Hacker News new | ask | show | jobs
by onlyrealcuzzo 1671 days ago
> the 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.

Can anyone ELI5 how this is working?

If the Covid #s SA is reporting are accurate, the entire country is only at around ~2.5k cases per day.

Since Delta has an R0 between 6-7, for this to be outcompeting it so substantially, it would need to have an R0 of 8-9 (if not higher) -- at which point it would be almost as contagious as Measles. For it to be this contagious, wouldn't there already HAVE to be ~10k+ cases per day in SA?

The original Covid had an incubation period of 5.4 days. Delta dropped to 4.

If this has been around for weeks, with an incubation period of 4 days, shouldn't this have already infected close to ~100k people? And shouldn't there be 10s of thousands of infections per day?

To be fair, the growth rate South Africa IS reporting is 10x in 4 days. If that trend continues for even three weeks, then it would infect the entire country...

Does anyone know how reliable South Africa's #s are?

1 comments

> Does anyone know how reliable South Africa's #s are?

This is what I was going to comment on as I was reading your post but glad you brought it up here at the end.

I would have a difficult time believing the COVID numbers in South Africa are being reported reliably (regardless of the reason).

SPECULATION:

I'd love to know more if this is incorrect but I think even in countries like the United States, or Denmark, or Germany, or wherever the numbers are likely to be undercounted based on people just getting sick and not doing anything about it. My intuition is that numbers in countries like South Korea, Singapore, and perhaps Israel are more likely to be closer to the "ground truth". Other countries in Asia I have less confidence in (Japan and China). We probably need to develop and deploy more rapid at-home testing.

There's always going to be some undercounting, as in any country, but in terms of being able to test enough cases and be consistent over time South Africa's numbers are reliable.

During earlier waves the testing infrastructure has detected orders of magnitude more cases, and the current lull in cases is following what epidemiologists predicted and expected before a fourth wave in December/January.

I think it is almost certain that China has successfully controlled the virus up til now.
I’d say sure it’s under control, I question the infection numbers and deaths. Then again maybe they’re posting the real numbers because they’re so good. But I’m not sure I buy that.
I think if infection numbers were wildly off we would be able to see it in antibody tests of people coming from China.

Given that tons of people were wearing masks even prior to the pandemic, I don't find it that ridiculous.

Sure. I think with China and COVID-19 so far my stance is guilty until proven innocent. Not really getting a lot of antibody testing done from people who don't travel or who have died. The CCP is inherently incentivized to fake numbers, underreport (this is a China-wide problem and you can see it manifest in the debt crises unfolding there), and downplay any problems so that the CCP looks strong.

And this has nothing to do with being pro or anti-China. I think it's just an obvious recognition of incentives and current state.