Focus on the clusters, not the trees.
October 6, 2020 8:54 AM Subscribe
Superspreader events are the key to understanding the pandemic. "By now many people have heard about R0—the basic reproductive number of a pathogen, a measure of its contagiousness on average. But unless you’ve been reading scientific journals, you’re less likely to have encountered k, the measure of its dispersion. The definition of k is a mouthful, but it’s simply a way of asking whether a virus spreads in a steady manner or in big bursts, whereby one person infects many, all at once. After nine months of collecting epidemiological data, we know that this is an overdispersed pathogen, meaning that it tends to spread in clusters, but this knowledge has not yet fully entered our way of thinking about the pandemic—or our preventive practices."
"Because of overdispersion, most people will have been infected by someone who also infected other people, because only a small percentage of people infect many at a time, whereas most infect zero or maybe one person. As Adam Kucharski, an epidemiologist and the author of the book The Rules of Contagion, explained to me, if we can use retrospective contact tracing to find the person who infected our patient, and then trace the forward contacts of the infecting person, we are generally going to find a lot more cases compared with forward-tracing contacts of the infected patient, which will merely identify potential exposures, many of which will not happen anyway, because most transmission chains die out on their own."
"Because of overdispersion, most people will have been infected by someone who also infected other people, because only a small percentage of people infect many at a time, whereas most infect zero or maybe one person. As Adam Kucharski, an epidemiologist and the author of the book The Rules of Contagion, explained to me, if we can use retrospective contact tracing to find the person who infected our patient, and then trace the forward contacts of the infecting person, we are generally going to find a lot more cases compared with forward-tracing contacts of the infected patient, which will merely identify potential exposures, many of which will not happen anyway, because most transmission chains die out on their own."
People are scared by math and exhausted by changing advice, so I'd rephrase the title - "to shorten the trees, find the clusters". "Clusters are the roots of the trees", maybe?
Tufekci has been doing great writing on the pandemic, I think my absolute favorite of the non-epidemiologist writers.
posted by clew at 10:45 AM on October 6, 2020
Tufekci has been doing great writing on the pandemic, I think my absolute favorite of the non-epidemiologist writers.
posted by clew at 10:45 AM on October 6, 2020
My spouse has relatives in Japan so we get fairly constant updates on what life is like and for the last 6+ months it's felt as if there've been less restrictions over there compared to where we are, Ontario. Masking is much more common there which I always figured was the main reason but I can totally believe that judicious application of the right restrictions would be more effective than widespread stringent restrictions, especially with respect to covid/lockdown fatigue. Our public health units must be looking at what other jurisdictions are doing, especially the more successful ones, so what is stopping us from implementing some of these measures?
posted by any portmanteau in a storm at 11:37 AM on October 6, 2020 [2 favorites]
posted by any portmanteau in a storm at 11:37 AM on October 6, 2020 [2 favorites]
> what is stopping us from implementing some of these measures?
It would be great if our leaders could say, "Hey, we have new information from science, so here are new guidelines that should work better than the way we've been going."
But politicians don't want to admit they made poor decisions; they need to justify changes in policy in ways that don't make them look bad. The fact that people look to politicians for answers rather than scientists is a big part of what got us into this mess. Also that a large number of our leaders are just batshit....
posted by Wilbefort at 11:44 AM on October 6, 2020 [14 favorites]
It would be great if our leaders could say, "Hey, we have new information from science, so here are new guidelines that should work better than the way we've been going."
But politicians don't want to admit they made poor decisions; they need to justify changes in policy in ways that don't make them look bad. The fact that people look to politicians for answers rather than scientists is a big part of what got us into this mess. Also that a large number of our leaders are just batshit....
posted by Wilbefort at 11:44 AM on October 6, 2020 [14 favorites]
The ones making the decisions everywhere are politicians, and I don't think the ones in the countries that have been doing well are any more receptive to science or any less willing to look bad than the ones in countries that haven't been doing well. Fine Canada and the US have strong federal structures so the responsibility gets divided between different levels of government but Australia is fairly similar and they're doing orders of magnitude better. And who doesn't want to be the politician who can say "the path we were going on wasn't working so I had the vision and bravery to go this other way and that was how we beat Covid"? That'll earn you a re-election at the very least.
posted by any portmanteau in a storm at 12:12 PM on October 6, 2020 [1 favorite]
posted by any portmanteau in a storm at 12:12 PM on October 6, 2020 [1 favorite]
what is stopping us from implementing some of these measures?
