The Strategy: Suppress then Test, Trace, Isolate

From internet comments I’ve seen some confusion on the suppress then “test, trace, isolate” strategy. The “flattening the curve” metaphor suggested that lockdown was all about spreading infections over time to keep the medical system operational. But more importantly, the purpose of lockdown is to reduce the infection rate, R, below 1. A virus needs hosts. Take away the hosts and it fades away. We can take away hosts by making people immune, either with a vaccine or through surviving exposure. We can also take away hosts by hiding–that’s what lockdown is for. If enough people hide, then the virus burns out and fades away.

Of course, hiding leaves us vulnerable to multiple rounds of infection. That’s where the second part of the strategy, test, trace and isolate comes into play. When the infection is running wild, as it is now, we don’t have enough tests to keep up with the virus. But after suppression we can put test, trace and isolate into effect very quickly as outbreaks flare up but before the virus runs out of control again. Increasing our test capacity dramatically makes this strategy even more viable. Thus, as V.V. Chari and Christopher Phelan write in a good op-ed:

…A wise use of the breathing room provided by mass quarantines would be to put in place the infrastructure to allow us to mimic the policies of countries such as South Korea, Taiwan, Singapore and Hong Kong. These countries have thus far controlled the pandemic at much lower economic cost…[using] aggressive but targeted quarantine policies. They quarantine people displaying symptoms, aggressively trace the people they have contacted, test their contacts, and then quarantine those who have the virus (and sometimes those who have just had contact with those who test positive), regardless of whether they are symptomatic or not.

It is a test, trace and isolate policy. These countries have not generally engaged in mass quarantines or shut down factories, shopping malls or restaurants.

After suppression, we can combine “test, trace and isolate” with mask wearing and other safety protocols and move towards reopening the economy.


Another arm is to reorganize economic activities to reduce the chance of infection.

For example, the golf industry quickly responded by temporarily changing a fundamental rule. Instead of finishing a hole by sinking a putt into the hole, requiring you to stick your hand in the 4.5" cylinder where other golfers have put their hands, to retrieve your ball, the cylinder can be raised above the green and you can count your strokes as finished when you bounce your ball off the cylinder.

Tennis could be made into a no-shared contact sport by having each person supply his own, differently colored ball when serving.

Skiing, which appears to have been an unfortunate vector in the early spread of the virus in Europe and the Western hemisphere, has a harder challenge if ski resorts are going to reopen next winter.

I've been trying to think through how to make barbershops and hair salons safer. There are some challenges (e.g., if the customer is masked, that will tend to deflect the customer's exhalations sideways and even backwards toward the hair stylist), but somebody more clever than I could likely overcome them.

Businesses could attest on their websites and in their shop windows how many of their industry's Best Practices they follow.

Stock market will be very strong tomorrow. Deaths will be down. We are turning a corner.

Thanks You

sikicem seni

It seems like one could, if one was conscientious about it, maintain 6-ft separation while skiing, ride 1 person per chairlift, etc. They might have to limit number of people in lodge simultaneously. Maybe, skiing was a vector in the early spread because people were not practicing distancing at the time?

Haircuts are much more challenging, not least because the stylist inevitably touches the customer's hair, which seems really close to the face. Maybe, the stylist could wear disposable gloves, changed out for each customer, to protect customers and wear a mask to protect the stylist (and customer). Also, maybe just testing customers on premises for temperature would provide some reduction in spreading. Yes, temperature testing would produce false-negatives for the asymptomatic but blocking only some fraction of contagious people still reduces R0. In Taiwan, they took the temperature of people entering many of the public spaces. Imperfect testing is better than no testing.

I love skiing. The problem is the lodges, not the slopes.

Time to rediscover the Flowbee.

Take the robotic surgery tech and adapt it to salons?

More seriously it seems to me if the stylist wears a mask both the customer is protected as well as the stylist. If she washes her hands well after each customer and wipes down the chair with wipes the odds of transmission probably go down dramatically. We don't need the space suit protocol people working in labs with live ebola use.

