German Chancellor Angela Merkel has gone into quarantine after being informed a doctor who administered a vaccine to her has tested positive for coronavirus.
Her spokesman said she was informed about the doctor's test shortly after holding a news conference yesterday announcing new measures to curb the spread of the virus.
Steffen Seibert said Ms Merkel had received a precautionary vaccine on Friday against pneumococcal infection.
He said the 65-year-old will undergo "regular tests" in the coming days and continue with her work from home for the time being.
Meanwhile, Placido Domingo has announced he has tested positive for the coronavirus.
The 79-year-old opera singer's illness comes after his own glittering career had recently been stained by sexual misconduct revelations.
The Spaniard said in a post on his personal Facebook account that "I feel it is my moral duty to announce to you that I have tested positive".
Italy, Iran and the US have reported soaring new death tolls as the coronavirus pandemic marches relentlessly across the globe.
The Italian Premier Giuseppe Conte went on live TV to announce he was tightening the country's lockdown and shutting down all production facilities except those providing essential goods and services.
"We are facing the most serious crisis that the country has experienced since the Second World War," Mr Conte said.
Italy announced its biggest day-to-day increase of infections, which rose to 53,000 people, with nearly 800 new deaths.
As bodies piled up in Italian hospitals, morgues and churches, and as medical workers pleaded for more help, there was no sign that Italy was yet taming its arc of contagion.
Italy now has 4,825 deaths, more than all of China, where the virus first emerged late last year.
In Spain, Europe's hardest-hit country after Italy, intensive care units in some areas were close to their limits even before yesterday's new tally of 28,572 infections and 1,720 deaths.
The army is building a field hospital with 5,500 beds in a convention centre in Madrid, where hotels are also being turned into wards for virus patients without serious breathing problems.
In the US, where several states have ordered residents to stay indoors, New York Governor Andrew Cuomo said the government was "literally scouring the globe looking for medical supplies".
Negotiators from Congress and the White House resumed top-level talks on a ballooning one trillion dollars-plus economic rescue package, urged by President Donald Trump to strike a deal to steady a nation upended by the coronavirus pandemic.
Nationwide, there were 26,747 cases and 374 deaths as the US overtook Germany as the country with the fourth-highest number of cases.
The Chinese city of Wuhan - where the global pandemic was first detected and the first city to be locked down - went a fourth consecutive day yesterday without reporting any new or suspected cases.