Ontario has cleared up a backlog of novel coronavirus tests and for the first time in weeks had no one under investigation Tuesday for the illness now known as COVID-19.

“Our lab is turning them around quicker,” Dr. David Williams, chief medical officer of health for the province, told a news conference.

Processing of nose and throat swabs checking for the virus that has infected 73,000 around the globe and killed more than 1,800 in China used to take 24 to 36 hours at Ontario’s public health labs but a new version of the test now produces results in six hours, Williams added.

There are usually about 20 to 25 tests being done daily, mainly on the roughly 40 travellers arriving daily at Pearson International Airport from the viral epicentre of the Hubei province — which includes the hard-hit city of Wuhan — who are showing symptoms of fever or cough.

In all, between 1,400 and 2,000 people arrive daily at Pearson on four to six flights from China. Some of those travellers are tested as an additional precaution if showing signs of illness.

So far, 421 people have been tested in Ontario out of an abundance of caution and there have been three confirmed cases of COVID-19, one a young woman who attends Western University in London who has been cleared.

A husband and wife who contracted the new coronavirus never before seen in humans after returning on a China Southern Airlines flight Jan. 22 are feeling better but tests have shown some traces of the bug. Williams said he is awaiting word “any day” from Toronto Public Health that the pair will be cleared.

The first plane load of Canadians flown back from Hubei province will finish their quarantine at CFB Trenton on Friday if they are free of coronavirus with the second cohort slated to wrap up their two weeks in isolation Feb. 25.

About 250 Canadians who have been quarantined on the stranded cruise ship Diamond Princess at Yokohama in Japan are scheduled to arrive at CFB Trenton on Wednesday and will be transferred east to the Nav Can Centre in Cornwall, where they will be closely monitored given how quickly the coronavirus had spread through that ship.

More than two dozen have contracted the illness while on board and will be kept in Japan for treatment.

“It raises questions, if you have a similar situation, would you do the same thing, yes or no? I don’t have an answer to that,” said Williams of the way the travellers were sequestered on the cruise liner despite a steadily rising number of coronavirus cases.

“It depends on the rigours of the (cruise ship) staff moving in and out, how good is the room, how much protection equipment is worn.”

There have been a total of eight confirmed novel coronavirus cases in Canada, with the other five in British Columbia.