Covid-19 at a homeless shelter in Boston: Implications for universal testing • Hacker News Board

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#21

Post by credit_guy » Wed, Apr 15, 2020, 6:17 PM UTC

jcp2fa wrote: post #6

> Cough (7.5%), shortness of breath (1.4%), and fever (0.7%) were all uncommon among COVID-positive individuals It seems the more important point here is that the majority of the COVID-positive individuals were asymptomatic, putting another datapoint towards the conclusion that there are orders of magnitude more people that have this disease than have tested positive. We need more studies to gather data on these asym…

My bet is that it's much more than 10%. In NYC I think it's at least 20%-30% by now. Obviously, I don't have any more data than what you can find online, but anecdotally, I think one of my sons had it; he most likely got it from his piano teacher who exhibited all the Covid symptoms (fever, dry cough, loss of smell), but was never tested. I think at least myself and my wife got this from him as well; likely his two siblings, but they were completely asymptomatic. Our kids' nanny has Covid now (tested at the hospital), and her son too (he's in ICU). I have other anecdotes, and no, I don't have systematic data, but I believe at least 20%-30% of NYC has had Covid by now.

Another point of reference is this: according to [1], a back-of-the-envelope estimate of the number of Covid-infected is 100 times the number of dead. It's about 8000 now in NYC, so about 800k infected. That's about 10% of NYC's population, exactly the number you mentioned.

[1] https://www.solipsys.co.uk/new/BackOfTheEnvelopeCOVID19.html...

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#22

Post by moneywoes » Wed, Apr 15, 2020, 6:19 PM UTC

jcp2fa wrote: post #6

> Cough (7.5%), shortness of breath (1.4%), and fever (0.7%) were all uncommon among COVID-positive individuals It seems the more important point here is that the majority of the COVID-positive individuals were asymptomatic, putting another datapoint towards the conclusion that there are orders of magnitude more people that have this disease than have tested positive. We need more studies to gather data on these asym…

Do a lot of these asymptomatic people end up developing severe symptoms?

If so, what does that mean for herd immunity?

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#23

Post by gnulinux » Wed, Apr 15, 2020, 6:19 PM UTC

raphlinus wrote: post #18

gnulinux wrote: post #8

Earlier quoted context omitted.

It seems to indicate this disease infected a lot more than what we see, and maybe mortality rate is lower than what we currently assume. Maybe it's around 0.1% to 0.5%. So is it possible this disease appeared in China way before December, maybe a few months back. Then in December it reached a saturation point (i.e. infected hundreds of thousands of people, so deaths started to get noticed by respiratory specialists).…

No. We know from genomic analysis [1] that "The common ancestor of circulating viruses appears to have emerged in Wuhan, China, in late Nov or early Dec 2019." It's fun to speculate about other possibilities, but I personally like to stick to what the science tells us. [1]: https://twitter.com/nextstrain/status/1248707010750640128

Very interesting, thanks for the link. In that case, how should that change our mental model? It seems like more people in Western countries are infected than visible, doesn't that mean the same would apply to China? How would it spread so fast in December?

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#24

Post by sjg007 » Wed, Apr 15, 2020, 6:19 PM UTC

pm_me_ur_fullz wrote: post #9

easytiger wrote: post #5

Earlier quoted context omitted.

Yup. And for far longer.

I really don't understand why people immediately want to discredit the idea that US patient zero was not the first in US. Or that this virus was around earlier and that there are limitations in contact tracing capabilities. This seems to have the toughest aspect of gaining consensus. Need antibody tests now, and ones that work reliably.

Because it's not true.

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#25

Post by sjg007 » Wed, Apr 15, 2020, 6:20 PM UTC

gnulinux wrote: post #8

easytiger wrote: post #5

Earlier quoted context omitted.

Yup. And for far longer.

It seems to indicate this disease infected a lot more than what we see, and maybe mortality rate is lower than what we currently assume. Maybe it's around 0.1% to 0.5%. So is it possible this disease appeared in China way before December, maybe a few months back. Then in December it reached a saturation point (i.e. infected hundreds of thousands of people, so deaths started to get noticed by respiratory specialists).…

No.

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#26

Post by gnulinux » Wed, Apr 15, 2020, 6:20 PM UTC

Retric wrote: post #20

gnulinux wrote: post #8

Earlier quoted context omitted.

