Seven-time Formula One world champion Lewis Hamilton will miss this weekend's Sakhir Grand Prix after testing positive for COVID-19.
Hamilton tested positive on Monday, the day after his victory at Sunday's Bahrain Grand Prix, in a mandatory polymerase chain reaction (PCR) test for the upcoming Sakhir Grand Prix at the same circuit this weekend.
Hamilton tested negative three times the previous week, including Sunday afternoon ahead of the Bahrain Grand Prix, but he woke up Monday morning with mild symptoms and subsequently tested positive. He was informed Monday that a contact prior to his arrival in Bahrain also had tested positive.
The 35-year-old has already secured this year's drivers' title, but he will miss this weekend's Sakhir Grand Prix and could miss the season finale the week after in Abu Dhabi if he fails to return a negative test following ten days in isolation.
It is not yet clear who will replace Hamilton at Mercedes, which has won 11 of this year's 15 races.
Stoffel Vandoorne is listed as the team's official reserve driver and is currently testing for Mercedes' Formula E team in Valencia. He last raced in F1 for McLaren in 2018, and he will travel to Bahrain later this week to join the Mercedes F1 team.
Hamilton is currently isolating in accordance with public health authority guidelines in Bahrain, and his contacts have been declared to the FIA.
"I'm devastated that I won't be racing this weekend," Hamilton wrote in an Instagram post. "Since we started the season in June, my team and I have been taking all the precautions we possibly can and following the regulations everywhere we've been in order to stay safe.
"Unfortunately, even though I returned three negative results this past week, I woke up yesterday morning with mild symptoms and requested another test which came back positive. I've immediately gone into self-isolation for ten days.
"I'm gutted not to be able to race this weekend but my priority is to follow the protocols and advice to protect others. I'm really lucky that I feel OK with only mild symptoms and will do my best to stay fit and healthy.
"Please look after yourselves out there, you can never be too careful. These are worrying times for everyone and we need to make sure we are looking after ourselves and each other. Stay positive."
Following his title victory in Turkey, Hamilton returned to his home in Monaco between races and spent time with his family before travelling to Bahrain.
Over the course of the season, he has gone to great lengths to isolate from others during race weekends, including staying in a motorhome at the circuit at European venues.
Mercedes team boss Toto Wolff recently said his drivers have "almost had to live like a hermit" to avoid contact with people outside of their close contact group or "bubble".
The team confirmed the news of Hamilton's positive test via a statement Tuesday morning.
"The Mercedes-AMG Petronas F1 Team regrets to announce that Lewis Hamilton has tested positive for COVID-19 and will be unable to take part in this weekend's Sakhir GP," the Mercedes statement said.
"Lewis was tested three times last week and returned a negative result each time, the last of which was on Sunday afternoon at the Bahrain International Circuit as part of the standard race weekend testing programme.
"However, he woke up on Monday morning with mild symptoms and was informed at the same time that a contact prior to arrival in Bahrain had subsequently tested positive.
"Lewis therefore took a further test and returned a positive result. This has since been confirmed by a retest.
"Lewis is now isolating in accordance with COVID-19 protocols and public health authority guidelines in Bahrain. Apart from mild symptoms, he is otherwise fit and well, and the entire team sends him its very best wishes for a swift recovery.
"We will announce our replacement driver plans for this weekend in due course."
Hamilton will be the third driver this year to miss a race because of a positive COVID-19 test in a season that has been completely rescheduled because of the pandemic.
Sergio Perez sat out of the British and 70th Anniversary Grands Prix at Silverstone earlier this year, and his Racing Point teammate Lance Stroll missed the Eifel Grand Prix after feeling unwell and later testing positive for COVID-19. Nico Hulkenberg substituted for both Racing Point drivers on those occasions.
Hamilton secured this year's championship in mid-November at the Turkish Grand Prix, with three races remaining on the calendar. He has not missed a Formula One race since he made his debut at the 2007 Australian Grand Prix.
Mercedes dominated this year's championship, taking 13 of the 15 race victories, 14 pole positions and both drivers' and constructors' world championships.