Down-the-line Covid exposure contact tracing--

[Kev Williams]

Since the FDA and CDC can't seem to get it together, I thought I'd consult the experts! :)

flowchart:

1 is contagious
2 contacts 1 last Thursday (5 days ago)
3 contacts 2 Friday
4 contacts 3 Saturday, football game
5 contacts 4 Sunday, family visit
6 and 7 in contact with 5 on Monday AND Tuesday

Questions: When does a 'merely' exposed person become contagious? What's the likelihood 5, 6 and 7 have actually contracted the virus?

--Guess who 6 and 7 are-- :mad:

[roger wiegand]

Once you get to 3-4 contact circles out you're talking everyone in the country. If I were 2 I'd watch carefully for symptoms, stay isolated, and get tested if possible. Three and beyond have a pretty good chance of having been exposed to someone who has been exposed to someone no matter what.

I can't quite fathom why we haven't embraced two bits of technology that could have brought this to a halt by now, one an antigen-based rapid diagnostic test that every person in the country could be taking every day they need to leave the house (based on other RDTs should cost about dollar each or so to make), and, two, a $50 powered respirator (put up a billion dollar prize for its development and deployment) for those who find masks too uncomfortable, distributed free to everyone who needs one. Even if each measure is only 80% effective on its own, combined with reasonable social distancing and hygiene the three combined would give a 99% reduction in transmission. Even if each is only 50% effective it would reduce transmission by nearly 90%, which should do the trick. Yes it would cost a few tens or even hundreds of billions to implement and inconvenience some people; what we are (not) doing now is costing trillions and being incredibly destructive.

Then of course there's the issue of getting folks to care enough about their family, friends, and neighbors to take on these simple measures without turning it into political theater. That one is not so readily solved.

[William Chain]

Souls 2 and 3 should be isolated, and beyond that will depend on exposure - masked/unmasked, duration of exposure, etc.

Casual exposure (e.g., passing in a hallway) is not high risk. Sitting at football game next to one another for over 10 minutes of common air space is high risk. Precisely why that kind of thing is discouraged or cancelled right now.

You'll have to make the call. If you are in a vulnerable group, I'd isolate for 14 days and see.

I've isolated twice now due to careless coworkers. It does suck, but it's necessary.

[Curt Harms]

I think Roger is correct on most counts. Having a relatively accurate at-home test, or perhaps take the sample at home and drop it off at your local pharmacy would encourage more widespread testing. Make it clear that a positive test could be a false positive are not a death sentence, just an indicator to get a more accurate test. This whole thing has been PBARd (politicized beyond all recognition) which unfortunately will probably cost lives.

[Stan Calow]

any or all those people could be exposed to other infected people during the surveillance period.

[Jim Becker]

S
Questions: When does a 'merely' exposed person become contagious?

Simple question and simple answer: They become contagious if and when the virus infects them. The incubation period for COVID-19 is 2-14 days, more or less.

[Bill Dufour]

If #2 is not sick by now you are probably okay. Of course they could be young and asymptomatic. They really should open up college campuses and let the young ones get sick and recover before going home at break. Allow only students who do not live at home to be physically on campus. Of course the staff does not like that idea. All those old rich professors will get sick and many will die and lose their tenure or emeritus. This policy would cause fewer deaths then drafting them and sending them to Vietnam or Afganistan.
Bil lD.

[Dennis McGarry]

https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html?fbclid=IwAR0umU1Dt4cIFdWTZAlCY-rdmWD8IPQ8jjAjlLix1O_4ZirSliHsUcJCXfM

[mike stenson]

You don't have to be young to be asymptomatic. Also, the young aren't completely immune to long term illness and consequences. Some of the people I've known who ended up being the sickest were in their 20s.. so far.

So much mis(dis)information.

[Kev Williams]

thanks all--

to update the info-
1 is known to be positive, not necessarily contagious, but I'm taking that for granted anyway-
Everyone but 1 is asymptomatic, and I'm not even sure if 1 is--
2, 3 and 4 are teenagers or pre-teens-
I assume 2 and 3 have been tested but not clear on that yet.
4 is my BIL's grandson, he was tested Tuesday, results Friday-
5 is my BIL who works with us.
6 and 7 are the wife and I-

The BIL and I have been within 2' of each other, side to side unmasked, probably 3 times in 2 days, for no more than 1 minute while he was watching and listening to me while I was setting up his laser jobs. which is normal. He spoke very little if at all best I recollect. Only rarely do we ever speak face to face, when we do talk we're usually at least 10' away. The past few days is no exception. He's only here about 5 hours a day. The wife's main exposure is to me. We all share the front and garage door knobs and the basement stairs handrail. Aside from the laser setups we've been separated by at least 10' or more almost constantly, which is normal...

