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Covid-19 Data, Models, References - NO DISCUSSION

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Testing - for both current infection and for post-infection evidence of immunity (two completely different tests using two completely different technologies) are essential to really getting to a less disruptive state of affairs, but getting good tests with good precision and accuracy take time, development and validation. Anybody with experience in the diagnostic area knew these rushed first gen tests were going to be noisy. Also, for the RNA-based infection testing (mostly nasal swabs), there is typically significant error introduced via sample collection, handling and preparation. So even a good test can give bad results depending on sample collection/management.

If the test isn’t practically perfect then it’s going to be letting sick people out in the community which completely defeats the purpose, and at what cost? In another thread someone said that an accurate flu test cost about $800. What’s another $200B? Are you only going to let someone go to work if they’ve had it and recovered? If you haven’t caught it yet, and someone with a false negative is walking around out there, then you still have a high chance of catching it...but you tested negative....are we gonna retest everyone every day? What good is it to know that I tested negative last week. I could still have it and spread it today.
 
If the test isn’t practically perfect then it’s going to be letting sick people out in the community which completely defeats the purpose, and at what cost? In another thread someone said that an accurate flu test cost about $800. What’s another $200B? Are you only going to let someone go to work if they’ve had it and recovered? If you haven’t caught it yet, and someone with a false negative is walking around out there, then you still have a high chance of catching it...but you tested negative....are we gonna retest everyone every day? What good is it to know that I tested negative last week. I could still have it and spread it today.
On the bright side, the "post-infection" confirmation tests are easier, cheaper and less error fairly low error after proper development. Mayo has reported it is close to having a decent one. I am sure many other diagnostics companies are barking up the same tree. I would guess by mid-summer we will have a reasonably reliable way of clearing those that have already gotten and recovered.
 
On the bright side, the "post-infection" confirmation tests are easier, cheaper and less error fairly low error after proper development. Mayo has reported it is close to having a decent one. I am sure many other diagnostics companies are barking up the same tree. I would guess by mid-summer we will have a reasonably reliable way of clearing those that have already gotten and recovered.

While I agree that a post infection test could have some usefulness, I think it’s usefulness is primarily in giving the person tested piece of mind, assessing who might be able to donate useful plasma, and possibly as a requirement to work in certain fields, like elder care, I don’t see it as having broad usefulness. Unless you want everyone on earth to get infected, it can’t be used to determine whether or not you can leave the house.

I was initially against the idea of herd immunity(and would stand by that for Ebola) I’ve decided that it’s the only reasonable endgame. If you read the entire Wiki page on the Spanish flu, it has some good points on why we may be going about this backward. It also shows a lot of parallels to what we’re dealing with now(cytokine storms for example) It suggests that usually milder mutations of viruses are selected for because someone with mild symptoms goes about their business as usual and infects others, but someone with severe symptoms stays home, and infects relatively few people. Supposedly WWI inverted that normal process. Countries with the most cases in the late winter and spring weren’t hit very hard the next fall as they were immune even to the severe form that circulated later. So right now we’re talking about mass testing and sending people with very mild illness home for two weeks, while the severely ill are coughing on doctors. I’m now leaning toward keeping the spread as low as we can a little longer while we fix the PPE shortage, research treatment, and asses exactly which demographics are most likely to be hospitalized. Once we have some of that covered, I think we could send the young and healthy back to work and get some degree of herd immunity in advance of a vaccine. There are better sources on the Spanish flu than Wikipedia, but they take a lot more reading. It also seems that the specific flu strain responsible for the Spanish flu is not any more severe than other flu strains.

The post infection testing could be a useful way to assess herd immunity, but so could a drop in new cases. The second one is fairly cheap and accurate.
 
