Formula for successful Covid-19 infection.

[Ronni]

This article is amazing. It's been doing the rounds so you may have already seen it. Written by Erin S. Bromage, Ph.D., Associate Professor of Biology at the University of Massachusetts Dartmouth, where he teaches courses in Immunology and Infectious disease, including a course this semester on the Ecology of Infectious Disease which focused on the emerging SARS-CoV2 outbreak in China.

It’s well written, easy to understand, and very informative. I hope you read the whole thing. But right now I’m excerpting from it to focus on this formula.

SUCCESSFUL COVID-19 INFECTION = EXPOSURE TO VIRUS X TIME.

That’s the formula for those of you who, like me, need schematics and charts and formulas to be able to understand this threat without losing my damn mind!!!

Here’s the breakdown: In order to get infected you need to get exposed to an INFECTIOUS DOSE of the virus. You can either receive that infectious dose in one load (a carrier coughs into your face or you rub your eyes with the virus load on your hands) OR you can be exposed to smaller amounts of the virus, but over an extended period of time. Grocery store people, hospital workers etc. (And there are combinations of factors too, but in the interests of simplicity, I’m making this black/white.)

Infectious dose studies with SARS and MERS estimate that as few as 1000 viral particles are needed for an infection to take hold. While further study is needed for more exactness, we can still use that number to demonstrate how infection can occur.
—EITHER 1000 viral particles you receive in one breath or an eye-rub,
—OR 100 viral particles inhaled with each breath over 10 breaths
—OR 10 viral particles inhaled with 100 breaths.

So, consider the volume of the air space you’re in (enclosed office area vs out in your backyard) the number of people (church gathering or party vs random people in store or park) time spent in the environment you’re in (grocery store vs all day at the office)
Here’s an example…..all those factors, taken together, for a person shopping: the low density, high air volume of the store, along with the restricted time you spend in the store, means that the opportunity to receive an infectious dose is low. But, for the store worker, the extended time they spend in the store provides a greater opportunity to receive the infectious dose and therefore the job becomes more risky.

Here’s another example. You’re going to go to granddaughter's baby shower with other guests. Volume of the space (living room and kitchen area of house so not large) plus the number of people in that space (20-30) plus how long you’re going to spend at the shower (2 - 3 hours.) All those factors taken together....as a guest, the enclosed space of your friend’s home along with the number of hours spent with 20 - 30 other people means that the opportunity for you to receive an infectious dose is pretty high, much higher than your trip to the grocery store. Higher still if you substitute your friends house for your enclosed work space, and that 2 or 3 hours for an 8 hour day.

We need to asses our environments and make judgments. How many people are there, how much airflow around you, how long will you be in the environment. Remember, it’s a combination of viral dose plus time in order for you to become infected. The more people = the greater potential for viral dose. The greater potential for viral dose, plus a longer amount of time spent with those people = higher potential for infection.

Here's the full article with lots more valuable info.

 

[MarciKS]

Ronni I put myself at risk each and every day when I choose to go to work to help take care of all our front liners including our own dept staff. I have to work. I am not able to stay home away from everyone. I wish I could. I'm at greater risk because of health issues and age. It is difficult to get those around you to understand the danger they're putting you in by being too close, not covering a cough or wearing a mask. They don't seem to get it. Just this evening on the way home from work I saw 4 people talking at close range with no masks.

I don't think people think this can happen to them. I can not always be 6ft. away from those I work with. It's literally impossible. But, 6ft isn't going to do anyone any good when this stuff can travel up to at least 12ft. Even a small cough can go 3ft. And my co-workers sit at a table for 8 in close to each other and directly across from each other. I shudder as I walk by them and sit down at another table. The whole time I'm eating I'm wondering if the room is filled with all of our breath and moving around and we're exposing each other there. One of the docs in a video I watched claimed that eating at the same table as an infected loved one was ok.

I just don't see it. If we're supposed to distance...why would that be acceptable you know?

All I can do is go to work and do my job serving people through nourishment and pray I don't get it. Luckily the co-workers have been somewhat respectable about my distancing. Some just laugh and sit down with me so I pick up my stuff and go to another table. I'm not shy about it.
They of course smart off but, I just ignore it. I spend all day concentrating on where my hands have been, have I washed them, do I need to wash them before, during or after a task, and keeping an eye on the location of co-workers plus trying to do my job in a mask 8 hrs a day.

This is a very high stress situation for all of us except the ones that don't take it seriously. I figure if I gotta go in and get gas and nobody is masked up and they wanna stare...let em.

You just worry about taking care of you. If the people in your life can't accept that...it's their problem.

 

[terry123]

When I have more time I will read and then check out with Snopes to verify. I have been sent so many articles like this and when verified with Snopes they have been fake. That is why I will not post anything like this without checking out first.

