Asymptomatic SARS-CoV-2 Infections - How rare?

[EastWest Gal]

It’s hard to recommend everyone wear a mask when no one has masks and hospitals are running out, and if wear one you are shamed for wearing it instead of giving it to a hospital. All these recommendations, and no materials to make them possible. It’s distressing.

 

[NW-Bound]

It’s hard to recommend everyone wear a mask when no one has masks and hospitals are running out, and if wear one you are shamed for wearing it instead of giving it to a hospital. All these recommendations, and no materials to make them possible. It’s distressing.

The South Korean doctor in the interview video that Nemo2 posted elsewhere said that he believed that masks helped. However, he also understood that the US had a shortage of masks. It's so sad how a rich country can get itself back against a wall for something so inexpensive. I don't know on whom we can blame this complacency. We are collectively at fault.

 

[ERD50]

The South Korean doctor in the interview video that Nemo2 posted elsewhere said that he believed that masks helped. However, he also understood that the US had a shortage of masks. It's so sad how a rich country can get itself back against a wall for something so inexpensive. I don't know on whom we can blame this complacency. We are collectively at fault.

It really isn't so hard to understand, IMO.

If you run a business, would you keep a ton of excess inventory on hand, "just in case" something happens that hasn't happened in 100 years? If you even thought about it, you might think that it was the business of those who bought your product to keep any anticipated inventory on hand. You just make it, you don't control the world, you aren't "king". And there are costs associated with inventory. If you keep inventory for a 1 in 100 year emergency, it makes it hard to compete with those who don't. You can't help anybody if you have to close your business.

So let's make a parallel to Sept 11, 2001, another "Black Swan" event. I vividly recall some radio/TV personalities being all "WTF!" over the fact that cell phone towers in NY shut down after a few hours. These radio/TV people said "The batteries went dead! WTF didn't they have more batteries on hand?". Like you could just go to Radio Shack and get a few dozen AA's and it would all be Hunky-Dorey.

Well, cell phone towers need huge amounts of power. They transmit high power so that your phone doesn't need to. They have directional antennas, and many of them, covering each direction. Your phone needs to be omni-directional. Bottom line, it would take a huge amount of batteries to provide days/weeks of back up in cell towers. And an emergency could strike anywhere. So we aren't just talking NY, every cell tower in the country would need this mass array of batteries. And those batteries would have to be replaced after 10 years or so. And most likely, they would never, ever have been used in their 10 year life. So the cell companies would need to be replacing humongous numbers of batteries each year, just to keep up, "just in case". It would be bad for the environment, it would be bad for business.

Sorry, but I think it's just too easy to say "why weren't we prepared?". Why should we be prepared (to this extent)? Who is going to pay for something that can't be foreseen? It's one thing to be prepared for hurricane season, or winter. But a pandemic of historic preportions? How far can we go?

-ERD50

 

[NW-Bound]

It really isn't so hard to understand, IMO...

No, it's not hard to understand. It's very simple. It is still sad that our medical workers are hamstrung for something so basic.

Of course nobody can stock up for everything. And knowing that our medical supplies are limited, and lack of good care can drive up the mortality rate, it's more the reason to do what we can to avoid overloading our hospital even more than it is already.

 

[martyp]

Yesterday I was reading some journal articles from 2009 around the time of the H1N1 outbreak. I've actually learned something new about how we expire droplets. Yes we eject droplets when coughing and sneezing but we also do it simply by talking. The louder you talk the more droplets you emit. Laughing (social situations), singing (churches?), shouting (indoor sporting events) all lead to droplets being spread in the near vicinity. Yes there is a larger volume in a good sneeze but being in a crowded closed environment for several hours generates an equal contamination load. Most of the droplets in a sneeze or cough are large enough to drop to the ground in a few minutes. The smaller droplets evaporate and linger for hours. Clearly there are examples of aerosol infection in the cruise ships, taxis, a Thai boxing stadium, church services, and Mardi Gras. That is how asymptomatic people spread aerosol droplets

Contact contamination is also possible Asymptomatic people will touch their face, touch a surface, and then you touch your face. I read an article examining infection pathways between a patient and a nurse in a closed room. They estimated 50-75% of the virus transfer was through contact contamination. However, interestingly, they mentioned that they didn't know the effectiveness of infection through virus infiltration through something like eye fluid. They said that breaking a small number of virus particles deep into your lungs would be a more efficient means of infection.

