Authorities in Alberta, Canada are advising people against eating raw or undercooked oysters, clams, mussels, scallops and cockles as raw shellfish increases risk of Vibrio parahaemolyticus infection.
The advisory comes as the authorities continue to investigate 19 cases of Vibrio parahaemolyticus infection in Alberta. The Alberta Health Services (AHS) is reminding all Albertans of the risk of this illness and important precautions to protect themselves.
Vibrio parahaemolyticus is a bacteria that occurs naturally in ocean waters with higher concentrations during summer months. The bacteria is found in shellfish such as oysters, clams, mussels, scallops and cockles.
The bacteria can cause illness in humans who consume raw or undercooked shellfish contaminated with high numbers of
this bacteria. Vibrio parahaemolyticus infection most commonly causes watery diarrhea and abdominal cramps. Other symptoms include nausea, vomiting, fever, headache and bloody stools.
Though everyone who consumes raw shellfish is at risk of this illness, people with weakened immune systems, young children, pregnant women and older adults are at increased risk for developing complications if they get sick. Symptoms typically last for three days to a week and usually do not require any treatment; however, any Albertan whose symptoms persist or become more severe should visit a doctor.
The following are the precautions to reduce the risk of illness:
- eat only properly cooked shellfish. As cooking will destroy the bacteria and decrease the risk of illness, it is recommended that Albertans avoid eating any raw or undercooked shellfish;
- discard any shellfish that do not open when cooked;
- eat shellfish right away after cooking and promptly refrigerate leftovers;
- keep raw and cooked shellfish separate;
- keep purchased shellfish cold. Refrigerate immediately after purchase, and keep at temperatures below 4°C;
- avoid eating oysters, or other seafood, when taking antacids, as reduced stomach acid may allow the Vibrio bacteria to survive and grow in the intestinal tract;
- avoid exposing open wounds or broken skin to warm salt or brackish water, or to raw shellfish. Wear protective clothing (like gloves) when handling raw shellfish;
- wash hands well with soap before handling any food. Be sure to wash your hands, cutting boards, counters, knives and other utensils after preparing raw foods.
