Canadian hantavirus case confirmed by national laboratory test

Laboratory testing has confirmed the presumptive positive case of the Andes strain of hantavirus reported in British Columbia

The Public Health Agency of Canada confirmed the results Sunday in a resident of the Yukon who had been on the MV Hondius cruise ship where there was an outbreak.

The agency said samples were sent to its national laboratory in Winnipeg for confirmatory testing, after B.C. health officials announced the presumptive positive test on Saturday.

One person's sample was confirmed positive, while their travelling partner's test was confirmed negative

"There have been no further cases identified at this time. All high-risk contacts are isolating and will continue to be monitored closely by local public health," a statement from the agency said.

B.C.'s provincial health officer announced Saturday that one of the four Canadians who was isolating on Vancouver Island had received a "presumptive positive" test.

Dr. Bonnie Henry told a news conference that the person was part of a couple from the Yukon who were isolating and developed mild symptoms on Thursday, including a fever and a headache.

The public health agency said it has provided the information about the positive case, which is the first in a Canadian, to the World Health Organization. 

"All confirmed cases to date have been passengers or crew on the MV Hondius cruise ship," the statement said. "Given the severity of this virus, we are taking a precautionary approach to ensure Canadians are protected."

Dr. Lynora Saxinger, an infectious disease expert at the University of Alberta, said the risk from the hantavirus outbreak on the ship continues to be low for the general public even after the confirmed case. 

The Canadian who is sick was on the ship where the initial outbreak happened, she said, and tested positive during the incubation period.

"What would worry me most, looking at any kind of an outbreak situation, is if we start to see a second or third generation of transmission away from the people who were exposed to the case that obviously had a high viral load on the ship," she said.

"Or if there was any kind of unlinked transmission, so a new case popped up and you didn't know where they'd gotten it."

A total of four people were flown to Vancouver Island after being on the ship and had been isolating when the person who has now tested positive began displaying symptoms.

B.C. health officials said Saturday that three of the four are now being cared for in hospitals while the fourth person continues to isolate at home. 

They have been identified as the couple in their 70s from the Yukon, a person in their 70s from Vancouver Island, and a person from B.C. in their 50s who lives abroad.

Saxinger said being elderly puts someone at higher risk of severe outcomes from the illness.

She said the group was transferred from the ship in a medically secure way and then were handled appropriately when they landed.

"And so I don't think that it really changes the risk equation for anybody else," she said.

So far, 12 worldwide cases of hantavirus have been linked to the cruise ship, including the one Canadian. 

On Thursday, Canada's chief public health officer said 26 people from across the country who were considered low risk were asked to monitor for symptoms, while another nine, including the couple, were classified as high risk. 

Those high-risk people in Ontario, Alberta and B.C. were asked to isolate, and were being monitored. 

Picture Courtesy: AP Photo/Misper Apawu