"9 Essential Lessons on Fighting Coronavirus From Around the World", The Interpreter, nytimes

It has been four months since the first known infection of the new coronavirus. In that time, the pandemic has reached 144 countries, infected over 200,000 people and killed more than 8,000.

But it has also produced hard data and workable lessons, handing humanity the weapons it needs to fight back.

Because not all outbreaks have been equal. How governments and societies respond, or don’t, can change the transmission and fatality rates by factors of 10 or more.

In Iran and Italy, the virus has spread like wildfire, devastating health care systems and pushing up death rates.

But it has circulated far more slowly, and proved far less lethal, in South Korea, Taiwan and Singapore.

And conditions can change. In China, weeks of catastrophe gave way to a response that the World Health Organization has praised as a global model. The United States has followed its own peculiar path, initially isolated from the virus, then criticized as complacent to its multiple parallel outbreaks, now responding more aggressively but to mixed results.

What follows are nine of the major lessons that have emerged so far, with the countries offering those lessons indicated in parentheses. While the world surely still has much to learn, a set of patterns is emerging, suggesting that slowing or even turning back the spread of disease is far from easy but is hardly impossible, either.

1. Testing early, often and widely makes all the difference. (China, South Korea)

Two broad principles show up over and over in these lessons.

First, countries succeed when they behave as if they are two weeks further into an epidemic than they appear to be — because they probably are.

It can take one to two weeks for a case to go from infection to diagnosis. The incubation time is thought to be five days, meaning it takes that long for symptoms to appear. It can take a few days for people with symptoms to get tested, depending on how informed they are about identifying symptoms, how eager they are to get tested (high health care costs or hassle factors can disincentivize testing when symptoms are mild) and their access to tests. Then another day or two for the results.

This lag, combined with the speed of the coronavirus’s spread (uncontrolled, the number of cases can double about every two days), means that the number of actual infections might be up to 128 times what they appear to be.

In other words, what looks like a handful of sick people might actually be a full-on outbreak. And what looks like a controllable outbreak might actually be well beyond the threshold of a public health disaster.

Countries do well when they assume as much, even if it initially looks like overreacting.

Second, proactive measures, imposed before things get bad, tend to be a lot more effective than reactive policies brought in after the virus has already spread. That’s partly because of the aforementioned lag. But it’s also because this lets health care systems exert more control over the pace of hospitalization and other treatments, helping to prevent those systems from becoming overwhelmed — which is what drives many of the deaths.

Aggressive testing addresses both of those. It gets countries better data on not just the overall spread of the virus but the particulars of how and where it is spreading.

South Korea has implemented the most widespread coronavirus testing in the world, often conducted at super-efficient drive-through centers. This has allowed officials to quickly identify and isolate not just infected individuals but transmission nodes like an infection-rich church or office.

South Korean leaders have emphasized testing as a cornerstone of the country’s breathtaking successes in rapidly containing what was initially one of the world’s worst outbreaks — and in producing a mortality rate of about 0.8 percent, a fraction of that in other countries.

“Testing is central because that leads to early detection, it minimizes further spread, and it quickly treats those found with the virus,” Kang Kyung-wha, South Korea’s foreign minister, told the BBC, calling testing “the key behind our very low fatality rate as well.”

China’s measures to rapidly, if belatedly, exert control over its once-severe epidemic also centered significantly on testing. Individuals with coronavirus-like symptoms were given a battery of questions as well as medical tests. Whole centers were set up to screen and test patients.

Together, this gave health workers a picture of how and where the virus was spreading. It allowed China’s government to shift from responding to outbreaks to containing them before they turned catastrophic. And, of course, it helped infected people get treatment early in their illness, which both improved survival rates and eased burdens on health centers.

Testing! It’s all about testing!

2. Contact tracing can be creepy but hugely effective. (Singapore, South Korea, Hong Kong)

Stories on Singapore’s stunning success tend to emphasize how normally life has proceeded there.

As our colleague Hannah Beech wrote earlier this week, “For all the panic erupting elsewhere, most Singaporeans do not wear masks out, because the government has told them it’s not needed for their safety. Most schools are still running, albeit with staggered lunchtimes to avoid big crowds. There is plenty of toilet paper.”

Singapore has focused less on extreme, society-wide lockdowns like those implemented in China, Europe and the United States than on a more precise approach known as contact tracing.

Every patient who tests positive is treated as the starting point of a miniature forensic investigation, in which health workers trace back all of the patient’s most recent contacts. Hence, contact tracing. Those other people are tested and, if necessary, quarantined.

