May 10, 2012, BREWSTER — Scientists have always warned there would be a price to pay for global warming and five people last year paid heavily. State health and fishery officials told shellfishermen and dealers at a meeting Wednesday night that warming ocean waters in the eastern part of Cape Cod Bay have created a more favorable environment for the Vibrio parahaemolyticus bacteria, both increasing its population size and lengthening its growing season.
The result was that, for the first time, the Massachusetts Department of Public Health confirmed that five people had fallen ill over the summer and fall after eating raw oysters that were contaminated with the bacteria.
"This wasn't five people getting diarrhea. These people were quite ill, and one came close to death," said Suzanne Condon, associate commissioner at the state Department of Public Health. The bacteria causes diarrhea, cramping, nausea, vomiting and fever. It can also cause bloodstream infections. Eating raw oysters is the most common way to contract it.
After the first two reported illnesses, which occurred last July at restaurants in Dennis, the Food and Drug Administration ordered the state DPH and Division of Marine Fisheries to come up with a plan before the summer to protect the public from June to September. The other three confirmed cases were from oysters eaten at the Wellfleet OysterFest in the fall.
Vibrio is a naturally occurring bacteria that likes warmer waters and multiplies rapidly in temperatures above 80 degrees. While our average water temperatures are cooler than that, much of the harvesting on Cape Cod Bay in the summer is done on tidal flats where oysters can be exposed to the sun for hours. Plus it can take hours to gather and transport them to the dealer or customers. That gives the bacteria an opportunity to multiply, health officials said.
Martin Dowgert, the FDA Northeast Region shellfish specialist, told the audience that scientific studies had determined that refrigerating or icing oysters within the first five hours after they had either been exposed by the tide or been harvested, with a goal of chilling it enough to lower the oysters' temperature to 50 degrees within 10 hours would stem the exponential growth of the bacteria and keep them at safe levels to be consumed.
Read the full story at the Cape Cod Times.