Separate the sick from the healthy: Why social distancing works

Giving people "breathing room" is one of the best ways to slow the spread of the coronavirus, experts say.
Image: Times Square
A nearly empty 7th Avenue in Times Square is seen at rush hour after it was announced that Broadway shows will cancel performances due to the coronavirus outbreak in New York, on March 12, 2020.Mike Segar / Reuters

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By Erika Edwards

In the past 48 hours, America has stepped closer to lockdown: Several states have closed schools, professional sports leagues have suspended their seasons, and companies across the U.S. have asked employees to work from home. These measures are all intended to limit social interactions, and hopefully, slow the spread of the coronavirus.

And while the response may seem extreme, one of the best methods in public health to slow the spread of a virus and minimize its effects on the most vulnerable populations is this very strategy, called social distancing.

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Public health officials say social distancing is not meant to induce panic. On the contrary, the goal is to protect people who are healthy by keeping them away from the sick.

"The best tool we have right now in this response is to give individuals breathing room from one another," Jason Schwartz, an assistant professor in the department of health policy at the Yale School of Public Health, said. "This is really critical."

The coronavirus is known to spread from person to person through droplets from a sneeze or cough, which can travel about 6 feet.

When healthy people inhale those droplets, or get them on their hands and then touch their eyes, nose or mouth, they can become infected, too, continuing the cycle of spread.

Enter the need for social distancing, a tried and true public health strategy that goes back centuries.

"It takes out the accelerant for outbreaks that comes when individuals are crowded together, with interactions between the sick and the healthy," Schwartz told NBC News.

"Social distancing is a way to calm the pace at which an outbreak is able to spread across a population," he said.

Nurses care for victims of a the influenza pandemic in Lawrence, Mass in 1918.Hulton Archive / Getty Images

History shows us it works, notably during the 1918 influenza pandemic.

When the first cases of flu were reported in Philadelphia on Sept. 17, 1918, authorities "downplayed their significance and allowed public gatherings to continue," according to a 2007 study in the Proceedings of the National Academy of Sciences.

Those public gatherings included a large parade in the city on Sept. 28. By the time officials in Philadelphia changed course and started closing schools and limiting large crowds on Oct. 3, it was too late. The virus had spread unchecked through the city, and its hospitals were inundated with nearly 50,000 cases. In the end, 12,000 people in Philadelphia died.

By contrast, the study found immediate social distancing in St. Louis lead to a much different outcome. The first cases in that city were reported on Oct. 5, 1918. Authorities worked quickly, implementing social distancing strategies within just two days.

The speedy action translated into just 1,700 deaths in St. Louis, and far fewer influenza cases than Philadelphia.

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That was two decades before the first flu vaccine was developed, and those in public health have learned much about outbreak control in the interim.

One of the first steps in controlling an outbreak is to identify who is sick through testing. That way, public health officials can isolate those people, treat them, track down their close contacts, and isolate those contacts.

But the U.S. has had multiple failures with its test for the coronavirus, and widespread testing has been sluggish.

Now, public health officials say, the country's best option (in addition to ramping up testing) is social distancing.

"When you can't contain, you have to mitigate," Dr. Jay Steinberg, chief medical officer at Emory University Hospital Midtown in Atlanta, said.

Slowing the spread also means health care systems, already inundated with seasonal flu cases, won't be overwhelmed all at once with new coronavirus cases.

"If we ignore these public health measures for too much longer, we are going to see infections in the millions," Steinberg warned.

"This is a pivotal time for us."

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