Italy's lockdowns prevented 200,000 hospitalizations and reduced coronavirus transmission by nearly half, a new study finds

• Italy's lockdowns reduced the transmission of the coronavirus there by 45%, a new study found.
• The researchers determined that Italy avoided 200,000 hospitalizations from February 21 to March 25 by restricting movement through the country.
• But cases could easily spike again if the lockdown is lifted too soon.
• For the latest coronavirus news, see Business Insider's live updates here or visit the homepage for more stories.

Italy has witnessed a gradual decline in its number of daily coronavirus cases, but the nation's lockdown remains in place.

Although some restrictions on shops and business operations have loosened, schools remain closed and residents are still being asked to practice social distancing.

The country has the third highest coronavirus case count in the world and second highest death count — more than 25,000 people there have died — behind only the US. But its outbreak would have been much worse without any containment measures, a new study found.

Researchers in Italy and Switzerland simulated what could have happened if Italy had relaxed restrictions in March — or not imposed them at all. The results showed that the country's lockdown prevented around 200,000 hospitalizations between February 21 (when Italy's first case was reported) and March 25.

The study also found that lockdowns reduced transmission of the virus in Italy by around 45%. The country's early containment efforts — lockdowns in 11 cities imposed in late February — reduced around 18% of transmission, then subsequent measures implemented in March provided another 34% reduction.

By March 8, the northern region of Lombardy and at least 14 neighboring provinces were under lockdown — a restriction that affected around 16 million people. The rest of the country was told to practice social distancing. By March 11, Italy had closed all non-essential businesses.

Relaxing lockdowns too soon could cause Italy's cases to spike again

One reason the pandemic has been been so difficult to contain is that the coronavirus spreads quickly and easily.

In February, Chinese researchers estimated that the virus had a "basic reproduction number," or R0, of around 2.2, meaning the average coronavirus patient infected at least two other people. More recently, researchers have determined that the virus was probably spreading even more in China during the early phase of the outbreak, with an R0 of 5.7 at the time.

The new study identified an R0 of 3.6 in Italy, meaning the average patient there infected three to four others. This is close to an estimate that researchers at Lancaster University made in late January.

When an outbreak is ending, the R0 will drop below 1, meaning every person will infect fewer than one other person on average. Public-health experts agree that this can be achieved through social distancing.

"Even measles, if it's out in the country, doesn't have a very high R0 because you have to interact with a certain number of people to be able to infect them," Elizabeth Halloran, a biostatistician at the Fred Hutchinson Cancer Research Center and University of Washington, told Business Insider. "Part of the transmission involves social contacts between people, and the R0 depends on how fast people are interacting with each other."

The R0 could easily rise again, she added, if lockdowns are lifted too soon.

Italy's current restrictions have been extended until May 3. But on Tuesday, Italian Prime Minister Giuseppe Conte wrote in a Facebook post that he would consider relaxing rules in certain parts of the country come May 4.

"I wish I could say: Let's reopen everything. Right away. We'll start again in the morning," Conte wrote. "But such a decision would be irresponsible. It would bring up the contagion curve uncontrollably and it would frustrate all the efforts we've put in so far."