Climate change is increasing the number of pathogens in oysters, according to a study published in the National Academy of Sciences. The bacteria Vibrio parahaemolyticus and vulnificus occur naturally in the ocean. Their numbers increase when the water temperatures increase. And oysters, since they are filter feeders, take up these bacteria. When the oysters are eaten raw, people get sick. There have been been many harvesting warnings and recalls of oysters for these pathogenic bacteria in the past few years. And in 2013, there was a Vibrio outbreak associated with raw oysters that sickened at least 104 people in 13 states. Most of these illnesses occur during May to October in the United States, when people eat raw oysters. The bacteria reproduce quickly when the water is … [Read more...]
Why Undercooked Oysters Can Make You Sick
Public Health-King County is telling consumers why raw oysters can make you sick. Jenny Lloyd, one of the epidemiologists who has been investigating foodborne illness outbreaks linked to oysters in that state, answered some questions. The current outbreaks in Seattle have been caused by Vibrio bacteria. That bacteria lives in marine waters. Their numbers increase during the warm summer months, which explains the current crop of outbreaks. Since oysters are filter feeders, the bacteria concentrate in their flesh. Eating raw or undercooked shellfish, especially oysters, is the main risk for contracting this illness. Most seafood should be cooked to an internal temperature of 145°F. Fish should be opaque and separate easily when tested with a fork. Clams, mussels, and oysters should … [Read more...]
Oysters Recalled in Washington After Norovirus Outbreak
The Washington State Department of Health is recalling oysters and closing harvest areas after a norovirus outbreak. Over the past few weeks reports of illness in people who have eaten raw oysters from several areas in the state have been received. Small harvest closures and recalls have been ordered over the past few weeks. The largest closed area is in Hammersley Inlet in Mason County. In that area, a recall has been issued for any shellfish harvested there since March 15, 2017. The three-mile stretch of commercial shellfish growing beds is harvested by 31 shellfish companies and is shipped to many areas around the word. The Department of Health is working with shellfish growers, officials in other states, and local health department to trace all of the product and recall it to … [Read more...]
Norovirus Outbreak in Washington Associated with Raw Oysters
Public health officials in Seattle and King County are investigating multiple reports of a norovirus-like illness in people who ate raw oysters. Since January, officials have received reports that as many as 39 people were sickened after eating that shellfish. Illnesses have been reported during the time period ranging from January 10 through March 20, 2017. Public health has reported the illnesses to the Washington State Department of Health Shellfish Program, which tracks the reports and harvest locations of the oysters implicated in this outbreak. The oysters were all harvested from different growing areas and bays in Washington state with the exception of four meals. Those four meals, which account for 22 of the illnesses, were made of oysters harvested from a small bay in the … [Read more...]
Norovirus Outbreak in Canada Linked to Raw and Undercooked Oysters
The Public Health Agency of Canada is investigating an outbreak of gastrointestinal illnesses linked to raw and undercooked oysters. The illnesses have occurred in British Columbia, Alberta, and Ontario. Testing of several cases, but not all, has confirmed norovirus. Officials think that norovirus is the cause of illness in the untested cases. The outbreak notice states "the risk to Canadians is low." This type of illness can be avoided if oysters are cooked to an internal temperature of 90°C/194°F for a minimum of 90 seconds, and proper hand washing and food safety practices are followed. As of February 7, 2017, 202 clinical cases of illness linked to oysters have been reported in three provinces. The case count per province is: British Columbia (143), Alberta (35), and Ontario … [Read more...]
Norovirus Outbreak in Washington Associated with Raw Oysters
King County Public Health is investigation a cluster of "norovirus-like" illnesses associated with eating raw oysters in their area. That virus is found in the stool and vomit of infected people. The virus is very contagious and is spread through contamianted food and person-to-person contact. Consuming raw and undercooked shellfish, especially oysters, increases your chances of getting sick. On January 19, 2017, Public Health was notified about 4 cases of norovirus-like illness from the same party who eat raw oysters at Taylor Shellfish, located at 124 Republican Street in Seattle on January 4, 2017. The patients got sick about 24 hours after eating the oysters, with symptoms including nausea, vomiting, diarrhea, abdominal cramps, headache, and muscle aches. Environmental Health … [Read more...]
Maryland Vibrio Outbreak in 2010 Traced to Asia
A study published in the Journal of Applied and Environmental Microbiology, of the American Society for Microbiology, has discovered that a Vibrio parahaemolyticus outbreak in Maryland in 2010 was caused by raw oysters harvested from the Chesapeake Bay, but the bacteria in those oysters came from Asia. The outbreak sickened two people who ate raw oysters at two different restaurants in Baltimore. Neither patient had graveled outside of the state in the week before they got sick, and neither had other risk factors for Vibrio infections. The outbreak strain of Vibrio, called "sequence type B" was identified because it was the only strain present in both the patients' stools and in the oysters. And that particular strain had previously only been found in Asia. So how did bacteria from a … [Read more...]
Hawaii Recalls Korean Raw Oysters After Norovirus Outbreak
The Hawaii State Department of Health is recalling frozen, raw oysters imported from Korea because they are associated with a norovirus outbreak. The oysters were sold in bulk to distributors and food establishments in the state. Peter Oshiro said in a statement, "the department has already conducted product trace-backs and embargoed all of the suspect product on November 24, 2015 at various local shellfish distributors and restaurants. Although this product is not sold directly to the public, a recall has been issued as an additional safeguard to further notify anyone who may possess the product that it is unsafe and should be destroyed." A product embargo prohibits businesses from using or selling a product suspected of causing illness. At least 11 people have been sickened with … [Read more...]
Martha’s Vineyard Oyster Beds Closed for Vibrio
The Massachusetts Department of Health has ordered a precautionary closure of oyster beds in Edgartown in Katama Bay effective August 26, 2015. There are three confirmed cases of Vibrio food poisoning linked to consumption of raw oysters harvested in that area. Environmental conditions are conducive to the growth of the Vibrio parahaemolyticus bacteria there. Harvesting and processing of shellfish from these areas for commercial use is prohibited for the next seven days. If more cases are confirmed, an extended FDA-enforced closure could be issued. This is the first time a harvest area in Massachusetts has been closed because of Vibrio contamination this year. Vibrio bacteria grow in warmer waters, multiply as the temperature increases. The current water temperatures in Katama Bay … [Read more...]
In Canada, Oysters Recalled for Vibrio
Industry is recalling oysters harvested from British Columbia coastal waters on or before August 18, 2015 and intended for use as raw consumption for possible Vibrio parahaemolyticus contamination. Consumers should not eat these oysters raw and retailers and food service establishments should not sell or use them. There is no UPC number on these products, and the oysters are sold in various sizes. If consumers are unsure if they have affected oysters, check with their place of purchase. Vibrio is a naturally occurring bacteria that is present at high levels in some coastal waters when the water is warm. Most people contract a Vibrio infection by eating raw or undercooked shellfish, especially oysters. There is a Vibrio outbreak associated with the consumption of these products. … [Read more...]