In this way, Singaporean officials don’t just treat the people who come in the door. They proactively identify entire networks of possible transmission, carving the infection out of society like a surgeon removing a cancer.

“We want to stay one or two steps ahead of the virus,” Vernon Lee, the director of the communicable diseases division at Singapore’s Ministry of Health, told Ms. Beech. “If you chase the virus, you will always be behind the curve.”

But health workers can only do so much and move so quickly on their own. So they broadcast the details of infected patients’ recent movements online, essentially enlisting the local population in helping to enforce a micro-quarantine around every possible trail of infection.

South Korea and Hong Kong have also made heavy use of both contact tracing and of publicly broadcasting their findings. In South Korea, smartphone push alerts notify people of new infections in the area. Hong Kong residents can track a real-time map of infections by building.

It’s a big trade-off of privacy for the sake of public health, but officials who use such policies swear by them.

3. Isolate people quickly and focus on individuals, not just communities. (China)

Shortly after visiting China to understand how it got its once-disastrous epidemic seemingly under control, Bruce Aylward, an assistant director-general at the World Health Organization, discussed his team’s findings with our colleague Donald G. McNeil Jr.

Mr. Aylward emphasized that China had seized upon a discovery that many transmissions occur within families. We may think of our home as a sanctuary from a threat emanating from the outside world, but the reality is often the reverse. As they say in horror movies, the call is coming from inside the house.

According to Mr. Aylward: “75 to 80 percent of all clusters are in families. You get the odd ones in hospitals or restaurants or prisons, but the vast majority are in families.”

Once Chinese officials understood this, they expanded their containment strategy from isolating communities to aggressively isolating infected individuals as well, even from their own families.

“They try to isolate you from your relatives as quickly as possible, and find everyone you had contact with in 48 hours before that,” Mr. Aylward said.

To be sure, China also isolated infected communities, especially those in the city of Wuhan, the epicenter of the pandemic. But, after initially struggling to contain its spread within Wuhan, authorities found success with rapidly identifying and isolating individuals.

China also put tremendous effort into shortening the time from infection to isolation, which cut down transmissions dramatically because sick people simply had fewer interactions while infected. This required more testing, better public education so that people knew how to identify symptoms and, maybe most of all, aggressively expanding health care capacity.

In the areas around Wuhan, authorities used aggressive pre-emptive testing to stop outbreaks before they really got going.

“To find sporadic cases, they do fever checks everywhere, even stopping cars on highways to check everyone,” Mr. Aylward said. “As soon as you find clusters, you shut schools, theaters, restaurants. Only Wuhan and the cities near it went into total lockdown.”

4. Free health care does wonders; expensive health care “will kill you.” (China, South Korea, United States)

In an epidemic, the public can either be an essential ally or an enormous burden in identifying and halting transmissions.

There aren’t enough health workers or body-temperature scanners to track everybody. So success or failure often comes down to whether or not everyday people are incentivized to pitch in on identifying possible transmission, including their own.

In countries where health care is free or heavily subsidized, like South Korea, people have more of an incentive to come forward. In China, the state guaranteed free coronavirus testing and full coverage for any treatments, which is thought to have nudged people forward.

But when health care is burdensome or expensive, as in the United States, people have an incentive to avoid potentially costly or unnecessary procedures. Or at least to wait until they’re sure that their symptoms require treatment before seeking it.

”In the U.S., that’s a barrier to speed,” Mr. Aylward told our colleague. “That’ll kill you. That’s what could wreak havoc.”

Fear of health care bills may have severely elongated the H1N1 epidemic in the United States, which killed 12,469 Americans in 2009 and 2010. Though public health officials had urged social distancing, three in 10 workers with H1N1 symptoms continued going to work, a study found. The researchers concluded that such behavior ultimately drove 27 percent of all infections.

5. Wartime-style mass mobilization keeps your heath care system running. (China, South Korea, Taiwan)

“They’re mobilized, like in a war,” Mr. Aylward said of China, where he’d seen delivery workers reassigned to contact tracing, highway workers reassigned to take patients’ temperatures and a receptionist reassigned to infection control.

In South Korea, there’s more focus on enlisting the private sector than on dragooning individual people, but the effect is similar. Fast-track regulatory processes allow health care companies to quickly spin up test kits and methods specially designed for the coronavirus. And public-private partnerships keep the government in control while it exploits the private sector’s capacity to do everything from test to treat to disinfect.