A horrific mix of nationwide hatred of expertise and a terminal dose of toxic masculinity. At least judging by the last 8 months...
posted by fifteen schnitzengruben is my limit at 12:19 PM on October 6, 2020 [19 favorites]
A horrific mix of nationwide hatred of expertise and a terminal dose of toxic masculinity. At least judging by the last 8 months...
posted by fifteen schnitzengruben is my limit at 12:19 PM on October 6, 2020 [19 favorites]
And who doesn't want to be the politician who can say "the path we were going on wasn't working so I had the vision and bravery to go this other way and that was how we beat Covid"?
Who doesn't want to be that politician? Not going to name any names but seems like we have a lot of them in the US who don't ever want to admit they could have been wrong about anything in the past. Doubling down on their errors seems to be something they consider a virtue.
posted by yohko at 12:20 PM on October 6, 2020 [1 favorite]
Who doesn't want to be that politician? Not going to name any names but seems like we have a lot of them in the US who don't ever want to admit they could have been wrong about anything in the past. Doubling down on their errors seems to be something they consider a virtue.
posted by yohko at 12:20 PM on October 6, 2020 [1 favorite]
I've seen a lot of people speak highly of this article, but it seems like a restatement of things we already knew about coronavirus: "super-spreading clusters of COVID-19 almost overwhelmingly occur in poorly ventilated, indoor environments where many people congregate over time." She kind of hints at a breakthrough here: "It might be that some people are super-emitters of the virus"... but she doesn't pursue that, since afaik there's not conclusive evidence to back that up. So, we're left with: "It’s not intellectually satisfying, but because of the overdispersion and its stochasticity, there may not be an explanation [for why some countries/regions are hit worse than others] beyond that the worst-hit regions, at least initially, simply had a few unlucky early super-spreading events."
posted by Noisy Pink Bubbles at 12:40 PM on October 6, 2020 [5 favorites]
posted by Noisy Pink Bubbles at 12:40 PM on October 6, 2020 [5 favorites]
I was trying to summarize this to my spouse the other day and found it was difficult. Partly it is that this is very similar to what we're doing already, but subtly different in important ways.
Also, many of the differences in outlook have more to do with how best to approach the pandemic at a large-scale societal level (what should the city/state/health dept do), rather than in changes in individual behavior--particularly if you're already social distancing, wearing a mask when needed, avoiding large indoor gatherings, etc.
Here is my try at summarizing the issue somewhat briefly.
----
COVID-19 transmission is not spread evenly among the infected population. Instead, just 10 to 20 percent of infected people are responsible for as much as 80 to 90 percent of COVID-19 transmission; many people barely transmit it. This fact changes our approach to stopping the spread of COVID-19 in important ways:
* Instead of thinking primarily in terms of individual spread, you are looking for "clusters" or "super-spreader events" and prioritizing contact tracing, follow-up, and prevention on those. Above all, prevent one cluster from igniting another--which leads to uncontrolled spread.
(Note: It is not so much that one particular type of person is a super-spreader, rather it is the situation that person happens to be in during the time of highest infectiousness that creates a super-spreader event. It is those super-spreader events we can work to prevent.)
* Prolonged contact, poor ventilation, a highly infectious person, and crowding are the key elements for a super-spreader event
* Identifying transmission events (someone infected someone else) is more important than identifying infected individuals
* Aggressive backward tracing to uncover clusters is far more important in terms of stopping spread of the disease than forward-tracing, which is what we tend to focus on in the U.S. For example: "When a series of clusters linked to nightclubs broke out in Seoul recently, health authorities aggressively traced and tested tens of thousands of people linked to the venues, regardless of their interactions with the index case, six feet apart or not."
* Certain kinds of businesses lead to super-spreading events, such as theaters, music venues, bars, sports stadiums--any place where many people crowd close together, especially indoors. When it comes to shut-downs, those are most vital.
* Emphasize improved ventilation.
Much of the above applies to needed societal changes--how best to contact trace, which venues are most important to shut down during and outbreak, what an owner or manager of a business or venue can do.
* For individuals, all the old recommendations still apply: Social distance (6ft or more best), wear a mask when around others, wash hands frequently, stay home/isolate when sick.
* The major new insight for individual behavior from this research: Particularly avoid places where the three C’s come together—crowds in closed spaces in close contact, and that goes double if there is talking, singing, shouting, chanting, etc in that venue.
posted by flug at 12:46 PM on October 6, 2020 [40 favorites]
Also, many of the differences in outlook have more to do with how best to approach the pandemic at a large-scale societal level (what should the city/state/health dept do), rather than in changes in individual behavior--particularly if you're already social distancing, wearing a mask when needed, avoiding large indoor gatherings, etc.
