Formula One's season-opening Australian Grand Prix will get underway with an air of anxiety this week, with members of two racing teams quarantined and local health authorities battling to contain spread of the coronavirus.
Team Haas said two of its staff were tested for coronavirus and have been confined to their hotel rooms after showing symptoms of a cold, while McLaren said one of its team members had self-isolated.
F1 organisers have already postponed the Chinese race scheduled for April, while the Bahrain Grand Prix, the calendar's second stop, will go ahead without spectators on March 22.
The Australian Grand Prix Corporation announced measures on Wednesday to limit interaction with fans, including scrapping the traditional autograph sessions along Melbourne Walk, a path near the paddock where fans take selfies with the drivers as they pass by.
However, race chief executive Andrew Westacott said on Monday there was "no chance" of a spectator ban at Albert Park, which is set to host thousands of fans from Thursday, when practice sessions and qualifying commence for lower-profile racing series at the street circuit.
Since Westacott's declaration, health authorities have confirmed multiple cases of community transmission in Melbourne and recorded a surge of infections in other Australian regions.
Two Melbourne schools were closed for containment efforts, including one two miles from the race circuit.
Some 86,000 spectators packed into the Melbourne Cricket Ground on Sunday to watch Australia's cricketers beat India in the final of the Women's Twenty20 World Cup, but a slew of other local events have been cancelled or postponed.
American pop star Miley Cyrus pulled out of a bushfire charity relief concert scheduled at Albert Park on Friday, citing advice from US health authorities.
Media pundits have questioned the wisdom of running the race, which involves thousands of staff and support personnel from across the globe, and lured more than 300,000 fans to Albert Park last year, according to organisers' estimates.
Renault cancelled a scheduled media Q+A session with drivers Daniel Ricciardo and Esteban Ocon at Albert Park after the drivers made an appearance in the team's new livery.
"Of course it's all tricky at the moment, but we are trying to make the best of it," Red Bull driver Max Verstappen said. "Hopefully [race week] will not be too different. It's difficult to say at the moment."
Should Sunday's race go ahead without incident, it will provide a first look at the teams' pecking order after winter testing.
Champion Lewis Hamilton will kick off his bid to match Michael Schumacher's record of seven F1 championships, with his Mercedes team again expected to set the benchmark in their chase for a seventh successive constructors' title.
Hamilton, who believes his all-conquering Mercedes is even better than last year, said: "It's been intense, with a huge amount of work from everybody at the track and back home at the factories.
"The car's feeling like a step forward from last year, but it's clear we've still got a few issues we need to iron out."
Mercedes head into the race with a new dual-axis steering system (DAS), which has inevitably sparked complaints from other teams over whether it is legal.
While Hamilton has taken every pole at Albert Park since 2014, he has won just once in that time, and it was teammate Valtteri Bottas who sizzled at pre-season testing.
The Finn will be looking for a second successive win in Australia after sweeping to an emphatic victory last year, a massive 20.9 seconds ahead of Hamilton.
"On a good day, when I get 100 percent out of myself, I feel I can beat anyone. But how to be there at every race weekend – that's the tricky thing," Bottas said.
Red Bull, who placed third in last year's series, had a strong winter testing and may be poised to challenge Mercedes' dominance.
Dutch driver Verstappen was third behind the two Mercedes last year and could be one of Hamilton's closest challengers in his Red Bull, which excelled in testing. "I definitely feel ready for Melbourne," said the 22-year-old, who won three races last year.
Ferrari head into the first race with some queries over their car's performance and the future of driver and four-times champion Sebastian Vettel, who is out of contract at the end of the season.
Charles Leclerc overshadowed teammate Vettel in his debut season for Ferrari, with the German four-time world champion looking to reassert himself this year.
"I don't see Charles going up and me going down. We have the same car and, for me, it doesn't change anything. That was also the case last season," the German said.