Lovely, lovely, lovely! For this you gotta first test. Is it allowed yet?
South Korea covid cases and indeed they seem to have flattened the curve. Their case load is a noisy 120 per day stable.

South Korea is also one of the densest places and has a city the size of New York. So, I would say they have definitely flattened the curve.

And why the South Koreans have extended various social distancing measures, as even that number is unsustainable over the longer term.

A linear growth rate of cases is sustainable. Yes, South Korea certainly cannot go back to business as usual in its current state. But South Korea's social distancing measures are much more liberal than those adopted elsewhere and it may be possible for South Korea to hold out until a vaccine or effective treatment is developed with minimal strain on its health system.

Also, to put South Korea's new cases in perspective, it has lately been recording 80-100 new cases every day but 200-300 recoveries every day. So unlike almost everywhere else, the number of actively infected people is slowly falling. The curve isn't just flat but is on a downward trend. That's still not great because South Korea's liberal version of social distancing is still costly and grating for the population. But it's something.

What I read is that 80-100 new cases a day means that effective contact tracing is no longer reliable, and that the number needs to be lower to keep numbers low. For each new infection, there is x new people to contact and put into quarantine - along with the people who had exposure to the contacted person, who may have had a couple of days to spread the disease too. Suppression is really hard when looked at through that perspective.

True, but "really hard to do" is better than a total meltdown of the economy, which is what the USA has now.

Bonus trivia: I discovered a palliative cure for Covid-19, check my exchange with Rick Zhang at the Pushkin post. I will apply for a Emergent Venture grant from Mercatus and split the prize with whatever team that finds the actual antihelminthic drug that works from the list I provided. Hey man, that's how actual invention works, it's often a team effort, not a lone wolf. Even and especially Thomas Edison (check out this Epic Rap video on this theme of 'theft' of IP: Nikola Tesla vs Thomas Edison. Epic Rap Battles of History - )

PS--when viewing this video for maximum pleasure, imagine TC as Edison ("so dope I even make NJ look good"), RL as Tesla (who my paternal grandfather knew and corresponded with), and note every verse and image is based on a historical fact or reference, even Margaret Cheney's book passage "stole [Tesla] from mankind", the pun "Reddit" (where Tesla often wins) and the last line is a quadruple [triple] pun: "Curse the Con Edison with every utility". Awesome!

It still works. They’ve had of the order of 100 new cases a day for 27 days now.

Right, it's pretty stable.
If they can keep it up (assuming a vaccine will come in a year and a half), they will have under 100k cases in a country of 50 million.
Seems a very good job to me.

A little unfortunate timing mentioning Singapore, which will shut down schools and most businesses for a month starting Tuesday.

Simply another example of viral time, which cares nothing about what people think.

And possibly, an example of the sort of bubble many people still seem to be living in, even though the pandemic has been a reality in Italy, Spain, France and Germany for more than a month at this point, even if the actions to fight its spread did not really start until around mid-March, and requiring considerable tightening in many countries until now.

Singapore just recalled all of their tens of thousands of citizens from abroad, thousands from infection hotspots around the globe including Europe and the US.

This is how Singapore will ensure they don't become a Germany, Italy or whomever. They will lockdown, continue actual test and trace, and go back to semi normal.

Singapore will never be a Covid failure like Germany or Italy or Spain.

gang aft agley

+1. If Singapore can't do it, the U.S. certainly can't. So the test, trace, isolate strategy after lockdown, while better than before the lockdown, will probably end up being a mitigation rather than a containment strategy. The alternative of an extended lockdown is simply untenable.

But Singapore never had a complete lockdown, just social distancing and tracing, see this premature self-congradulatory piece:

Yes, but Singapore before its lockdown had a very low infection rate comparable to what a successful post-lockdown situation would look like in the U.S.

The mistake, in my opinion, was not immediately quarantining the earliest returning college students when they all arrived at the same time. Once we noticed infections going up, we forced the rest to stay in hotels for two weeks upon arrival, but by then there was untraceable community spread. I believe the current plan is to go back to the previous measures if the community spread burns out this month.

Ideally an at home infection and/ or antibody test would get us back to normal almost immediately.