Here is my try at summarizing the issue somewhat briefly.
----
COVID-19 transmission is not spread evenly among the infected population. Instead, just 10 to 20 percent of infected people are responsible for as much as 80 to 90 percent of COVID-19 transmission; many people barely transmit it. This fact changes our approach to stopping the spread of COVID-19 in important ways:
* Instead of thinking primarily in terms of individual spread, you are looking for "clusters" or "super-spreader events" and prioritizing contact tracing, follow-up, and prevention on those. Above all, prevent one cluster from igniting another--which leads to uncontrolled spread.
(Note: It is not so much that one particular type of person is a super-spreader, rather it is the situation that person happens to be in during the time of highest infectiousness that creates a super-spreader event. It is those super-spreader events we can work to prevent.)
* Prolonged contact, poor ventilation, a highly infectious person, and crowding are the key elements for a super-spreader event
* Identifying transmission events (someone infected someone else) is more important than identifying infected individuals
* Aggressive backward tracing to uncover clusters is far more important in terms of stopping spread of the disease than forward-tracing, which is what we tend to focus on in the U.S. For example: "When a series of clusters linked to nightclubs broke out in Seoul recently, health authorities aggressively traced and tested tens of thousands of people linked to the venues, regardless of their interactions with the index case, six feet apart or not."
* Certain kinds of businesses lead to super-spreading events, such as theaters, music venues, bars, sports stadiums--any place where many people crowd close together, especially indoors. When it comes to shut-downs, those are most vital.
* Emphasize improved ventilation.
Much of the above applies to needed societal changes--how best to contact trace, which venues are most important to shut down during and outbreak, what an owner or manager of a business or venue can do.
* For individuals, all the old recommendations still apply: Social distance (6ft or more best), wear a mask when around others, wash hands frequently, stay home/isolate when sick.
* The major new insight for individual behavior from this research: Particularly avoid places where the three C’s come together—crowds in closed spaces in close contact, and that goes double if there is talking, singing, shouting, chanting, etc in that venue.
posted by flug at 12:46 PM on October 6, 2020 [40 favorites]
For me, it helped to read this article around the same time as a New York Times piece on the super-spreader event that seeded outbreaks across Europe: the outbreak in the Austrian ski resort of Ischgl.
posted by rory at 1:04 PM on October 6, 2020 [1 favorite]
posted by rory at 1:04 PM on October 6, 2020 [1 favorite]
The second person to officially die of Covid in Portugal was the Chairman of the Santander Bank's Portuguese unit, Antonio Vieira Monteiro. He had been to Ischgl on a ski vacation. [Link is in Portuguese, another in English here.]
The first person to die of the virus in Portugal was the former physical therapist of a small football (soccer) team, and a personal friend of Jorge Jesus, now (again) the coach of Lisbon powerhouse Benfica.
Both of these people were well-known quasi-celebrities and I think the fact that they were the first victims helped everyone take this a lot more seriously from the get-go.
posted by chavenet at 1:22 PM on October 6, 2020 [2 favorites]
The first person to die of the virus in Portugal was the former physical therapist of a small football (soccer) team, and a personal friend of Jorge Jesus, now (again) the coach of Lisbon powerhouse Benfica.
Both of these people were well-known quasi-celebrities and I think the fact that they were the first victims helped everyone take this a lot more seriously from the get-go.
posted by chavenet at 1:22 PM on October 6, 2020 [2 favorites]
But politicians don't want to admit they made poor decisions; they need to justify changes in policy in ways that don't make them look bad.
I see this every day; less so from politicians than their followers who view “not spreading disease” as a culture war issue. “Well, when the virus had been identified only weeks before, they said x and now they say y, so clearly they are just making stuff up.” Er, no.
I wonder if there is a decent book anyone could recommend on the circa-19th century shifts in medicine. Seems to me in a couple of generations the miasma theory, humorism, and phrenology were all discarded in a generation or so; there just have been a lot of people arguing for “common sense” in lieu of this faddish “germ theory.”
posted by ricochet biscuit at 1:27 PM on October 6, 2020 [3 favorites]
I see this every day; less so from politicians than their followers who view “not spreading disease” as a culture war issue. “Well, when the virus had been identified only weeks before, they said x and now they say y, so clearly they are just making stuff up.” Er, no.
