ROME — Italy's nationwide lockdown is showing the first small signs of payoff. The number of coronavirus cases is still rising, but at the lowest day-on-day pace since the outbreak began. The World Health Organization calls the slowdown encouraging. The health chief in the hardest-hit region says there's "light at the end of the tunnel."

The temptation, for a cooped up and stressed out country, is to embrace the first sign that crisis might be easing at last.

But while President Trump has talked about revving up the U.S. economy by Easter, Italy has set no such timetable — and experts say the nation, if it loosens its guard, is still at risk of the virus resuming its extraordinary, deadly trajectory.

Italy was the first among Western countries to contend with a mass-scale outbreak and order a lockdown. But it is now at the forefront of a more delicate calculation, in trying to figure out how long the restrictions should last.

"If we loosen [restrictions] too early, we risk to jeopardize all the results," said Roberto Burioni, a professor of microbiology and virology at Vita-Salute San Raffaele University in Milan. "My recommendation is: don't go after wishful thinking. You have to face the reality" of an extended lockdown.

Officially, Italy's lockdown — which restricts people's movement outside their homes and includes the closure of restaurants and retail stores — is supposed to end on April 3. But the government has signaled that the measures will surely be extended, something of little surprise to most people in Italy.

As a way to guard against potential restlessness, Prime Minister Giuseppe Conte this week said he was increasing fines, from 400 euros to 3,000, for people who left their apartments or houses without valid reason. Fines are steeper still for people in vehicles who violate the lockdown. People who go outside after testing positive for the coronavirus could face up to five years in prison.

Conte did not specify how long the lockdown might last, though he batted down rumors in the Italian media that it might be extended through the end of July.

"We are actually confident that, well before this hypothetical deadline, we can truly go back to our life habits," he said.

Some virologists say that, rather than an end date, Italy and other countries will have to release the brakes gradually — as China is now trying to do. Still, there are many uncertainties that could influence when to begin letting up the pressure, including whether the virus wanes during hotter and more humid months.

Even the size of Italy's outbreak is unknown. Government officials and experts have said that, because of limitations on testing, the spread of the virus could be magnitudes larger than the official data suggests. Andrea Crisanti, a virologist advising the Veneto region, said the country would have to conduct granular testing for the virus — in several geographic areas — to better gauge the true size of the outbreak and then determine more accurately how it is changing.

"You aggressively sample a big part of the population in a few infected areas" before you can consider changing the lockdown, Crisanti said. "Then, you maybe start to open some factories, test all people. I don't think the lifting of the quarantine will be in one go."

In the 4 1/2 weeks since Italy saw the first signs of the outbreak, the country has seen more than 7,500 people die of the virus. And even as the total number of documented cases has slowed — reaching 7.5% daily growth Wednesday, lowest since the outbreak began — the toll has been staggering, with 683 people reported dead over the previous 24 hours.

Though most of those deaths have taken place in the north, a nationwide sense of horror has helped with the enforcement of the restrictions. The lockdown has had widespread support: between 76% and 90% approve of the measures, according to various polls.

Though some Italian politicians, like the mayor of Milan, encouraged people in the early days of the outbreak to stay calm and socialize responsibly, that messaging has stopped cold. Italian politicians have not embraced Trump's argument that the economic price of fighting the virus might be worse than the virus itself.

The main opposition, the far-right League, has its stronghold in the north, the area hardest-hit by the virus. League regional governors in the north have criticized Conte for ordering the lockdown too late, and for initially allowing too many loopholes.

Politically, that means Conte does not face much pressure to relieve the restrictions prematurely. But Italians, under de facto house arrest for more than two weeks, have a natural desire to get back to normal.

"If at the first signs [of] improvement we break ranks, we could have another peak on our hands in two to four weeks," said Paolo Setti Carraro, an Italian doctor who was also involved in the global response to Ebola.

The temptation to get out of the house at the first chance was evident last weekend in Tokyo, when cherry blossoms were blooming, and people packed together in parks and restaurants, dropping the restrictions of social distancing. Japan has seen a far smaller outbreak than Italy, but experts there worried that the impulse to socialize as they did before could allow the virus to rapidly spread.

Elsewhere, Hong Kong, Singapore and Taiwan appeared to have controlled the spread of the virus, but they are again seeing rising infections.

“The risk is for the emotional feeling to prevail and to have people say, ‘Things are going better, let’s get rid of all this anguish,’” said Paolo Cruciani, a retired professor of psychology and a former deputy head of the psychologists’ association in Italy’s Lazio region. “Then, boom — the virus comes back. The way to prevent this is a carefully considered mass communication to strengthen their rational vision. It’s a delicate moment: people can’t wait for all of this to end.”