 

[CarolfromTX]

Well, if that's the case, then sooner or later, we'll all be infected. Unless of course, we never leave the house again, which seems to be the goal of this article.

 

[Ronni]

When I have more time I will read and then check out with Snopes to verify. I have been sent so many articles like this and when verified with Snopes they have been fake. That is why I will not post anything like this without checking out first.

I completely understand. I researched this information extensively on Snopes and FactCheck, and found nothing. I extensively research everything before I post it. I abhor the propagation of misinformation so I do my very best not to be part of that problem.

Here is a further link to the author's credentials: He is definitely legitimate.

Professor Bromage's credentials

Faculty information

 

[Ronni]

Well, if that's the case, then sooner or later, we'll all be infected. Unless of course, we never leave the house again, which seems to be the goal of this article.

No.

If that's your conclusion then you either didn't read the article, or you misunderstood its information.

 

[CarolfromTX]

Well, that's the conclusion I came to. You came to a different conclusion. Doesn't mean I'm wrong. You have clearly appointed yourself as an expert on the virus. People are not going to stay in forever. They're just not.

 

[Ronni]

Well, that's the conclusion I came to. You came to a different conclusion. Doesn't mean I'm wrong. You have clearly appointed yourself as an expert on the virus. People are not going to stay in forever. They're just not.

God no I'm no expert! I wish I were, then I might feel a bit better about this whole situation, instead of the constant low level hum of anxiety I deal with all day long.

I didn't mean to be rude. I'm sorry. I just can't figure out how you came to the conclusion you did from the information in the article. And I agree completely, folks are NOT going to stay in forever. Well, probably some will, but even as frightened as I am with all this, I know that I won't be one of them. I mean, I'm gonna take all kinds of precautions, but I won't live the rest of my life as a hermit.

 

[garyt1957]

I didn't read the article so maybe somebody who did can answer this, so if as it says a viral load of 1000 gets you infected, either all at once or 100 small exposures of 10 to equal the 1000 gets you infected. In what period of time do those small doses of 10 have to be? In other words an hour? 8 hours? a day? a week? How long do those small doses last in your body?

 

[CarolfromTX]

Well, according to the article, you an either get the virus in one big blast or by exposure over a long period of time. That last bit implies that the more you go out, the more likely you are to come down with it. So it makes it sound inevitable, unless you isolate yourself completely. We are being bombarded by news of this virus 24/7, from every news outlet and hundreds of so-called experts with conflicting information. It's absolutely manipulative. The cynic in me wonders if some of these experts have a hidden agenda.

 

[Ronni]

I didn't read the article so maybe somebody who did can answer this, so if as it says a viral load of 1000 gets you infected, either all at once or 100 small exposures of 10 to equal the 1000 gets you infected. In what period of time do those small doses of 10 have to be? In other words an hour? 8 hours? a day? a week? How long do those small doses last in your body?

I've been researching that very thing @garyt1957

The answer to that is a more complex science involving viral load and how long the virus stays active inside a human body. The article talks about number of viral particles per x amount of breaths, but the time factor is missing. To expand on your question, over what time frame are viral-particle-inhaled breaths occurring? If I pass the same infected jogger every day and inhale 20 virus copies each time I pass him, will those copies accumulate in my system over a week or two or three, ultimately resulting in enough viral load that I become infected?

There's also the factor of immune system response. If you have a compromised immune system, your body will take a longer time to fight off any viral particles you inhale. If you have a relatively healthy immune system, your body fights off the viral particles faster/more effectively. So it makes sense that the period of time that the viral particles can survive in a person's body will vary. That variance will affect the period of time that the infectious dose can accumulate.

A stronger immune system will change the outcome. Keep in mind though that as we age, our immune systems just overall become less strong. The reduced production of B and T cells in our bone marrow and also decreased lymphocyte function (I think that's the right word) means that our senior immune systems don't respond as robustly as a younger one. That's why there's a higher percentage of older folks who are otherwise healthy, die from the virus than their younger counterparts. So, you not only have to factor in health issues in individuals of any age, you have to allow for weaker immune systems in the elderly.

Like I said, complex science. Beyond my understanding or ability to extrapolate any more than I already have, so I'll just keep researching.

 

[MarciKS]

Ronni I don't have the information to back this up so I hope it won't upset you. I believe in the very beginning when this whole thing started, I thought I recalled reading in the Washington Post that infection was possible if you were in an area with an infected person for 10 min or more.

 

[Ronni]

Well, according to the article, you an either get the virus in one big blast or by exposure over a long period of time. That last bit implies that the more you go out, the more likely you are to come down with it. So it makes it sound inevitable, unless you isolate yourself completely. We are being bombarded by news of this virus 24/7, from every news outlet and hundreds of so-called experts with conflicting information. It's absolutely manipulative. The cynic in me wonders if some of these experts have a hidden agenda.