I wonder if there is a decent book anyone could recommend on the circa-19th century shifts in medicine. Seems to me in a couple of generations the miasma theory, humorism, and phrenology were all discarded in a generation or so; there just have been a lot of people arguing for “common sense” in lieu of this faddish “germ theory.”
posted by ricochet biscuit at 1:27 PM on October 6, 2020 [3 favorites]
I'm interested in knowing if "crowds in closed spaces in close contact" was alliterative in the original Japanese.
In NZ govt has gone to great lengths to ensure the words and statements makes sense and understanding is very widespread. We've essentially been trained how to do this now, even in the face of a denying government ( which we have to prepare for in case the evil right wing get in).
posted by unearthed at 3:03 PM on October 6, 2020 [2 favorites]
In NZ govt has gone to great lengths to ensure the words and statements makes sense and understanding is very widespread. We've essentially been trained how to do this now, even in the face of a denying government ( which we have to prepare for in case the evil right wing get in).
posted by unearthed at 3:03 PM on October 6, 2020 [2 favorites]
Florence Nightingale was an opponent of germ theory. I don't remember on what grounds; she was an early advocate for the use of statistics in medicine, but I don't see how that would have led her astray — unless she saw illnesses as radically random and uncaused, or suchlike
posted by jamjam at 3:58 PM on October 6, 2020
posted by jamjam at 3:58 PM on October 6, 2020
Interesting that here in Canada, we don't have widespread use of the slogan "crowds, closed spaces, close contact" when it really does summarize the dangers.
posted by storybored at 4:18 PM on October 6, 2020 [1 favorite]
posted by storybored at 4:18 PM on October 6, 2020 [1 favorite]
From Wikipedia on Florence Nightingale:
posted by clew at 4:23 PM on October 6, 2020 [5 favorites]
Though Nightingale is sometimes said to have denied the theory of infection for her entire life, a 2008 biography disagrees,[41] saying that she was simply opposed to a precursor of germ theory known as contagionism. This theory held that diseases could only be transmitted by touch. Before the experiments of the mid-1860s by Pasteur and Lister, hardly anyone took germ theory seriously; even afterwards, many medical practitioners were unconvinced. Bostridge points out that in the early 1880s Nightingale wrote an article for a textbook in which she advocated strict precautions designed, she said, to kill germs.And she definitely introduced hand washing and cleaning the drains at Scutari and the other Crimean hospitals she did her first work in.
posted by clew at 4:23 PM on October 6, 2020 [5 favorites]
I don't think the ones in the countries that have been doing well are any more receptive to science or any less willing to look bad than the ones in countries that haven't been doing well.
Oh hey I was just today reading an article about how Portugual is doing:
Oh hey I was just today reading an article about how Portugual is doing:
Unlike in Spain and Italy, Costa hasn’t had to contend with sniping from the opposition. Politicians have called a coronavirus truce that’s provoked open-mouthed envy in Madrid.posted by aniola at 4:30 PM on October 6, 2020 [8 favorites]
Spain’s far-left Podemos, junior party in the governing coalition, posted an applause emoji-laden tweet after a speech in which Portugal’s center-right opposition leader Rui Rio pledged support to the Socialist government’s battle to contain the virus.
“This is how they do opposition in Portugal … so near and yet so far,” gushed Podemos.
“This is a time for collaboration, not for opposition,” said Baptista Leite of Rio's PSD.
“We’re no longer dealing with the Socialist government; we are dealing with the government of Portugal,” he said. “We are having very candid but supportive meetings to present constructive criticism and also solutions through back channels, showing a sense of unity for the national interest.”
The political solidarity was maintained as government took measures such as fast-tracking all residency requests from migrants and asylum seekers to give them access to health care and social security; and granting early release to over 10 percent of inmates to reduce the risk of contagion in prisons.
I'm interested in knowing if "crowds in closed spaces in close contact" was alliterative in the original Japanese.
