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Oyster farmer Jack Blake hauls oysters from his Katama Bay lease last fall. — Photo courtesy of Jack Blake

A contingent of Massachusetts state officials from the Department of Public Health (DPH) and the Division of Marine Fisheries (DMF) met with Martha’s Vineyard oyster farmers, local health agents, and shellfish constables at the Katharine Cornell theater in Vineyard Haven on Monday morning, to discuss the increasing impact of the Vibrio parahaemolyticus virus (Vp) on the growing Vineyard oyster aquaculture industry.

Last September, an outbreak of Vp led to a month-long closure of oyster operations in Katama Bay. It was just one of numerous closures across the state.

“We’d like feedback from the individuals in this room; this is why we’re here today,” said Julian Cyr, director of policy and regulatory affairs from the Massachusetts Department of Health. “Last year’s closure was significant. We really want to work with you on how we can avoid closures in the future.”

Mr. Cyr was joined on the panel by Michael Hickey, DMF Shellfish Program Director, Michael J. Moore, DPH Food Protection Program, Daniel McKiernan, DMF Deputy Director, and DMF senior biologist Thomas Shields. The group was on a fact-finding tour across Massachusetts as they prepared for the Interstate Shellfish Sanitation Conference (ISSC) being held later this month in San Antonio, Texas. The ISSC governs interstate shellfish sales in the United States—which totaled $500 million in 2013—and also determines the criteria for illness investigations and closures.

The outbreak

Historically, Vibrio was linked to oysters from the balmy Gulf of Mexico. That changed in 2011 when 13 cases of the disease Vibriosis, which causes severe intestinal distress, were reported in Massachusetts. That number has more than doubled every year — 27 cases were reported in 2012 and 58 cases were reported in 2013.

The ISSC defines an outbreak of foodborne illness as two or more cases, not from the same household, from a particular growing area. A Vibrio outbreak caused a shellfishing closure on Katama Bay from September 9 to October 4 of last year. According to DPH reports, the offending Katama Bay oysters were eaten at The Port Hunter in Edgartown on July 6, and at Nancy’s restaurant in Oak Bluffs on August 1.

Following the closure, Oak Bluffs health officials and local oyster farmer Jack Blake questioned if the second oyster which triggered the shutdown was actually a Katama Bay oyster, in this case from Sweet Neck Farm, which Mr. Blake owns with his wife, Susan, since it was later discovered that Nancy’s restaurant was selling oysters from more than one source, and was not keeping proper track of the identifying tags.

There is, however, no doubt that the water temperature is rising along the east coast, as are the number of confirmed cases of Vibriosis. Last year Vibrio shut down oystering in Connecticut, New York, New Jersey, and Virginia. Overall, 104 people in 13 states became ill with Vibriosis from May 12, 2013, through August 19, according to the Center for Disease Control (CDC). The CDC also estimates that for every confirmed diagnosis of Vibriosis, there are 142 people who contract it and don’t seek medical help.

A perplexing foe

It’s a general consensus among the experts that warming ocean temperatures are behind the spread of Vibrio. But there’s great uncertainty about how, and if, Vibrio can be controlled.

“The more we look into Vibrio, the more we realize we don’t know,” said Mr. Hickey. “On the east coast alone, 29 different strains of Vibrio have been identified. We don’t know which strains are pathogenic or not.

“The strain of Vibrio that shut down the east coast this past summer is a pandemic strain. It’s worldwide, it’s been around. It’s the same one that shut down Washington state last year, and probably originated in India.”

Mr. Hickey said another complication is that tracing the source of a Vibrio outbreak is a slow and costly process. In the best of circumstances, it can take more than a month after a harvest to determine where the infected bivalve came from.

As demand for commercially raised oysters increases, so does the need for better industry oversight. According to Mr. Moore, the 351 local boards of health in the state, many of them already overstretched, will be crucial in the process. “I speak gently about the local boards of health because I was a health agent for over 20 years,” said Mr. Moore. “Most of them are already busy with home inspections and septic inspections as well as food safety, and you have an increasing number of establishments across the state that are serving oysters. So we’re challenging them to do something they’re not normally asked to do. But we will do our best to help them.”

Mr. Blake said the state needed to do what it could to help. “It seems like the state is relying quite a bit on the local boards of health,” he said. “I feel the state has more expertise. Perhaps they should be the ones to follow up on the initial investigations.”

Mr. Moore told Mr. Blake that there were only four statewide inspectors on the job last year. More inspectors will be added in 2014 with money appropriated by state legislature at the request of Governor Deval Patrick. But the onus will remain on the local farmers and local governments, he said.

Thomas Pachico, Tisbury health agent, questioned a process that could potentially shut down the entire industry at the beginning of the summer because of two retailer mistakes. He also suggested that people may get sick from Vibrio simply because they haven’t built up an immunity. “Who’s to say some person from Michigan isn’t more susceptible to Vibrio than someone like me, who’s been eating oysters my whole life and never got sick” he said.

Looking ahead

Mr. Shields told the farmers that the Food and Drug Administration has raised questions about the technique of air drying — pulling oysters out of the water for 48 hours to kill harmful organisms that grow on their shells, like jingle shells, barnacles, and mussels. Oyster farmer Ryan Smith, to the agreement of many in the room, said that air drying is a crucial step, and without it, he’d have to scrape every oyster individually, which would keep the oysters out of the water even longer, and would also be economically unfeasible.

Mr. Shields asked the assembled fishermen if they would consider re-submerging all air-dried oysters for two weeks after air drying, as an extra precaution. They quickly and unanimously agreed.

Mr. Blake suggested that the group consider banning same-day sales to give time to chill the oysters at or below a Vibrio-killing 50 degrees before they’re sold. Mr. Cyr said this was already a regulation in New Jersey, although its efficacy has yet to be proven.

Based on Monday’s discussion, it would be easy to conclude that despite the best precautions of Vineyard oyster farmers, there will be many opportunities for the Vibrio bacteria to befoul bivalves after they leave Katama Bay. It can occur when the oysters are transported to the dealer, or if the the dealer mishandles them. It can occur when the dealer transports them to the retailer, or when they’re mishandled by the retailer, or the chef, or the wait staff. The rapid growth of oyster sales on the internet has only added to the retail challenge.

“I grew up around the oyster industry,” said Mr. Cyr. “I know there is a lot of abuse at the retail level.”

There’s also little the Katama farmers can do about warming ocean temperatures, which experts agree is the driving force behind Vibrio’s northern expansion. According to the most updated science from the CDC, the four months without an “R” in them are indeed the time oysters are at greatest risk of Vibrio. The idea dates back to Englishman Henry Buttes’s 16th century cookbook, “Dyets Dry Dinner.”

Eating raw shellfish always involves an element of risk, no matter what time of year, but since the heat from cooking kills Vibrio, it’s a risk any oyster lover needn’t take, at any time of year.

Mr. Cyr said there will be a second round of meetings on the Vineyard sometime in February to discuss the outcome of the ISSC meetings. There will also be training seminars for local boards of health in April, after which they hope the boards of health will in turn hold seminars for retail establishments and restaurants.

“We’re trying to find out what’s going to work here,” said Mr. Hickey. “We’ll be back in a few weeks.”