Alberta: Gastrointestinal illnesses may be linked to raw oysters in Edmonton
Ten cases of gastrointestinal illness potentially linked to consumption of raw oysters are under investigation in the Edmonton Zone, prompting Alberta Health Services (AHS) to remind all Albertans of the risk of illness associated with consumption of raw shellfish.
To reduce risk of illness, AHS advises Albertans to:
- Eat only properly cooked shellfish. Cooking will decrease the risk of illness and it is recommended to avoid eating any raw or undercooked shellfish.
- Specific to oysters, cook to an internal temperature of 90 C for 90 seconds.
- 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.
- Wear protective clothing (such as gloves) and wash your hands both before handling any food and frequently while handling raw shellfish.
- Sanitize cutting boards, counters, knives and other utensils after preparing raw foods.
Illnesses associated with raw oysters or shellfish contaminated with viruses or bacteria commonly cause watery diarrhea and abdominal cramps. Other symptoms can include nausea, vomiting, fever, headache and bloody stools. Although anyone who consumes raw shellfish is at risk of illness, people with weakened immune systems, young children, pregnant women and older adults are at increased risk for developing complications if they get sick.
Individuals who develop these symptoms within 10 to 50 hours of eating raw shellfish are advised to contact Health Link at 811 to report the illness. As with most gastrointestinal illnesses, symptoms typically last for one day 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 cluster of gastrointestinal illnesses currently under investigation in the Edmonton Zone experienced onset of symptoms between Jan. 10 and 12, 2017. The type of illness has not been lab-confirmed. This is the first outbreak investigation into illness potentially linked to consumption of raw oysters in Alberta since 2015, when 19 cases of Vibrio parahaemolyticus infection were linked to consumption of raw oysters.