Covid II: Medical Info and Implications

[pogi]

6 hours ago, Rain said:

If you get one vaccine do you need to get the same vaccine for the second shot?  I would assume so, but don't want to make assumptions on this kind of thing.

Yes, it needs to be the same.  

[pogi]

12 hours ago, The Nehor said:

That is the best case. The studies showing possible long-term damage from the virus means that a short immunity and children getting it a lot might be worse for them. The problem is we don’t have any long-range data at this point. Hopefully it is not a dengue-fever effect where the second (and third and so on) cases are likely to be worse. It is normally the trend for viruses to become less deadly over time because viruses that kill the patient tend to die out more quickly but that is a trend and not a surety and that is in the long-term.

All indications suggest that second infections are less severe, thankfully.  That has been my observation too after talking to multiple people with re-infections.   If this virus acted like Dengue on second infection, probably over half the population would be dead in a matter of years.  Sobering thought.

Another good reason to believe that it does not act like dengue is that the vaccine for Covid actually works to reduce symptoms with subsequent exposure to the virus.  The problem in developing an effective vaccine for dengue is that the vaccine acts as a primary infection, priming the system for a more deadly second infection if the person is subsequently bitten by a dengue infected mosquito.  They actually developed a dengue vaccine in the Philippines and people started dying in large number after being bitten by dengue mosquitos even though they had never been infected with Dengue before. Nasty infection!

 

Edited January 15, 2021 by pogi

[pogi]

Looks like it's Utah's turn...

Numbers will likely start spiking soon because of it.  Now, more than ever, we need to follow mask and distancing precautions. 

https://www.ksl.com/article/50088603/new-uk-covid-19-variant-detected-in-utah-cdc-projects-strain-will-be-dominant-in-us-by-march

[Calm]

Blast it.  I was hoping to get back to the therapy pool in February if I can manage to keep the vertigo at bay.  And not worry about my husband teaching and getting sick.

It does feel like it has turned the corner from it being unusual for extended family and friends to be sick to hearing someone else has it every other day.

 I am finally I think getting bugged by the isolation.  I have never hated January before, feeling I was already so over winter.  I like hibernating now usually. 

Edited January 16, 2021 by Calm

[The Nehor]

3 hours ago, pogi said:

All indications suggest that second infections are less severe, thankfully.  That has been my observation too after talking to multiple people with re-infections.   If this virus acted like Dengue on second infection, probably over half the population would be dead in a matter of years.  Sobering thought.

Another good reason to believe that it does not act like dengue is that the vaccine for Covid actually works to reduce symptoms with subsequent exposure to the virus.  The problem in developing an effective vaccine for dengue is that the vaccine acts as a primary infection, priming the system for a more deadly second infection if the person is subsequently bitten by a dengue infected mosquito.  They actually developed a dengue vaccine in the Philippines and people started dying in large number after being bitten by dengue mosquitos even though they had never been infected with Dengue before. Nasty infection!

 

Glad to hear.

[Calm]

On 12/22/2020 at 6:50 PM, bsjkki said:

No asymptomatic  spread??? https://alachuachronicle.com/university-of-florida-researchers-find-no-asymptomatic-spread/
 

This was also found in a study out of Wuhan....but who trusts them? This is some confirmation of the Wuhan study. 
 

https://www.bmj.com/content/371/bmj.m4695

“Virus cultures were negative for all asymptomatic positive and repositive cases, indicating no “viable virus” in positive cases detected in this study.”

https://www.nature.com/articles/s41467-020-19802-w

 

 

I love this epidemiologist's FB page as I think she explains issues and policies very well.  She addresses this here:

https://m.facebook.com/story.php?story_fbid=227219035567420&id=110965280526130

Quote

✅ 𝐋𝐨𝐧𝐠 𝐚𝐧𝐬𝐰𝐞𝐫: The new study in JAMA evaluated how many COVID-19 cases are attributed to symptomatic transmission and how many to asymptomatic transmission. What did they find?
--- 60% of cases came from asymptomatic infections - Of these, 35% from presymptomatic people and 24% from people who never had symptoms.
--- The infectious period duration was maintained at 10 days and peaked between 3 and 7 days. This highlights the need to quarantine and isolate correctly!
--- Over 50% of transmission occurred without the people knowing they were sick. That's a huge proportion! Think of the daily new COVID-19 cases. We had 250,000 yesterday - 125,000 transmissions occurred prior to the people even knowing they were sick. Just imagine the number of cases that would be reduced if we took asymptomatic spread seriously.
--- This continues to show the importance of masking, distancing, and washing hands around anyone - especially with the positivity rates so high right now.
--- A good rule of thumb? Assume anyone is a carrier and can spread and act accordingly.