Positive Antibodies = Immune and free to leave the house.

Positive CV19 = 14 day stay at hone quarantine.

Thankfully, the at home antibody test may be here soon.

An at-home fingerprick blood test may help detect your exposure to coronavirus news/home-fingerprick-blood-test-may-help-detect-your-exposure-coronavirus-n1176086

A mega-church in Sacramento spread more than 70 coronavirus cases. Appears we learned the wrong lesson from South Korea. No large gatherings you a**holes!!

A Kentucky church facing backlash for holding a revival service that helped trigger a significant outbreak of the novel coronavirus in the area says that the criticism from leaders and residents is “unjust.”

Star of Bethlehem Church in Dawson Springs, Ky., is one of two churches in Hopkins County that many in the state are blaming for an outbreak resulting in more than 50 coronavirus cases and at least four deaths. Kentucky Gov. Andy Beshear (D) had been pushing for religious institutions to cancel all public gatherings, a move that’s been ignored by churches, like Star of Bethlehem and Life Apostolic Church in Madisonville, Ky., which participated in revivals filled with worshipping, singing and preaching.

I understand the argument that saving human lives is worth the cost of crashing the entire economy. However, what is the argument that extending the worldly lives of some for a few years is worth sacrificing the immortal souls of others for all of eternity?

Or, are "externalities" just not the right way to think about disease. When people decide whether to attend various public gatherings they take on an internalized risk to themselves of infection weighed against an internalized benefit of saving their souls, enjoying a meal at a restaurant, whatever.

"But more importantly, the purpose of lockdown is to reduce the infection rate, R, below 1 by building a limited form of herd immunity."

No. You misunderstand. Lockdown decreases the infection rate, so fewer people get infected, so the development of a population with immunity takes much much longer to develop in a world without a vaccine.

After a year of significant social isolation and lockdown public policy, the total population infected would still likely be below 20%. The more effective the lockdown and isolation measures, the lower that percentage of recovered individuals will be.

What is being done is first and foremost to avoid overwhelming the medical system, and the concomitant increase in CFR that comes with that. Second, we are playing for time to develop more effective treatments and vaccines.

If we stumble upon a miracle treatment, then a herd immunity strategy might be reasonable.

He completely misunderstood one of the most fundamental principles of public health measures against an infectious disease. And the idea of herd immunity without vaccination is close to meaningless, apart from defining it as a concept to see how a contagious disease ebbs and flows over time in a population. We only began eliminating diseases through vaccination, not because a high percentage of people became immune to polio or measles by being infected.

I agree with your main point about the need for expanding tests. If the number of active cases drops and the number of tests greatly expand then we have multiple avenues for reopening the economy.
However... that is not what herd immunity is. See for a succinct discussion. A lockdown and getting to herd immunity both decrease R, but I don't see the benefit of muddling the terminology by referring to a lockdown as "building a limited form of herd immunity"

"I don't see the benefit of muddling the terminology". Propaganda, of which Alex is a vector.

No point arguing about terminology so I removed those words. The meaning is unchanged.

Sorry, I apologize, this was rude and unwarranted.

How do we get back to normal - I think the answer will be by zoning. Once an area has been virus free for two weeks entry into that zone will have to be carefully controlled with only proven virus free people allowed in. By virus free either a test showing no virus present, or an antibody test showing you are immune.

Rapid testing will be needed for this, but I understand this is already possible, but needs to be scaled up.

By zones I mean natural areas, maybe in some cases it could be an entire state, in other cases maybe cities or towns. There should be sufficient natural barriers between zones to prevent easy transit between them.

Heavy penalties should be in place for people who travel into zones without having had a negative test in the previous 24 hours. And very heavy ones who try to cheat by faking it.

If a zone gets an outbreak, of any size, the whole zone goes back into lockdown for two or three weeks.

I think that could happen, but I think it would take a worse to make it happen.

Someone mentioned yesterday that we didn't even really stop China travel. That 40,000 people have entered (returned?) Under various exceptions to the ban.

No, as Alex says, "we" should just get to work on the public health.

