Very early report on Delta, describing higher loads in oropharyngeal swabs: https://www.medrxiv.org/content/10.1101/2021.07.07.21260122v...
> I've seen documentation of higher nasal swab loads, but not higher systemic circulating virus.
You'll have almost no reports of "systemic circulating virus" load, because there's not really an accepted definition for how this measurement would be taken. Plasma concentrations don't appear to be particularly meaningful except in late stages of critical disease.
> higher waste water levels.
My understanding of the evidence is that fecal loads of Delta are higher than other variants, but not as elevated in comparison to how much throat and nose swabs are elevated. I.e. both statements appear true (higher loading overall, and even higher loading in upper respiratory tissue).
Wait, what? This seems completely at odds with the literal definition of viral load per https://en.wikipedia.org/wiki/Viral_load:
> Viral load, also known as viral burden, is a numerical expression of the quantity of virus in a given volume of fluid, including biological and environmental specimens.
Yes, in a specific fluid. Grandparent doesn't like viral load data coming from upper respiratory swabs-- preferring some kind of "higher systemic load" number.
Well, there's no magical "real systemic" load. You can measure it in the nose; you can measure it (sometimes) in the bloodstream (but this is sporadic and small even in severe cases, though it has prognostic value in critical care). You can measure it in feces, etc.
has it ? I've seen this claim made over and over, w/out documentation.
I've seen documentation of higher nasal swab loads, but not higher systemic circulating virus. Higher upper respiratory loads (e.g. mucosal) would also lead to increased transmissibility, but not higher waste water levels.