I was also very curious, so I looked it up and found that it was the three Mi's in Japanese:
密閉空間 - mippei kuukan (confined space)
密集場所 - misshuu basho (crowded place)
密接場面 - missetsu ramen (intimate scene)
posted by Aznable at 5:59 PM on October 6, 2020 [17 favorites]
I was also very curious, so I looked it up and found that it was the three Mi's in Japanese:
密閉空間 - mippei kuukan (confined space)
密集場所 - misshuu basho (crowded place)
密接場面 - missetsu ramen (intimate scene)
posted by Aznable at 5:59 PM on October 6, 2020 [17 favorites]
The statement in there that rapid tests are accurate at identifying negatives is wrong. She links to an article that discusses low sensitivity with high specificity. That combination means you can be confident about positives but should verify negatives with a more sensitive test. The negatives are not particularly accurate....
posted by Tandem Affinity at 7:19 PM on October 6, 2020
posted by Tandem Affinity at 7:19 PM on October 6, 2020
I know this isn't the first global pandemic nor is it the first air travel enabled coronavirus (hello SARS in 2003), and yet... the volume and speed of international travel in 2020, the volume and spread of social media in 2020 (I spend so much time reading through epidemiologist and virologist Twitter), the fact that the early outbreaks were in Asia, Europe and the Middle East, with the U.S. barreling down the road to catch up with everyone a few months later has meant that the global coverage has been comprehensive and substantive to a startling degree. Early mistakes, hesitations, miscalculations are noticed and remembered, even in the churn of news coverage.
posted by spamandkimchi at 8:05 PM on October 6, 2020
posted by spamandkimchi at 8:05 PM on October 6, 2020
What I found useful about this article is not so much the science (though backwards contact tracing for the win!) but the politics. Caution combined with humility. Yes New Zealand had a better leader, but it also was damn lucky.
What measures make sense? Why do we keep on closing down parks and beaches? When will megachurches get with the program?
How can we open up schools and universities?
Can we at least open up the libraries and computer labs again and give students a place to study away from overcrowded apartments and access to computers? Some of my students have been attending class via their phones because their laptops broke down...
The outbreaks I've heard of in Southern California at public universities (largely commuter schools, with a much smaller population living on campus) have occurred at house parties, not on campuses. Can we train the students in contact tracing and give them jobs?
posted by spamandkimchi at 8:06 PM on October 6, 2020
What measures make sense? Why do we keep on closing down parks and beaches? When will megachurches get with the program?
How can we open up schools and universities?
Can we at least open up the libraries and computer labs again and give students a place to study away from overcrowded apartments and access to computers? Some of my students have been attending class via their phones because their laptops broke down...
The outbreaks I've heard of in Southern California at public universities (largely commuter schools, with a much smaller population living on campus) have occurred at house parties, not on campuses. Can we train the students in contact tracing and give them jobs?
posted by spamandkimchi at 8:06 PM on October 6, 2020
spamandkimchi, the article about Ischgl said air travel tourism had started increasing enormously in the early 2000s, so maybe the 2003 SARS just squeaked In beforehand. Certainly there wouldn’t have been so many locations that depended on the tourist money and argued against any travel bans (also a big part of the Ischgl article.)
posted by clew at 8:50 PM on October 6, 2020
posted by clew at 8:50 PM on October 6, 2020
it's true a lot of this article has been covered in earlier reporting but she does bring it together in ways that's concise enough for me to share with people. and also it does help in individual-level risk assessment. i can't tell how infectious a person is, esp if u can be so while asymptomatic for a while, nor can i actually see if the surfaces are adequately disinfected (tho it seems fomite transmission is overestimated in this case) but measure of dispersion considers a lot of environmental design characteristics, and that i can quickly assess as i go about my day. it's interesting, the coronaviruses are making the case at pop science level to seriously consider airborne transmission as more than miasma theory remnant or a nightmare scenario of highly infectious viruses. we might see a cultural shift to ventilation design moved up in priority.
posted by cendawanita at 8:59 PM on October 6, 2020 [2 favorites]
posted by cendawanita at 8:59 PM on October 6, 2020 [2 favorites]
spamandkimchi - re luck - I think NZ's more biologically-aware population means it is easier for people here to take science advice on board, we have huge numbers of people at all literacy levels who work with plants, animals and bio, we also have very aware hunting/fishing/bush communities who take a science approach to life.
A second thing is we've had a serious cattle disease (Mycoplasma bovis) that we're nearly at the point of stamping out (a world first as previous right wing govt said it was impossible and left it for Jacinda), and most people were already aware of what it's taken to do this.
Thirdly Maori have kept alive the stories of Spanish Flu and took it on themselves to run blockades to keep people out of many remote areas. This got a lot of air play and most people I know were okay with it as they too know what happened in 1918.
4th tourism was well down due to the Australian fires casting a pall over us.
posted by unearthed at 10:42 PM on October 6, 2020 [1 favorite]
A second thing is we've had a serious cattle disease (Mycoplasma bovis) that we're nearly at the point of stamping out (a world first as previous right wing govt said it was impossible and left it for Jacinda), and most people were already aware of what it's taken to do this.
