Thriving in high salt concentrations, this bacteria lives in coastal waters and marine mud. Vibrio parahaemolyticus becomes particularly active in water temperatures of 15° C or higher. As such, seafood caught when water temperatures are warm (and large concentrations of Vibrio parahaemolyticus are breeding) can carry the bacteria. In turn, improper handling after capture, during distribution, or while cooking can result in Vibrio parahaemolyticus multiplying and causing food poisoning.
Secondary contamination via cutting boards and cooking implements can also cause food poisoning with this bacteria.
Vibrio parahaemolyticus is characterized by a multiplication rate that is much faster than other food poisoning-causing bacteria. However, this bacteria cannot multiply in fresh (tap) water. Food poisonings caused by Vibrio parahaemolyticus gradually increase from May to June and occur with particular frequency from July to September. In recent years, however, cases of Vibrio parahaemolyticus-induced food poisoning have occurred even in winter.
Which foods can cause Vibrio parahaemolyticus infection?
The most common example is seafood sashimi and sushi. Food poisoning cases also occur due to secondary contamination via cooking implements and hands after preparing raw seafood.
What are the symptoms of Vibrio parahaemolyticus infection?
The incubation period lasts from 8 to 24 hours (2 to 3 hours in the shortest cases), after which the primary symptoms of infection are intense stomach pain and diarrhea. Some victims also experience fever, nausea, and vomiting.
What are the key points to preventing Vibrio parahaemolyticus?
- Thoroughly wash seafood in fresh (tap) water prior to cooking to rinse away bacteria.
- Thoroughly wash and disinfect cooking implements used with seafood to prevent secondary contamination.
- Do not cut vegetables or other foods on cutting boards just used to prepare seafood (use different cutting boards for different foods).
- Take sufficient care when preparing and eating raw seafood during the summer and if at all possible store in a refrigerator below 4° C, even for brief intervals between preparation.
(Vibrio parahaemolyticus cannot multiply under cool temperatures. Note that while cool temperatures prevent Vibrio parahaemolyticus from multiplying, freezing, at least for short periods of time, does not kill this bacteria.)
- When thawing frozen seafood, use a dedicated thawing fridge or in your refrigerator.
- When cooking, ensure that seafood is heated sufficiently so that heat penetrates to the center of food (60° C for 10 or more minutes).