While I agree that a post infection test could have some usefulness, I think it’s usefulness is primarily in giving the person tested piece of mind, assessing who might be able to donate useful plasma, and possibly as a requirement to work in certain fields, like elder care, I don’t see it as having broad usefulness. Unless you want everyone on earth to get infected, it can’t be used to determine whether or not you can leave the house.
If I test negative for active infection (or am say 60 days post symptom) and I test for appropriate titer on the post-infection ELISA than I am free to move as I wish. I can't get sick and I can't give to others. A lot of activities could resume or continue with less stress for those with such results. In two years will be irrelevant as we will have vacines and herd immunity (all provided that this virus results in sustained immunity, not all do) - but between now and then, this pair of tests could make a big difference.
 
That scenario would provide incentive for many younger/healthier people to get (and hopefully recover from) Covid-19 as soon as possible to return to the workforce/normal life as soon as possible. Interesting.
 
If I test negative for active infection (or am say 60 days post symptom) and I test for appropriate titer on the post-infection ELISA than I am free to move as I wish. I can't get sick and I can't give to others. A lot of activities could resume or continue with less stress for those with such results. In two years will be irrelevant as we will have vacines and herd immunity (all provided that this virus results in sustained immunity, not all do) - but between now and then, this pair of tests could make a big difference.

Yeah, but are you just screwing everyone who never got it?
 
how? no different that walking around for decades after having the chicken pox
By not letting them go back to work. If you have to prove that you caught it and aren’t infectious, then most people will remain stuck at home. If you only have to prove that you don’t currently have it, then one single false-negative ruins the whole scenario.

I’m not saying that the post infection test has no value, just saying that I don’t see it as the key to opening the world back up. I’d be glad to get a post infection test for piece of mind. Heck, I wouldn’t be surprised if I’ve had it. We had a church event for new parents in Jan, and two days later my son had hand-foot-and-mouth plus a positive flu test and had a fever for ten days. turns out that by Wednesday 23 people at that event had gotten sick. I never ran a fever, but I was exhausted for over two weeks. No one at church died though, so....
 
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By not letting them go back to work. If you have to prove that you caught it and aren’t infectious, then most people will remain stuck at home. If you only have to prove that you don’t currently have it, then one single false-negative ruins the whole scenario.
It isn't a blanket rule - but it helps with the opposite problem of having millions who have probably already be exposed but had low symptoms get on with things.

As for "single error", statistically it doesn't change much. For example, HIV blood tests aren't perfect, but we have a working blood donor infrastructure these days.
 
It isn't a blanket rule - but it helps with the opposite problem of having millions who have probably already be exposed but had low symptoms get on with things.

As for "single error", statistically it doesn't change much. For example, HIV blood tests aren't perfect, but we have a working blood donor infrastructure these days.

Regarding HIV, we also don’t allow high risk populations to donate blood. If we did blood drives in prisons with zero exclusion criteria we’d find some false negatives really quickly and no one would take donated blood.

A single false-negative in the scenario of only allowing those testing negative to go back to work resulting zero transmission, would only result in patient 0.1.
 
Regarding HIV, we also don’t allow high risk populations to donate blood. If we did blood drives in prisons with zero exclusion criteria we’d find some false negatives really quickly and no one would take donated blood.

A single false-negative in the scenario of only allowing those testing negative to go back to work resulting zero transmission, would only result in patient 0.1.
Yup combination of testing and criteria, not new - the same could apply here at some point, but we don't have the testing ability yet.
 
I don't know if the following image is really even related to corona. But I think it does illustrate that we probably shouldn't be looking for a one size fits all solution.

1585859048953.png
 

Im still not sold that testing is terribly important. For other diseases sure, but cold, flu, covid-19 I’m not seeing it. We don’t treat colds, we have flu tests if a doctor wants to treat with Tamiflu, doctors should be using whatever PPE they can get while administering the test. Any doctor willing to try off-label treatments for covid-19 is probably willing to try it in the absence of a test if the flu test comes back negative. I’m not against testing, I just don’t think it’s going to fix as much as it’s being touted to.

I’m not certain either way, but I’m beginning to wonder if it might actually be best to leave those suffering few to no symptoms out spreading it.
 

14 days later...


Yeah Larry... bet you don't think my sitka hoody is over priced now

1585872132891.png
 
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