New York, which has now become the epicentre of the global outbreak, has carried out tens of thousands of tests in a matter of weeks.

The state of New York is now recording nearly half the whole country’s total, with 40,000 of the 86,000 cases.

Andrew Cuomo, its governor, said on Thursday that it had done 122,100 tests for its 19.5 million residents, or one test per 160 people. For comparison, South Korea, one of the best testers in the world, has carried out 300,000 for its 51 million population, or 1 in 170 people.

In South Korea, there is free and easy access to testing for anyone whom a doctor deems needs it, and authorities have been tracing the contacts of infected patients.

The picture countrywide, however, is a different one. Nationally, America has tested just 125 people per one million.

States have been hit with testing shortages.

The lack of kits and testing supplies has led to rationing of coronavirus tests in states like Georgia, Oklahoma and others.

"We are flying a plane in really foggy weather without radar,” is how one medical expert in Georgia described the situation.

Mr Cuomo said New York has carried out 25 per cent of all tests in the country. It has 10 times the number of cases than the next nearest state, neighbour New Jersey.

Los Angeles County has been carrying out an average of 500 per day, compared to New York’s capacity of up to 18,000.

This suggests that the number of people with coronavirus in America is likely much higher than the official figure.

Why is New York so bad?

Just look at the map below. New York has nearly 40,000 confirmed cases - half the total for the US, and dwarfing any other major US city.