 

[JoeWras]

Yes we eject droplets when coughing and sneezing but we also do it simply by talking. The louder you talk the more droplets you emit.

Yep! And for those who want details, here is a pointer to very detailed research on how talking, especially loud talking, emits virus laden aerosols.

Think about this the next time to sit down to dinner at a loud restaurant. (Probably 3 years from now, LOL.) We are constantly expelling stuff as we enjoy each other's company. Many droplets fall onto the table. The silverware. The food. Some fall onto the other people at the dinner, maybe right onto their face.

Oh, it is so lovely out there for a virus.

 

[becca]

My 73 yo brother tested positive for CV. His only symptoms were a one day temperature of 103, slight sore throat, slight cough and slight chest pain all relieved with one dose of tylenol. He only got tested because he was getting ready to have surgery for another matter and they were concerned about the 1 day fever. He was only sick one day. That was 2 weeks ago. His wife has had no symptoms even though they have been sleeping together, riding in car together, going everywhere together, so you can assume she might be an asymptomatic carrier?

The only places he had been to catch it was a doctors appointment and the grocery store.

 

[JoeWras]

Becca: WOW! Glad your brother and SIL are doing good through this. Also encouraging to hear everyone over 50 isn't doomed, as the news wants us to believe.

 

[braumeister]

That's the most encouraging news I've heard in a while. Thanks for posting that.

 

[airforce1]

Several studies show confirm a significant portion of asymptomatic case which I posted in another thread:

Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan
https://www.eurosurveillance.org/con....25.10.2000180

Estimating the generation interval for COVID-19 based on symptom onset data
https://www.medrxiv.org/content/10.1...815v1.full.pdf

Clinical Characteristics of 24 Asymptomatic Infections with COVID-19 Screened among Close Contacts in Nanjing, China
https://www.medrxiv.org/content/10.1....20.20025619v2

The youtube video in question about Dr. Kim Woo Ju is located here and can explain some of the reasons why there is asymptomatic spread and why masks are key to reducing its transmission

 

[tmm99]

However, interestingly, they mentioned that they didn't know the effectiveness of infection through virus infiltration through something like eye fluid. They said that breaking a small number of virus particles deep into your lungs would be a more efficient means of infection.

I read that eyes have a lot of ACE2 receptors which the coronavirus loves sticking to, like lungs, so until someone says definitively that the chance of catching the virus via our eyes is next to nil, I will try to protect my eyes (in addition to my mouth and nose) as much as possible.

 

[tmm99]

Becca, thank you for sharing your brother's story. Great news that your brother had it but his symptoms were so mild.

This story also makes me wonder how many people have already been infected and got over it with minor symptoms. Some scientists say 20%. I have a feeling it's higher. The Princess Diamond study says around 45% (as they tested every one on the ship) and I believe that their number is closer to reality.

 

[JoeWras]

Becca, thank you for sharing your brother's story. Great news that your brother had it but his symptoms were so mild.

This story also makes me wonder how many people have already been infected and got over it with minor symptoms. Some scientists say 20%. I have a feeling it's higher. The Princess Diamond study says around 45% (as they tested every one on the ship) and I believe that their number is closer to reality.

And consider this. The ship had an older population. Even then, the number was over 40%. Just how many kids have had it, and how many are asymptomatic? We don't know, but there are suspicions it is very high.

Once they can finally start doing some antigen testing, I hope we can get a real picture.

 

[Ready]

I believe the high percentage of asymptomatic carriers is the main reason why this disease has become so much more deadly than any flu virus. With the flu you generally were only contagious when you were symptomatic. People naturally stay in bed away from others when they are not feeling well.

