OSTON –– The Massachusetts Department of Public Health (DPH) and the Massachusetts Department of Fish and Game’s, Division of Marine Fisheries (DMF) today issued a week-long precautionary closure of oyster beds (V:20) in Katama Bay in the community of Edgartown, MA effective August 26, 2015. This precautionary closure is due to three confirmed cases of vibrio linked to consumption of raw oysters from the area, and the presence of environmental conditions conducive to the growth of Vibrio parahaemolyticus (Vibrio) in oysters harvested from the area.
Harvesting and possession of shellfish from these areas for commercial purposes is prohibited for seven days with the issuance of this precautionary closure. Should more cases be confirmed, an extended US FDA-enforced closure could be issued. This is the first time a specific harvest area in Massachusetts has been closed due to Vibrio this year. The decision to issue a precautionary closure was made jointly between DPH and DMF officials in response to warming waters in Katama Bay, anticipated high air temperatures forecast for the coming days, and identification of a third confirmed case of Vibrio tied to the Katama Bay harvest area. In each of the cases, the individuals who consumed the raw oysters have recovered.
Vibrio is a bacteria that thrives in warmer temperatures, multiplying as water and ambient air temperatures increase. The more Vibrio present in oysters the greater the risk of infection. Current water temperatures in Katama Bay are consistent with water temperatures and environmental conditions that were associated with an increased occurrence for Vibrio illnesses in 2013 and 2014.
DPH and DMF have successfully partnered with industry to develop controls to mitigate risk of Vibrio associated with Massachusetts harvested oysters. A statewide Vibrio Control Plan has been in effect since 2013.
The Vibrio season in Massachusetts runs from May to October. Health officials are reminding all persons who are at high risk, especially those who are elderly or immune compromised, to avoid eating any raw shellfish.
Background
Vibrio is a bacteria that occurs naturally in coastal waters in the United States and Canada. It has caused illnesses in the Gulf Coast and West Coast of the United States for a number of years. It is not related to pollution of Massachusetts shellfish.
When ingested, Vibrio causes watery diarrhea, often with abdominal cramping, nausea, vomiting, fever and chills. Usually these symptoms occur within 24 hours of ingestion and last three days. Severe illness, increased risk of infection, and serious complications, including death, may occur in the very young, elderly, pregnant women, and immune impaired individuals such as people with underlying medical issues, such as liver disease or alcoholism. About 10 percent of cases will develop a blood infection that may require hospitalization. Vibrio can also cause an infection of the skin when an open wound is exposed to warm seawater.
In 2012, the FDA recommended that DPH and DMF – the two state agencies with joint authority over shellfish sanitation and control – implement a Vibrio control plan for shellfish harvest and growing areas in Eastern Cape Cod Bay. Due to the increase in Vibrio cases in 2012, and continued reports of Vibrio among consumers reporting consumption of raw oysters in waters beyond Eastern Cape Cod Bay, the FDA advised Massachusetts to expand Vibrio controls to all oyster harvest areas in 2013.
More information on Vibrio parahaemolyticus is available here.
Source: Massachusetts Department of Public Health (DPH)