✅ Here's my previous post where we discuss the Wuhan 10 million meme and the Florida study: https://www.facebook.com/friendlyneighborepidemiologist/posts/218553516433972

 

Edited January 16, 2021 by Calm

[provoman]

5 hours ago, pogi said:

 

Edited January 16, 2021 by provoman

[Calm]

Not the most reliable of sources, need to see if I can find original report. 
 

Highly concerning if accurate though. 
 

https://nypost.com/2021/01/18/1-in-8-recovered-covid-19-patients-die-within-5-months-study/
 

Quote

Many people who suffer long-lasting effects of the coronavirus develop heart problems, diabetes and chronic liver and kidney conditions, according to the report.

The research also found a higher risk of problems developing in various organs after people younger than 70 and ethnic minorities were discharged from the hospital, according to the Guardian.

“People seem to be going home, getting long-term effects, coming back in and dying. We see nearly 30 percent have been readmitted, and that’s a lot of people. The numbers are so large,” study author Kamlesh Khunti said.

“The message here is we really need to prepare for long COVID. It’s a mammoth task to follow up with these patients and the NHS is really pushed at the moment, but some sort of monitoring needs to be arranged,” added Khunti, a professor of primary care diabetes and vascular medicine at Leicester University.

Hasn’t been peer reviewed yet. 

[Calm]

Here is the original report:

https://www.medrxiv.org/content/10.1101/2021.01.15.21249885v1

Quote

Individuals discharged from hospital following COVID-19 face elevated rates of multi-organ dysfunction compared with background levels, and the increase in risk is neither confined to the elderly nor uniform across ethnicities. The diagnosis, treatment and prevention of PCS require integrated rather than organ- or disease-specific approaches. Urgent research is required to establish risk factors for PCS.

 

Edited January 20, 2021 by Calm

[Rain]

2 hours ago, Calm said:

Not the most reliable of sources, need to see if I can find original report. 
 

Highly concerning if accurate though. 
 

https://nypost.com/2021/01/18/1-in-8-recovered-covid-19-patients-die-within-5-months-study/
 

Hasn’t been peer reviewed yet. 

Interesting that it would affect the pancreas too.  Before this point I've not heard that. 

[provoman]

On 1/15/2021 at 4:58 PM, pogi said:

Looks like it's Utah's turn...

Numbers will likely start spiking soon because of it.  Now, more than ever, we need to follow mask and distancing precautions. 

https://www.ksl.com/article/50088603/new-uk-covid-19-variant-detected-in-utah-cdc-projects-strain-will-be-dominant-in-us-by-march

With this fast spreading variant, is there anything the general public should to avoid it? After seeing this article I started limiting my non-essential mask wearing trips out of the home. It worries me that someone with no travel history tested positive for it.

[pogi]

22 minutes ago, provoman said:

With this fast spreading variant, is there anything the general public should to avoid it? After seeing this article I started limiting my non-essential mask wearing trips out of the home. It worries me that someone with no travel history tested positive for it.

It sounds like you are doing every thing right.  Thank you for that!  The best things we can do is what we have been taught all along...and get vaccinated.   This will rapidly become the dominant variant.  I don't think there is much we can do to stop it considering the how unsafe much of the nation is being.  Vaccination is our greatest hope. 

[MiserereNobis]

My state (New Mexico) placed those who work in schools in phase 1B of the vaccine rollout. It looks like we went to phase 1B because I got an email out of the blue this morning telling me I can get vaccinated today if I want to. Of course I did! I got the Pfizer vaccine. It was so good to see so many fellow teachers and staff standing in line. I'm hoping this portends a reopening of the schools sooner rather than later.

I also just took a covid test. Our district is mandating that a random 10% of employees that are regularly in a building get tested every 2 weeks. I guess my number came up. It was an unusual test. I received a package in the mail with a tube. I had to spit into it while on a Zoom meeting in front of a technician. I then send the tube off via UPS tomorrow to the lab. @pogi, what's the story with a saliva test? I hadn't heard about it before.

All in all, a positive covid day for me  

Edited January 21, 2021 by MiserereNobis

[pogi]

15 minutes ago, MiserereNobis said:

@pogi, what's the story with a saliva test? I hadn't heard about it before.

