Former US vice president Joe Biden, flanked by his wife, Jill, addresses supporters after big primary wins in Michigan, Mississippi and Missouri (AFP)

Joe Biden moved a step closer on Tuesday to a November showdown with Donald Trump, notching up big primary wins over Bernie Sanders, his sole remaining challenger for the Democratic presidential nomination.

Biden, 77, the centrist former vice president, scored a resounding win in Michigan, where Sanders, 78, the leftist senator from Vermont, had hoped to make a stand.

He also cruised to victory in Missouri, Idaho and Mississippi.

The race was too close to call in Washington, the other major prize at stake, while North Dakota was also still counting votes.

Addressing supporters in Philadelphia as his victory took shape, Biden struck a presidential tone as he declared on national television that he would lead "a comeback for the soul of this nation."

"We're bringing this party together," he said. "Tonight we're a step closer to restoring decency, dignity and honor to the White House."

Biden reached out to his sometimes bitter rival Sanders and his supporters, telling them "we share a common goal."

"Together we'll defeat Donald Trump," he said.

Biden's huge victory in Mississippi, where he won around 80 percent of the vote, reflected his popularity among strategically vital African-American voters. He defeated Sanders by 25 points in Missouri.

His win in Michigan, the Midwestern industrial state which could be a key battleground in November, was a major setback for Sanders, who narrowly beat Hillary Clinton there four years ago.

Barring surprises, Biden now has a clear path to becoming the Democratic standardbearer in a potentially bruising and deeply divisive matchup with Trump.

The main question remaining is whether Sanders, a self-declared democratic socialist, will fight to the bitter end as he did four years ago against Clinton or bow out early.

Many Democrats accuse the firebrand Sanders and his devoted supporters of damaging Clinton just as she was struggling -- ultimately unsuccessfully -- against the Trump insurgency. (AFP)

Italy, the hardest-hit country in Europe, said its death toll from the COVID-19 virus had risen by a third to 631 (AFP)

Italians braced for a second day of national lockdown Wednesday after a sharp spike in coronavirus-related deaths, as New York deployed the National Guard to contain a disease that has sown worldwide panic.

Europe's hardest-hit country said the death toll from the COVID-19 virus had risen Tuesday by a third to 631, with the surging epidemic playing havoc with global sporting, cultural and political events.

While authorities in China, where the outbreak began, have declared it "basically curbed", cases are multiplying around the world, sparking panic buying in shops, and wild swings on financial markets.

Its seemingly relentless march has now claimed its first victim in Central America, with a 64-year-old man dying in Panama on Tuesday. Indonesia also reported its first death.

China remains the hardest-hit overall with more than 80,000 cases and 3,000 deaths, out of a global total of 117,339 cases and 4,251 fatalities in 107 countries and territories, according to an AFP tally.

Beijing reported an increase in imported cases Wednesday, fuelling concerns that infections from overseas could undermine its progress in halting the spread of the virus.

Nevertheless, some companies in Wuhan, the Chinese city where the virus emerged late last year, are to be allowed to return to work -- a sign things are gradually returning to normal.

Coronavirus is infecting all walks of life, including politics, with US Democratic presidential hopefuls Bernie Sanders and Joe Biden both cancelling campaign rallies and British health minister Nadine Dorries saying she had tested positive.

And amid criticism of the US authorities' response, New York deployed the National Guard for the first time during the crisis to help contain the spread of the disease from an infection-hit suburb.

 A patient, who had tested positive for COVID-19 in Indonesia, died on early Wednesday, at around 2 a. m. local time, according to government spokesperson for COVID-19 handling, Achmad Yurianto.

At the Presidential Palace, Wednesday, Yurianto stated that the patient was identified as case-25.

He expounded that the 53-year-old patient was suffering from pre-existing serious illnesses, including diabetes, lung disease, hypertension, and respiratory obstruction.

"This patient was admitted to the hospital in a serious condition with pre-existing diseases, such as diabetes, hypertension, pulmonary issues, and chronic obstruction. This patient was a foreign national. The embassy’s concerns were informed since the start, and now, the process is underway to send her back to her country, and she was accompanied by her husband during treatment," he added. (ANTARA)

Health minister and Conservative MP Nadine Dorries has been diagnosed with coronavirus (BBC)

Ms Dorries, the first MP to test positive, said she had taken all the advised precautions after finding out and has been self-isolating at home.

This comes as a sixth person died from the virus in the UK, which has a total of 382 cases.

The latest person to die was a man in his early 80s who had underlying health conditions.

The Bank of England has announced an emergency cut in interest rates in response to the economic impact of the coronavirus outbreak.

Rates have been cut from 0.75% to 0.25%, taking the cost of borrowing back down to the lowest level in history.

Meanwhile, Manchester City's Premier League match against Arsenal on Wednesday has been postponed as "a precautionary measure" because of the outbreak.

A number of Arsenal players are in self-isolation after coming into contact with Olympiakos owner Evangelos Marinakis, who tested positive for the virus.

The government will unveil its first Budget later, amid growing fears about the impact the outbreak will have on the UK economy.

Chancellor Rishi Sunak has pledged the NHS will get "whatever resources it needs" during the crisis, while he is also expected to unveil measures to boost the self-employed and small businesses who are left out of pocket.

Meanwhile, NHS England said it was scaling up its capacity for testing people for the infection, with the number of cases set to rise. (BBC)