ROME—Italian newscaster Alessandro Politi was shocked when he tested positive for COVID-19 on March 11. He and other colleagues were swabbed out of an abundance of caution after a co-worker contracted the virus. The 30-year-old had a slight fever and a sore throat, but none of the chest tightness or other nightmarish symptoms so many have suffered.

Following the Italian Health Institute guidelines for releasing someone from self-isolation, Politi was tested again two weeks after his positive swab. But, fever-free and with no symptoms at all, he tested positive once more. The test was carried out a week later, 21 days after his diagnosis, and he still tested positive for the virus. Now, 30 days later, Politi has just tested positive again, calling into question just how long the novel coronavirus stays in some people’s systems and whether that might play a role in why, despite a month-long draconian lockdown, Italy just can’t seem to shake the virus.

Politi’s case and a study of others involving people with mild or no symptoms who continued to test positive long after the two-week standard quarantine ended has prompted the northern region of Lombardy to rethink its quarantine guidelines, and there are potentially profound implications for any country, including the United States, searching for a way to end economy-crushing lockdowns.

Lombardy, Italy’s wealthiest region, is where the outbreak began in this country. It has more than 60,000 of Italy’s nearly 160,000 cases and 60 percent of the country’s more than 20,000 deaths. On Saturday, Milan alone logged as many deaths in one day as the entire region around Rome has recorded since the outbreak began on Feb. 25.

Starting this week, everyone in the region of Lombardy who tests positive, or who displays symptoms and is told to self-isolate in lieu of a swab, must now self-isolate for 28 days, twice the CDC and WHO recommendation of two weeks.

Massimo Galli, director of the biomedical and clinical sciences department of the Sacco Hospital in Milan, says that the fact that some people take longer to shed the virus could be why it is taking so long for Italy, which flattened the curve on infections more than 10 days ago, to start seeing a drastic decrease in cases.

“Politi is not an isolated case,” Galli said on Sunday. “We need to understand how to act to avoid the worst. Taking millions of swabs is impossible but countermeasures and solutions must be found because patients like Politi, completely asymptomatic or not very symptomatic but fully positive after many days, are a problem.”

The extra vigilance is especially important as Italy starts to lift restrictions of its nationwide lockdown that started March 10. “Now that we have started thinking about a restart we must absolutely avoid conditions and situations that can put us in serious crisis again,” Galli said.

Lombardy Health and Welfare Minister Giulio Gallera said at a press conference Sunday that despite criticism for what many feel is an overreaction, the decision to double the quarantine comes from the fact that no one really knows just how long infected people stay positive, or how long they are contagious.

No reliable antibody tests have been able to even determine if, or for how long, those who are infected are immune. “There are many people who are still testing positive after 14 days,” Gallera said, adding that there are also a vast number of people who have symptoms but aren’t tested at all, but who likely have the virus. If those people self-isolate for only two weeks on their own accord assuming they have COVID-19, and then go out again, they could actually be silent spreaders because they think they are immune.

Authorities are especially worried about those in the region’s vast underground migrant population—many from China—who, as undocumented workers, have kept even lower profiles during the pandemic. Lombardy has Europe’s tightest connection to China after Italy signed on to the New Silk Road project a year ago. Multiple daily flights between Milan and Chinese cities were added in the fall to facilitate lucrative new business deals, which easily explains why Lombardy became the largest epicenter outside of China when the pandemic began in February.

Those deals also spawned a network of workers who live under the radar, much like Italy’s garment district outside of Florence, which has the country’s largest documented and undocumented population of Chinese immigrants. The community has a remarkably low number of confirmed COVID cases, likely because much of Italy’s vast Chinese community started locking down in their own communities long before the nation did on March 10. Many people also returned to China when the outbreak began there, before flights were banned.

Italy is supposed to start Phase II of the lockdown on May 3, but in Lombardy, anyone who tests positive for COVID-19 between now and then will now have to stay strictly quarantined for the full 28 days to avoid a second wave of the disease.

Dr. Galli believes that if asymptomatic infected people or those who shed the virus slowly are contributing to the continued spread of the virus, which has led to the difficulty with which Italy has had in decreasing cases and deaths drastically, keeping them locked down is the only option.

Galli also has helped Lombardy institute more aggressive testing in the area ahead of the lifting of some restrictions. “The data fluctuates based on the number of swabs but there are at least 10 times more positives out there which continue to spread the virus,” Galli said. Over the weekend, more than twice the usual number of tests were carried out in Milan, which has seen a spike in cases in recent days.

Giovanni Rezza, head of the Italian Superior Health Institute, said that some of that is because families living together and even people in the same condominium are likely infecting each other unknowingly. When one person starts to show symptoms, it is often too late.

“Transmission has carried on after the lockdown,” he said Monday. “This means that after the lockdown is lifted, there will still be a trail of lingering cases. There will still be an incubation period for those who don’t know they have the disease who spread it unknowingly.”

But Rezza is convinced that the high number of cases Italy still logs every day are people who were infected up to 20 or 30 days ago, essentially those who are not shedding the virus quickly. And, as such, in 20 days time—May 3, when Phase II is supposed to begin—the level of confirmed infections should subside, but there could still be more infectious people circulating.

He points to a decrease in hospitalizations, people intubated and sent to ICU wards, and faster recoveries as a point of optimism, “No doubt about it, these are positive signals that will have to be proven with time.” But he cautions, “This doesn’t mean that we are all free now, this is still phase 1.”

Politi says he will stay in quarantine as long as it takes to test negative twice, which is what the Italian health system requires for those who have tested positive to leave self-isolation. The alternative for anyone who breaks quarantine is arrest and a five-year jail term.

“I keep having to ask myself, if after 30 or more days I am still positive with a full viral load, theoretically super contagious, how many are we in Italy like this?” Politi wonders. “In light of the fact that there have been many positive cases even 40 days after the end of the symptoms, how many are there who are not tested but after the 14 day quarantine go around and infect others, or even risk their own lives?”