All in all, a positive covid day for me  

The positive thing about them is that they are less invasive and give rapid results.  On the down-side, they are less reliable with more frequent false results.   I just talked to a 19 year old kid today who was convinced he had Covid and went to get tested with a saliva test.  Results were negative.  He was convinced that it was wrong and got tested with a second saliva test.  Negative again.  He was absolutely certain he had Covid with all of his symptoms including loss of small and taste, so he went to go get tested again.  This time he did a PCR (nasopharyngeal).  Yep, he was positive.  He asked me on the phone who he needs to complain to about the saliva tests as he is concerned that they may be the cause for outbreaks due to false confidence.  He has a point. 

Edited January 21, 2021 by pogi

[MiserereNobis]

10 minutes ago, pogi said:

The positive thing about them is that they are less invasive and give rapid results.  On the down-side, they are less reliable with more frequent false results.   I just talked to a 19 year old kid today who was convinced he had Covid and went to get tested with a saliva test.  Results were negative.  He was convinced that it was wrong and got tested with a second saliva test.  Negative again.  He was absolutely certain he had Covid with all of his symptoms including loss of small and taste, so he went to go get tested again.  This time he did a PCR (nasopharyngeal).  Yep, he was positive.  He asked me on the phone who he needs to complain to about the saliva tests as he is concerned that they may be the cause for outbreaks due to false confidence.  He has a point. 

Thanks, pogi. I wonder why our school district chose to use the saliva test, especially since it involves sending things in the mail, when the nasal covid tests are available for anyone at the local CVS pharmacy. The cynic in me wonders if they are hoping for false negatives, ha. Or maybe they are just cheaper.

[Rain]

5 hours ago, MiserereNobis said:

Thanks, pogi. I wonder why our school district chose to use the saliva test, especially since it involves sending things in the mail, when the nasal covid tests are available for anyone at the local CVS pharmacy. The cynic in me wonders if they are hoping for false negatives, ha. Or maybe they are just cheaper.

Probably because it is easier to have people do them (you can do it on your own) and it isn't painful like the other is. 

[The Nehor]

19 hours ago, Calm said:

Here is the original report:

https://www.medrxiv.org/content/10.1101/2021.01.15.21249885v1

 

The headline in the news stories about this is misleading, It should be 1 in 8 recovered patients who were hospitalized with Covid are dead in five months.

Still not good and it does continue to highlight how much we don’t know about the long term effects of Covid but not as dire as the tabloid journalism about it makes it sound.

Edited January 21, 2021 by The Nehor

[bsjkki]

Updated guidance on PCR testing from the WHO. It is not as definitive as most people think. False positives do happen. 
 

“Users of IVDs must read and follow the IFU carefully to determine if manual adjustment of the PCR positivity threshold is recommended by the manufacturer.

WHO guidance Diagnostic testing for SARS-CoV-2 states that careful interpretation of weak positive results is needed (1). The cycle threshold (Ct) needed to detect virus is inversely proportional to the patient’s viral load. Where test results do not correspond with the clinical presentation, a new specimen should be taken and retested using the same or different NAT technology.

WHO reminds IVD users that disease prevalence alters the predictive value of test results; as disease prevalence decreases, the risk of false positive increases (2). This means that the probability that a person who has a positive result (SARS-CoV-2 detected) is truly infected with SARS-CoV-2 decreases as prevalence decreases, irrespective of the claimed specificity. 

Most PCR assays are indicated as an aid for diagnosis, therefore, health care providers must consider any result in combination with timing of sampling, specimen type, assay specifics, clinical observations, patient history, confirmed status of any contacts, and epidemiological information.

Actions to be taken by IVD users:

1. Please read carefully the IFU in its entirety. 
2. Contact your local representative if there is any aspect of the IFU that is unclear to you. 
3. Check the IFU for each incoming consignment to detect any changes to the IFU.
4. Provide the Ct value in the report to the requesting health care provider.

https://www.who.int/news/item/20-01-2021-who-information-notice-for-ivd-users-2020-05

[Harry T. Clark]

1 hour ago, bsjkki said:

Updated guidance on PCR testing from the WHO. It is not as definitive as most people think. False positives do happen. 
 

“Users of IVDs must read and follow the IFU carefully to determine if manual adjustment of the PCR positivity threshold is recommended by the manufacturer.

