Massachusetts oysters blamed for Vibrio illnesses

Massachusetts  Department of Public Health testing has shown that eight people became ill this year from eating bacteria-laden oysters, despite brand new regulations that were specifically designed to keep consumers safe.

The Cape Cod Times reports that until the DPH traced two Vibrio parahaemolyticus cases back to Cape oysters in 2011, the state had never seen that particular gastrointestinal illness caused by oysters harvested in Massachusetts waters. The state’s colder waters and climate seemed to discourage the growth of the bacteria, which have a reproductive rate that jumps dramatically with higher water and air temperatures.

One reason for this year’s higher number of cases may be increased awareness by the public and medical professionals, leading to more testing and reporting, DPH Associate Commissioner Suzanne Condon wrote in an email to the Times. But her agency also believes warmer water and air temperatures this past summer were primary factors.

The confirmation of the two 2011 cases prompted the federal government to require the state to create a vibrio management plan. Since vibrio population numbers double every 15 minutes, the primary goal is to inhibit growth by cooling the shellfish. The plan requires that shellfishermen shade their oysters from the sun immediately upon harvesting them and either put them on ice or refrigerate them within five hours. A wholesaler has 10 hours to bring the oysters’ internal temperature down below 50 degrees and keep them at that temperature until they reach consumers.

Former Wellfleet shellfish constable Bill Walton, now an associate professor at Auburn University in Georgia, agreed that not enough data has been collected to support the climate change theory. He criticized the U.S. Food and Drug Administration, saying the agency even wants to end the sale of raw oysters. “They just seem to take a stance that these shouldn’t be sold at all,” he said. “As a consumer, I don’t want to see that. I love my raw oysters, and I don’t see why the world has changed.

“There’s always been some risk and suddenly that’s not acceptable.”

13 sickened with norovirus; sewage spill linked to bad oysters in 2009 NZ outbreak

Don’t eat poop. And if you do, cook the poop. Thoroughly.

Which is why I don’t eat raw oysters. Who knows what poop they’ve filtered through their bivalves.

In 2009 public health authorities traced the source of two outbreaks, in Auckland and Waikato, back to the Coromandel, according to today’s New Zealand Medical Journal.

Ten people were infected at a catered event in Auckland and three at a Cambridge restaurant. Four more at the Auckland event ate oysters but did not fall ill. Neither venue nor the oyster farm is named in the journal report.

In Cambridge, two of the unlucky diners ate their oysters raw while the third consumed cooked oyster Kilpatrick but complained the shellfish was undercooked and sent it back for re-cooking.

The Food Safety Authority closed the growing area where the oysters came from in late July 2009 following the Auckland outbreak but eight days before the Cambridge diners had their contaminated meal.

The journal report says the leaking sewer was found only by chance. In early August 2009 the Thames Coromandel District Council reported the sewer had been disturbed during maintenance of the wastewater treatment plant near the oyster growing area.

"The pipe had been leaking partially treated effluent into the stream that flowed into the affected growing area," says the report by public health doctor Richard Wall and colleagues.

Dr Wall and colleagues say temperatures above 60C deactivate norovirus, although cooking oysters has not been shown to reliably inactivate viruses.

In 2006 imported Korean oysters were blamed for five outbreaks of the disease. One of these was at Eden Park in which it was estimated more than 300 corporate guests at an All Blacks-Ireland test were poisoned after eating the raw oysters.