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For many countries staring down fast-rising coronavirus case counts, the race is on to “flatten the curve.”

The United States and other countries, experts say, are likely to be hit by tsunamis of Covid-19 cases in the coming weeks without aggressive public health responses. But by taking certain steps — canceling large public gatherings, for instance, and encouraging some people to restrict their contact with others — governments have a shot at stamping out new chains of transmission, while also trying to mitigate the damage of the spread that isn’t under control.

The epidemic curve, a statistical chart used to visualize when and at what speed new cases are reported, could be flattened, rather than being allowed to rise exponentially.


“If you look at the curves of outbreaks, they go big peaks, and then come down. What we need to do is flatten that down,” Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told reporters Tuesday. “That would have less people infected. That would ultimately have less deaths. You do that by trying to interfere with the natural flow of the outbreak.”

The notion that the curve of this outbreak could be flattened began to gain credence after China took the extraordinary step of locking down tens of millions of people days in advance of the Lunar New Year, to prevent the virus from spreading around the country from Wuhan, the city where the outbreak appears to have started. Many experts at the time said it would have been impossible to slow a rapidly transmitting respiratory infection by effectively shutting down enormous cities — and possibly counterproductive.


Source: Carl Bergstrom, UW & Esther Kim Alex Hogan/STAT

But the quarantines, unprecedented in modern times, appear to have prevented explosive outbreaks from occurring in cities outside of Hubei province, where Wuhan is located.

Since then, spread of the virus in China has slowed to a trickle; the country reported only 19 cases on Monday. And South Korea, which has had the third largest outbreak outside of China, also appears to be beating back transmission through aggressive actions. But other places, notably Italy and Iran, are struggling.

For weeks, a debate has raged about whether the virus could be “contained” — an approach the WHO has been exhorting countries to focus on — or whether it made more sense to simply try to lessen the virus’ blow, an approach known as “mitigation.”

That argument has been counterproductive, Mike Ryan, the head of the WHO’s health emergencies program, said Monday.

“I think we’ve had this unfortunate emergence of camps around the containment camp, the mitigation camp — different groups presenting and championing their view of the world. And frankly speaking, it’s not helpful,” Ryan told reporters.

Caitlin Rivers, an assistant professor of epidemiology at the Johns Hopkins Center for Health Security, said any lessening of spread will help health systems remain functional.

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“Even if we are not headed to zero transmission, any cases that we can prevent and any transmission that we can avoid are going to have enormous impact,” she said. “Not only on the individuals who end up not getting sick but all of the people that they would have ended up infecting. … And so the more that we can minimize it, the better.”

On any normal day, health systems in the United States typically run close to capacity. If a hospital is overwhelmed by Covid-19 cases, patients will have a lower chance of surviving than they would if they became ill when the hospital’s patient load was more manageable. People in car crashes, people with cancer, pregnant women who have complications during delivery — all those people risk getting a lesser caliber of care when a hospital is trying to cope with the chaos of an outbreak.

“I think the whole notion of flattening the curve is to slow things down so that this doesn’t hit us like a brick wall,” said Michael Mina, associate medical director of clinical microbiology at Boston’s Brigham and Women’s Hospital. “It’s really all borne out of the risk of our health care infrastructure pulling apart at the seams if the virus spreads too quickly and too many people start showing up at the emergency room at any given time.”

Countries and regions that have been badly hit by the virus report hospitals that are utterly swamped by the influx of sick people struggling to breathe.

Alessandro Vespignani, director of the Network Science Institute at Northeastern University, is gravely worried about what he’s hearing from contacts in Italy, where people initially played down the outbreak as “a kind of flu,” he said. Hospitals in the north of the country, which the virus first took root, are filled beyond capacity, he said, and may soon face the nightmarish dilemma of having to decide who to try to save.

“This was what was really keeping me up at night, to unfortunately see Italy approaching that point,” Vespignani said, adding that now that the country has effectively followed China’s example and put its population on lockdown, “hopefully this will work.”

Vespignani, along with colleagues, published a recent modeling study in Science that showed travel restrictions — which the United States has adopted to a degree — only slow spread when combined with public health interventions and individual behavioral change. He’s not convinced that people in the United States comprehend what’s coming.

“I think people are not yet fully understanding the scale of this outbreak and how dangerous it is to downplay,” he said.

Mina agreed: “Without a very clear signal coming from our government at the national level, it’s really just like a small trickle as people start to recognize that this is happening.”

Rivers and colleagues from Harvard’s T.H. Chan School of Public Health have looked at what U.S. hospitals might endure if Wuhan-scale spread occurred in this country. Their analysis, posted on a preprint server in advance of peer review, came to a chilling conclusion.

“If a Wuhan-like outbreak were to take place in a U.S. city, even with strong social distancing and contact tracing protocols as strict as the Wuhan lockdown, hospitalization and ICU needs from COVID-19 patients alone may exceed current capacity,” they wrote. “We don’t want to go that route,” Rivers told STAT. “So it’s the top priority right now that we bend the curve.”

As of Tuesday, the Centers for Disease Control and Prevention said there had been 647 cases and 25 deaths in the country. A website maintained by Johns Hopkins University — which is considered the go-to website for Covid-19 statistics — scrapes data from a variety of sources. It suggested late Tuesday afternoon that there had been 808 cases in the U.S. and 28 deaths. Most in the deaths have been in the Seattle area.

