Dozens of top players are forced to isolate for 14 days, throwing their preparations into disarray.

image captionAustralian Open organisers have insisted that the tournament will go ahead despite the coronavirus disruption
The Australian Open has been thrown into disarray after four people tested positive for Covid on two flights that brought tennis players to the tournament.
Others on the flights, including at least 47 players, have gone into hotel isolation for 14 days.
One of the positive cases, a coach, said he was “sorry for the consequences now on everyone’s shoulders”.
A fourth case linked to the tournament in Melbourne was confirmed on Sunday.
Players had to test negative before boarding flights and were then placed in designated Australian Open quarantine hotels in Melbourne and Adelaide.
They are allowed out for up to five hours a day to practise on court, except for those on the two offending flights who have been confined to their rooms.
The confinement period has angered some players, who said the rule was not made clear to them.
“If they would have told us this rule before I would not play Australia… I would have stayed home,”
Romanian player Sorana Cirstea wrote on Twitter.
Top players such as Victoria Azarenka, Sloane Stephens, Kei Nishikori, Angelique Kerber and the UK’s Heather Watson are also among those affected, badly impacting their preparations.
But Australian Open director Craig Tiley insisted the tournament – the first Grand Slam of the year – would go ahead as planned on 8 February.
“We always knew there would be significant risk with this pandemic, you can never tell,” Mr Tiley told the Channel Nine TV station.
Organisers of the Australian Open have been arranging chartered flights for players and their teams to be transported to Melbourne ahead of the tournament. These flights have frustrated many Australians, who have not been able to return home because of travel restrictions during the pandemic.
The four coronavirus cases connected to the Australian Open were on two flights, one arriving from Los Angeles in the US, and another from Abu Dhabi in the United Arab Emirates (UAE).
Three people – a crew member, a tennis coach and a member of a broadcast team – tested positive on the flight from Los Angeles.
Sylvain Bruneau, the coach of 2019 US Open champion Bianca Andreescu, said he was the positive case on the flight from Abu Dhabi.
The Canadian coach said he had followed all the safety protocols, including testing negative for Covid-19 within 72 hours before the flight’s departure.
“I am extremely saddened and sorry for the consequences now on everyone’s shoulders sharing my flight,” he said in a statement tweeted by Tennis Canada.
“The rest of my team is negative, and I sincerely hope that any further disruption is kept to a minimum.”
Tournament organisers quashed rumours about a positive case on one of the two flights that brought the game’s biggest names into Adelaide.
While most players touched down in Melbourne, superstars including Novak Djokovic, Rafael Nadal, Serena Williams and Naomi Osaka instead flew into the South Australian city.
The Australian Open had already been hit by the withdrawal of injured Roger Federer, while three-time major winner Andy Murray tested positive for the virus before departure so did not fly to Australia.
media captionInside one of Australia’s five-star quarantine hotels