A Canadian resident who set sail on the cruise ship at the center of a global hantavirus outbreak has become the first person in North America to test positive for the illness.

Dr Bonnie Henry, British Columbia's provincial health officer, announced on Saturday that one of the four Canadians isolating in the province after disembarking the MV Hondius ship earlier this month received a 'presumptive positive' test.

She said the unidentified individual is part of a couple in their 70s from the Yukon who have been isolating since they returned to the country on May 10, and developed 'mild symptoms' on Thursday including a fever and a headache.

A test on the individual late Friday evening then came back positive for the Andes strain of hantavirus, which was later confirmed with further testing by the National Microbiology Laboratory in Winnipeg, according to the CBC. 

The other person also had 'minor symptoms' when they were assessed, but tested negative for the virus.

'The patient [who tested positive] is stable, the symptoms remain mild at this point and they are still in hospital in isolation, being monitored and receiving care as needed by the healthcare worker team in the hospital,' Henry said.

At the same time, she said, a third cruise passenger who was in isolation in British Columbia, also in their 70s, has been transferred to a hospital for assessment and testing out of an abundance of caution. 

Meanwhile, a fourth person from British Columbia in their 50s who lives abroad, continues to isolate at home.

Those in the hospital are being held in negative pressure rooms, said Dr Reka Gustafson, chief medical health officer for the Island Health Authority, as she assured the public that the two hospitals are prepared.

Henry has also noted that the province had infection control precautions in place from the moment the four cruise passengers arrived in British Columbia.

'I'm confident there's no additional risk to anybody else outside of the people who've been caring for these individuals,' she said. 

'They have no contact with the public, and health care workers are using well-established protocols that they know well, that are able to protect them, to protect the other patients in the health care facility, and visitors as well.'

The Public Health Agency of Canada echoed that statement, saying the overall risk to the general population from the Andes hantavirus outbreak linked to the cruise ship remains low.

'All confirmed cases to date have been passengers or crew on the MV Hondius cruise ship,' the agency said in a statement.

'Given the severity of this virus, we are taking a precautionary approach to ensure Canadians are protected.' 

The four Canadian cruise ship passengers from British Columbia had all been isolating on Vancouver Island for a minimum of 21 days to limit exposure, The Globe and Mail reports.

However, on Saturday, Henry said officials are still considering how long they will have to quarantine.

'But make no mistake, we will be following the four individuals daily, actively for at least 42 days,' she said.

Canada's Chief Public Health Officer, Dr Joss Reimer, previously said provincial and territorial public health authorities were asking 26 people across the country to monitor for symptoms - even though they were considered 'low risk' after sharing a flight with someone who tested positive for the virus.

Another nine were classified as high-risk and were told to isolate in Ontario, Alberta and British Columbia because they were either passengers onboard the MV Hondius or had close contact with someone infected with hantavirus on a flight.

But until now, officials have said nobody in Canada had shown any symptoms of the hantavirus, which has an incubation period that could last weeks.

The confirmed case in Canada now marks the 12th case linked to the cruise across the world, including three deaths. 

It is believed the outbreak started after a Dutch couple contracted the virus while bird watching in Argentina.

The Andes strain of the virus has been linked to previous incidents in which hantavirus spread via human transmission, though the virus normally spreads through contact with rat droppings.

There is no evidence so far that the virus that spread onboard the ship has any new characteristics that would make it more transmissible or more dangerous, according to France's Pasteur Institute.

It had announced over the weekend that it has fully sequenced the virus detected in a French passenger on the MV Hondius and found that it matched viruses already known in South America, according to The Guardian.

Still, in the United States, the Centers for Disease Control and Prevention has said it is monitoring 41 Americans across 16 states who had potential hantavirus exposure.

One American, a doctor who was a guest on the cruise ship, began treating ill passengers when the ship's doctor was sickened, tested positive for the virus, but he has since tested negative three times. 

About half of the Americans are being monitored by the CDC at quarantine centers in Georgia and Nebraska, while the other half are isolating at home.

Admiral Brian Christine, a controversial Trump-nominated assistant health secretary who is now leading the country's hantavirus response, said last week the risk of hantavirus to the American people is 'very, very low.'

He also said health officials are promising a response 'grounded in science' and 'grounded in transparency,' noting that the Department of Health and Human Services has taken the situation 'seriously from the very beginning.'