The Duke Margolis Center for Health Policy and several co-authors from other institutions in work funded by the Rockefeller Foundation has issued a new analysis on how we can use testing to reduce community transmission and thus more safely operate key infrastructure, facilities and services.
One of the big-takeaways from this report that I got as I was writing was the wide variety of approaches that are capable of achieving a variety of goals. There are a lot of different testing technologies out there. We really care about two primary characteristics of a test; how sensitive is it and how quickly can a result be reported back? The ideal test is a perfectly sensitive test that will only report true positives (100% sensitive) in two seconds or less and costs less than a pack of supermarket check-out line gum. That test does not exist. Everything is a trade-off and the trade-off space is quite large and varied. I love Figure 2 as it illustrates what communities could potentially do:
A community can choose a targeted reduction in the current (R)eproductive rate and then apply a variety of tests. Given that national R is around 1 which means each infected person will infect on average about 1 other person and therefore the daily new case count is roughly stable, a 60% reduction and a 90% reduction in R both mean that the epidemic burns itself out fairly quickly. The quick rule of thumb is that more sensitive tests with slightly slower turn-around times are roughly equal to less sensitive tests with fast results.
The National Football League has taken a choice of very sensitive PCR tests conducted on a daily cadence with results reported within 24 hours to wipe out within-team transmission:
It has worked!
Latest COVID numbers, via the NFL: From Aug. 30-Sep. 5, the league conducted 17,519 COVID-19 tests to players. Only one player tested positive.
— NFL Update (@MySportsUpdate) September 8, 2020
This is overkill and rubble bouncing from a public health perspective. The goal is to significantly reduce local R in order to make clusters become singletons and avoid large infection chains. Once community prevalence is down, good things can and should happen like kids going back to school. We can do that soon. We don’t quite have the current cheap enough and good enough testing supply but within the next few months, hundreds of millions of cheap enough, good enough and fast enough tests will be hitting the US market. That will allow us to test our way out of trouble.
MelissaM
My husband is a UofIllinois employee, currently at home, but having to test 2x per week because he may need to enter a building on campus at any time, so needs to be in the clear. Yesterday the U said all staff, workers and grad students are now down to 1 test per week. Undergrads remain at 2x per week with some at 3x. Not sure who is 3x per week, but I suspect that depends on living arrangements (greek houses, dorms.) It was determined that the undergrads are the problem with the increase and spread. No surprise there.
Jeffro
I’m ok with overkill and rubble-bouncing (love that phrase!)
Let’s get to it, America. We could have our kids safely back in school (and all the other things, too) by Thanksgiving!
Zzyzx
I’m so looking forward to those tests but they’re starting to feel like fusion technology: always just around the corner but never here.
DAVID ANDERSON
@Zzyzx:
Past 2 weeks have had a huge stream of Emergency Use Authorizations for manufacturers who are promising 10’s of millions per month.
Haroldo
@Zzyzx:
Let’s hope those tests aren’t the canonical 20 years away. (Tho’ the canon may have changed to 30 years in recent times.)
Zzyzx
Yeah the 20 year thing has vanished. High capacity batteries for electric cars are there too.
Zzyzx
@DAVID ANDERSON: I’m really hoping. I mean I already wake up and test my blood sugar levels and my blood pressure. What’s one more test?
If everyone going to a concert could prove a recent negative test, it would allow such things.
Gvg
But we still need trump gone because he doesn’t like tests. He doesn’t even understand that it could help him.
What Have the Romans Ever Done for Us?
I have to say, one of the things that I’m kind of furious about at the moment…my wife works in primary care at Children’s National Medical Center (DC Children’s Hospital). For the first 2 months or so of the pandemic she was full time telemedicine, but since then she has been seeing patients in person 2 days a week. She has not once been tested, nor have any of the other providers in her clinic, at least not to her knowledge. If the NFL can test daily, and large universities with tens of thousands of students can test students ~1 time per week…why the F can’t we be testing front line health care workers at least that frequently? I don’t know if it’s just her department that is incredibly lax on testing (or at least it seems that way) or if the entire hospital has just decided to keep their heads in the sand about spread amongst staff.
raven
Stolen and distributed.
raven
@Zzyzx: Damn, it hasn’t been that long.
Roger Moore
@Zzyzx:
The antibody based tests should be here really soon. It’s well understood technology; it just takes some time to get new antibodies in production and the manufacturing lines set up for the new product. The big question is whether we’re going to get enough. To reach something like twice weekly testing for the whole population, we will need almost 3 billion tests per month. The problem from the manufacturers’ standpoint is that we’ll only need that many tests for a couple of months before the disease is really knocked down and we can go to a somewhat more relaxed testing rate. It’s going to be hard to convince them to spend a bunch of money building the capacity to produce that many tests if they know in advance it’s only going to be for a short time.
Pete Mack
bluefoot
@What Have the Romans Ever Done for Us?: I know of multiple cases like that; where front line workers, including healthcare workers and staff, can’t get tested through their place of employment. Which is crazy.
My sister is a school teacher, and they are back in person. She can only get tested through normal channels i.e. according to country health department guidelines (needs to be symptomatic and/or exposed to someone who is positive), pay out of pocket, and wait 3-5 days for a result.
My company had been offering free voluntary testing (every 2 weeks) through the summer but ended it a couple of weeks ago….just as schools are opening up. It seems short-sighted at best.
