Testing, testing: Why social distancing alone is not enough

Jeanne Lenzer and Shannon Brownlee

Now that most of America has hunkered down to reduce the spread of COVID-19, the question on everyone’s mind is, “When can we stop social distancing?” Last week, the President pledged to “open the country” by Easter. Now he’s backtracked after learning that the public thinks the country should stick with it, but political pressure to relax the social distancing measures may yet emerge again.  

Lifting the restrictions on public gatherings and businesses too soon almost certainly risks a surge in infections, unless we start emulating other countries, in particular Singapore, and South Korea.  These countries, along with Taiwan and Hong Kong, managed to get their COVID-19 infection rates under control without instituting Draconian lockdowns. Their schools weren’t shut down, restaurants didn’t close. 

They did it through widespread testing and other infection control measures that we are not even contemplating. That’s the bad news. The good news is, even though the U.S. has stumbled badly on the first step, which is testing, it’s not too late to slow the outbreak. Here’s how.

Widespread testing

Topping the list of steps taken by South Korea and other countries are the three T’s: widespread testing, contact tracing, and rigorous treatment. Their mantra was “You cannot fight what you cannot see.” Testing is the key to seeing where the virus is moving, how many people have been infected, how many are likely to be infected, and what steps should be taken to stop transmission. As of March 30, South Korea had tested 400,000 individuals and identified 9,600 cases. That’s more testing than most other countries compared to their population. 

What does testing do? For one thing, it allows health officials to estimate the “case fatality rate,” or number of people who are likely to die should they be infected. 

In the early days of any epidemic, case fatality rates are likely to be high because only sick people are identified and tested. But with wider testing of not-so-sick and asymptomatic individuals, the number of people who are infected but who do not die goes up. That increases the denominator (the total number of people infected), while failing to increase the numerator much or at all. In this way, the case fatality rate plummets toward its actual rate as testing increases. 

For example, the case fatality rate among patients tested in Wuhan between January 1 and January 10 was a whopping 17.3 percent. By February 4, as contacts of infected patients were traced and more tests were done, the rate dropped to 4.9 percent. In South Korea, where many more people were tested, the case fatality rate is currently 1.7%. Dr. John P.A. Ioannidis, an epidemiologist and professor of medicine at Stanford University and co-director of Stanford’s Meta-Research Innovation Center, says the most complete data available comes from the Diamond Princess cruise ship, where one percent of infected passengers died.

Testing for case tracing

Public health agencies also need to be able to test lots of people in order to break the chain of transmission. Widespread testing of even asymptomatic people allows them to identify who is sick, trace their contacts, and put everybody who does not need to be hospitalized in isolation. South Korea then used aggressive tracking measures to identify infected individuals. Once an individual tested positive, the health authority retraced the patient’s recent course of movement to find and isolate others who came in close contact with the patient using security camera footages, credit card transactions and even GPS data on the patient’s cars and cellphones. One Korean “super spreader” was suspected of infecting more than 300 others.

According to a report released by the South Korean health authority, the key to this aspect of infection control was “the high level of civic awareness and voluntary cooperation” by ordinary citizens. In the U.S., people might not be amenable to the level of government intrusion that worked in South Korea, but many people who are infected will undoubtedly be willing to provide information voluntarily about their movements and close contacts to fight the virus.

Testing for treatment

Once patients are identified, a number of countries  have utilized “fever hospitals,” places where people who are infected can be housed until they are given a clean bill of health. Obviously, some people will be sick enough to be in the hospital, where they will certainly be isolated. But for those who are not so sick, just staying home won’t prevent them from spreading the virus. If infected patients are simply told to self-isolate, the outcome for family or household members can be devastating as household members may fall ill as well. They might need to go out to work or get groceries, potentially widening the spread.

Some critics say it would be impossible to have such centers in the U.S. because only a totalitarian government like China could impose such a solution. Besides, they say, people in the U.S. simply won’t accept it. However, South Korea is a democracy and their people stand behind the isolation centers. In addition, many people who become infected express a strong wish not to infect their family and loved ones. Having a place to go, where they can be attended to for a few weeks while they recover should be a win-win for reducing exposure of those who aren’t infected and providing assistance for those who are. There are plenty of buildings that could be used to house people who are infected such as hotels, stadiums and convention centers, all of which are mostly empty.

Getting people back to work

The U.S. should also invest heavily in serological, or “immunity” tests, which can show whether or not a person has been infected and developed antibodies against COVID-19. Those who have can safely return to work. These tests will be especially important for health care facilities, who will likely face staffing shortages over the coming weeks and months. China also used widespread serology testing as a means of estimating the rate of infection. 

We had the chance to follow the examples of other countries and execute a proven strategy of widespread testing, contact tracing and isolation before the virus could take off. Having failed to do so, we are now facing large numbers of infections and deaths, hospitals that are overwhelmed. Then there’s the toll that lockdowns are taking on financially vulnerable people and the economy as a whole. There’s still time to reverse much of the damage, but only if we are willing to mobilize widespread testing and the other public health measures that have been shown to work in other countries.