Because we're a business we have hand sanitizer galore and masks are worn by all when customers are present. We also have several cans of disinfectant spray and Clorox disinfectant hand-sprayer cleaners. EVERYTHING that comes into this house, groceries, mail, packages, PO's, customer parts, even cash, gets sanitized. The BIL is staying home until he hears any test results of those above us in this chain, which I hope is sooner than later. I'm going to see if I can locate a place that does rapid tests and get myself checked today.

I'll be collecting my first SS payment any day now. Last thing I need is to be a victim of the 'retirement curse'. 'Specially since I'm not retired yet!

[Andrew Joiner]

Once you get to 3-4 contact circles out you're talking everyone in the country. If I were 2 I'd watch carefully for symptoms, stay isolated, and get tested if possible. Three and beyond have a pretty good chance of having been exposed to someone who has been exposed to someone no matter what.

I can't quite fathom why we haven't embraced two bits of technology that could have brought this to a halt by now, one an antigen-based rapid diagnostic test that every person in the country could be taking every day they need to leave the house (based on other RDTs should cost about dollar each or so to make), and, two, a $50 powered respirator (put up a billion dollar prize for its development and deployment) for those who find masks too uncomfortable, distributed free to everyone who needs one. Even if each measure is only 80% effective on its own, combined with reasonable social distancing and hygiene the three combined would give a 99% reduction in transmission. Even if each is only 50% effective it would reduce transmission by nearly 90%, which should do the trick. Yes it would cost a few tens or even hundreds of billions to implement and inconvenience some people; what we are (not) doing now is costing trillions and being incredibly destructive.

Then of course there's the issue of getting folks to care enough about their family, friends, and neighbors to take on these simple measures without turning it into political theater. That one is not so readily solved.

Thank you Roger! Your professional experience is valued here. I've been thinking the same thing.
Not sure anyone who find masks uncomfortable would wear a powered respirator, but yes great ideas.
How about a recommended standard for masks? Sure any face covering is better than nothing. A leaky, droopy mask or bandana is less effective and just as uncomfortable as the best masks.

I finally settled on KN95 masks. Best comfort and protection.

[roger wiegand]

I think the current work suggests that N95s and surgical masks are both about equally effective (and quite good). N95s with relief valves are less effective for protecting bystanders, aerosol droplets easily escape out the valve. Cloth masks are less effective but way, way better than nothing (and may be better than a valved N95 for protecting others). In a situation where I knew I was going to be exposed to an infectious person I'd double mask with a surgical mask over an N95 (lots of docs who see sick patients are doing this), changing the outer surgical mask between patients.

I don't go out much, but I use a well made cloth mask thats big enough to pretty well cover my beard (and my big nose). There's still a national shortage of N95's so I will leave them for folks on the front lines for now. In MA at this point I think our numbers are such that you have to be both unlucky and doing something wrong to pick up an infection in a "normal" socially distanced community setting. Mask compliance here is close to 100%. I'm comfortable with the cloth mask in that setting. We'll see how that changes as all the students return.




How about a recommended standard for masks? Sure any face covering is better than nothing. A leaky, droopy mask or bandana is less effective and just as uncomfortable as the best masks.

I finally settled on KN95 masks. Best comfort and protection.

[Stan Calow]

...How about a recommended standard for masks?

Faces are too non-standard to have a perfect mask.

[Kev Williams]

, and, two, a $50 powered respirator [...], distributed free to everyone who needs one.

https://www.hammacher.com/product/electronic-hepa-filtered-face-mask?promo=hp_cat1_fall-supplement-2020

Not hardly free and not sure of it's actual usefulness...

[roger wiegand]

https://www.hammacher.com/product/electronic-hepa-filtered-face-mask?promo=hp_cat1_fall-supplement-2020

Not hardly free and not sure of it's actual usefulness...

That one doesn't filter both incoming and outgoing air, so wouldn't meet my design criteria.

I'm thinking something like my old AirMate helmet, but a *lot* less clunky and lighter weight, with a push/pull airflow system that filters both ways and allows the wearer to not have a mask close to their face. It should run for >2h on a charge, have interchangeable batteries for longer use, charge on a USB charger, and have filters that can be sterilized in a pressure cooker or dunked in 10% bleach. If we can build an iphone how hard could this be?

And after COVID all the woodworkers could breathe a lot less sawdust.

[Mike Soaper]

LG is also making a powered assist facemask, seems the press relase is not clear as if it filters exhaled breath.

https://arstechnica.com/gadgets/2020/08/lgs-battery-powered-face-mask-will-make-breathing-effortless/

[Matt Day]

Contacts of contacts generally don’t need to be quarantined. Depending though on whether the contact has symptoms. So 3, 4, and 5 wouldn’t need to quarantine assuming 2 doesn't have any symptoms. Your local health department should be the one to ask though.

