Greater Seattle testing study yields less than 1% prevalence - Printable Version
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Greater Seattle testing study yields less than 1% prevalence - magnus - 04-17-2020
And decreasing
https://publichealthinsider.com/2020/04/17/greater-seattle-coronavirus-assessment-network-scan-releases-data-from-first-18-days-of-testing/
Test started March 23rd. Participants received swabs, self swabbed and sent them back in.
2/3 claimed to have covid like symptoms when applying, but less than 2% ended up testing positive.
More data to talk about. =)
RE: Greater Seattle testing study yields less than 1% prevalence - OutsiderFan - 04-18-2020
What does it all mean?
And how can the higher death rates in the Northeast, Michigan, and Louisiana, be reconciled with the lower death rates on the West Coast? I mean regardless of testing, CA’s death rate is 29th in the U.S.
- Do we understand the implications of reinfections?
- Does original infection destroy T-cells?
- If T-cells are destroyed, are they only in those who develop symptoms, or in everyone exposed?
- Will degree of symptoms with initial infection have any bearing on symptoms with reinfection?
- Can reinfected shed and transmit virus?
- if reinfected can shed and transmit, what does this tell us about vaccine viability?
- What determines who can effectively fight off the virus without symptoms and who can’t?
It seems the data demonstrates there are at least 10x more infections than confirmed cases. Is the population of infected but not confirmed where future confirmed cases mostly come from, or is there another population that develops symptoms and is more rapidly tested, where most new confirmed case growth comes? If the former, then there are a ton of new cases that are going to develop and continue pressuring health care capacity, regardless of NPIs. If the latter, we can assume NPIs are absolutely working to prevent infections in a very significant way.
There was a study of a Boston homeless living facility I saw cited. All 400 something staying there were tested and 36% were positive, all asymptomatic, though one later ended up in hospital. Did they all later test positive, or did some simply not get infected? If not, why not? And how many of the 36% later did or will develop symptoms?
RE: Greater Seattle testing study yields less than 1% prevalence - burger - 04-19-2020
(04-18-2020, 11:32 PM)OutsiderFan Wrote: It seems the data demonstrates there are at least 10x more infections than confirmed cases.
I want to focus on this for a second. I don't think this is correct. There are indications that this might be true in some places. But it would be a mistake to assume that 10x rule of thumb is a good estimate everywhere.
In places that have done very little testing, the multiplier is probably bigger than 10. In places that have done a lot of testing or where you have a lot of susceptible people which means that more people end up in the hospital (where they get tested), the multiplier might be lower.
10x is really just a very, very rough estimate, and the real number will differ from place to place.
RE: Greater Seattle testing study yields less than 1% prevalence - chrisk - 04-19-2020
The high death rates in New York have a lot to do with the fact that the virus got further out of control there before controls were implemented. They have higher proportions of vulnerable/elderly/minorities which were much more exposed and subsequently died.
Even in Santa Clara County, the Hispanic population is over represented in cases and deaths. San Jose has the highest rate of cases in the county. Palo Alto is 2nd in cases.
Cupertino, which is heavily Asian, has about 1/3 the rate of cases of Palo Akto.
RE: Greater Seattle testing study yields less than 1% prevalence - M T - 04-19-2020
(04-19-2020, 07:41 AM)chrisk Wrote: The high death rates in New York have a lot to do with the fact that the virus got further out of control there before controls were implemented. They have higher proportions of vulnerable/elderly/minorities which were much more exposed and subsequently died.
Even in Santa Clara County, the Hispanic population is over represented in cases and deaths. San Jose has the highest rate of cases in the county. Palo Alto is 2nd in cases.
Cupertino, which is heavily Asian, has about 1/3 the rate of cases of Palo Akto.
What does "minorities" have to do with it? Maybe "ethnic groups", because ethnic groups tend to be self associate, and tend to include (often family) units that share housing, which is a predominant mechanism of spread.
In Santa Clara County, the white, non-Hispanic population is about 20% above the Hispanic population, and the Asian population is 20% higher than the white, non-Hispanic.
(In NYC, the mixture of race/Hispanic is 32% White, non-Hispanic, 29% Hispanic, 24% Black/African-American, 14% Asian)
(You also say that "Hispanic population is over represented in cases." I don't see that SCC publishes a case count or percentage by ethnic group. Where are you getting that from?)
It is a zero sum situation. One or more ethnic group is under represented is equivalent to One or more ethnic group is over represented. How much each group is over/under represented can differ.
I've not seen anything yet that suggests one ethnic group is more/less susceptible to the disease, or to severe outcome or death, based on their genetics, after adjusting for known comorbidities. I would expect that some groups have fewer/more of the gender, age, or comorbidities that have been identified as associated with worse outcomes. I would also expect whether an ethnic group has a higher percentage of people in essential jobs may have an impact, but I couldn't begin to guess which groups do.
The Census Bureau demographic estimates for Santa Clara County in 2019, with today's listing of Covid-19 death rates.
Note that because we don't have case rates for the ethnic groups, you can't use the SCC death % to estimate a death rate per group, without making the assumption that each group is infected at a proportion related to their population proportion, or conversely, assume that the IFR rate is constant across each group and then calculate an infection rate.
| Group | SCC Pop % | SCC Covid-19 death %(n=73) |
| African American | 2.8% | 8.22% |
| Asian | 38.3% | 24.66% |
| Latino/Hispanic | 25.3% | 34.25% |
| Other | 2.6% | 1.57% |
| White | 31.0% | 31.51% |
RE: Greater Seattle testing study yields less than 1% prevalence - BostonCard - 04-19-2020
(04-18-2020, 11:32 PM)OutsiderFan Wrote: There was a study of a Boston homeless living facility I saw cited. All 400 something staying there were tested and 36% were positive, all asymptomatic, though one later ended up in hospital. Did they all later test positive, or did some simply not get infected? If not, why not? And how many of the 36% later did or will develop symptoms?
Here's the Boston homeless study:
https://www.medrxiv.org/content/10.1101/2020.04.12.20059618v1.full.pdf
The study excluded the 15 patients who were diagnosed with COVID-19 because they had symptoms. Out of 408 homeless people who were tested, 147 came back positive and 261 were negative. Interestingly there was no significant difference in the proportion who had symptomamtic. As others have mentioned, they didn't necessarily follow the patients who tested positive to determine whether they became symptomatic. So we don't know if these were presymptomatic cases or asymptomatic cases. Still, 10-fold more patients without symptoms than with symptoms is concerning.
BC