It seems to indicate this disease infected a lot more than what we see, and maybe mortality rate is lower than what we currently assume. Maybe it's around 0.1% to 0.5%. So is it possible this disease appeared in China way before December, maybe a few months back. Then in December it reached a saturation point (i.e. infected hundreds of thousands of people, so deaths started to get noticed by respiratory specialists).…

No for several reasons. The Dimond Princess had over 100 crew of young healthy adults test positive and only 25% where asymptotic long term. Additionally South Korea has a massive effort into contact traction which demonstrated just how rapidly the disease spread. Their mortality numbers looked to be about 0.6% early on, but eventually hit 2% a month after the peak with people spending weeks in critical condition. On…

When we say long term here, do we mean within the 14 day incubation period that's been going around? Or does this imply incubation period is likely a lot more than 14 days, maybe in the order of months?

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#27

Post by smallgovt » Wed, Apr 15, 2020, 6:22 PM UTC

zadkey wrote: post #2

(Regarding the Headline) Surely you mean 35% of homeless who were tested. We can't say for certain that the sample is an exact representation of the general population of the homeless in Boston. "Upon observing a cluster of COVID-19 cases from a single large homeless shelter in Boston, Boston Health Care for the Homeless Program conducted symptom assessments and polymerase chain reaction (PCR) testing for SARS-CoV-2…

> We can't say for certain that the sample is an exact representation of the general population.

I actually think we can say for certain this is NOT a good representation of the general population. The general population has not been living in close quarters with multiple COVID positive people.

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#28

Post by DenisM » Wed, Apr 15, 2020, 6:23 PM UTC

smallgovt wrote: post #17

jcp2fa wrote: post #6

> Cough (7.5%), shortness of breath (1.4%), and fever (0.7%) were all uncommon among COVID-positive individuals It seems the more important point here is that the majority of the COVID-positive individuals were asymptomatic, putting another datapoint towards the conclusion that there are orders of magnitude more people that have this disease than have tested positive. We need more studies to gather data on these asym…

> We need more studies to gather data on these asymptomatic cases if we want to reopen the economy soon. I don't understand what's so hard about measuring population infection rate. Assuming the population infection rate is between 1-10%, we would only need to do around ~500 randomized tests to achieve a 95% confidence interval of +/- 1%. For example, let's say we tested 500 random NYC residents for COVID and found t…

False positive rate of some antibody tests is 9%, which makes any effect size below that invisible.

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#29

Post by bgorman » Wed, Apr 15, 2020, 6:23 PM UTC

smallgovt wrote: post #17

jcp2fa wrote: post #6

> Cough (7.5%), shortness of breath (1.4%), and fever (0.7%) were all uncommon among COVID-positive individuals It seems the more important point here is that the majority of the COVID-positive individuals were asymptomatic, putting another datapoint towards the conclusion that there are orders of magnitude more people that have this disease than have tested positive. We need more studies to gather data on these asym…

> We need more studies to gather data on these asymptomatic cases if we want to reopen the economy soon. I don't understand what's so hard about measuring population infection rate. Assuming the population infection rate is between 1-10%, we would only need to do around ~500 randomized tests to achieve a 95% confidence interval of +/- 1%. For example, let's say we tested 500 random NYC residents for COVID and found t…

The thing you are missing is world governments want to milk this crisis, not act objectively. There is simply no other explanation.

Re: Covid-19 at a homeless shelter in Boston: Implications for universal testing

#30

Post by Retric » Wed, Apr 15, 2020, 6:23 PM UTC

gnulinux wrote: post #23

raphlinus wrote: post #18

Earlier quoted context omitted.

No. We know from genomic analysis [1] that "The common ancestor of circulating viruses appears to have emerged in Wuhan, China, in late Nov or early Dec 2019." It's fun to speculate about other possibilities, but I personally like to stick to what the science tells us. [1]: https://twitter.com/nextstrain/status/1248707010750640128

Very interesting, thanks for the link. In that case, how should that change our mental model? It seems like more people in Western countries are infected than visible, doesn't that mean the same would apply to China? How would it spread so fast in December?

US is generally not testing people with mild symptoms to significant symptoms. We are mostly telling people to stay home until you have difficulty breathing.

That’s why are deaths to cases ratio is so high before the new infection rate has dropped to near zero for weeks. Adjusting for infection vs death curve in China US deaths from people currently infected are likely to hit in the ballpark of 50k to 100k. Assuming we get new infections under control in the next few days and keep it low for the next month.