Ooooh. @CarolfromTX I see where you're going now!!! Doh, my bad!

OK. What I'm currently researching is the TIME factor. Not just amount of time exposed, but also how long those viral particles live in the body, which would contribute to your ultimate viral load. The virus, if there isn't enough of it in a body to actually infect someone, has to degrade over time and be expelled, just like any other foreign or toxic substance would. I just don't know how long that takes.

 

[Ronni]

Ronni I don't have the information to back this up so I hope it won't upset you. I believe in the very beginning when this whole thing started, I thought I recalled reading in the Washington Post that infection was possible if you were in an area with an infected person for 10 min or more.

Based on what I've read and a lot of what has been discussed or referenced here, there's simply not enough information in what you've stated to draw a conclusion. How close are you to the infected person? What size is the space you're in? Are you masked? Is he/she? Did you come into contact with any other infected person during that time? So many variables that it's just not possible to draw a conclusion.

 

[garyt1957]

Without a general time limit of how long a viral load can last in the body the knowledge that smaller "doses" of virus can eventually infect us is pretty useless. Hopefully it can't sit in your body for weeks or even days waiting for more of it's brethren to join it so it can infect you. That would be very bad for working people who might be exposed to small loads daily. I would think, but of course have no real idea, that it wouldn't be much different then when the virus gets on surfaces, it would only last awhile before dying. Although that can be days on some surfaces. But hopefully our immune systems would kill it off faster. Or would our immune systems even react to such a small load that isn't even infecting us? So many questions.

 

[Ronni]

Without a general time limit of how long a viral load can last in the body the knowledge that smaller "doses" of virus can eventually infect us is pretty useless. Hopefully it can't sit in your body for weeks or even days waiting for more of it's brethren to join it so it can infect you. That would be very bad for working people who might be exposed to small loads daily. I would think, but of course have no real idea, that it wouldn't be much different then when the virus gets on surfaces, it would only last awhile before dying. Although that can be days on some surfaces. But hopefully our immune systems would kill it off faster. Or would our immune systems even react to such a small load that isn't even infecting us? So many questions.

Yeah. Way too many questions and not enough answers. People get so angry that "they" can't give us answers, that the information is always changing, that the guidelines are different now than they were, that we don't know how long this is going to go on etc. But really? This is not simple science, as just the conversation about this one things shows. It's so nuanced and multi layered and many faceted, it's no wonder that our Doctors and Scientists and Experts are still looking for answers. And will be for some time to come I would imagine.

 

[Sunny]

I looked for it in Snopes and didn't find anything either. That proves nothing, of course. Snopes does not study every article that is ever written on every subject; imagine how impossible that would be. I think they concentrate on heavily circulated facts and rumors.

Since this thing started, I have wondered if a single virus making its way into my body (from whatever source, who knows?) could give me the disease. This article was pretty reassuring on that score. It sounds like you do have to get a certain number of viruses at one time, like having someone sneeze very near you, or a small amount continuously drifting over to you over a period of time. So I do feel slightly better on that score, providing it's true.

 

[Ronni]

I looked for it in Snopes and didn't find anything either. That proves nothing, of course. Snopes does not study every article that is ever written on every subject; imagine how impossible that would be. I think they concentrate on heavily circulated facts and rumors.

Since this thing started, I have wondered if a single virus making its way into my body (from whatever source, who knows?) could give me the disease. This article was pretty reassuring on that score. It sounds like you do have to get a certain number of viruses at one time, like having someone sneeze very near you, or a small amount continuously drifting over to you over a period of time. So I do feel slightly better on that score, providing it's true.

@Sunny for whatever it’s worth, I did a couple hours more research on how viruses work, just generally, the validity of viral load etc. That whole aspect of science was studied for many years as a result of AIDS and HIV, and the ultimate conclusions became an integral part of the reduction of mortality and management of that disease.

The article is based on a foundation of solid science from everything I’ve read, so I found it pretty reassuring.

 

[Lethe200]

A friend forwarded me a copy to that article the other day. I agree, it's an outstanding explanation of how the virus works, and why social distancing and masks make a difference.

In a discussion on Quora recently, one person made a very good point about the lockdowns. He said people, especially media, are not understanding the important point. It's not about the # of deaths, it's about the number of hospitalizations.

The lockdowns are to cut down on the #s of people needing admittance, because no matter where you live, rural or urban, there are a limited number of beds and staff.

What you don't want to do is overwhelm your facilities and first line responders, because that causes the #s to go up even faster.

 

[MarciKS]

Based on what I've read and a lot of what has been discussed or referenced here, there's simply not enough information in what you've stated to draw a conclusion. How close are you to the infected person? What size is the space you're in? Are you masked? Is he/she? Did you come into contact with any other infected person during that time? So many variables that it's just not possible to draw a conclusion.

I was simply trying to give you a starting point for your search is all.