First announced in Alberta on Jan. 20, this outbreak remains active and has sickened 40 Albertans with gastrointestinal symptoms as of March 7. Some of these cases have been lab-confirmed as norovirus.
As illnesses linked with consumption of raw and undercooked B.C. oysters continue to be reported, AHS is again reminding Albertans of the health risks associated with consumption of raw oysters and strongly encouraging all Albertans to take the following precautions:
• At this time, if oysters are from B.C., be sure to only consume if fully cooked. Do not consume if raw or undercooked.
• In general, eat only properly cooked oysters and shellfish. Cooking will decrease the risk of illness.
• Cook oysters to an internal temperature of 90 C for 90 seconds.
• Discard any shellfish that did 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 and undercooked oysters or other 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 or undercooked 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 oysters or 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 Alberta cases have been reported in Calgary and Edmonton Zones, and all experienced onset of symptoms between January and February. This is the first outbreak investigation into illness linked to consumption of raw oysters in Alberta since 2015, when 19 cases of Vibrio parahaemolyticus infection were linked to consumption of raw oysters.
For more information, visit: http://www.phac-aspc.gc.ca/phn-asp/2017/outbreak-norovirus-eclosion-eng.php.