WHO guidance Diagnostic testing for SARS-CoV-2 states that careful interpretation of weak positive results is needed (1). The cycle threshold (Ct) needed to detect virus is inversely proportional to the patient’s viral load. Where test results do not correspond with the clinical presentation, a new specimen should be taken and retested using the same or different NAT technology.

WHO reminds IVD users that disease prevalence alters the predictive value of test results; as disease prevalence decreases, the risk of false positive increases (2). This means that the probability that a person who has a positive result (SARS-CoV-2 detected) is truly infected with SARS-CoV-2 decreases as prevalence decreases, irrespective of the claimed specificity. 

Most PCR assays are indicated as an aid for diagnosis, therefore, health care providers must consider any result in combination with timing of sampling, specimen type, assay specifics, clinical observations, patient history, confirmed status of any contacts, and epidemiological information.

Actions to be taken by IVD users:

1. Please read carefully the IFU in its entirety. 
2. Contact your local representative if there is any aspect of the IFU that is unclear to you. 
3. Check the IFU for each incoming consignment to detect any changes to the IFU.
4. Provide the Ct value in the report to the requesting health care provider.

https://www.who.int/news/item/20-01-2021-who-information-notice-for-ivd-users-2020-05

There were officials questioning the cycle threshold all along, including Fauci.  40 cycles, the current test level, is way too much.  I wonder how our collective reaction to this would have been had the cycle threshold been at 24 as some were advocating all along.  How many false positives were there?  How did the amount of false positives drive lockdown decisions, mask decisions, etc.?  https://off-guardian.org/2020/12/18/who-finally-admits-pcr-tests-create-false-positives/ 

[bsjkki]

2 minutes ago, Harry T. Clark said:

There were officials questioning the cycle threshold all along, including Fauci.  40 cycles, the current test level, is way too much.  I wonder how our collective reaction to this would have been had the cycle threshold been at 24 as some were advocating all along.  How many false positives were there?  How did the amount of false positives drive lockdown decisions, mask decisions, etc.?  https://off-guardian.org/2020/12/18/who-finally-admits-pcr-tests-create-false-positives/ 

Those are all good questions.

[pogi]

35 minutes ago, Harry T. Clark said:

There were officials questioning the cycle threshold all along, including Fauci.  40 cycles, the current test level, is way too much.  I wonder how our collective reaction to this would have been had the cycle threshold been at 24 as some were advocating all along.  How many false positives were there?  How did the amount of false positives drive lockdown decisions, mask decisions, etc.?  https://off-guardian.org/2020/12/18/who-finally-admits-pcr-tests-create-false-positives/ 

Keep in mind that false negatives are more common than false positives, so if you are worried about numbers influencing decisions, you are worrying in the wrong direction.  Especially after considering that despite false positives, actual cases are WAY higher than reported, as many never test. 

Edited January 21, 2021 by pogi

[Harry T. Clark]

18 minutes ago, pogi said:

Keep in mind that false negatives are more common than false positives, so if you are worried about numbers influencing decisions, you are worrying in the wrong direction.  Especially after considering that despite false positives, actual cases are WAY higher than reported, as many never test. 

This article by the NY Times https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html  says 85% to 90% of those testing "positive" via a 37 to 40 cycle PCR tests conducted over the summer in MA, NY and NV barely had any virus, were asymptomatic and not infectious.  That is a high number and probably explains why there are so many asymptomatic "positives." 

From the article:

Quote

In Massachusetts, from 85 to 90 percent of people who tested positive in July with a cycle threshold of 40 would have been deemed negative if the threshold were 30 cycles, Dr. Mina said. “I would say that none of those people should be contact-traced, not one,” he said.

The false negative rate is 100% on day one after exposure according to this study and then goes down to 21% false negative.  https://www.acc.org/latest-in-cardiology/journal-scans/2020/05/18/13/42/variation-in-false-negative-rate-of-reverse

Is this to what you are referring?  Sure, 100% false negative beats the 85 to 90% false positive.  Maybe the PCR test is what its discoverer thought it was with respect to virus detection, meaningless?   https://www.bitchute.com/video/wOSeTz57xrCF/ 

[pogi]

1 hour ago, Harry T. Clark said:

This article by the NY Times https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html  says 85% to 90% of those testing "positive" via a 37 to 40 cycle PCR tests conducted over the summer in MA, NY and NV barely had any virus, were asymptomatic and not infectious.  That is a high number and probably explains why there are so many asymptomatic "positives." 