A worse disease

"After suppression, we can combine “test, trace and isolate” with mask wearing and .. "

We can, for some definitions of "we."

I saw yesterday that Massachusetts is trying to hire thousands of tracers. Good job Massachusetts. But if the effort is not uniform across the country it will create quite uneven outcomes, and possibly continuous reinfection of safe areas.

I understand why people keep pointing to SK/T/HK/S as countries that responded to the virus better than others but I’m not sure how applicable they are compared to the US because they’re more like city states and the US is an empire.

A Republic, sir.

For better and worse.

More relevantly, the US is a low trust-dysfunctional bureaucratic state.

Which is why I cannot imagine the US being capable of implementing a successful test and trace program.

Has the US been able to successfully do anything aside from mail checks and set cash on fire for the MIC in the last 45 years? Nothing comes to mind

That could be a sadly fulfilling prophecy.

More people will suffer if they buy into "a low trust-dysfunctional bureaucratic state."

A technocratic state should have a technocratic solution to the problem and not be forced to rely on evil Straussian neocon lies. So what's your technocratic solution for our relatively low trust-dysfunctional bureaucratic state, Mr. Solutionist? (Impeaching and removing Trump is not a solution).

I don't think that in a true "technocratic state" you would ask random commenters for their solution.

Not that I am actually for technocratic states.

I am for democracies which respect expertise, and so I )a citizen) would want to hear from the best epidemiologists who are looking at the best data.

Peter Navarro less so.

As opposed to:

“test, trace and isolate” does appear to be an effective strategy in South Korea but would Americans or Europeans be accepting of the invasion of privacy necessitated by this strategy?

In South Korea when someone tests positive, his or her phone and financial data are analysed to track movements. Then people who have been in the vicinity of this person are notified.

This has led to people being victimised, harassed and affairs uncovered.

Why should any rational and law-abiding person now care about "invasion of privacy"? Why should government sacrifice at least $1 trillion per month from lockdown because of luxury beliefs of some people about "people being victimised, harassed and affairs uncovered"?

So in order to test, would you support both an exporting restriction as well as a ban on price-gouging of both the tests as well as any supplies needed to administer the test? Or should we sell tests to the highest international bidders first and move H1-B candidates and illegal immigrants to the front of the testing line? Maybe we can have black marketeers work with big banks to really restrict the supply of tests so anyone that wants to be tested has to pay the “real market price”. So many questions.

Some personal anecdata. In the circle of my very close relations (close family members and long-time close friends, all people I have been in long vacations with), that I evaluate to 100 persons, 11 have being infected by Covid-21with clear symptoms (6 in Paris and 5 in Berlin), in three separate households.

Among them 8 have recovered now, 6 by themselves and 2 after an hospital stay; the three others are at an early stage of the illness.

Interestingly, only three have been tested (1 in Berlin, 2 in Paris), all positive -- one in each household.

It is possible that many other in the same circle have been infected with milder and no symptoms. I suspect that it could be the case for myself, and also for my wife (independently, as the confinement found us separated by an Ocean and I have not seen her in a month)

All of this doesn't prove anything, but it confirms my intuition that the real rate of infection, at least in big cities, is much bigger than the official rate around 0.1% -- bigger by a factor much bigger than ten.

And in the same of order an idea, a very recent article of La Stampa, see there:

The post makes total sense. We will have problems implementing this on a state by state basis though.

Alex, love your site and the articles. However on "suppress", there are numerous problems with this strategy. It makes sense to cancel large events where many strangers would meet. It makes sense to lock down or restrict meeting to 10 for about the first two weeks, However, after that, the strategy is just an obscene display of power and fear which results in an open-ended, unending crisis which becomes conflict between those who want to keep such restrictions and those whom want to lift them.
The "suppress" does not kill any virus at all. It is a "runaway" tactic doomed to fail as the virus never goes away. What does work is washing hands with soap between activities and places. This creates an actual barrier by killing off the virus.

Andrew +1. All the ideas of suppressing the virus, eradicating it, are wrong-headed. We only eradicated a infectious disease once, the smallpox (or variole), an ADN virus, and it took 200 years. ARN viruses like our coronavirus mutates rapidly and are even harder to eradicate.