Anyone who deals with the general public in person for their job should have regular testing available, free.
Roger Moore
@What Have the Romans Ever Done for Us?:
I think the underlying problem is the same kind of inequality that’s so generally bad for the country. Sports leagues can afford massive overkill in testing because they have at most a few thousand players and are ridiculously rich. Universities can test that much because they have the trained staff and equipment already on hand, and if they don’t they’re the places new technology is developed. The rest of us are stuck with the leftovers.
FWIW, I work in a research hospital (a Comprehensive Cancer Institute) and we’re kind of halfway between. I know there are people on our campus working on new testing technology- my former boss has just applied for a patent and an EUA- but it hasn’t gotten far enough to start regularly testing all our staff. I’m really looking forward to everyone here being able to get a real test once or twice a week.
raven
Kristine
Thanks, David–this is the most optimistic thing I’ve read about what the next few months could bring.
Roger Moore
One of the big things this diagram shows is how shortsighted the FDA insistence on PCR testing and only PCR testing was. They completely blew off the value of rapid turnaround, lower sensitivity testing in favor of high sensitivity, slow turnaround tests. It makes sense if your main goal is to determine which patients have it so you can figure out treatment, but it’s absolutely wrong for public health.
bluefoot
@Roger Moore: Way back in early/mid-February, when the WHO published the primer sequences and protocol for the RT-PCR test, I joked with some colleagues than maybe I should order some primers to have on hand to do some surveillance testing of our colleagues over time. (The genomics group had the rest of the reagents and RT-PCR machines.) I’m no longer in the lab, and consequently don’t have freezer space or a bench, so I didn’t. But I should have.
Zzyzx
@raven: are you sure? I know the calendar says 6 months but it’s felt like decades.
MomSense
Yesterday someone came into our office without a mask and the office manager who refuses to wear a mask freaked out and left her desk to get away from the unmasked client. She started to complain to me about people not wearing masks – while not wearing a mask. Anyway, someone else helped the guy but when I said something about how stressful it is when people won’t wear masks, she sort of snapped back at me that it shouldn’t bother me because I wear a mask. So I explained to her that my mask is protecting everyone else from me in case I am asymptomatic but my mask isn’t effective at blocking the virus from people who aren’t wearing masks. She clearly didn’t know this. Even still she said well that’s good that you wear one but I’m not wearing a mask. I also found out that the new assistant who used to wear a mask stopped wearing one because the office manager told her masks look stupid.
I’m starting to hope the Silver shit she takes every day turns her skin blue.
Is there a handy dandy chart that explains why masks are important. Everyone here seems to think 6 feet apart (which we don’t really adhere to either) is sufficient.
PaulB
@MomSense: I found this link Why everyone needs to wear a mask online from Providence St. Joseph Health
MomSense
@PaulB:
Thank you!
raven
@Zzyzx: I’m with ya. I second with your hand on a hot stove is like a lifetime and a lifetime with a beautiful woman is like a second. I’ll yell this upstairs to the sewing lady
FlyingToaster
Well, WarriorGirl’s school has restarted; today is the first day. PK-5 and grade 6 are live, half days this week. Full Days next week, M-T, F remote; 7 starts live on Monday and 8 starts live on Wednesday. The Middle School is live mornings, podded, with masks and masked teachers moving between classrooms; afternoon is Zoom, podded and masked if you stay at school (like, your parents both work) and barefaced from home otherwise.
No chorus classes that we can find (and believe me, that was a serious bone of contention last spring, as it didn’t work); violin has moved to afterschool Zoom. Everyone from grade 4+ has been or will be issued a Chromebook and can go remote at the drop of a hat. The Fall Musical has been replaced with a Fall Zoom Play (yep, WG is in the play, as usual). The school has retained the older chromebooks for grades PK-3; the whole school can go remote if the state mandates.
Massachusetts is doing targeted town testing, the universities are running their own labs (the benefit of having 3 medical schools in Bwahstin), and employers have to pay for tests as mandated. Most public schools have delayed opening, are starting remote, are staging students in by grade (pk-2, 3-5, 6-8, 9-12).
There are currently 8 towns with high R0; they’re all towns that supply a LOT of retail and service industry workers. The state is concentrating testing in those towns, and contact tracing is by either the state or municipalities (Watertown and Somerville are both running their own via their health departments, as the state was missing too many contacts).
Northeastern University expelled 11 Freshmen for breaking distancing protocol; they were housed in the Copley Westin and all crammed into 1 room, maskless, for a party. And posted to social media. And caught by NU staff. NU is keeping their $36K tuition.
No breakouts are associated with the unis thus far, my big worry remains BU, BC and Tufts, where they didn’t thin out the dorms/frats.
Aleta
@MomSense:
Sounds maddening and truly upsetting. (Giant understatement.) Suzanne linked this a few days ago. It can’t go on a wall like a chart, but it’s so clear it could make a strong impression if anyone is willing to watch.
A simulation for an open office layout, by architects who wanted to know how + how far droplets might spread through theirs. (About 1.5 min each, set to start after the introductions.) Coughing w/o a mask. Coughing with a mask.
Their site, for other ones they plan to do. They say email questions are welcome.
MomSense
@Aleta:
I’m beyond upset at this point. I wish we had a mandatory mask order
Aleta
@MomSense: I just can’t believe how resistant some places are. Employers out of self-interest alone would want to avoid a shut down and losing 1/4 of their employees all at once, it seems like.