Big thank you to @EricCarroll for pointing out this new WHO document on SARS-CoV-2 transmission.
This document is pretty complex, in-depth, dense, and I still expect it to evolve as we learn along the way. They have some of the correct people to be working on this, for once. Hello Lidia Morawska signing off on it at the beginning of the forward.
First, a tldr. If you don't care about how it came to be, or the science, and just want to know the outcome, here it is:
https://partnersplatform.who.int/tools/aria
Go to the calculator, enter your data, and come out with a probability of infection in a given situation along with the number of expected secondary infections from that interaction.
Here's the document itself if you want to follow along:
https://iris.who.int/bitstream/handle/10665/376346/9789240090576-eng.pdf?sequence=1&isAllowed=y
Disclaimer - This is evolving science.
I'm going to split this up in a thread, because I took a lot of notes of what stood out to me on a first read, and I hope to come back to it, and use it as a general reference moving forward.
All of this leads us closer to where we're going, specifically, what the heck is my probability of infection and how did you decide to calculate it?
"Probability of infection
The interaction between the emission and the removal rates provides the infectious particles’ concentration, which, multiplied by the exposure time, enables estimation of the cumulative absorbed dose for a given scenario. The probability of infection is then appraised considering the host-pathogen interaction which includes the dose-response model, the specific SARS- CoV-2 variant considered, the host immunity and the sum of the short- and the long-range risk.
…
Multiple studies evaluated the percentage of asymptomatic SARS-CoV02 infections with results ranging from 1.4% to 78.3% [139]. For the above reason, the model aims to assess the risk of infection defined as the host probability to infection, proxy by seroconversion regardless of symptom onset."
Aha, asymptomatic infections. One of those variable that the COVID cautious drive ourselves crazy over. Just thought it was interesting. As I've long said, a big range, and also more common than you'd suspect.
