There is cause for cautious optimism that the spread of the COVID-19 epidemic is slowing, Canada's top doctor said Wednesday, as the country's central bank warned that the economic downturn tied to the virus would be the worst on record.

Even as the country passed the grim milestone of 1,000 deaths on Wednesday, chief public health officer Dr. Theresa Tam said there is evidence the epidemic's rate of spread is slowing.

Tam noted the number of cases in the country is now doubling every 10 days or so, compared to every three days in late March. But she warned that emerging from COVID-19 would "be like making our way down the mountain in the darkness," stressing that it was too soon to ease physical distancing measures.

"We mustn't rush or let go of our safety measures, or the fall will be hard and unforgiving," she said in her daily briefing in Ottawa.

Prime Minister Justin Trudeau said Wednesday that widespread testing and contact-tracing will be key to an eventual reopening of the Canadian economy — something he said is still weeks away.

"We have to be through this first wave sufficiently to be able to know we have the capacity to stamp out and restrict any future outbreaks as they come along," he said. "That means technology, that means better testing capacity, that means continued vigilance, not just by governments but by all Canadians .... We're still a number of weeks away from that."

Trudeau announced New Brunswick company LuminUltra was increasing production of chemicals needed to provide the required weekly supply for COVID-19 tests in all provinces. The country has received more shipments of the swabs needed for the tests, he said.

The pandemic has led to an unprecedented economic collapse, forcing the closure of businesses and sharp declines in consumer spending as people have been urged to stay home to stop the spread of the virus.

Bank of Canada Governor Stephen Poloz spoke with reporters in Ottawa on Wednesday. 2:58

Economic activity dropped a record nine per cent in March, according to preliminary data released by Statistics Canada.

Despite the bleak news, Trudeau was blunt as he warned that easing restrictions too soon could unleash a second wave of infections just as damaging as the first.

"If we reopen too soon, everything we're doing might be for nothing," he said.

Conditions for economic rebound

Provinces including P.E.I., New Brunswick, Newfoundland and Labrador and Manitoba each reported three or fewer new cases on Wednesday, but devastating outbreaks continued to sweep through long-term care centres, killing vulnerable seniors by the dozens.

The death toll across the country surpassed the 1,000 mark with the announcement of 51 more fatal cases in Ontario and 52 in Quebec. As of 2 p.m. the country counted more than 28,000 confirmed COVID-19 cases, with over half of them in Quebec.

The province's premier, Francois Legault, made a desperate plea for family doctors and medical specialists to help out in long-term care homes, where major outbreaks have exacerbated long-running staffing issues.

Quebec has released a five-page list of seniors' residences and care homes with at least one COVID-19 case, including 25 institutions where at least a quarter of residents are infected. Those include a long-term care home in Laval, north of Montreal, which counted 26 dead and more than 120 infected.

Ontario, meanwhile, had 98 facilities reporting COVID-19 outbreaks that have together killed at least 145 residents, including 29 who died at Pinecrest Nursing Home in Bobcaygeon, and 27 at Eatonville Care Centre in Toronto. In an effort to counter the economic blow of COVID-19, the Bank of Canada kept its key interest rate target on hold at 0.25 per cent, saying that it is effectively as low as it can go.

The central bank's economic outlook said the speed of the anticipated rebound rests on the shoulders of containment efforts to bring the pandemic under control.

Bank of Canada Governor Stephen Poloz spoke with reporters in Ottawa on Wednesday. 3:07

Some six million people had filed claims by Sunday night for a $2,000-a-month emergency benefit for help during the first four-week eligibility period.

To give a boost to struggling workers, Trudeau expanded the criteria of the Canada Emergency Response Benefit on Wednesday to include seasonal workers, those who are still working but earning less than $1,000 a month and those whose employment insurance has run out.

He said he would also be working with the provinces to raise the salaries of essential workers who earn less than $2,500 a month, which includes many working in care homes.