But with COVID-19 it is now believed that a significant percent of the population may be carrying the disease while being asymptomatic. And so they are not taking the same precautions they would normally be taking. And that is why the disease is running rampant throughout the world.

 

[MissMolly]

I think it's possible I had it. On the night of March 11th I went to bed with terrible coughing. I woke up during the night with chills, alternating freezing and burning up, terrible pain in my chest and laboring to breathe. After who knows how long (I don't feel I was really aware of anything, I think I must have had a high fever) I finally fell asleep. Awoke the next morning with no chills, no chest pain and breathing normal but still coughing and running a fever, but a low grade fever. The fever and coughing persisted for the next 2 weeks. Never felt horrible, but never felt good. Then last Thursday night, my fever climbed to over 100 (which is high for me because my normal is 97.6). Took Tylenol which brought it back down. Woke up on Friday with no fever and feeling good and have remained so. So did I have it? Dunno and probably never will.

 

[bmcgonig]

I think it's possible I had it. On the night of March 11th I went to bed with terrible coughing. I woke up during the night with chills, alternating freezing and burning up, terrible pain in my chest and laboring to breathe. After who knows how long (I don't feel I was really aware of anything, I think I must have had a high fever) I finally fell asleep. Awoke the next morning with no chills, no chest pain and breathing normal but still coughing and running a fever, but a low grade fever. The fever and coughing persisted for the next 2 weeks. Never felt horrible, but never felt good. Then last Thursday night, my fever climbed to over 100 (which is high for me because my normal is 97.6). Took Tylenol which brought it back down. Woke up on Friday with no fever and feeling good and have remained so. So did I have it? Dunno and probably never will.

Antibody test will tell you, whenever we can get one.

 

[audreyh1]

I think it's possible I had it. On the night of March 11th I went to bed with terrible coughing. I woke up during the night with chills, alternating freezing and burning up, terrible pain in my chest and laboring to breathe. After who knows how long (I don't feel I was really aware of anything, I think I must have had a high fever) I finally fell asleep. Awoke the next morning with no chills, no chest pain and breathing normal but still coughing and running a fever, but a low grade fever. The fever and coughing persisted for the next 2 weeks. Never felt horrible, but never felt good. Then last Thursday night, my fever climbed to over 100 (which is high for me because my normal is 97.6). Took Tylenol which brought it back down. Woke up on Friday with no fever and feeling good and have remained so. So did I have it? Dunno and probably never will.

Sounds very likely that you had it and I hope you are able to get an antibody test to show that you did.

 

[FIREd_2015]

I think it's possible I had it. On the night of March 11th I went to bed with terrible coughing. I woke up during the night with chills, alternating freezing and burning up, terrible pain in my chest and laboring to breathe. After who knows how long (I don't feel I was really aware of anything, I think I must have had a high fever) I finally fell asleep. Awoke the next morning with no chills, no chest pain and breathing normal but still coughing and running a fever, but a low grade fever. The fever and coughing persisted for the next 2 weeks. Never felt horrible, but never felt good. Then last Thursday night, my fever climbed to over 100 (which is high for me because my normal is 97.6). Took Tylenol which brought it back down. Woke up on Friday with no fever and feeling good and have remained so. So did I have it? Dunno and probably never will.

In today's White House coronavirus briefing, Dr. Birx said the ELISA test (antibody) could be easily done by hospitals and private labs in the near future. These tests are readily available in South Korea so it's not like we have to invent something from scratch. Given the rate which everything in moving in this space I wouldn't be too surprised if by the end of April I could go to my local pharmacy and get an antibody test done. I had a mild cold/flu in early March that included fever and dry cough that did not progress to an upper respiratory infection which is really unusual for me so I'm also interested in getting an antibody test. In the Korean interview that someone else posted earlier, the Korean doctor said the test costs around $150(?) but if the result is positive then the test is free. I think if we do something similar here it would definitely get people back to work faster.

Added: There is some controversy as to how long one will have immunity. Towards the end of the interview the Korean doctor said there were some people who tested positive for the antibodies but were re-infected.