Because the PCR test is so sensitive, it will indeed detect small amounts of virus.  This could mean several things:  1) the person tested very early after exposure before the virus had a chance to replicate.   We see this all the time!  People find out that they may have had a close contact with someone at school or work and freak out and go test immediately before waiting 5-7 days (as recommended) and/or before even showing any symptoms.  

Another scenario we see regularly is that people wait to test after their symptoms have resolved.  I see it all the time.  

None of this means that they are not or were not or will not be contagious with Covid.  The fact is, if the virus is in them, they are infected.  The difficult part is determining what stage of infection they are in.  This can't be done simply by looking at the result of the test.  It requires an interview.  That is where contact tracing comes in handy.  We determine symptom onset.  Quite regularly I see cases who test positive before they even show symptoms for the reason I mentioned above.  If these tests were less sensitive , these people would have received a false negative, even though they were in the early stages of infection with low viral count.  This would give them a false assurance that they are not contagious and may never isolate despite symptom development.  It is a double edged sword that way.  

I also regularly contact people who when I contact them after receiving their positive test results, inform me that their symptom onset was 3 weeks ago!  Do these people need to isolate further?  Nope.  Again, that is why contact tracing comes in handy.  If someone doesn't need to isolate because their contagious period is already complete and they are in the late stage of infection, we don't make them.    

I have explained this several times but the test is a single snap-shot in time.  If the viral count was low when they tested positive, it doesn't mean that it will still be low the next day, or the next day, etc.  And it also doesn't mean that they didn't have a higher count yesterday, or the day before.    So take this article with a grain of salt.   Contact tracing helps weed out some of the problems of a highly sensitive test.  Keep in mind that the incubation period of the virus can be up to 2 weeks!  Having a less sensitive test would miss lots of cases who test early in the 2 week period of incubation when the viral count is still very low and would give them a false assurance. 

It would be wrong to glean from this article that 85% to 90% of positive COVID cases are not contagious.  That simply is not true.  That is not what these numbers mean.  If that was true, that would mean that only 10%-15% of cases were actually symptomatic, and that a HUGE percentage of that 10%-15% of cases are serious and/or deadly.   That is an easily disputed non-fact. 

Either way, you can't dispute that the numbers are WAY lower than actual cases, despite false positives.  

Quote

Is this to what you are referring?  Sure, 100% false negative beats the 85 to 90% false positive.

No.  You are misunderstanding the numbers.  Hopefully what I said above helps some.  The 85% to 90% numbers are NOT false positives.  They did indeed detect virus.  In other words the person is positively identified as having the Covid virus in them.  The question is, what stage of infection are they in and should they isolate?  That is where my line of work comes in.

Edited January 21, 2021 by pogi

[Harry T. Clark]

8 minutes ago, pogi said:

Because the PCR test is so sensitive, it will indeed detect small amounts of virus.  This could mean several things:  1) the person tested very early after exposure before the virus had a chance to replicate.   We see this all the time!  People find out that they may have had a close contact with someone at school or work and freak out and go test immediately before waiting 5-7 days (as recommended) and/or before even showing any symptoms.  

Another scenario we see regularly is that people wait to test after their symptoms have resolved.  I see it all the time.  

None of this means that they are not or were not or will not be contagious with Covid.  The fact is, if the virus is in them, they are infected.  The difficult part is determining what stage of infection they are in.  This can't be done simply by looking at the result of the test.  It requires an interview.  That is where contact tracing comes in handy.  We determine symptom onset.  Quite regularly I see cases who test positive before they even show symptoms for the reason I mentioned above.  If these tests were less sensitive , these people would have received a false negative, even though they were in the early stages of infection with low viral count.  This would give them a false assurance that they are not contagious and may never isolate despite symptom development.  It is a double edged sword that way.  

I also regularly contact people who when I contact them after receiving their positive test results, inform me that their symptom onset was 3 weeks ago!  Do these people need to isolate further?  Nope.  Again, that is why contact tracing comes in handy.  If someone doesn't need to isolate because their contagious period is already complete and they are in the late stage of infection, we don't make them.    

I have explained this several times but the test is a single snap-shot in time.  If the viral count was low when they tested positive, it doesn't mean that it will still be low the next day, or the next day, etc.  And it also doesn't mean that they didn't have a higher count yesterday, or the day before.    So take this article with a grain of salt.   Contact tracing helps weed out some of the problems of a highly sensitive test.  Keep in mind that the incubation period of the virus can be up to 2 weeks!  Having a less sensitive test would miss lots of cases who test early in the 2 week period of incubation when the viral count is still very low and would give them a false assurance. 