Thirdly Maori have kept alive the stories of Spanish Flu and took it on themselves to run blockades to keep people out of many remote areas. This got a lot of air play and most people I know were okay with it as they too know what happened in 1918.
4th tourism was well down due to the Australian fires casting a pall over us.
posted by unearthed at 10:42 PM on October 6, 2020 [1 favorite]
…found that it was the three Mi's in JapaneseIt's actually the three mitsus (mittsu no mitsu), mitsu being the reading of the shared initial character 密 on its own (to forestall any further pedantry on top of my own, a reading of the character, not the only one).
posted by Strutter Cane - United Planets Stilt Patrol at 1:27 AM on October 7, 2020 [5 favorites]
@rory - the NYT article is similar to The Guardian article. However the NYT piece does highlight one thing that The Guardian article doesn't - this was happening at many ski resorts, such is the crowded and social nature of these places and the timing.
An example is the small resort I live in - the population swells from around 2,000 to ten times that in peak season. We have four international schools with students that all come back after the holiday period. We had the 2020 Winter Youth Olympics in the village this year, adding dozens more countries and thousands more visitors.
Another factor is the Magic Pass - prior to 2017 it was rare for the telecabine car park to be full, even on powder days. Now the car park is overflowing before 10am most weekends, even last season which was pretty poor for snow coverage. People come up from the valley and head back home at night, or for weekend trips, this probably spread the virus around Switzerland.
We know the virus blasted through the village back in Feb/Mar as for the year round inhabitants everyone knows a few people who had the virus - either confirmed by testing or having had the symptoms, in some cases quite seriously. We found out later that there were a few cases in the schools, so it was spreading there too.
This is a resort that lacks most of the aprés-ski that you would find in places like Ischgl. In Verbier the village doctor wanted the government to quarantine the entire village due to the number of cases.
posted by lawrencium at 1:55 AM on October 7, 2020
An example is the small resort I live in - the population swells from around 2,000 to ten times that in peak season. We have four international schools with students that all come back after the holiday period. We had the 2020 Winter Youth Olympics in the village this year, adding dozens more countries and thousands more visitors.
Another factor is the Magic Pass - prior to 2017 it was rare for the telecabine car park to be full, even on powder days. Now the car park is overflowing before 10am most weekends, even last season which was pretty poor for snow coverage. People come up from the valley and head back home at night, or for weekend trips, this probably spread the virus around Switzerland.
We know the virus blasted through the village back in Feb/Mar as for the year round inhabitants everyone knows a few people who had the virus - either confirmed by testing or having had the symptoms, in some cases quite seriously. We found out later that there were a few cases in the schools, so it was spreading there too.
This is a resort that lacks most of the aprés-ski that you would find in places like Ischgl. In Verbier the village doctor wanted the government to quarantine the entire village due to the number of cases.
posted by lawrencium at 1:55 AM on October 7, 2020
what is stopping us from implementing some of these measures?
The sheer volume of cases in America makes this pretty impossible. You cannot effectively cluster bust when you have 40,000+ positive tests a day. Every local public health agency is going to be seriously overwhelmed even in what would be considered largely under-affected areas.
Cluster busting might help in just about every other nation than the U.S. though.
I also think this analysis, like so many before it, over emphasizes a single strategy (though she does mention the others). You need to do all the contact tracing both backwards and forwards, testing infrastructure needs huge improvement, NPI strategies need to be adopted and enforced. Quarantines, separate from families, need to happen - subsidized and enforced. Universal paid sick leaves with job security needs to happen. Regional lockdowns need to happen. Travel restriction needs to happen. We need to do all the things. Also it would nice if, in a scenario where 260 thousand + Americans have died, the precautionary principle were invoked instead of the do the absolute minimum we think we can get away with principle we are currently adhering to.
Even the recent push to recognize aerosol transmission is resulting in attentional mistakes. People are starting to disregard fomite transmission as a vector and are loosening their hygiene strategies or calling them 'pandemic theater' when deployed in restaurants and shops yet NZ just today reported a contact traced cluster linked to a contaminated garbage lid and an elevator button.