In Taiwan, the government agency tasked with testing has enlisted a large number of private doctors and labs.

Taiwan has implemented another wartime-style measure: fines for disobeying public orders such as quarantines or for concealing infections. It’s a civil liberties curb, but one that Taiwanese officials seem to believe has helped in keeping infections there low.

6. Impose emergency measures before it’s an emergency, not after. (China, Taiwan, Italy)

Timing is everything when it comes to the coronavirus.

In China, for instance, a new study used computer modeling to estimate what would’ve happened if authorities had moved faster. Implementing its same policies just one week earlier, the researchers concluded, would’ve prevented 66 percent of infections. Three weeks earlier? 95 percent.

In fairness to China, very little was known about the virus’s danger, much less how to contain it, three weeks before authorities had stepped in. But the point is that other countries can learn from this.

It’s not just a hypothetical. Authorities in Taiwan credit much of their success to imposing an epidemic-level lockdown before the epidemic actually came. Indeed, they acted weeks before many governments even considered that the virus might spread beyond mainland China. Perhaps as a result, Taiwan, despite its proximity and heavy migration to mainland China, has been hardly affected.

Italy shows the dangers of waiting. Though the country has imposed similar measures, it waited to do so until it was already facing a full-blown crisis. By then, not only was the virus too widespread to easily contain, but the disease’s incubation period meant that infections were already far more numerous and geographically widespread than they appeared.

But Italy’s gravest warning for the world isn’t about the number of cases; it’s about what happens to even a well-funded and sophisticated health care system when it is overwhelmed by a rapid influx of seriously ill people. Because that is exactly what can happen when the coronavirus is allowed to spread unchecked even for just a couple of weeks.

As our colleagues in Italy documented in disturbing detail, the result has been health care workers physically and psychologically overwhelmed (and often becoming infected themselves) and insufficient resources to care for those who most need it. There are even reports of hospitals, facing more dire cases than they can feasibly address, leaving older patients to die.

In case there was any doubt that timing has been central to Italy’s disaster, a study led by Jennifer Beam Dowd of the University of Oxford compared two otherwise similar towns. Lodi and Bergamo both began seeing a very small number of cases in late February. Lodi imposed social distancing rules immediately, on February 23rd. Bergamo waited to do so until March 8.

Up through March 7 — well after Lodi had imposed its restrictions — the two towns had similar numbers of cases, about 750. From the surface, Lodi’s rules looked unnecessary and unsuccessful. But, by March 13, the two towns had diverged. Lodi had 1,133 cases and an infection rate that was getting slower and slower. Bergamo had 2,368 cases — more than twice as many — and accelerating every day.

It’s a two-part lesson: Lodi’s intervention worked because it was made very early. But, because of the lag between infection and diagnosis, its success was not apparent for weeks.

7. If you’re moving late, aggressive testing can make up for lost time. (Italy, China)

The caveat to point number six is that missing the opportunity to pre-empt an epidemic does not doom a society to simply let itself be overrun.

Two cases from northern Italy, the center of that country’s outbreak, have given hope that belated containment is still possible.

As an experiment, a team of outside experts worked with authorities in the small town of Vò, near Venice, to test all 3,300 residents, sometimes multiple times.

This allowed them to identify carriers of all kinds earlier than they would have if they’d waited for people to report themselves sick.

It also allowed them to identify asymptomatic carriers — the bane of health care workers, as such people can spread infections widely without ever thinking to get themselves tested. A stunning 1.5 percent of people in Vò — half of all people with coronavirus — turned out to be asymptomatic carriers. It’s too small a sample size to draw conclusions from, but it hints at the possibility that a larger-than-thought proportion of coronavirus carriers might never show symptoms, which could help explain how it travels so widely.

8. Secrecy, spin, and political infighting are killers. (China, United States, Iran, Egypt)

Flaws and contradictions in China’s political system, which often incentivizes low-level officials to downplay or cover up problems for fear of angering the bosses in Beijing, slowed China’s response in those crucial early weeks.

But China is not the only country with political imperfections. In the United States, President Trump has been criticized for initially downplaying the threat and spread of the coronavirus. The slowed response is thought to have helped allow the virus to gain a foothold in multiple American states.

Much remains unknown about the extent of the coronavirus outbreak in Iran as well as any political failures that may have allowed the virus’s spread. But both are thought to be severe, with political infighting and crosscutting lines of authority believed to have hampered the government’s response. (In fairness, American-led economic sanctions, some of which target the health care sector, are also thought to have played a role.)