Right - the CDC stat most similar is that for every Covid positive person, there are 10 out there that have it (or had it) and haven’t been tested.
@somemom — the R0 for COVID-19 is estimated to be between 2 and 3 — meaning that in an unexposed population, with no one taking precautions, it is estimated that on average, each person spreads the disease to 2 or 3 other people. The current transmission rate, Rt, even in the worst-hit places in the US, is currently estimated to be below 2.
Asymptomatic people are believed to have relatively low amounts of virus and are thought to be less contagious than symptomatic patients. At least, this is what research that I have heard about has suggested to date. However, PREsymptomatic patients can be quite contagious.
I looked up the question of lung damage in asymptomatic patients and found a news article that suggested that. However, the original source that the article cited did not say that. It said that some people from the Diamond Princess had subclinical abnormalities on CT. Here is the link:
https://www.acpjournals.org/doi/10.7326/M20-3012
The abstract does not say when the scans were done, but the implication was that they were done at the time of diagnosis. I would assume that those mild abnormalities cleared up later, but if you have a source that says otherwise, please post it.
I think mask wearing is important as long as COVID-19 is circulating in the community. The goal is to get the transmission rate (Rt) below 1, and keep it there. That ensures that the number of cases in a given area will decrease. Masks are not fully protective. They are a tool, along with physical distancing, that helps to decrease the transmission rate in the community, which drives down case numbers. In my view, this is the most important reason why mask wearing is protective— if it helps to shift Rt below 1, then disease prevalence in the community becomes low, and that makes everyone safer.
Lung damage may not be noticed if your pre-existing lung capacity was greater than what you routinely use, and the damage only reduces the “excess” capacity somewhat.
But if your pre-existing lung capacity was just barely enough for what you routinely use, you are more likely to notice any damage.
This is not what I have read, either as to the amount of virus the asymptomatic people have, or as to how contagious they are.
I sit corrected. There was early information that asymptomatic people had detectable viral loads similar to symptomatic people, but that duration of viral shedding was very brief. However more recent information shows significant transmission.
@MaineLonghorn I cried through that episode as well. It was just so hard to watch. But then I cried through many scenes and episodes of Lenox Hill. I thought it was one of the best medical documentaries I’ve ever watched.
I wish that the people making decisions for our school district would have read the more recent articles, too!! I am trying to figure out how to bring the medical community (locally) into those discussions.
Well, kind of depends on the definition of “damage” somewhat. There are all sorts of “damage” that people sustain over a lifetime which is not really noticed or diagnosable except via testing that usually doesn’t get done unless and until there is a reason. A lot is cumulative – it doesn’t cause a problem, until it does. So it could very well be that an asymptomatic Covid infection causes some level of damage to the lungs. So does exposure to second-hand smoke. (From the CDC website: “Even brief secondhand smoke exposure can damage cells in ways that set the cancer process in motion.”)
I’m not saying that the asymptomatic Covid lung changes are the same as second-hand smoke exposure, just analogous.
Right, I get that. Just wondering where this speculation of damage in asymptomatic Covid victims is coming from. This early on, there is no way of knowing. Maybe I missed some study or something.
More speculation is that children are getting it, asymptomatically, and passing it around. Hopefully that’s not the case, and even if it is, hopefully it’s not causing them long term damage. What’s going on is scary enough for those getting really sick - plus now this speculation of long term damage in people who never even knew they were infected. It may be the case, or not.
@BunsenBurner thank you so much for posting that terrific article from the Seattle Times. I live in an area that is having a big spike and have been asking my high-risk spouse to put off going to the dentist for a routine cleaning until our numbers drop. That article finally convinced them to delay for a couple of weeks.
This is not new speculation. Some people who had asymptomatic COVID-19 on the Diamond Princess were found to have lung abnormalities by CT scan after recovery. However, this did not cause obvious functional issues (though it may have been that the people involved never routinely use their maximum lung capacity, so they would not notice even if their lung capacity is now reduced), and there does not appear to have been any longer term followup to see if there were permanent effects.
There are plenty of examples or anecdotes of people with symptomatic COVID-19 (particularly if severe enough to be hospitalized) who ended up with very reduced lung capacity (to the point of being winded walking around the house or some such). But there does not seem to be a lot of research indicating how common longer term damage or disability is, and whether it is permanent or slowly heals.
I wonder if he was extrapolating, not the R0, but the continued links of infections, I infect you, you infect her, etc? He was posting to some pretty resistant “hoax” people on a different forum. I agree, it’s either a typo/error/or means that one person is ultimately responsible for 10 infections?
In that case, someone may be responsible for 11 million (and counting) COVID-19 infections.
@ucbalumnus — do you have a link to a study or article about the asymptomatic Diamond Princess patients and persistent lung findings on imaging?
Here’s an article about asymptomatic Diamond Princess patients and lung findings.
“We revealed a high incidence of subclinical CT changes in COVID-19 infected cases…” “Subclinical CT changes” here means asymptomatic lung abnormalities. This paper does not document persistent changes, as the study was done shortly after the Diamond Princess docked.
My lay person’s impression is, this kind of lung abnormalities can be persistent. I can’t find any studies re-testing any of these people a month or two later.
https://pubs.rsna.org/doi/10.1148/ryct.2020200110
I had read that my husband is considered immunocompromised since his spleen was removed years ago. He asked our PCP about it, and she said the spleen helps fight BACTERIAL infections, not viral. So I guess he’s not as high risk if he contracts COVID-19 as I was afraid. Whew!
https://www.health.harvard.edu/blog/no-spleen-what-you-need-to-know-to-stay-healthy-2020042419641 has some information about the effects of not having a spleen. It mentions COVID-19, but mainly in that the effect is not really known for sure.
@“Cardinal Fang” - My clinical impression is the opposite. The type of abnormality seen with COVID, i.e. ground glass opacities, in this setting (i.e. infection) typically represents inflammatory change that most often resolves over time. (Just to be clear, for any of you personally reviewing your own CT reports, ground glass lung nodules are a different entity that has to be followed due to risk of lung cancer.)
It would be interesting to know what follow-up scans showed, but these, if done, would most likely be done at a minimum of 3 months after the first ones.
Thanks for the information from someone who knows something, @CIEE83 . If someone has ground glass opacities, how quickly would they be expected to go away?
Arizona COVID doc: Rapid reopening without mask mandate is catastrophic | Guest opinion
http://www.tucsonsentinel.com/opinion/report/062820_covid_doctor_op/arizona-covid-doc-rapid-reopening-without-mask-mandate-catastrophic/
Scary! Definitely not just like the flu.