 

[martyp]

Yeah, I've definitely encountered my share of "spray" talkers over the years. And the eating vector also makes sense. But both of these modes of transmission require fairly close contact with others. So I would be far less worried about casual interaction with an asymptomatic person (say, in a grocery store aisle) than an obviously sick person.

You are correct to say that your exposure from a single asymptotic person is very low but that is not the scenario public health officials are worried about. It Is about larger numbers of asymptomatic individuals cumulatively infecting an enclosed space. Spaces like a room, taxi, train car, bar, church, funeral, school, office, etc. Also laughing, singing, and shouting produce more aerosol particles than just talking. Half a dozen people coming over to my condo for a birthday party and staying 3-4 hours can easily become a significant exposure even if only one person is infected.

 

[NW-Bound]

I watched the interview with the Korean doctor, and believed that the US$140 test was for the PCR test (RNA identification). The antibody test should be quite cheaper.

There was a clinic in the LA area that was able to import the test strips from South Korea, and the test was less than $50 if my memory serves. The FDA allowed its use under some emergency rules.

 

[Aerides]

Interesting piece in business insider about the development of antibody testing:

New tests cold be available within "weeks" from a simple finger-prick test, results in minutes
CDC estimates up to 25% of cases are completely asymptomatic


https://www.businessinsider.com/why-we-need-coronavirus-antibody-test-identify-immune-people-2020-3

 

[Ready]

Interesting piece in business insider about the development of antibody testing:

New tests cold be available within "weeks" from a simple finger-prick test, results in minutes
CDC estimates up to 25% of cases are completely asymptomatic


https://www.businessinsider.com/why-we-need-coronavirus-antibody-test-identify-immune-people-2020-3

So if this all plays out as they say, it would appear that getting COVID-19 and recovering fully from it is basically like getting sprung from jail. You are free to do whatever your want since you can’t infect anyone nor get infected.

 

[NW-Bound]

Interesting piece in business insider about the development of antibody testing:

New tests cold be available within "weeks" from a simple finger-prick test, results in minutes
CDC estimates up to 25% of cases are completely asymptomatic


https://www.businessinsider.com/why-we-need-coronavirus-antibody-test-identify-immune-people-2020-3

From the above link:

Other US companies are already selling antibody tests abroad. The California biotech company Biomerica sells coronavirus antibody tests for less than $10 in Europe and the Middle East, while Chembio Diagnostics, a medical-device company based in New York, is sending its antibody tests to Brazil and plans to study them in the US, Reuters reported last week...

The American-made tests are exported, but not allowed to be used in the US? These tests are no good or what? Not FDA-approved?

I remember reading about the imported Korean test strips, and these were not FDA-approved either, but allowed to be used under certain provisions.

 

[tmm99]

Interesting piece in business insider about the development of antibody testing:

New tests cold be available within "weeks" from a simple finger-prick test, results in minutes
CDC estimates up to 25% of cases are completely asymptomatic


https://www.businessinsider.com/why-we-need-coronavirus-antibody-test-identify-immune-people-2020-3

Every time someone mentions about an antibody test, I've been asking which strain it's supposed to test, as there are at least two strains found by scientists that many scientists seem to agree with, but there may be even more strains. Nobody has given me any answers so far.

Does anybody know if this test is supposed to be able to detect different strains of COVID-19? I am not sure if anybody should go back to work if the person has only had one strain, but not the other strain... Or does having been infected by one strain make the person immune to the other strain?

 

[USGrant1962]

Every time someone mentions about an antibody test, I've been asking which strain it's supposed to test, as there are at least two strains found by scientists that many scientists seem to agree with, but there may be even more strains. Nobody has given me any answers so far.

Does anybody know if this test is supposed to be able to detect different strains of COVID-19? I am not sure if anybody should go back to work if the person has only had one strain, but not the other strain... Or does having been infected by one strain make the person immune to the other strain?

Everything I've seen about COVID-19 strains (and there a bunch) says they are not very different and don't behave any different. From what I can tell, the "different strains" meme is totally academic and not relevant to actual treatments or vaccines.

And antibody tests don't detect COVID-19, they detect the antibodies that your body generates to fight it.