ROME (AFP) - Italy's coronavirus epidemic may be slowing, but critics warn that the government is falling seriously behind on strategies to lift the punishing nationwide lockdown and reboot the economy.

Nearly 12,500 people have died of the virus so far according to official data. Despite a slowdown in new death and infection rates, the government has extended an economically crippling lockdown until "at least" mid-April over fears of a second wind.

But poverty and unemployment numbers are already skyrocketing.

Analysts have warned that the euro zone's third-largest economy will suffer its worst recession in decades, contracting 6 per cent in 2020 should the lockdown last through to May.

"It's horrible to have to choose between putting the economy in a corner or exposing many people to the risk of dying," US expert Paul Romer told Italy's Fatto Quotidiano daily on Wednesday (April 1).

The government needs "a credible plan to revoke the shutdown very soon, while guaranteeing the safety of workers even if the virus is still present", said the co-winner of the 2018 Nobel Prize for Economics.

Italy's business lobby Confindustria said on Tuesday each additional week beyond the end of May could see the economy shrink by an additional 0.75 percentage points - billions of euros a week.

Prime Minister Giuseppe Conte told opposition leaders on Wednesday: "We must plan a return to normality, and it must be done gradually and must allow everyone, eventually, to return to work safely". But he has yet to publish a blueprint.

'Intelligent isolation'

Finance Minister Roberto Gualtieri said the recession forecasts were "realistic", but warned against jumping the gun on easing the lockdown, saying "the more rigorous and efficient we are in combating the epidemic, the sooner we can restart".

His department was planning economic support measures worth some €500 billion (S$783 billion), he said in an interview.

According to official figures, just over 100,000 people have been infected in Italy since the epidemic began, but experts say there could be anywhere between 700,000 and six million cases - up to 10 per cent of the population.

That could mean large numbers of people have already had the virus without suffering symptoms and could return to work.

As morgues overflowed and fear reigned, opposition parties largely curbed criticism of the government. But with good news on the infection rate, ex-prime minister Matteo Renzi has broken ranks to insist mass testing be done to end the lockdown.

"We'll have to live with Covid-19 for months, maybe years. Those who tell you otherwise are lying. We cannot stay locked indoors for years, we must find a way to get out safely and work within the rules," he said.

Mr Romer called for "a policy of intelligent isolation, which means people are tested repeatedly, once every two weeks".

Those who test negative can work; those who don't, remain in isolation.

"You need to test on a large scale... for at least two years. And be ready to find through tests those who have (since) become contagious, because the virus will come in (to Italy) from other parts of the world," he said.

"In past wars, countries mobilised production to produce new equipment. They have to do that again. Each country in Europe is rich enough and developed enough to do it."

'Simple equation'

Italy has blood tests capable of quickly identifying who has the virus and who has the antibodies, but they are still in a trial phase, according to Dr Guido Marinoni, head of the doctors' union in hard-hit Bergamo in the country's north.

Such tests would provide important data on "the population's temporary immunity to the virus", he said.

But according to Italian virologist Roberto Burioni, the tests only reveal antibodies some 14 days after infection.

"We don't know yet what extent of defence those antibodies provide," he said.

Once the epidemic slows, the few people still infected "can kick-start a fresh upswing and we'd be back where we started", Dr Marinoni warned.

Nor will seeing fewer seriously ill coronavirus patients ease the pressure on hospitals immediately.

Free beds will go those unable to get one before. More people have been dying at home or in care homes than in hospital, Dr Marinoni said.

"We can only take a breath as long as the entire country is closed, because otherwise cases will emerge again," he said.

"The worry is that just that when everything goes well, the mistakes made at the start of the epidemic are repeated."

The virus epicentre is Italy's wealthy north, while the poorer south has been relatively spared.

Should the virus return and flare in the south, the fear is that hospitals weakened from years of painful cuts and corruption could be overwhelmed.

Dr Holger Schmieding, chief economist at Berenberg, said a longer lockdown now would do less damage to the economy than relapses down the line.

"The equation is fairly simple," he said.

"Italy needs to reduce the spread of the virus to a speed the health system can cope with, and that does not appear to be the case yet."