There seems to be a tendency to want singular explanations involving singular pathways with singular interventions as if our pandemic response working memory can only hold a single thing at a time. Reality is not the New Yorker with only the space for a single Malcom Gladwell-esque article each month. Our current opponent is cleverly evolved but ultimately stupid. The only problem is that right now we are being stupider....than a microbe.
posted by srboisvert at 9:02 AM on October 7, 2020 [4 favorites]
The sheer volume of cases in America makes this pretty impossible. You cannot effectively cluster bust when you have 40,000+ positive tests a day. Every local public health agency is going to be seriously overwhelmed even in what would be considered largely under-affected areas.
Cluster busting might help in just about every other nation than the U.S. though.
I also think this analysis, like so many before it, over emphasizes a single strategy (though she does mention the others). You need to do all the contact tracing both backwards and forwards, testing infrastructure needs huge improvement, NPI strategies need to be adopted and enforced. Quarantines, separate from families, need to happen - subsidized and enforced. Universal paid sick leaves with job security needs to happen. Regional lockdowns need to happen. Travel restriction needs to happen. We need to do all the things. Also it would nice if, in a scenario where 260 thousand + Americans have died, the precautionary principle were invoked instead of the do the absolute minimum we think we can get away with principle we are currently adhering to.
Even the recent push to recognize aerosol transmission is resulting in attentional mistakes. People are starting to disregard fomite transmission as a vector and are loosening their hygiene strategies or calling them 'pandemic theater' when deployed in restaurants and shops yet NZ just today reported a contact traced cluster linked to a contaminated garbage lid and an elevator button.
There seems to be a tendency to want singular explanations involving singular pathways with singular interventions as if our pandemic response working memory can only hold a single thing at a time. Reality is not the New Yorker with only the space for a single Malcom Gladwell-esque article each month. Our current opponent is cleverly evolved but ultimately stupid. The only problem is that right now we are being stupider....than a microbe.
posted by srboisvert at 9:02 AM on October 7, 2020 [4 favorites]
It sucks that we have institutions that have completely lost/abused public trust. Times like these are when data can be used to achieve breakthroughs. But without the publics' cooperation, large scale data gathering is just not possible. The early notes on various automatic contact tracing apps were so promising. But everything came to naught once the potential for abuse started to crop up. Doing backward propagation and various other analysis would have been straightforward with reliable data.
posted by asra at 9:11 AM on October 7, 2020
posted by asra at 9:11 AM on October 7, 2020
> The statement in there that rapid tests are accurate at identifying negatives is wrong. She links to an article that discusses low sensitivity with high specificity. That combination means you can be confident about positives but should verify negatives with a more sensitive test. The negatives are not particularly accurate....
This is a great example of how this type of test (not super-accurate but fast and above all CHEAP) is ideal and much-needed for public health screening purposes but not so much for diagnostic purposes.
The idea here is that if you have say 40 people who were in a potential superspreader cluster and you test them all with a simple $1 lick-a-stick type test, and all 40 come back negative, you can be pretty sure that you're NOT looking at a super-spreader event there.
But it does NOT tell any individual much about their current situation. You could easily have 1 or 2 actual positives there. But you definitely don't have 10 or 20.
Even better you give all 40 people 7 of the $1 lick-a-stick tests to take every day for a week. If those all come back negative then you're pretty sure.
This is something you simply cannot do with the more accurate but far, far more costly and far, far slower PCR type tests.
That's why for public health screening purposes, cheap, fast, and easily available beats super-accurate but slow, costly, and not easily available, every time.
But you absolutely CANNOT take one test, get a negative, and say "All good, I'll just go around giving everyone in sight a sloppy kiss."
(Hint: You can't do that with PCR testing, either. It's frequent, easily available, inexpensive testing PLUS all the other measures that make it work. As the White House has so recently and visibly demonstrated to everyone.)
posted by flug at 10:56 AM on October 7, 2020 [2 favorites]
This is a great example of how this type of test (not super-accurate but fast and above all CHEAP) is ideal and much-needed for public health screening purposes but not so much for diagnostic purposes.
The idea here is that if you have say 40 people who were in a potential superspreader cluster and you test them all with a simple $1 lick-a-stick type test, and all 40 come back negative, you can be pretty sure that you're NOT looking at a super-spreader event there.
But it does NOT tell any individual much about their current situation. You could easily have 1 or 2 actual positives there. But you definitely don't have 10 or 20.
Even better you give all 40 people 7 of the $1 lick-a-stick tests to take every day for a week. If those all come back negative then you're pretty sure.
This is something you simply cannot do with the more accurate but far, far more costly and far, far slower PCR type tests.
That's why for public health screening purposes, cheap, fast, and easily available beats super-accurate but slow, costly, and not easily available, every time.
