The number of confirmed coronavirus cases in the US has surged tenfold in a week to over 50,000, but the number of actual cases in the country is likely significantly higher, officials have acknowledged.

The total number of global COVID-19 cases now stands at 407,485 as of Tuesday, and at least 18,200 of those have been fatal, according to data compiled by Johns Hopkins University.

In the US, the virus has infected at least 53,972 people and killed 728 as of March 24. Confirmed US cases stood at 5,000 just one week ago, increasing ten times in 7 days. On March 1, there were roughly 100 confirmed cases in the US.

However, officials have acknowledged that the number of actual cases in the US is likely significantly higher since testing in the country has been hindered by severe shortages of medical supplies and a restrictive diagnostic criteria that limited who could get tested.

President Donald Trump continued to downplay the exponential spread of the coronavirus across the US on Monday, comparing the rising death toll to the number of Americans killed in car crashes and by the seasonal flu.

US health experts have sharply rebuked the Trump administration for initially downplaying the crisis and lagging behind in testing efforts.

The World Health Organization said on Tuesday infections in the United States had greatly increased and the country could become the global epicenter of the coronavirus pandemic.

“We are now seeing a very large acceleration in cases in the US. So it does have that potential [to become the global epicenter],” WHO spokeswoman Margaret Harris said.

US surgeon general

New York State has become the US epicenter of the coronavirus epidemic, overwhelming hospitals after suffering another quick and brutal rise in the number of cases on Tuesday, as California said it could be facing the next major wave of the disease.

The US surgeon general issued his starkest warning to date on Monday about the health risk posed by the coronavirus outbreak, warning Americans that the crisis was “going to get bad” this week.

Over the previous 24 hours, 85 percent of new cases were in Europe and the United States, and of those, 40 percent were in the United States.

The highly contagious coronavirus has caused entire regions to be placed on lockdown. In some places soldiers are patrolling the streets to keep consumers and workers indoors, halting services and production and breaking supply chains.

“The global health crisis is rapidly morphing into a global recession, as there is a clear tension between preventing infections and ruining the economy,” said Edoardo Campanella, an economist at UniCredit Bank in Milan.

Some US state and local officials have decried a lack of coordinated federal action, saying that having localities act on their own has put them in competition for supplies.