The US Food and Drug Administration (FDA) has issued an emergency limited use authorisation for two anti-malaria drugs to treat patients hospitalised with coronavirus in the United States.

Key points: There is little scientific evidence that hydroxychloroquine and chloroquine are effective in treating COVID-19

There is little scientific evidence that hydroxychloroquine and chloroquine are effective in treating COVID-19 The US has the world's highest infection rate with over 160,000 cases and over 2,900 deaths

The US has the world's highest infection rate with over 160,000 cases and over 2,900 deaths New York's Governor issued an urgent appeal for medical volunteers, saying an additional 1 million healthcare workers were needed

US President Donald Trump touted the two drugs, which are used to treat malaria and other conditions, as the "one of the biggest game changers in the history of medicine".

In a statement published, the US Department of Health and Human Services detailed recent donations to a national stockpile of the two drugs — hydroxychloroquine and chloroquine, both being investigated for possible COVID-19 treatment.

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It said it allowed them "to be distributed and prescribed by doctors to hospitalised teen and adult patients with COVID-19, as appropriate, when a clinical trial is not available or feasible."

But there is little scientific evidence and only anecdotal reports that hydroxychloroquine and chloroquine are effective in treating COVID-19.

Many health experts have warned about the drugs' potential side effects and to remain cautious until larger clinical trials validate smaller studies.

Janet Woodcock, director of the Centre for Drug Evaluation and Research at the FDA, said in a tweet that it was important to remember that the benefits of these drugs in the treatment of coronavirus had not been proven.

Donald Trump extended the US social-distancing guidelines until April 30. ( Reuters: Al Drago )

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The US has become the "new epicentre" of coronavirus and has reported over 160,000 infections and over 2,900 deaths, with New York City the nation's worst hot spot.

New Orleans, Detroit and other cities have also seen alarming clusters.

Following the rising outbreak and death toll from coronavirus across the country, Mr Trump extended social distancing guidelines by another month, to April 30.

Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, told CNN prior to the President's announcement that the country's outbreak could cause between 100,000 and 200,000 deaths.

"Whenever the models come in, they give a worst-case scenario and a best-case scenario," Dr Fauci said, adding he did not want to be "held" to his estimate.

But Dr Fauci softened his dire predictions at a subsequent briefing with Mr Trump, saying they were based on models that were run to show the worst-case scenario if Americans did not follow stay-at-home directives.

New York death toll continues to rise

New York's Governor issued an urgent appeal for medical volunteers, saying an additional 1 million health care workers were needed. ( Reuters: Mike Segar )

New York's Governor issued an urgent appeal for medical volunteers, saying an additional 1 million health care workers were needed amid a "staggering" number of deaths from coronavirus.

"Please come help us in New York now," Governor Andrew Cuomo said as the state's death toll climbed by more than 250 in a single day for a total of more than 1,200 victims, most of them in the city.

"We've lost over 1,000 New Yorkers. To me, we're beyond staggering already," he said.

Even before the Governor's appeal went out, close to 80,000 former nurses, doctors and other professionals in New York were stepping up to volunteer.

A Navy hospital ship, also sent to the city after the September 11 terrorist attacks in 2001, had arrived with 1,000 beds to relieve pressure on the city's overwhelmed hospitals.

With cases growing nationwide, Mr Trump said the US Government was sending an additional 1,000 ventilators over the next two days to Michigan, New Jersey, Illinois, Louisiana and Connecticut.

"Challenging times are ahead for the next 30 days, and this is a very vital 30 days," Mr Trump said.

"The more we dedicate ourselves today, the more quickly we will emerge on the other side of the crisis."

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