But you absolutely CANNOT take one test, get a negative, and say "All good, I'll just go around giving everyone in sight a sloppy kiss."
(Hint: You can't do that with PCR testing, either. It's frequent, easily available, inexpensive testing PLUS all the other measures that make it work. As the White House has so recently and visibly demonstrated to everyone.)
posted by flug at 10:56 AM on October 7, 2020 [2 favorites]
BTW the Rose Garden Massacre is a great example of how you would treat situations differently under the "superspreader" theory vs. how we currently handle things.
The instant you realized the Rose Garden event was a multiple-spreader event--about 4 days later, it looks like--you send EVERYONE there into quarantine. Then similarly with the Gold Star Ceremony held the next day, the President's debate prep sessions, the White Houses's press meetings, and other similar events held through that time period. Pretty soon you realize the White House is the center of a super-spreading event; you send everyone there into quarantine.
What that does, is stop all further spread in its tracks.
You can see what the alternative is: A LOT of further spread happens as a result of the initial incident.
And then everyone ends up in either isolation (sick personally) or quarantine (directly exposed to someone sick) anyway.
It just happens a little later and involves a LOT more people. And also, because so many people are involved, it guarantees further spread of the disease.
BTW what brings this up is this: VP Pence cleared for debate, because rules-lawyering came to the conclusion he wasn't "a close contact of any knoiwn person with COVID-19".
That's bullshit. He was at the Rose Garden. He met and mingled with numerous people there, who soon thereafter came down with COVID. He and his wife and everyone else there is in quarantine for 14 days now.
P.S. At the Rose Garden Massacre, Pence was sitting within 2 feet of Sen. Lee, who tested positive soon thereafter. COVID has an incubation period of up to 14 days. Draw your own conclusions.
posted by flug at 11:19 AM on October 7, 2020 [6 favorites]
The instant you realized the Rose Garden event was a multiple-spreader event--about 4 days later, it looks like--you send EVERYONE there into quarantine. Then similarly with the Gold Star Ceremony held the next day, the President's debate prep sessions, the White Houses's press meetings, and other similar events held through that time period. Pretty soon you realize the White House is the center of a super-spreading event; you send everyone there into quarantine.
What that does, is stop all further spread in its tracks.
You can see what the alternative is: A LOT of further spread happens as a result of the initial incident.
And then everyone ends up in either isolation (sick personally) or quarantine (directly exposed to someone sick) anyway.
It just happens a little later and involves a LOT more people. And also, because so many people are involved, it guarantees further spread of the disease.
BTW what brings this up is this: VP Pence cleared for debate, because rules-lawyering came to the conclusion he wasn't "a close contact of any knoiwn person with COVID-19".
That's bullshit. He was at the Rose Garden. He met and mingled with numerous people there, who soon thereafter came down with COVID. He and his wife and everyone else there is in quarantine for 14 days now.
P.S. At the Rose Garden Massacre, Pence was sitting within 2 feet of Sen. Lee, who tested positive soon thereafter. COVID has an incubation period of up to 14 days. Draw your own conclusions.
posted by flug at 11:19 AM on October 7, 2020 [6 favorites]
I wouldn’t call the rapid tests that sometimes miss cases « ideal », although they can be useful if interpreted correctly.
The safer, more ideal type of rapid test to let loose into the public is a rapid test that is inaccurate more often on the side of having false positives. But I don’t think that exists yet.
People are going to naturally want to believe a negative and resist the correct interpretation of the current rapid tests (which would be, in the case of a negative, that it should be confirmed by PCR last I heard). And so these tests are risky, and FDA has correctly been very conservative in their approval of such tests.
posted by Tandem Affinity at 7:16 PM on October 7, 2020
The safer, more ideal type of rapid test to let loose into the public is a rapid test that is inaccurate more often on the side of having false positives. But I don’t think that exists yet.
People are going to naturally want to believe a negative and resist the correct interpretation of the current rapid tests (which would be, in the case of a negative, that it should be confirmed by PCR last I heard). And so these tests are risky, and FDA has correctly been very conservative in their approval of such tests.
posted by Tandem Affinity at 7:16 PM on October 7, 2020
Fomite transmission of COVID-19 in NZ - incident referred to by srsboivert upthread. Also notable in this case: an infected individual returned negative test results during a 14-day quarantine before being released and infecting others.
posted by storybored at 9:50 PM on October 8, 2020 [1 favorite]
posted by storybored at 9:50 PM on October 8, 2020 [1 favorite]
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