The number of confirmed coronavirus infections worldwide has topped 600,000 as new cases stacked up quickly in Europe and the United States.

The latest landmark came only two days after the world passed half a million infections, according to a tally by Johns 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 over 28,000 deaths.

While the US 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.

A priest wearing a face mask to protect against coronavirus waits in front of the cemetery chapel during the coronavirus outbreak in Madrid, Spain
A priest wearing a face mask waits in front of the cemetery chapel during the coronavirus outbreak in Madrid, Spain (Bernat Armangue/AP)

The virus has already 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.

German Chancellor Angela Merkel’s chief of staff Helge Braun said that Germany, where authorities closed non-essential shops and banned gatherings of more than two in public, will not 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 non-stop.

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.

People stand in a spaced line as they wait to buy pork at the entrance gate of a closed residential community in Wuhan in central China’s Hubei Province
People stand in a spaced line as they wait to buy pork at the entrance gate of a closed residential community in Wuhan in central China’s Hubei Province (Chinatopix via AP)

“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.”

As the epicentre 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 a 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.

A man wearing a mask cycles along a section of the Grand Concourse that has been temporarily closed to traffic during the coronavirus pandemic in the Bronx borough of New York
A man wearing a face mask cycles along a section of the Grand Concourse that has been temporarily closed to traffic in the Bronx borough of New York (Mark Lennihan/AP)

In a possibly hopeful sign, the US Food and Drug Administration cleared a new rapid test from Abbott Laboratories, which the company says can detect the coronavirus in about five minutes.

Medical device maker Abbott announced the emergency clearance of its cartridge-based test on Friday night, saying the test delivers a negative result in 13 minutes when the virus is not detected.

While New York remained the worst-hit city in the US, Americans braced for worsening conditions elsewhere, with worrying infection numbers being reported in New Orleans, Chicago and Detroit.

Virus cases have been rising rapidly in some American cities such as Detroit, where poverty and poor health have been problems for years. Mayor Mike Duggan pointed to aggressive testing as a reason behind the quickly growing numbers.

“Part of what we’re seeing in Detroit is that there’s such a high number of individuals who have those underlying conditions, who have the diabetes and the heart disease, who may have obesity,” said Dr Joneigh Khaldun, Michigan’s chief medical executive, who previously led the city’s health department.

“What you’re seeing now is when you have really generations of concentrated poverty and what we call those social determinants of health that impact a city like Detroit, when you have pandemics like this, it’s going to hit those places harder.”

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

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

Mr Trump signed a 2.2 trillion dollar (£1.78 trillion) stimulus package, after the House approved the sweeping measure by voice vote. It will send cheques to millions of Americans, boost unemployment benefits, help businesses and offer a lifeline to an overwhelmed healthcare system.