HOUSTON, July 8 — The US coronavirus outbreak crossed a grim new milestone of over three million confirmed cases yesterday as more states reported record numbers of new infections, and Florida faced an impending shortage of intensive care unit hospital beds.

Authorities have reported alarming upswings of daily caseloads in roughly two dozen states over the past two weeks, a sign that efforts to control transmission of the novel coronavirus have failed in large swaths of the country.

California, Hawaii, Missouri, Montana, Oklahoma and Texas yesterday shattered their previous daily record highs for new cases. About 24 states have also reported disturbingly high infection rates as a percentage of diagnostic tests conducted over the past week.

In Texas alone, the number of hospitalised patients more than doubled in just two weeks.

The trend has driven many more Americans to seek out Covid-19 screenings. The US Department of Health and Human Services said yesterday it was adding short-term "surge” testing sites in three metropolitan areas in Florida, Louisiana and Texas.

In Houston, a line of more than 200 cars snaked around the United Memorial Medical Center as people waited for hours in sweltering heat to get tested. Some had arrived the night before to secure a place in line at the drive-through site.

"I got tested because my younger brother got positive,” said Fred Robles, 32, who spent the night in his car. "There's so many people that need to get tested, there's nothing you can do about it.”

Dean Davis, 32, who lost his job due to the pandemic, said he arrived at the testing site at 3am yesterday after he waited for hours on Monday but failed to make the cutoff.

"I was like, let me get here at three, maybe nobody will be here,” Davis said. "I got here, there was a line already.”

In Florida, more than four dozen hospitals across 25 of 67 counties reported their intensive care units had reached full capacity, according to the state's Agency for Health Care Administration. Only 17 per cent of the total 6,010 adult ICU beds statewide were available yesterday, down from 20 per cent three days earlier.

Additional hospitalisations could strain healthcare systems in many areas, leading to an uptick in deaths from the respiratory illness that has killed more than 131,000 Americans to date.

A widely cited mortality model from the University of Washington's Institute for Health Metrics and Evaluation (IHME) projected on Tuesday that U.S. deaths would reach 208,000 by November 1, with the outbreak expected to gain new momentum heading into the fall.

A hoped-for summertime decline in transmission of the virus never materialised as previously predicted, the IHME said.

"The US didn’t experience a true end of the first wave of the pandemic,” IHME Director Dr Christopher Murray said in a statement. "This will not spare us from a second surge in the fall, which will hit particularly hard in states currently seeing high levels of infections.”

'Pressure on governors'

US President Donald Trump, who has pushed for restarting the US economy and urged Americans to return to their normal routines, said on Tuesday he would lean on state governors to open schools in the fall.

Speaking at the White House, Trump said some people wanted to keep schools closed for political reasons. "No way, so we're very much going to put pressure on governors and everybody else to open the schools.”

New Covid-19 infections are rising in 42 states, based on a Reuters analysis of the past two weeks. By Tuesday afternoon, the number of confirmed US cases had surpassed three million, affecting nearly one of every 100 Americans and a population roughly equal to Nevada's.

In Arizona, another hot spot, the rate of coronavirus tests coming back positive rose to 26 per cent for the week ended July 5, leading two dozen states with positivity rates exceeding 5 per cent. The World Heath Organisation considers a rate over 5 per cent to be troubling.

The surge has forced authorities to backpedal on moves to reopen businesses, such as restaurants and bars, after mandatory lockdowns in March and April reduced economic activity to a virtual standstill and put millions of Americans out of work.

The Texas state fair, which had been scheduled to open on September 25, has been canceled for the first time since World War Two, organisers announced yesterday.

In Ohio, Governor Mike DeWine said the state was ordering people in seven counties to wear face coverings in public starting this evening. — Reuters