Oysters that recently sickened 22 people with vibriosis, an intestinal disease resulting from the ingestion of tainted raw oysters, seem to have come from the southwestern part of the state and King County, a state Department of Health spokesman said Friday.
“The good news is that none of them are in your area,” said Gordon MacCracken, public information officer for the department.
However, the Health Department advises people to refrain from eating raw oysters during July and August, when warm weather and low tides encourage the growth of the vibrio parahaemolyticus bacteria.
“We advise people not to eat raw oysters this time of year,” MacCracken said.
“If oysters are cooked properly, they should be safe.”
The state department said last week that, so far, 18 vibriosis illnesses have been linked to commercial operations and four illnesses to recreational harvesting in Puget Sound and on the Washington coast.
No commercial operations in East Jefferson County are implicated in the illnesses, MacCracken said.
“Our information is that the oysters came from the southwestern part of state and King County,” he said.
None of those who fell ill were from the Peninsula, he said.
Locations of cases
Five were from King County, while another five were from Pacific County.
Two each were reported in Grays Harbor and Skagit counties, while one each were from Clark, Thurston, Island, Mason, Yakima, Pierce, Snohomish and Lewis counties.
None of the illnesses was fatal. MacCracken said vibirosis, which can be contracted by eating raw oysters containing vibrio parahaemolyticus bacteria, is “usually mild to moderate.
“It can threaten people’s lives, especially if they have immunity issues or liver issues,” he said, “but in most cases, it’s an unpleasant disease and not usually deadly.”
Oysters should be cooked at 145 degrees for at least 15 seconds to destroy the vibrio bacteria, MacCracken said.
The bacteria that causes the illness is a “naturally occurring bacteria that especially occurs during summer when water is warmer and tides are low,” he said.
Vibriosis symptoms may include diarrhea, nausea, stomach cramps, headache, vomiting, fever and chills.
Symptoms typically appear within 12 to 24 hours after infected shellfish is eaten and can last two to seven days.
Health Department tips
Tips for those who harvest oysters recreationally:
■ Put oysters on ice or refrigerate them as soon as possible after harvest.
■ If a receding tide has exposed oysters for a long time, don’t harvest them.
■ Always cook oysters thoroughly. Rinsing fully cooked oysters with seawater can recontaminate them.
The Health Department also encourages people to check the website or phone before harvesting oysters to get the most recent information about safety, MacCracken said.
For commercial harvesters, special control measures are in place from May through September, the Health Department said.
Shellfish companies must quickly refrigerate oysters after they’re harvested and are required to keep detailed harvest and temperature control records to show that the oysters were handled properly.
For more information, visit www.doh.wa.gov/ehp/sf/default.htm or phone the Health Department’s toll-free hotline at 800-562-5632.