But the reality is that with state and local laboratories in the country still getting up to speed with how to test for this infection, the full extent of spread is not known.

Without that kind of data, public officials have been loath to take the types of measures that would help to flatten the country’s epidemic curve. Those measures include banning concerts, sporting events, and other mass gatherings, closing movie theaters, telling people who can telecommute to work from home, and potentially closing schools. (The jury is still out on how much school closures would help slow spread.)

“I think that in terms of the decision-makers, we are in a place right now where we don’t have the data we wish we had in order to inform these decisions,” Rivers said. “So what I think we’re seeing is decision-makers struggling to pull the trigger on these really big, impactful decisions without having a clear sense of the current status.”

“But we know from pandemic planning and previous experiences that the sooner we implement these measures, the more effective that they are,” she said.

Mina said the lack of evidence of widespread transmission in the country may be making people feel any aggressive step right now may be an overreaction. But this is precisely the time when public health measures of this sort can have an impact, he said.

“We are all wondering if our actions are melodramatic. And we’re feeling silly,” he said, noting people still feel self-conscious bumping elbows instead of shaking hands.

“But this is the problem, that people aren’t recognizing that we are at this moment and we can make a decision right now to flatten this curve by … being OK with wondering if we’re being melodramatic,” he said.

“Should we be canceling classes? Should we be canceling our flights? Should we not be shaking hands? All of these things are things that I want the public to keep wondering if we should be doing this. Because the moment we’re no longer wondering whether we should be doing it, it’s too late,” Mina said. “That means that we know we should be doing it. And that is a bad place to be.”

Andrew Joseph contributed reporting.

  • The article title is an oxymoron.

    “Why ‘flattening the curve’ may be the world’s best bet to slow the coronavirus”

    Of course flattening the curve will slow the coronavirus. That is what the curve represents.

  • Dear Mrs Branswell,
    Our government in the Netherlands is basing their strategy completely on the above model, and I’m convinced it will be a disaster.
    The idea is that gradually al large part of the population has to become immune (app. 60%). That means app. 10 out of 17 million people have to be infected. In case 5% of the infections need IC (intensive care), the maximum number of infections our health care can handle is app. 13.000.
    If an infection lasts 2 weeks, 348.000 infections can be handled. We’ll need 30 years to reach sufficient immunity.
    Why not use the Chinese approach: from peak to zero infections in 6 weeks!
    Jan Welvaarts

  • OMG, there’s thick black smoke rolling out of the eaves of the house, but there’s no visible fire! There’s people inside, but for we don’t want to over-react, so don’t call the fire department until we see the fire!

  • “The virus does not seem lethal in most cases if proper medical oversight is given.” according to infectious diseases expert Osterholm, it has 10 – 15 times the fatality rate of the flu. He projects that 480, 000 people will die in the coming months. Harvard’s top infectious diseases epidemiologist Lipsitch projects deaths in the millions.

  • You are overlooking the fact pointed out by Michael Osterholm that when these infected and “distanced” people eventually get out and into the workplace, public spaces, public transportation, etc., they will contribute to another spate of contagion and resulting deaths.

  • “Manage the Curve” (Thanks Vijay!)
    I just wrote this on a friend’s linked-in, and he thought I should share as a manner to get through this with the least lethal, societal and economic impact.

    The virus does not seem lethal in most cases if proper medical oversight is given. Given that this virus is so transmittable, and is contagious before it is felt, there is a high likelihood that it will be flaring up and continuing to disrupt life for everyone for more than a year, possible much longer. This begs for hard thought into the arena of Planned Infection as an effective handling of this pandemic. If a suitably supplied army of health personnel could cycle this virus through the population and treat those people that require extra help to get them safely past the critical point, this virus MAY have much less of a lethal and economic disruption to the world than the current variably applied isolation and business disruption natural course. Hard questions sometimes need innovative and hard decisions. This might be one of those times!
    #coronavirus #disruption #innovation

  • The time to act is clearly now. Any delay means more people will die. Everyone who can telecommute should be required to do so. Schools should be utilizing virtual classrooms. Unnecessary large gatherings should be canceled.

    This is not the flu. It is a viral pneumonia that is far more contagious and deadly than the flu. While a vaccine and treatments are developed, strong actions must be taken.

  • The WHO has failed in their lack of guts to make tough decisions, they’ve been on the potty squaking about global Angst instead. This will be the detriment of many already dead and countless more that will die from this virus (particularly in a contintent like Africa). That they now portray to “affirm what they have been saying all along” is the pinnacle of cowardish babble.
    To any in doubt about compliance : everyone must take this pandemic event seriously, and each and everyone needs to take responsibility of all the action needed to curb spread. If tough containment worked for China and South Korea, then so should it also for the rest of the world. Many over 50 years in i.e. Europe have experienced similar before, it is a royal, tough and limiting inconvenience – but it is temporary. And in 2020 it is by far not as isolating due to the internet, cell phones, social and other media. But everyone has to comply, or be forced to comply – for the benefit of all. “Suck it up”, do your share, so that there’ll be a lot more life to live yet after this period.

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