Meet your new friends: Isolation and Quarantine

I am an epidemiologist. I remember when I first learned about epidemiology and I thought: ‘WOW! Tell me what that is again?’ The short answer is that epidemiology is the what and how (the determinants) and the who, where and how many (the distribution) of disease. It all started with a guy named John Snow, (not the Game of Thrones guy). He was a 19th century British physician who figured out that the source of a deadly cholera outbreak in London was a local well.

This is a great example of the backward then forward nature of how epidemiology works. There has to be an epidemic in order to figure out where it started. Once we understand what, where, who and how, we can take action. Not actions that I’ve made up. Actions that are in the standard playbook of epidemic control, some of which date back to the Middle Ages. How did John Snow fix the problem? He simply removed the handle from the well so that people could no longer access the cholera contaminated well water.

Epidemiology and coronavirus

We know that coronavirus spreads through droplets. That makes a difference. It is much harder to avoid droplets when someone sneezes, coughs or even breathes near you than it does to avoid a poisoned well. This coronavirus is a huge success story in the virus world. No one has immunity to it. It spreads easily and quickly. It lasts for hours to days on the surfaces that we touch daily. Even if we’re not near an infected person, we can still get infected. It mimics other diseases that we know well, like flu and pneumonia. Familiarity breeds complacency. There is no cure. It’s no wonder that poor decisions have been made in addressing the pandemic. We, everyone, just couldn’t believe what was happening right in front of our eyes.

Yet, there are steps that can still be taken to mitigate the impact of the coronavirus on our healthcare systems, the health of the global population and our economy.

Step one: Deal with the unprecedented strain on our healthcare system by tackling the looming equipment shortages (e.g., ventilators, beds, test kits). None of this will be helpful, if healthcare workers don’t have the masks, gowns and gloves they need to stay healthy. Step two: Protect other front-line people—police and firefighters, supermarket cashiers, delivery people to name a few—so they don’t become patients. They are what’s keeping society going. Step three: Follow government orders to stay home! If you keep six feet away from others, you massively decrease your risk of acquiring--or transmitting--coronavirus. Social distancing is a proven epidemic control strategy. It has worked for centuries. Step four: Aggressively test as many people as possible for coronavirus. We know that people with coronavirus spread it to two or three other people, often unknowingly. Only when we know who has coronavirus will it be possible to slow down the spread and get healthy people back to work.

Meet your new friends: isolation and quarantine

Testing for the coronavirus allows the identification and, importantly, the separation of people into three groups: Group 1, people who test positive for coronavirus, Group 2, people who currently test negative but who have had contact with coronavirus positive individuals; these people are exposed to coronavirus, and Group 3, people who test negative and who haven’t had contact with coronavirus positive individuals. During epidemics, these three groups should be physically separated from each other.

What is isolation? People in Group 1, those who test positive, are at high risk of spreading coronavirus to others. They should be isolated from the rest of the population until they recover. Just plucked out of their lives and put into isolation—alone and with no visitors. Harsh, but necessary. In Wuhan, China, where the pandemic started, 75% of the people who became infected with coronavirus were family members, close friends and colleagues. That’s why they built the 1,000-bed hospital in an astounding ten days—to isolate mild to moderate coronavirus test positive individuals. As we speak, the Javits Convention Center in New York City is in the process of being converted into such a hospital.

What is quarantine? People in Group 2, who test negative but have exposure to coronavirus, should be quarantined. Quarantine means that Group 2 people should be separated from both Group 1 test positive individuals AND Group 3 individuals who test negative and haven’t been exposed to coronavirus. Quarantine should last 14 days. No one is allowed in or out of quarantine. The majority of people in quarantine who do become infected, will usually get symptoms about five days after exposure. Everyone should be tested on Day 14 anyway, since some infected people never have symptoms. Many people in quarantine will not become infected, since the source of infection was quickly removed and isolated. An important part of quarantine is figuring out exactly who had contact with coronavirus positive individuals. This is called contact tracing. It’s a lot of work, not always straightforward, but necessary to control the spread of coronavirus.

Everyone else: People in Group 3, who test negative and have no exposure, should work like crazy to avoid catching coronavirus. It makes it much, much easier for people in Group 3 to not catch coronavirus, if Group 1 people are isolated from the rest of the community and Group 2 people are quarantined for 14 days until they either become infected and are isolated OR they don’t, and they join Group 3. The bad news is that it doesn’t make Group 3 people immune. People in Group 3 could go on to be exposed to coronavirus, say by someone who hasn’t been tested.

Meet your current reality: lockdown and shelter in place

Remember the 14th century and the bubonic plague? Despite scientific advances inconceivable 700 years ago, 70 years ago, even 7 years ago, our current pandemic response is from the Middle Ages. In many places in Europe and the US, we are telling sick people to stay at home with their families, often guaranteeing that other family members become infected. We’ve also introduced social distancing in the hopes of keeping coronavirus from entering our homes. While we are putting 700-year-old strategies to good use, we also have the ability to test for coronavirus. Testing greatly refines epidemic control strategies, but only if you test entire populations.

In the US, we’re basically rationing healthcare by giving tests only to sick people. That’s not a great idea. Evidence from Iceland, where they’ve tested a large chunk of the population, suggests that up to 50% of the coronavirus test positive population is asymptomatic. Testing everyone gives a much better idea as to where, who and how many people are infected with coronavirus. (That’s distribution of disease in epidemiology-speak.) The more we know, the more targeted and effective our actions can be to mitigate the course of the pandemic and to return our lives back to normal.

This article was originally published March 24, 2020 here: