U. S. Food and Drug Administration
Center for Food Safety and Applied Nutrition
FDA Prime Connection

University of Florida - Food Safety Considerations on Ready-to-eat-Seafoods
 
 
                            Ready-to-eat-Seafoods
 
                     Important Food Safety Considerations
 
                   Dr. W. Steven Otwell, Seafood Specialist
                  Food Science and Human Nutrition Department
         University of Florida, IFAS Cooperative Extension Service and
              Florida Sea Grant Program with support through the
        U.S.Department of Agriculture's Cooperative Extension Service.
 
                       Sea Grant Extension Fact Sheet-13
 
 
 
Ready-to-eat seafoods are those items that require no heating or cooking just
prior to consumption. These products can be raw (i.e., oysters, clams, sushi,
etc.) or pre-cooked (i.e., boiled shrimp, fresh crabmeat, fabricated seafood
analogs, etc.). They can represent a safe, nutritious selection, but if they are
cross-contaminated and mishandled, they could act as a vector for seafood
poisoning.
 
 
Problems
 
Cross-contamination of ready-to-eat seafoods refers to bacterial contamination
which, if allowed to grow, could pose a health threat. Potentially harmful
bacteria can come from the immediate surroundings, other foods, and/or
individuals handling the foods. The preface `cross' means the clean or
ready-to-eat items have come in contact with a surface or food that harbors the
harmful bacteria.
 
 
Typical examples of these events include:
 
- storing and handling pre-cooked seafoods in the same container previously used
for raw seafoods or other uncooked foods
 
- handling ready-to-eat seafoods with utensils, gloves, or on work surfaces that
have been previously used for raw seafoods
 
- wiping work surfaces and containers with rags and brushes previously used in
handling raw seafoods
 
- temporarily storing or thawing ready-to-eat items in a sink or container
previously used to hold raw seafoods
 
 
In summary, any practice by fisherman, seafood processors, retailers,
restaurants, recreational fishermen or consumers that allows transfer of bacteria
from a raw food to a ready-to-eat seafood can contribute to potential food
poisoning.
 
 
Vibrio parahaemolyticus
 
One common bacterial culprit in cross-contamination is Vibrio parahaemolyticus,
a widely distributed marine water bacterium associated with warm water regions.
This bacterium is found in coastal waters throughout the world. It is not
considered a water contaminant in that it is part of the natural flora. It will
naturally accompany the raw seafoods harvested from waters where these bacterium
may be present. The potentially harmful varieties of this bacteria are more
prevalent in warm water regions during summer months. This seasonal occurrence
often coincides with increased recreational activity and harvests. A typical
adverse consequence involves cooked shrimp or crabs being served from the same
basket or bucket previously used to hold the initial raw catch.  Although cooking
easily destroys these heat-sensitive Vibrios, cross-contamination and improper
storage can allow the pre-cooked items to yield a harmful dose of pathogenic
bacteria. Once a ready-to-eat item is cross-contaminated, the Vibrios require
some time to grow to a harmful dose level. Note, these Vibrios can survive in
refrigeration and grow at temperatures above 46 degrees F. Thus, proper
refrigeration is an essential control for ready-to-eat seafoods. In the event of
poisoning due to Vibrio parahaemolyticus, the resulting symptoms include
diarrhea, abdominal cramps, nausea, vomiting, headaches, fever and chills. Onset
is within 9 to 24 hours and duration of the illness can last for 2 to 3 days.
 
 
Prevention
 
Careful handling of ready-to-eat seafoods should always be mindful of any
potential transfer of bacterial contaminants from other foods, particularly raw
seafoods.
 
- Keep raw or live seafoods separate from cooked seafoods.
 
- Do not store seafoods in a manner such that the raw items could drip or drain
on the pre-cooked items during storage or handling.
 
- Do not package pre-cooked seafoods in the same materials, boxes, wrapping,
etc., as previously used for raw seafoods.
 
- Storage, handling and thawing should always employ properly cleaned items.
 
- Storage temperatures must be maintained near or preferably below 35 degrees F.
 
- Utensils, brushes and cleaning towels used about raw seafoods should be
separated from those used about ready-to-eat seafoods.
 
 
Additional Advice
 
University of Florida
Seafood Technology
Dept. Food Science and Human Nutrition
Gainesville, FL 32611
(904) 392-1991
 
Food Marketing Institute [for Retailers]
1750 King St., NW
Washington, DC 20006
 
"Retail Food Store Sanitation Code"
Association of Food and Drug Officials
P.O. Box 3425
York, PA 17402
 
                                                                    (06/09/95)