The virus will stay with us forever, at least for the foreseeable future. We need to continue our life as normally as possible. Eventually, when enough of the population has been infected and has at least a partial immunity, plus we get a vaccine with some efficiency (maybe not much, like 30 to 60% like the flu vaccine) and some form of helpful, but not miracle, treatment, the virus will look like a mild flu -- every evidence indicates this, since even after running for more than 3 months in the world population without any immunity to it, the virus has a very
mild death toll of about 60,000 worldwide (it will surely increase at least tenfold, perhaps a hundredfold, but that will still be in the same order of magnitude as a big flu season).

Confinement saves lives by minimizing the saturation of healthcare systems. However, the number of lives so saved is not huge, because the hospitals have no real treatment to offer at this point to seriously ill patients. As a recent article from a doctor in the NYT explains it, unfortunately ventilators mostly prolongates life by a week or two, and rarely save it.

A shutdown of the economy worldwide with cause deaths, many of them.
So we have to carefully weigh the usefulness of the confinement to compute its optimal duration. I believe that when all is finished, it will be clear that this optimal duration was very short or even 0.

How will you "continue our life as normally as possible" when there is a deadly pathogen on the loose?
In China, the virus is almost eradicated at this point and life is still not normal and probably won't be in the foreseeable future (at least a year):

The fact that we have (deliberately) eradicated only 2 viruses so far doesn't mean we cannot eradicate others in the future.
Modern service economy is built on trust and lack of fear of in-person interactions between (semi-)strangers.
With this pathogen on the loose, this is impossible.

It's either complete or almost complete eradication (like measles, which is not eradicated completely only because anti-vaxxers are morons) or the end of life as we know it.

Nobody is going to "return to normal" when there is a virus out there that has a 1% chance of killing them and a higher chance of leaving them permanently disabled.

"How will you "continue our life as normally as possible" when there is a deadly pathogen on the loose?" The same way we are living "normally"
with many other deadly pathogens in the loose : various strains of flu, HIV, cholera, malaria, tuberculosis, Ebola, Syphilis, etc. All this illness are still endemic in the world and affects together hundred of millions of person.
Without proper treatment (which is the situation for many in poor countries) they are all quite lethal, and with treatment the mortality rate is non zero. The coronavirus without treatment and on a population without any immunity is already one of the lest lethal of this list.

So we will continue to live normal life, except if the governments try to prevent us, in which case there will be revolutions and civil wars, much more lethal than the coronavirus.

None of those pathogens has the macro level effects of coronavirus so the comparison is moot.
Also, people will ALWAYS choose security over some abstract "liberty" to go to restaurants/church/whatever.

You are living in a libertarian dreamworld. Nobody will follow you in real life.

In August 1914 no one followed Lenin. Everyone in every country were united in a beautiful showing of solidarity, ready to fight the mortal enemy at whatever cost, thinking that "it is ever complete victory or the end of the life as we know it"

Three years later things were different. Rendez-vous in three years.

No Alex. Stop working for the politburo.

The purpose of #flattenthecurve was to not overwhelm the medical system. The end. It was to extend the infections over a longer time so the, oh so important, medical system could apply their treatments. Critically, it was about not having photos of hospitals overflowing which would be used in political attack ads.

R* is a metric that is a social construct. If you take the most infectious disease, measles has an R* of around 10 but everyone wears space suits, the measured R* will drop to zero, obviously.

A disease increases as long as it's R*>1, when R*<1, the disease infects fewer and fewer new people in each generation until it vanishes.

Flattening the curve not only preserves the medical system but it also results in fewer overall infections.

"Critically, it was about not having photos of hospitals overflowing which would be used in political attack ads."

This is the type of thing a very comfortable, ignorant person would say. When you grow up and start to actually need a hospital for yourself or family members, you'll appreciate that 'overflowing hospitals' are a primary good in themselves.

Yeah, I guess we agree, and we both disagree with Alex (Tyler is too Straussian , se we never know if we agree or disagree with him). I think he is sincere though. Let's see if we can convince him.

