Security personnel check the temperature of workers before they board buses to go back to their homes in province during a government-imposed nationwide lockdown as a preventive measure against the COVID-19 coronavirus, at an industrial zone on the outskirts of Colombo on March 28, 2020. (Photo by LAKRUWAN WANNIARACHCHI / AFP) (Photo by LAKRUWAN WANNIARACHCHI/AFP via Getty Images)

BERLIN — The number of confirmed coronavirus infections worldwide topped 600,000 on Saturday as new cases stacked up quickly in Europe and the United States and officials dug in for a long fight against the pandemic.

The latest landmark came only two days after the world passed half a million infections, according to a tally by John Hopkins University, showing that much work remains to be done to slow the spread of the virus. It showed more than 607,000 cases and a total of over 28,000 deaths.

While the U.S. now leads the world in reported infections — with more than 104,000 cases — five countries exceed its roughly 1,700 deaths: Italy, Spain, China, Iran and France.

“We cannot completely prevent infections at this stage, but we can and must in the immediate future achieve fewer new infections per day, a slower spread,” German Chancellor Angela Merkel, who is in quarantine at home after her doctor tested positive for the virus, told her compatriots in an audio message. “That will decide whether our health system can stand up to the virus.”

The virus already has put health systems in Italy, Spain and France under extreme strain. Lockdowns of varying severity have been introduced across Europe, nearly emptying streets in normally bustling cities, including Paris where drone photos showed the city’s landmarks eerily deserted.

Merkel’s chief of staff, Helge Braun, said that Germany — where authorities closed nonessential shops and banned gatherings of more than two in public — won’t relax its restrictions before April 20.

Spain, where stay-at-home restrictions have been in place for nearly two weeks, reported 832 more deaths on Saturday, its highest daily total yet, bringing its total to 5,690. Another 8,000 confirmed infections pushed that count above 72,000.

Doctors, nurses and ambulance drivers in its worst-hit regions are falling ill at an alarming rate and working nonstop. More than 9,000 health workers in the country have been infected.

“We are completely overwhelmed,” said ambulance medic Pablo Rojo at Barcelona’s Dos de Maig hospital. “Seven or eight (patients transported today) and all with COVID-19. … And the average age is decreasing. They’re not 80 years old anymore, they are now 30 and 40 years old.”

“Sometimes you become a bit paranoid, you don’t know any more when you pick up the phone if you have cleaned your hands, if you’ve sanitized them or not. You touch your face with your hands,” Rojo said.

Spain has struggled to get coronavirus tests and protective gear for health workers. The government has started flights to transport the supplies directly from China to reduce waiting times.

As the epicenter has shifted westward, the situation has calmed in China, where some restrictions on people’s lives have now been lifted. Six subway lines restored limited service in Wuhan, where the virus first emerged in December, after the city had its official coronavirus risk evaluation downgraded from high to medium on Friday. Five districts of the city of 11 million people had other restrictions on travel loosened after their risk factor was downgraded to low.

For most people, the coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. But for others, especially older adults and people with existing health problems, the virus can cause more severe illness, including pneumonia, and lead to death.

More than 130,000 people have recovered, according to Johns Hopkins’ tally.

In one way or another, the effects of the COVID-19 outbreak have been felt by the powerful and the poor alike.

On Friday, British Prime Minister Boris Johnson became the first leader of a major country to test positive for the virus. He said he would continue to work from self-quarantine.

Countries are still scrambling bring home some citizens stranded abroad by border closures and a near-shutdown of flights. On Saturday, 174 foreign tourists and four Nepali nationals on the foothills of Mount Everest were flown out days after being stranded on the only airstrip serving the world’s highest mountain.

In neighboring India, authorities sent a fleet of buses to the outskirts of the capital to meet an exodus of migrant workers desperately trying to reach their home villages during the world’s largest lockdown.

Thousands of people had fled their New Delhi homes after Prime Minister Narendra Modi announced a 21-day lockdown that began on Wednesday and effectively put millions of Indians who live off daily earnings out of work.

In parts of Africa, virus prevention measures have taken a violent turn as countries impose lockdowns and curfews or seal off major cities, with police in Kenya firing tear gas and officers elsewhere captured in mobile phone footage whacking people with batons.

In the United States, New York remained the worst-hit city, but Americans braced for worsening conditions elsewhere, with worrisome infection numbers being reported in New Orleans, Chicago and Detroit.

New Orleans’ sprawling Ernest N. Morial Convention Center, along the Mississippi River, was being converted into a massive hospital as officials prepared for thousands more patients than they could accommodate.

In New York, where there are more than 44,000 cases statewide, the number of people hospitalized with COVID-19 passed 6,000 on Friday, double what it had been three days earlier.

Gov. Andrew Cuomo called for 4,000 more temporary beds across New York City, where the Jacob K. Javits Convention Center has already been converted into a hospital.

The struggle to defeat the virus will take “weeks and weeks and weeks,” Cuomo told members of the National Guard working at the Javits Center.

President Donald Trump invoked the Defense Production Act on Friday, ordering General Motors to begin manufacturing ventilators.

Trump signed a $2.2 trillion stimulus package, after the House approved the sweeping measure by voice vote. Lawmakers in both parties lined up behind the law to send checks to millions of Americans, boost unemployment benefits, help businesses and toss a life preserver to an overwhelmed health care system.

Dr. John Brooks of the U.S. Centers for Disease Control and Prevention warned Americans remained “in the acceleration phase” of the pandemic and that all corners of the country were at risk.

“There is no geographic part of the United States that is spared from this,” he said.