Movement Restriction & Social Distancing: Effective?

A little over a year ago, I wrote an article about movement restriction and social distancing for 3BY (you can read the whole article by clicking HERE). 

Epidemic (also known as pandemic when widespread) disease is one of the more likely larger-scale disasters we might have to deal with. One common aspect of such outbreaks is the erection of barriers to free movement during epidemics. How well do these barriers work? Should we push for them in our own communities? If so, how should they be set up?

If you just want the executive summary of the older piece:

• Treatment and containment centers are only effective for slowing spread if they actually offer valuable treatment. Otherwise, people evade being contained.
• Movement barriers alone generally fail. People sneak through.
• Controlled movement, such as doing testing before allowing travel out, helped quite a bit.

With what we’ve seen so far with the COVID-19 outbreak, does my older article’s thesis hold water? What else have we learned? How does social distancing play into this?

What the COVID-19 pandemic has added to our understanding so far:

Very tight movement controls in China, when coupled with other containment approaches, apparently worked. As of this writing on March 25, the cases in China have nearly leveled off. Since they didn’t come anywhere near seeing full exposure of their populations, that’s a win.

We’ve also seen that half-hearted and ‘feel-good’ measures don’t work. I was reading pieces that said the infection was asymptomatic for two weeks in one paragraph, then assuring us all that we were safe because they were taking temperatures at airports. Hello? Two asymptomatic weeks? News flash: Didn’t work. The U.S. is well over fifty thousand cases about a month later.

The U.S. has not and is not now doing meaningful movement restrictions. We can get in our cars and drive about anywhere; it’s just getting out when we stop that’s being discouraged. I suspect we won’t ever try that for COVID-19. That horse has left the barn.

Sure, they did temp checks at airports as a movement restriction…but they knew the virus is shed by people without fevers.

Social distancing vs. movement restrictions

Movement restrictions are designed to keep an infection from moving to new geographic areas. They don’t do a thing for people already in the hot spots.

Social distancing, if done effectively, slows transmission within affected areas, as well as outward dispersal. The concept is that one person who is shedding virus isn’t getting close enough to spread it to many others.

The U.S. has not used movement restrictions against COVID-19, but social distancing is being encouraged. Does it make a difference?

Is slowing the movement within a population even meaningful?

Is the difference meaningful? Sounds like everyone will be exposed eventually in these situations, right?

Not necessarily. There are three potential benefits:

1. If the transfer is reduced enough, the spread dies out. 
2. Slower transmission means less overloading of medical resources; and that saves lives.
3. We learn more about how to treat and perhaps vaccinate over time.

If neither social distancing nor movement restrictions are tight enough to be effective, what then?

So far, the U.S. isn’t doing a stellar job of social distancing, and we did no meaningful movement controls when they could have been effective. So does that mean we’re out of luck?

Well, it means worse disease outcomes for the population as a whole, yes. Some of that can still be mitigated by removing some of the many loopholes in the social distancing efforts. 

But there’s also the individual level. Social distancing is only effective for the population when carried out by the population. However, it can be effective for the individual when practiced by the individual. 

I’m going to spend some time tomorrow dropping off bags of groceries for some of my neighbors who’ve requested delivery. If those folks are careful about how they handle the packages I drop off and they stay tucked in, they’re not likely to get COVID-19 any time soon. Oh, they may be exposed eventually if the virus continues to pass around. But if they can avoid it while the hospitals are overfull and our understanding of treatments improves, that may well be enough to prevent a bad outcome.

Note: Here’s the free Harvard Global Health course I took that helped me learn about movement restrictions: https://www.edx.org/course/lessons-from-ebola-preventing-the-next-pandemic