Right on the heels of a Vibrio outbreak in Missouri, the Washington state Department of Health is warning consumers to cook oysters before eating them. Traditionally, raw oysters are avoided in the summer months (months without an “R” in the name) because Vibrio parahaemolyticus grows more readily in brackish water during the warm summer months.
Jerrod Davis, director of the Department of Health’s Office of Shellfish and Water Protection, said in a statement, “Vibriosis is completely preventable. We want people to enjoy our state’s wonderful shellfish, and following some simple safety tips can help keep people healthy this summer.” Most people cook shellfish, such as oysters, mussels, and clams, until the shells open. But that’s not enough to kill any bacteria that may be present. Shellfish should be cooked to a minimum internal temperature of 145 degrees F for at least 15 seconds to be safe.
If you boil shellfish, cook for 3 to 5 minutes after the shells open, then check the internal temperature with a food thermometer. If you choose to steam shellfish, cook for 4 to 9 minutes after the shells open. Check with that thermometer again. Unfortunately, shellfish can be the source of other illnesses, according to the Department. The Office of Shellfish and Water Protection also monitors shellfish for biotoxins, such as paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), and diarrhetic shellfish poisoning (DSP) that exist in the waters off the coast.
Those toxins are not destroyed by cooking; anyone who eats shellfish, cooked or raw, contaminated with those toxins can die. You can’t tell by looking at, smelling, or tasting shellfish if it contains those toxins; only lab tests can detect them. There were 825 cases reported to the Centers for Disease Control and Prevention in 2009, the latest year for which statistics are available.