[Kev Williams]

I finally found some basic answers to my basic questions on WebMD of all places ;)

What they state:

an infected person will usually show symptoms at 5 days after infection--

an infected person can infect others (shed) 2-3 days before symptoms show.

Ergo, that leaves a 2-3 day 'grace period'; if a person contacts someone who's contact date was less than 2-3 days prior, that person's chances of infection are slim to none...

In my 'chain', #2 is the one most probable to get infected since #1 was likely shedding. #'s 3 thru 7 all made contacts on the next day...

So I'm hoping... :)

[Andrew Joiner]

There's still a national shortage of N95's so I will leave them for folks on the front lines for now.
The N95 is approved for medical use in the USA. You can't buy them in the USA when I search. They're fairly rigid and must be properly fitted to ones face size.
The KN95 has the same filtering ability, costs about $2. You can buy them online. They are approved for medical use all over the world but not in the USA. Similar to surgical masts in comfort but tests show the KN95 to beat surgical masks in protecting the wearer.

[Brian Elfert]

I can't quite fathom why we haven't embraced two bits of technology that could have brought this to a halt by now, one an antigen-based rapid diagnostic test that every person in the country could be taking every day they need to leave the house (based on other RDTs should cost about dollar each or so to make), and, two, a $50 powered respirator (put up a billion dollar prize for its development and deployment) for those who find masks too uncomfortable, distributed free to everyone who needs one. Even if each measure is only 80% effective on its own, combined with reasonable social distancing and hygiene the three combined would give a 99% reduction in transmission. Even if each is only 50% effective it would reduce transmission by nearly 90%, which should do the trick. Yes it would cost a few tens or even hundreds of billions to implement and inconvenience some people; what we are (not) doing now is costing trillions and being incredibly destructive.


Don't you think if a $1 test was possible, profitable, and could be sold by the tens or hundreds of millions per day that someone would be making such a test?

I doubt anyone who finds a mask uncomfortable would find a powered respirator to be any better. If they aren't going to wear a simple mask could you see them wearing a bulky respirator?

[roger wiegand]

Don't you think if a $1 test was possible, profitable, and could be sold by the tens or hundreds of millions per day that someone would be making such a test?

I doubt anyone who finds a mask uncomfortable would find a powered respirator to be any better. If they aren't going to wear a simple mask could you see them wearing a bulky respirator?

Many such tests are made and sold for a wide variety of purposes, the pregnancy test being the one most people are likely to have seen in person. Such tests for COVID are wending their way to market; they could have been there long since had they been prioritized and funded they way the vaccine development is with purchase commitments and such. Abbott is about to launch such a test, for example. Unfortunately FDA is currently requiring that it be administered by a "qualified medical professional" meaning that the delivered cost is going to be in the $100+ realm with all the usual hassles of doctors office visits and different insurance companies not paying for it and such. Abbot and others are certainly going to be pricing them using the "all the market will bear" philosophy currently in fashion in the drug industry. This is not a recipe for getting 50 million tests a day run over a couple of months to get this under control. I've worked with teams deploying such tests for other diseases in resource challenged countries; a couple bucks is a reasonable actual cost to deploy such an assay at modest scale; $1 I'd think is very possible when you start talking the scale of a billion tests-- for actual cost that is, not selling price. Hence the need to engage in some WWII style manufacturing and distribution prioritization.

As to masks and PAPRs, I find a world of difference between a tight fitting mask that resists breathing and fogs your glasses like the ones I use when painting and the PAPR I use when turning. I don't think I'm alone in that. Personally I'd opt for the convenience of a simple mask, others apparently find them sufficiently intolerable that they're willing to go out and infect other people rather than wear them. Just trying to think of a better way to address the objections I've heard. YMMV.

[Tom Stenzel]

As far as the contact tracing goes, my daughter was called by our Wayne County tracers. She was told that she should start a 14 day quarantine since she had been in contact with someone who had been diagnosed with The Covid.

Problem is that we knew who it was that had been diagnosed. My daughter was called and told to start the quarantine 3 weeks after she had seen the person.

Somehow barn doors, open status and horses come to mind.

-Tom

[mike stenson]

As far as the contact tracing goes, my daughter was called by our Wayne County tracers. She was told that she should start a 14 day quarantine since she had been in contact with someone who had been diagnosed with The Covid.

Problem is that we knew who it was that had been diagnosed. My daughter was called and told to start the quarantine 3 weeks after she had seen the person.

Somehow barn doors, open status and horses come to mind.

-Tom

I have a friend who is a contact tracer. There are several things that come to mind.

• There are not enough of them (not enough have even been hired in most areas)
• People refuse to talk to them
• People have abused them verbally, rather than answer questions
• People believe their rights are being violated by contract tracing

So, it's the general public that mostly puts the horses out.

