompt the investigator to suspect the food worker(s). If a food worker is
implicated in the absence of laboratory and/or epidemiologic evidence, please
explain in the “Remarks” section.
XII. Symptoms, Signs and Outcomes
For each outcome listed, provide the number of patients with the outcome, and the total
number of patients for whom you have such outcome information available. If
applicable, list other outcomes (and the relevant numbers) in the blank spaces provided.

Revised: November, 2005
A list of possible outcomes is provided to the right of the table.
XIII. Incubation Period
Indicate the shortest, median, and longest incubation period, and indicate whether each
period is measured in hours or days.
XIV. Duration of Illness
Indicate the shortest, longest and median duration of illness among those who recovered.
Indicate whether each period was measured in hours or days.
XV. If a Cohort Investigation was Conducted
Report the attack rate if a cohort investigation was conducted only when you have an
implicated vehicle. This is the vehicle attack rate, not the event attack rate. The formula
is provided to aid in keeping our definition of attack rates consistent across
investigations.
XVI. Location where Food was Prepared?
Indicate where suspected/implicated food was prepared. Select all applicable options.
XVII. Location of Exposure or where Food was Eaten?
Indicate where suspected/implicated food was eaten. Select all applicable options.
XVIII. Traceback
Indicate whether a traceback investigation was conducted and include all available
information.
XIX. Recall
Indicate whether there was a recall associated with this outbreak and include all available
information.
XX. Available Reports
Indicate whether there are any additional reports and include them as an attachment.
References should be cited for published papers.
XXI. Agency Reporting this Outbreak
Include the contact information for the agency reporting this outbreak.
XXII. Remarks
Describe other important aspects of the outbreak that may not have been reported
elsewhere in the form.
Parts 3-6: Additional Sections
Fill in additional information in the appropriate section(s) if the outbreak was associated
with a school, ground beef, Enterohemorrhagic E. coli, Salmonella enterica Enteritidis, or
eggs.