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Comment by wpietri | Hacker News Reader

Down toward the bottom they have a link to 5 indicators that they will be using to evaluate progress: https://www.sccgov.org/sites/covid19/Pages/bay-area-health-o...

I like that they have clear numerical targets for all of them.

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Yeah, this seems to be about the right direction. California as a whole (I don't have access to Bay Area data specifically) is clearly at a relatively stable peak, but the new infection rate hasn't dropped much and there's comparatively little room for error.

Other states are looking better[1]. Vermont, Alaska, Montana and Hawaii are all well below their peak infection rates and still dropping. Those are the places that should start relaxing rules earlier.

[1] Some are looking much worse, of course. Watch Nebraska in particular: their new infection rate has been growing at close to 10% per day for almost three weeks, and at that rate they'll be at a New York scale outbreak in just two more. I haven't seen any coverage of what's going on there (i.e. whether it's a specific local outbreak like the Smithfield one in SD).

Vermont and Montana are sparse states so not surprising. Hawaii - that is interesting. Are those numbers accurate?

People give too much weight to overall sparsity/density, discounting how much human behavior has a role in creating personal density even in seemingly sparse areas. You can see massive infections in very sparse rural areas so long as people are congregating and not taking precautions. That seems to be what's happening in Nebraska.

Behavior matters more. Here in Manhattan we're past the peak solely because of changes in behavior. It doesn't matter how sense the built environment is when most people are barely leaving their homes.

New arrivals including domestic flights to Hawaii are being subject to heavy quarantine with follow-up, requirements of full documentation of where you will be staying, etc.

https://hidot.hawaii.gov/blog/2020/04/24/improved-verificati...

They do not have the hospital capacity for this getting out of control.

No one has the hospital capacity for COVID19 getting out of control. That's the fundamental reason for the quarantines everywhere.

Preaching to the choir. I guess what I mean is that as a small island state far from anywhere else, if it gets bad, it gets _much worse_ than on the mainland.

Bay Area has dropped significantly: https://covid-19.direct/metro/BayArea

Santa Clara has dropped even more significantly: https://covid-19.direct/county/CA/Santa%20Clara. It's at 10 cases/day/million now (3% test positive rate), below even Germany who is opening schools.

Vermont had it's first day today in 7 weeks with 0 new cases:

https://vtdigger.org/2020/04/29/vermont-reports-zero-new-cas...

Interesting metrics.

Indicator 1 (cases) and 2 (hospitalization) are clearly met.

Indicator 3 (test capacity) has a very aggressive target. 200 tests a day per 100k? Why must it be this high? (Germany by comparison, opening schools now, is at 80 per 100k). Santa Clara County is already at a 3% positive rate week to date (Korea level during their Feb epidemic)

Indicator 4 (case investigation) status is not disclosed but I would guess is met or close to met in Santa Clara county given how steep the drop-off has been in cases and confirmation by other counties (Contra Costa). Of course, it gets harder to contact trace as you ease restrictions.

Indicator 5 is a bit fuzzy - supply under what hospitalization assumptions?

Interestingly, LA county is nearly at that target. The public health system (excluding internal test capabilities at hospitals etc) can do 16K tests/ day for a population of 10 million. So about 160 tests a day/ 100 K.

The Bay Area counties included here are all pretty dense, so it makes sense that they'd want to have more test coverage per capita than a full country might need.

3) might be linked to cases per million and relative growth rates. Germany has roughly 400 active cases per million, California has about 1,000, and I wouldn’t be surprised if the Bay Area is well above CA as a whole given its density.

Bay Area is well below CA as a whole. Cases have grown by ~375/million in last 14 days to proxy for "active" cases. Santa Clara County's growth is only ~235/million

If it can give you a comparison point, France wants to be able to do 700k tests per week in less than 2 weeks time to have test and trace capability and start lifting the lockdown. That comes out to approximately 150 tests a day per 100k. The following reason was given.

The models predict 1000-3000 new cases a day around the time lockdown would be lifted. Each new case will imply 20-25 other persons in contact in the preceding days. 3000 x 25 = 75k tests per day, ie ~115 per day per 100k. Going to 150 allow an extra margin to also set up testing campaigns in sensitive places, eg nursing homes.

I suspect 5 isn't fuzzy in practice. My guess is that they delegate the details to each hospital, which will have very detailed notions of what they need. Especially given that their supply people will have been sweating this question for the last six weeks.

Regarding #4, with the ubiquity of call blocking, I don't see how it is possible for them to reach 90% of the people that may have been exposed, especially once people find out that picking up that phone call means you will be in quarantine. To make matters worse, the authorities likely won't be able to tell you where/when you were exposed and to whom (medical privacy). This target is basically unreachable IMHO.

A round number repeated for 4 metrics in a row is never really meant to be taken seriously. If it turns out that they can only reach 80% of contacts, they'll adjust the plan to account for that - nobody's going to let it be the one factor that keeps restrictions from being loosened.

I guess this is another reason something should have been done about the spam calls. Who answers the phone now for an unknown number?

> Indicator 3 (test capacity) has a very aggressive target. 200 tests a day per 100k? Why must it be this high? (Germany by comparison, opening schools now, is at 80 per 100k). Santa Clara County is already at a 3% positive rate week to date (Korea level during their Feb epidemic)

To actually be able to control the outbreak while people are out and about you need to be able to test lots of people whenever a new case is discovered to see if they actually passed it on to anyone. Each new case will trigger many cases especially if they're showing up sick at the hospital/doctor which means they've potentially been spreading the disease for 2 weeks.

3% week to date might change (in either direction). SCC reports tests by date of specimen collection, so the last 2 days are definitely not complete data, and a significant portion of the last 5 days are not either.

Thanks for highlighting that link.

I also like that there are numerical targets for these indicators. It's also great that the entire Bay Area is coordinating a regional response. What I'd like to see is some alignment at the state level, as well, but it doesn't look like the state has actually published specific benchmarks yet.

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