Epidemiologists: Why social distancing is so critical against COVID-19

Imagine studying the solar system but you only have reliable data about Earth. You might have information about Earth’s atmosphere, its climate and inhabitants, but the rest of the solar system is unknown in both size and scope.

You don’t know, for example, if there are other planets, and if so, how many. You also don’t know whether they have water or living creatures. Yet, you have to make conclusions with the limited data available.

This is essentially what is happening right now with the COVID-19 pandemic.

Epidemiologists, scientists, and clinicians only have good data on what is happening in clinical settings with the sickest patients. We can count the number of tests conducted and the number of positive results, and we can use those data to make epidemic curves and maps. But those data only tell us a portion of what we need to know.

The time to argue about what to do is behind us. We must take immediate and stringent action to protect those most vulnerable and buy scientists more time to understand the epidemiology and pathology of the virus, develop effective treatments, and evaluate and distribute a vaccine.

To achieve this, social distancing is the single best strategy available today to save lives, and it should be expanded across the U.S. and especially intensified in the U.S. Southeast.

To understand why social distancing can be so effective, consider three levers epidemiologists must consider as they derive ways to slow an epidemic: how long a person is contagious, how likely it is that transmission occurs between two people if one of them is infected and, last, the rate at which people contact each other.

Let’s talk about lever number three.

Reducing the contact rate means reducing and changing the ways that individuals and populations interact and therefore spread infectious agents. Isolating people with COVID-19 is one way to reduce the contact rate between infected and uninfected people, as is quarantining people who may have been exposed to someone with COVID-19. But those strategies work best when you can identify with certainty who has the disease and who does not.

In the current situation, when we mostly don’t know who is infected and who isn’t due to testing delays and lots of people about possibly with asymptomatic infections, reducing the contact rate essentially means that the entire population needs to reduce mixing.

This, in the absence of a vaccine, which will be many more months away, lever number three is our most effective disease control strategy.

Data released this week suggest the majority of the U.S. drastically restricted movement starting in March – except in the U.S. Southeast. Smartphone movement data suggests that many people in Georgia, Louisiana and other southern states have continued to move about their daily lives despite urgent news about the pandemic on the horizon and case counts increasing rapidly.

Unnecessary trips to the grocery store, group outings on the beach or interactions with others at the park could mean life and death for someone’s grandmother or diabetic brother, for example. We should be overcautious and assume that those in the street, those in aisles at the grocery store and those passing on the hiking trail are infected.

And, even if you aren’t already infected, you don’t want to be. Don’t be fooled; “Mild illness” can still mean debilitating illness, just short of requiring hospitalization.

This means, for example, that a healthy 45-year-old runner can find themselves sick in bed for one-to-three weeks feeling worse than the worst influenza of their life. It could mean a week of feeling tired and achy with a long-lasting cough that makes it feel like your ribs are bruised or broken. You don’t want COVID-19.

The time to act is now. Strict adherence to social distancing and sheltering in place – meaning no unnecessary trips out of your house and limiting any contact to non-household members by six feet or more – is our only large-scale, community strategy to interrupt the largest pandemic of our lives.

During this unprecedented time, remember that every interaction we take will lead to higher numbers of deaths, and every inaction will save the people we love.

This story was originally published April 1, 2020 at 2:15 PM.