Norovirus outbreaks linked to oysters sign of water pollution: shellfish group

Marsha Taylor, B.C. Centre for Disease Control epidemiologist, said norovirus contaminates foods

Oysters contaminated with norovirus in British Columbia have become a costly problem and the issue magnifies a broader failure to keep oceans clean, says the provincial shellfish growers association.

Darlene Winterburn, the executive director with the B.C. Shellfish Growers Association, said the latest outbreak this spring will likely take a “significant” toll on the province’s industry that is still trying to absorb $9.1 million in losses from last year.

“It’s significant because a lot of people haven’t recovered from last time, it’s significant because branding is being affected and it’s significant because the uncertainty is making particularly small guys very hesitant to reinvest,” she said.

The Public Health Agency of Canada said 172 people reported getting sick in B.C., Alberta and Ontario in March and April after eating raw oysters. It follows an outbreak that started in November 2016 and sickened 400 Canadians over a five-month period, ending in March 2017.

Norovirus, a gastrointestinal illness, causes diarrhea and vomiting and is easily spread from person to person with symptoms beginning as early as 12 hours after exposure to the virus, the agency said. Most people feel better after a day or two, although those with compromised immune systems can suffer from more severe symptoms.

The latest outbreak led the United States Food and Drug Administration to release a warning this week for consumers and retailers to avoid potentially contaminated oysters from Canada.

The U.S. warning said the raw oysters were harvested in the south and central parts of Baynes Sound, an area between Denman Island and Vancouver Island, and could be distributed in a number of states including Washington, New York, and Massachusetts.

READ MORE: Two B.C. oyster farms closed by norovirus

READ MORE: Reported illnesses from eating raw B.C oysters appear to be dropping

The California Department of Public Health said about 100 people became ill with norovirus after consuming raw B.C. oysters.

The Canadian agency said the number of people reporting illnesses has been on the decline since April 27 and the investigation into the specific source of the contamination is ongoing.

Marsha Taylor, an epidemiologist with the B.C. Centre for Disease Control, said norovirus can contaminate various foods and oysters are typically affected when taking in sewage from water.

“(Oysters) filter the water that can be contaminated with norovirus and then they become contaminated with norovirus and then we unfortunately consume them and make ourselves sick that way,” she said.

Sickness can be prevented by cooking oysters for at least 90 seconds at 90 degrees Celsius, Taylor said, adding practising good hygiene, such as hand washing, can help prevent the spread of the virus.

Winterburn said although the specific source of the contamination wasn’t pinpointed in last year’s outbreak, the current investigation is likely to be more conclusive, which can help prevent future incidents.

Farms in the area of Baynes Sound have been closed as a precaution while the investigation is underway, and Winterburn said oysters from other areas of B.C. remain safe for consumption.

“The vast majority of the industry is functioning as normal,” she said, adding that unaffected farms are still seeing a decline in orders because of fears the problem is more widespread.

Winterburn said these incidents point to a broader issue of polluted oceans.

“The oyster is telling us something,” she said. “We need to be very cognizant of what it is we’re putting into our water.”

Sewage treatment practices, the quality of septic systems and illegal dumping from vessels are all areas Winterburn said improvements could be made that would prevent contamination and better preserve the marine environment.

Linda Givetash, The Canadian Press

Just Posted

The coroner on scene of a workplace fatality in Oak Bay on Oct. 20, 2020. (Nina Grossman/News Staff)
Police investigate workplace death during tree trimming in Oak Bay

Traffic restricted on McNeill Avenue near Byng Road

A bear similar to this black bear is believed responsible for killing a llama in Saanich on Oct. 19. (Black Press Media file photo)
Saanich residents warned to watch livestock after bear kills llama

Officers with Conservation, Saanich police could not track the bear they feel may not fear humans

Freighters have becomd abundant in the Trincomali Channel on the east side of Thetis Island.
Federal NDP leader promises to champion freighter traffic control of southern Vancouver Island

Jagmeet Singh, local NDP candidates spoke in North Saanich Saturday morning

People will soon be able to vote on the “human” names of the two newly born calves of the Southern Resident killer whale population, J57 and J58. (The Canadian Press/ The Center for Whale Research)
Vancouver Islanders can help choose names for two new baby orcas

Southern Resident killer whales J57, J58 born Sept. 4 and 24

Working smoothly together on May 11, 2020, health minister Adrian Dix, B.C. Liberal health critic Norm Letnick, provincial health officer Dr. Bonnie Henry and sign language interpreter Nigel Howard. (B.C. government video)
COVID-19 co-operation a casualty of B.C.’s pandemic election

NDP’s Horgan weaponizes senior care, B.C. Liberal Wilkinson calls for ‘wartime economy’

RCMP crest. (Black Press Media files)
RCMP cleared in fatal shooting of armed Lytton man in distress, police watchdog finds

IIO spoke to seven civillian witnesses and 11 police officers in coming to its decision

A 34-year-old man was treated for a gunshot wound in Williams Lake Monday, Oct 19, 2020. (Angie Mindus photo - Williams Lake Tribune)
Williams Lake man treated for gunshot wound after accidental shooting: RCMP

Police are reminding residents to ensure firearms are not loaded when handling them

A injection kit is seen inside the newly opened Fraser Health supervised consumption site is pictured in Surrey, B.C., Tuesday, June 6, 2017. THE CANADIAN PRESS/Jonathan Hayward
B.C. records 127 fatal overdoses in September, roughly 4 each day

Vancouver, Surrey and Victoria continued to see the highest numbers of overdoses

Investigators work at the Sagmoen farm in Silver Creek. - Image credit: Observer file photo.
Sex workers allegedly called to farm of Okanagan man convicted of assault, RCMP investigating

Curtis Sagmoen, convicted in relation to assault of sex trade workers, is prohibited from soliciting escorts

(Black Press Media files)
Early voters more likely to favour NDP, but overall B.C. election is tightening: poll

According to Elections BC, 383,477 people cast a ballot during advanced voting days

A jail cell at the Nanaimo RCMP detachment. (News Bulletin file photo)
Woman reports she was injured by Nanaimo RCMP while being jailed

Independent Investigations Office of B.C. looking into Oct. 1 incident

(Pixabay)
Wave of racist emails ‘unleashed’ on B.C. researchers investigating racism in health care

The team has received close to 600 calls and emails since the investigation started in July

Two Saanich businesswomen are taking over what was previously Dig This gardening store in Broadmead Village Shopping Centre, and turning it into a hub for local food and community. (Google Maps)
New restaurant, grocery hybrid brings local food and community to Saanich

Niche Grocerant is partnering with restaurants and producers to bring local food to the suburbs

Most Read