It would be wrong to glean from this article that 85% to 90% of positive COVID cases are not contagious.  That simply is not true.  That is not what these numbers mean.  If that was true, that would mean that only 10%-15% of cases were actually symptomatic, and that a HUGE percentage of that 10%-15% of cases are serious and/or deadly.   That is an easily disputed non-fact. 

Either way, you can't dispute that the numbers are WAY lower than actual cases, despite false positives.  

 

Here is how the contagious period is defined for colds, flu and pneumonia:  https://www.medicinenet.com/how_long_is_a_cold_or_flu_contagious/article.htm

So, are you figuring in that people are probably contagious with covid-19 at least one day prior to symptoms showing?  Is that why you say it is simply not true, because a false positive could somehow turn positive and have been contagious one day prior to the onset of symptoms?  I think you are misconstruing the study from the NY Times article.  The false positive was determined by never getting covid-19 but having a positive test nonetheless.

Maybe you could walk me through how covid-19 is somehow different from any other viral infection where people have to have enough viral load in order to get sick and pass it on to others.  If a certain amount of the virus is needed to infect and cause covid-19, how can someone with less than that threshold amount cause another to go over the threshold amount?  Has there been a study on what the bare minimum amount is needed to cause covid-19?  Probably healthy individuals are less susceptible as they need more of a viral load than the immunocompromised, right?  So, I can see where a healthy exposed individual could cause an immunocompromised person to get sick as the immunocompromised would not need as much viral load to get covid-19.

[pogi]

36 minutes ago, Harry T. Clark said:

So, are you figuring in that people are probably contagious with covid-19 at least one day prior to symptoms showing?  Is that why you say it is simply not true, because a false positive could somehow turn positive and have been contagious one day prior to the onset of symptoms?  

2 days, actually.  People are considered contagious 2 days before symptom onset.  The incubation period, however, is up to 2 weeks!  I other words a person could be exposed to the virus 2 weeks ago, test 2 days after initial exposure, after finding out that they were exposed by a coworker, test positive (because the virus is actually in him), but only have a tiny viral load at this point and would not by symptomatic or contagious for up to 10 days later.

The PCR tests are not false positives if they actually detect Covid virus (even if it is a small amount).  The person has the virus, but may not be symptomatic or contagious for another 10 days.   The problem that might arise with a less sensitive test is that if a person tested negative 2 days after exposure, then developed symptom 10 days later, they may blow it off thinking they couldn't have been infected by that contact because they tested negative.  "Must be a cold or allergies!"

36 minutes ago, Harry T. Clark said:

I think you are misconstruing the study from the NY Times article.  The false positive was determined by never getting covid-19 but having a positive test nonetheless.

To be honest, I can't read the article (it requires a subscription - but we have discussed this article already).  I am just going off what you have quoted.  Here is what you stated about the article:

Quote

This article by the NY Times https://www.nytimes.com/2020/08/29/health/coronavirus-testing.html  says 85% to 90% of those testing "positive" via a 37 to 40 cycle PCR tests conducted over the summer in MA, NY and NV barely had any virus, were asymptomatic and not infectious.

"Barely having any virus" at the time of testing, and "never getting covid-19" are two VERY different things!  If they barely have any virus, they still have the Covid virus in them!   Again, the question is, what stage of infection are they in?  We can't rely on that freeze-frame snap shot of this article to determine if these people will never be symptomatic or contagious, or if they never were symptomatic or contagious before being tested. (2 weeks is a large window!)  I also have no way to examine their methods. Not all studies are created equal.

36 minutes ago, Harry T. Clark said:

Maybe you could walk me through how covid-19 is somehow different from any other viral infection where people have to have enough viral load in order to get sick and pass it on to others.  If a certain amount of the virus is needed to infect and cause covid-19, how can someone with less than that threshold amount cause another to go over the threshold amount?  Has there been a study on what the bare minimum amount is needed to cause covid-19?  Probably healthy individuals are less susceptible as they need more of a viral load than the immunocompromised, right?  So, I can see where a healthy exposed individual could cause an immunocompromised person to get sick as the immunocompromised would not need as much viral load to get covid-19.

I hope I have answered this some with the above, but we don't know for sure what the threshold is.  If it is like other viruses, it is likely can vary from person to person.  The point I am making is that simply because they had a low viral count on the day they tested positive, that is NOT a guarantee that they will not be contagious in the near future, or have not been contagious previously.

Edited January 21, 2021 by pogi