VANCOUVER -- As the federal government prepares to evacuate 237 Canadians from a cruise ship that's been on lockdown in California, the country's top doctor is warning the public to avoid cruises altogether.

At a press conference Monday, Chief Public Health Officer Dr. Theresa Tam said the Public Health Agency of Canada is recommending all Canadians to stay away from cruises due to COVID-19 concerns.

"Cruise ships have passengers from around the world who may be arriving from areas with known or unknown spread of the novel coronavirus," Tam said. "The virus can spread quickly on board cruise ships due to the close contact between passengers."

The Grand Princess was forced to idle off the coast of California for days because 21 on board tested positive for COVID-19 and one person subsequently died.

"We are working hard to help Canadians return home and make sure appropriate measures are in place to prevent and limit the spread of COVID-19,” Foreign Affairs Minister Francois-Philippe Champagne said in a written statement.

Passengers will be screened for symptoms before they board a chartered plane. Those without symptoms will be quarantined for 14 days in a Canadian forces base in Trenton, Ont. Those who show symptoms will stay in the U.S.

2 COVID-19 patients were on cruise ship

Two British Columbians, a man and a woman in their 60s, are now hospitalized in the Lower Mainland after they returned from a previous voyage on the Grand Princess last month.

Over the weekend, B.C. Health Minister Adrian Dix told people not to board cruise ships. On Monday, Dr. Bonnie Henry echoed that sentiment.

"There's really no way to effectively screen people out of cruise ships so it is really taking a chance on your health at the moment," Henry said.

Vancouver's cruise ship season is scheduled to kick off in three weeks , but Henry said there are ongoing discussions with federal officials whether that date should be postponed.

"We are in a very critical time around the world and it is my belief that we should be delaying our cruise season until we are in a safer place internationally," she said.

The International Cruise Line Association said its members have taken added measures to protect the health and safety of everyone on board.

Some of the changes include deny boarding to everyone who has travelled from or visited airports from several countries and who have been in contact with anyone suspected or diagnosed as having the coronavirus, and conduct pre-boarding and temperature screenings.

“We remain in close contact with local governments around the world, and while we regret that these changes will result in the denial of boarding for some of our guests, travellers should know that their health and safety is the absolute priority for the industry,” said Kelly Craighead, President and CEO of CLIA, in a statement.

Tourism taking a hit

Louise Vargas' Gastown Soapworks has a perfect vantage point of Vancouver's popular steam clock, a magnet for visitors.

But lately, she has noticed there are fewer people roaming the Gastown streets.

"This block is normally full of people at this time of day, but it's pretty quiet now," she quipped.

She said she has noticed fewer Asian tourists who typically stop by Gastown before or after their trips to the ski hills.

"The skiers have not been coming. So cruise ships? We will have to wait and see," she said.

Since Vargas' store specializes in soaps, she said she has actually seen an uptick in business from locals.

"Before, we would see people purchase one or two bars, but now they repurchasing three or four at a time. They're sort of stocking up, I think," she said.

Dr. Henry said the province's tourism industry has been impacted by the outbreak.

"The tourist industry is being hard hit by this but my primary concern is the health and safety of British Columbians and I have grave concerns about cruises right now," she said.

The first ship to pull into port in Vancouver is the Grand Princess, the same ship with known coronavirus cases, which is scheduled for April 2.

The port authority said there are ongoing discussions about possible itinerary changes with cruise line partners and other agencies.

"At this point, we are still waiting on any guidance from Health Canada and relevant agencies with respect to this year’s cruise season," said Danielle Jang, spokesperson for Vancouver Fraser Port Authority, in an email statement to CTV News.

She said they expect to receive an update from the federal government soon.