This was to Reason above.

Agreed. The idea that we will conduct a multi-trillion dollar experiment to see if some technocratic pipe dream is workable is asinine.  

The correct path, which was being taken by most government entities, was to let the disease run its course, perhaps with low cost mitigations. Sadly, there was considerable hype by the media/social-media flywheel and the politicians lost their nerve.  We're now in a desperate situation where it is near impossible to predict the end result. We've made large swaths of the economy illegal and the unknowable shock waves are working their way through the system.   

At this point we have few options.  

Agree. I was reading these comments and thinking “why do these smart people seem to think we can stop this? What am I missing?”

Distancing doesn’t solve it... our “go get the Coronavirus at Target while you get paper towels” strategy seems to be slow-leaking this thing rather well. But perhaps too slowly in some places?

If the goal really is to lower deaths and ICU visits... it seems pretty obvious how to cut those significantly. I know where I would put my resources if I were the mayor. But that requires making choices and trade offs and dealing with unpleasant outcomes. You need cover from above... a FEMA mindset rather than an FDA mindset.

Yawn, shutdowns are 'technocratic'? Shutdowns are as simple and as old school as washing your hands. Humanity has used them since the beginning of time to deal with plague and other communicable diseases they lacked treatment for.

You know what's technocratic, schemes like trying to get all the younger people to get the virus to achieve a fast 'herd immunity' as the UK proposed, until someone noticed a bad spreadsheet formula and opps, that would kill hundreds of thousands and destroy the hospital system. So are calls from people like Robin Hanson to try improvised Hail Mary shots like variolation.

And let's dispense with the fear mongering economic nonsense. If you're telling me the modern economy cannot handle people pulling back from consumption activity for a few weeks or else it will collapse you're saying the modern economy is unfit for human use. I'm not inclined to such extreme views.

Many Asian economies seem to have weathered this pretty well. They have had hard experiences with outbreaks and pandemics and they seem to have a set of protocols that range from public mask wearing and moderate social distancing in normal times to fast and rigerous lockdown combined with test and trace protocols to control outbreaks of novel pathogens. They nonetheless have cultures where people can go out, enjoy mass public events like concerts and movie. They aren't indulging in schemes like injecting huge numbers of healthy people with live pathogens just to see what will happen.

You seem tired. You might better go to sleep.

Simple SOP for the future, no inventions or R&D breakthrus required:

1. Surveillance for the emergence of novel pathogens. International information sharing.

2. Hospital protocol to treat all patients with minimal PPE (i.e. masks gloves) in normal times. Let the supply chain adjust production upwards over time to accommodate that.

3. Mask wearing by the general public. Again the supply chain can accommodate that. Japan produces a few billion masks per year, the average person goes through 44 every year. Most of us wear underwear, the economy that can keep you in tighty whities can also provide you 44 good masks each year without a problem.

4. Require hospitals to have a surge capacity of PPE equal to, say, 10 times normal for 30 days. Maintain national stockpiles to run the country for say a full year at normal consumption or a month @ 12 times normal.

5. Ensure hospitals and mass public places have high quality ventilation .

6. Practice and establish protocols for all health establishments to go into high PPE mode.

7. Encourage work from home options. I predict there's going to be a lot of innovation coming in the next years for remote learning and working. A massive amount of investment in office space is going to be 'creatively destroyed'.

None of this requires any real invention or discoveries. But some nice to have R&D work:
* Universal flu vaccine. Get flu off the table.
* Common cold cure/vaccine. Alphabet (Google) was taking a shot at this.
These are nuisances but they clog up the health care system, cause people endless confusion and do kill a steady stream of people.

* Rapid vaccine discovery, testing and production.

* Downsizing factory farming on the top end and sloppy 'wet markets' on the bottom end.

How dare you talk about “ reopening the economy”. You want to kill Pop-Pop just to make your Wall Street friends richer? Shame.

“We’re all Keynesians in a foxhole” even MR. Now I want Alex and Tyler to propose how to establish a social contract with the lowest 15%. Those who struggle to fill out forms due to a variety of psych and intellectual challenges.

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