[Stan Calow]

You can google-up KN95 vs N95 and see the difference. KN95 is the Chinese standard, and I've seen masks labeled KN95 all over, including my local Ace hardware. N95 is the US NIOSH standard, even if the mask is made in China (which most are). I would use whichever you can find. I've used N95s in previous jobs and in the workshop. There are many brands of N95s, and the design, fit and finish are all different. Nothing high tech or foolproof about them, and most untrained people don't wear them right anyway. Not sure there are any that will fit right over beards.

[Curt Harms]

Simple question and simple answer: They become contagious if and when the virus infects them. The incubation period for COVID-19 is 2-14 days, more or less.

I heard from a infectious diseases Dr. at the Cleveland Clinic that current thinking is that people are most contagious 3-6 days after becoming infected. I have no idea how correct that is.

[Jeff Body]

Something I found interesting after talking to my infection control department.... According to the CDC guidelines you're only considered to be in contact if you're within 6 ft of a person for 15 minutes. No one ever mentions the 15 minute part.

My hospital has given up on contact tracing. They have gone to a "if you have symptoms then leave and don't come back until you're symptom free for 24 hours." About 4 weeks ago my boss had a 1 on 1 annual evaluation with us on Thursday because he was due to have knee surgery the next day on Friday. Thursday night he got a call his covid test came back positive and his surgery was canceled. He emailed his staff and everyone all the way up to the VP updating them.
Wouldn't you know Friday no one even bothered to check on us or tell his what we should do. It would have meant the whole department would be closed while we self quarantined. We just kept working. Later the next week we were informed that is long as you're not showing symptoms then just keep working.

He never had any symptoms or got sick. I was sure he had a false positive but his wife tested positive also and never had symptoms or got sick and none of his staff got sick either.
None of it makes sense to me anymore.

[Tom M King]

The reason it keeps spreading is that non-symptomatic people can spread it. The part about not having symptoms, and keeping working/doing whatever you've been doing, is the reason it keeps spreading. Having the symptoms means you have it worse than most who get it, but since most people who have symptoms are staying to themselves, the non-symptomatic people keep spreading it. Some will continue to get it worse than others.

Since the CDC is now being influenced by politics, you can mostly not bother to hang your hat on what they say.

[Mel Fulks]

I think it's hard to tell how much politics. Some of the non political science people ....are certainly changing as they get
more used to being on TV. Dr. Fauci is starting to remind me of Milton Berle. But I'm confident he knows more about
plagues than Milton Berle did. But he's not as funny .

[Kev Williams]

So Wednesday I found out the chain was actually 2 persons shorter than we all thought, which didn't help the nerves any...
But the BIL just called, first words were: "See ya at work Tuesday!!"--

-Grandson came back NEGATIVE-
http://www.engraver1.com/gifs/party.gif
That's a load off!

[Lee DeRaud]

Something I found interesting after talking to my infection control department.... According to the CDC guidelines you're only considered to be in contact if you're within 6 ft of a person for 15 minutes. No one ever mentions the 15 minute part.
...
None of it makes sense to me anymore.I suspect that's a rather arbitrary cutoff to prevent the contact tree from exploding exponentially.

Think of "contact" as the volume of air potentially shared with the other person: "time divided by distance" pretty much determines that, with some unknown multipliers for being inside vs outside, airflow direction etc. If you can do longer distance, good. If you can do shorter time, good. If you can do both, even better.

[Jerome Stanek]

Isn't there a saying that you are only 2 people away from knowing everyone on earth

[roger wiegand]

Isn't there a saying that you are only 2 people away from knowing everyone on earth

Six links is the accepted number. Hard to prove it's true, but it seems close, not counting extreme isolated populations. About 4 links among twitter users.

[Lee DeRaud]

Six links is the accepted number. Hard to prove it's true, but it seems close, not counting extreme isolated populations. About 4 links among twitter users.Or if you were in the cast of "A Few Good Men". :)
https://oracleofbacon.org/

[Kev Williams]

lots of years ago, in the 70's I guess, I remember a 'thing' on TV that ended with a statement that no one on earth was any farther apart by relation than 22nd cousins... maybe we're up to 24th by now? ;)

(and how many 'links' is 22nd cousins?)

[Jim Becker]

lots of years ago, in the 70's I guess, I remember a 'thing' on TV that ended with a statement that no one on earth was any farther apart by relation than 22nd cousins... maybe we're up to 24th by now? ;)

(and how many 'links' is 22nd cousins?)

My mother's and father's lines cross at about the 13th generation with the Hapsburgs (Kings of the Holy Roman Empire) based on my work on Ancestry dot com. Catherine of Aragon is a relative on my mother's side. So I can imagine I'm related to many of you on the forum in some way, considering the lines encompass so much of Europe and the British isles and how bloodlines flowed to the "new world", as it were.