[whimsicalism]

> biggest piece of worrying evidence is that it's growing as a proportion of cases in south africa at such an intensely fast rate that it's outcompeting the delta variant as though it isn't even there, which means it's far more transmissible than any other variant.

OTOH - cases in SA were very low, so we would see this sort of growth of a variant very quickly just due to founder effects without anything nefarious going on.

Delta arrived when the background number of cases was much higher so it took longer to become a high proportion of cases.

[baq]

cases in SA are low because the testing infrastructure there has been complete garbage. real numbers are unknown.

[_djo_]

That's objectively false, seeing as though the test infrastructure has been able to detect hundreds of thousands more cases during the country's waves. If your claim was accurate, South Africa's case rate would have plateaued at a level and just stayed there.

Sure, the testing infrastructure is not as good as in a developed country, but it has many orders of magnitude more capacity than the current case rate.

[dredmorbius]

If testing is limited but effectively randomly sampling, then measured incidence will be proportionate to actual incidence.

If testing is targeted toward regions of higher interest and likelihood, then test positivity should skyrocket out of proportion to actual positives. (I'm not sure what the case is for South Africa.)

Using deaths as a lagging indicator of cases, South Africa reports about a 3% CFR (based on reported cases and deaths), as opposed to about 2% for the US. This would suggest a somewhat lower testing prevalence in ZA, by about a third, but not an especially bad record. This does assume that Covid deaths are being accurately assessed and reported. Total excess mortality is the usual check for that.

My read is that ZA's testing infrastructure is reasonably good, and that the B.1.1.539 variant's growth is extraordinary.

I'm relying on Worldometers data:

https://www.worldometers.info/coronavirus/country/south-afri...

https://www.worldometers.info/coronavirus/country/us/

[whimsicalism]

But have they become relatively more garbage in recent weeks? If not, then the relative number of cases is much lower.