The Cape Cod Times is reporting that eight cases of Vibrio food poisoning were reported in Massachusetts this year from oysters. Last summer the state designed new regulations to keep consumers safe from this bacteria, but they failed. The eight cases were linked to oysters harvested from Wellfleet, Orleans, Edgartown, Duxbury, Kingston, Barnstable, and Dennis.
Public health officials think that increased public awareness may be part of the cause of this outbreak, but warmer water and air temperatures this last summer may be to blame. Vibrio was not seen in Massachusetts oysters until 2011 because the state’s colder water temperatures discouraged the growth of the bacteria. In every month in 2012, the mean air temperatures were higher than average, including the third-warmest April and the warmest August on record. Sea surface temperatures this year were the highest ever in the Northest.
Vibrio populations double every 15 minutes, so keeping shellfish cool is critical to controlling bacterial growth. The Vibrio Control and Management plan called for recreational harvesters to consume or refrigerate oysters within five hours of catch. Commercial oyster harvesters had to record the time of harvest and ice the oysters within five hours and ensure that the oysters were not exposed to direct sunlight.
If the oysters were not brought down to 50 degrees F within 15 hours, they would be destroyed. And the only allowable storage was in a refrigerator “owned and maintained by a wholesale dealer subject to control measures required by state food safety regulations,” according to the plan.
For next year, coverage of the plan may be extended to include additional towns, and may place limits on the harvesting season time frame. Symptoms of Vibrio food poisoning include nausea, vomiting, watery diarrhea, and abdominal cramps. The symptoms usually begin 4 hours to 3 days after eating contaminated products.
It is probably not true to say that the new regulations “failed.” It is probably more accurate that incomplete compliance with the new regulations caused the illnesses. If all of the shellfish harvested were refrigerated according to the new regulations, I suspect there would not have been any illnesses in Mass this year. Unfortunately, not everyone has taken the new regulations to heart. There are pirates, thieves and fly-by-night harvesters who don’t play by the rules and they put the entire industry at risk.
I agree, to a point. I do think that warmer air and water temperatures over the oyster harvesting months played a part in the Vibrio numbers increase.