Hacker News Reader

Comment by arenaninja | Hacker News Reader

Yep.. I saw a similar headline claiming LA infections are 55x the reported rate. I think the math is likely simpler, and the infection is somewhere between 3x-5x (10x tops). I've read a few reports saying about 50% of people are asymptomatic, 30% show symptoms that aren't bad enough for hospitalization and 20% require hospitalization. I can't find the source I got it from but I believe it was a Chinese study

View on HN

Based on several studies using different methods, the death rate (infection fatality rate, or IFR) is likely around 0.5%

So if you go back the average time from infection to death (2-3 weeks) you can get a sense what the ratio was in your area back then.

[1]: https://mothership.sg/2020/03/iceland-covid-19/ (I did the work on the side, extrapolated to about 0.2%-0.5%)

[2]: https://www.land.nrw/sites/default/files/asset/document/zwis... (Germany study, 0.37%, decent sampling method)

[3]: https://www.ncbi.nlm.nih.gov/pubmed/32234121 (Diamond princess ship, 0.5%)

[4]: https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v... (Santa Clara county study, 0.15% - 0.3% if you do the math). Methodological problems with the method of sampling that might increase the number of positives and the test specificity issues might increase false positives, but probably still in the ballpark

Dimond Princess had 14 deaths out of ~700 infected or a 2% fatality rate though that number has slowly climbed over time. As they tested everyone initially finding a large number of asymptotic cases that’s likely extremely accurate.

The difference is the population was more heathy than the general population, and while older on average, it had a lower percentage of people 95+ years old.

If anyone has good data on the asymptomatic proportion, I'd appreciate a link. I keep seeing 50% (or sometimes 'up to 50%'), but to the extent that I've looked at actual sources, it seems that people are conflating presymptomatic positive tests with lastingly asymptomatic infections.

This also came out today. http://publichealth.lacounty.gov/phcommon/public/media/media... We really have no idea what the IFR is, just that is probably in the .1% to 1% range. Also, it takes around 2 weeks to develop antibodies, so the tests are showing how many people had covid 2 weeks before testing.

That antibody timeline was an estimate derived from data obtained from the "original" SARS virus, but it isn't accurate with the SARS-CoV-2 virus. IgM antibodies are present within hours of the onset of symptoms, and IgG antibodies after a few days.

Source?

Sure, find any manufacturer of rapid antibody test kits and look at their documentation for a nice trailhead into plenty of literature about antibody response times with this virus.

Reply on news.ycombinator.com