(Bloomberg) -- In the U.S., Covid-19 infections are shrinking by the day. In France, officials are preparing to ease lockdown restrictions and jump-start air travel. In the U.K., workers are returning to offices in numbers not seen since the start of the pandemic as the vaccination rollout continues and cases fall.

Not so in the oil sands of western Canada, where thousands of roughnecks have descended upon barracks in work camps and have turned the area, which accounts for more than half of America’s oil imports, into a hot spot for a resurgence of the pandemic.

It’s the latest blow to the oil-rich province of Alberta that in the past years has struggled with two crude-market crashes, rising unemployment, plus devastating wildfires and floods. Now, the pandemic that’s led scores of restaurants and other businesses to shut in urban centers like Calgary is hitting the industry that accounts for 16% of the economy.

“It’s out of control,” said Allan Adam, chief of the Athabasca Chipewyan First Nation, an indigenous community in the region. He pegs the surge in new cases to the fly-in-fly-out nature of many jobs in the oil sands. “I am more worried about our health care system. If that collapses, then all hell breaks loose.”

A slower rollout of vaccines in Canada, combined with growing outbreaks of more contagious variants, has prompted lockdowns across the country and restrictions on inter-provincial travel.

Twelve oil-sands production sites have been listed for outbreaks just as contractors are flying in for maintenance season.

Over 2,000 Covid-19 cases have been linked to the facilities, with 752 considered active, according to Alberta Health data. Two people have died. The latest was a woman in her 50s in a case linked to Suncor Energy Inc.’s Base Plant.

Sites owned by Exxon Mobil Corp.’s Imperial Oil and Canadian Natural Resources Ltd. have also seen outbreaks.

The surging case numbers and hospitalizations prompted the Regional Municipality of Wood Buffalo in northern Alberta to declare a state of local emergency on Sunday.

In the remote town of Fort McMurray, the gateway to the oil sands that was devastated by massive blazes five years ago, the Northern Lights Regional Health Center has postponed 40 elective surgeries and some ambulatory care services are being limited, Kerry Williamson, a spokeswoman for Alberta Health Services, said.

More than 1.5% of Fort McMurray’s population is currently infected with coronavirus, the highest rate in Alberta, which has the highest rate in Canada, government data show.

When the pandemic started last year, oil sands companies and work camp operators that housed them faced a similar situation. Employees who weren’t required at the production sites were told to work from home. Workers were spread out on the buses that transport them to and from the oil sands sites and employees took lunch breaks at different times to ensure mess halls didn’t become overcrowded. This latest wave of infections is worse.

So far, oil sands companies haven’t reported any impact to production, but the outbreaks are affecting maintenance work.

Suncor has postponed to June from May the shutdown for maintenance of the U2 upgrader at its Base Plant, which turns thick bitumen dug out of open-pit mines into as much oil a day as what’s produced in the entire state of Wyoming. Two other Suncor sites have also been linked to outbreaks, with a total of 166 active cases.

Suncor has implemented protocols to keep workers safe and is offering rapid antigen screening to quickly detect asymptomatic individuals, keeping transmission rates “very low,” the company said by email.

Syncrude Canada, which is majority-owned by Suncor, began maintenance involving 2,000 people from the local communities and around Alberta on its 350,000-barrel-a-day upgrader last month but stretched the work out over a longer-than-normal time frame to control the spread of disease, Will Gibson, a company spokesman, said. Still, there are 221 active cases of Covid-19 linked to its operations.

“We have seen an increase and that reflects the increase in the wider community in Fort McMurray,” Gibson said, adding that some asymptomatic cases were detected because of rapid testing.

At Canadian Natural’s Horizon upgrader, Alberta Health has been notified of 294 active cases. Maintenance work at Horizon this month should reduce production by 250,000 barrels a day, company President Tim McKay said in March. The company also has 22 cases in two other sites.

The company has been “rapid testing asymptomatic staff during our Horizon maintenance period in April,” Julie Woo, a spokeswoman, said by email. “This testing is helping us to quickly identify, contact trace and limit the spread of COVID-19 at our work site.”

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