Coronavirus

[AlanSubie4Life]

More info in the release for anyone interested (I haven't reviewed in detail yet).

Maybe you should have?:

"The researchers used a rapid antibody test for the study. The FDA allows such tests for public health surveillance to gain greater clarity on actual infection rates. The test's accuracy was further assessed at a lab at Stanford University, using blood samples that were positive and negative for COVID-19.

In addition to Sood and Simon, other authors and institutions contributing to the study include Peggy Ebner of the Keck School; Daniel Eichner of the Sports Medicine Research & Testing Laboratory; Jeffrey Reynolds of LRW Group; Eran Bendavid and Jay Bhattacharya of Stanford University School of Medicine."

I'm going to assume they are using the same statistical "methods" they used from their last study in Santa Clara, until shown otherwise (I don't see their paper - why not provide the link in the press release?). Which means we should probably view their multiplier as a modest overestimate, until the analysis is complete and the specificity of the test is properly understood. A modest overestimate would likely put things in line with what we assume the prevalence to be.

Apparently these guys are undeterred by last week's fiasco. Maybe this time they confirmed the positives with ELISA testing?

 

[Norbert]

It also creates suspicion if a press release suggesting policy changes comes ahead of the scientific details of the study.

 

[TheTalkingMule]

Clear evidence at least 5% of LA County has already been exposed/infected.

Do we have a plan? What are the goals? How are we measuring progress?

 

[AlanSubie4Life]

Clear evidence at least 5% of LA County has already been exposed/infected.

WTF?

 

[AlanSubie4Life]

Do we have a plan? What are the goals? How are we measuring progress?

No there is no plan.

The goal should be to get positive daily cases down to 1 per million, and in parallel ramp up testing, tracing, hire public health workers to help trace, build up support structure for quarantine and isolation and support for people in quarantine/isolation, build up PPE stocks and hospital surge capacity, continue to fortify protections for vulnerable populations (nursing homes!). Etc. The appropriate steps are relatively obvious and have been widely covered in detail by experts in public health.

Then when we get down to that 1 case per MM per day, start phased re-opening with all of the countermeasures in place, and monitor results and keep driving case numbers down.

 

[Norbert]

I think these studies do prove one thing: that we need more testing.

 

[Daniel in SD]

LA County of Public Health and USC have issued a press release on the first round of antibody studies conducted by USC in Los Angeles.

Here is a summary of results:

"Based on results of the first round of testing, the research team estimates that approximately 4.1% of the county's adult population has antibody to the virus. Adjusting this estimate for statistical margin of error implies about 2.8% to 5.6% of the county's adult population has antibody to the virus- which translates to approximately 221,000 to 442,000 adults in the county who have had the infection. That estimate is 28 to 55 times higher than the 7,994 confirmed cases of COVID-19 reported to the county by the time of the study in early April. The number of COVID-related deaths in the county has now surpassed 600.​

"We haven't known the true extent of COVID-19 infections in our community because we have only tested people with symptoms, and the availability of tests has been limited," said lead investigator Neeraj Sood, a USC professor of public policy at USC Price School for Public Policy and senior fellow at USC Schaeffer Center for Health Policy and Economics. "The estimates also suggest that we might have to recalibrate disease prediction models and rethink public health strategies." Press Release:USC-LA County Study: Early Results of Antibody Testing Suggest Number of COVID-19 Infections Far Exceeds Number of Confirmed Cases in Los Angeles County
​

More info in the release for anyone interested (I haven't reviewed in detail yet).

I will fully admit that I am extremely biased and not just because you posted it, Jay Bhattacharya seems to be involved.
They used the same rapid test as the Stanford study and they don't seem to say if the 4.1% is the raw test results or an "adjusted" number.
I guess we'll see, hopefully it's way less deadly than previously thought!

 

[AlanSubie4Life]

https://t.co/ku0Z8S64DO?amp=1
Ohio prison antibody

What indicates these are antibody tests? From context it looks like RT-PCR. Sorry if I am missing something.

 

[Daniel in SD]

What indicates these are antibody tests? From context it looks like RT-PCR. Sorry if I am missing something.

They are PCR. 73% of one prison infected. So I guess we can say that the sensitivity of a properly administered PCR test is greater than 73%? I gather that false negatives with PCR tests are due to poor sample collection.
I wonder what the quarantine procedures were at the prison over the last month? 73% is crazy.
73% Of Inmates At An Ohio Prison Test Positive For Coronavirus

 

[jerry33]

They are PCR. 73% of one prison infected. So I guess we can say that the sensitivity of a properly administered PCR test is greater than 73%? I gather that false negatives with PCR tests are due to poor sample collection.
I wonder what the quarantine procedures were at the prison over the last month? 73% is crazy.

At a for-profit prison. There wouldn't be any.

 

[EVNow]

Total COVID-19 Mortality in Italy: Excess Mortality and Age Dependence through Time-Series Analysis : COVID19

We estimate that the number of COVID-19 deaths in Italy is 47,000 +/- 2000 as of April 11 2020, more than a factor of 2 higher than the official number.

We estimate that the Population Fatality Rate (PFR), defined as the ratio of COVID-19 related deaths to the total population.

It has reached 0.2% in the most affected region of Lombardia as of April 11, and 0.4% in the most affected province of Bergamo, which is also a lower bound to the Infection Fatality Rate (IFR).
​

Note that NYC PFR is now about 0.18%.

 

[EVNow]

One of the most pessimistic takes I've read on Covid in India.

'Herd Immunity Is the Only Lasting Solution to the Coronavirus', Says Leading Epidemiologist

The initial 21 days lockdown was extended by 19 more days. Doesn't seem to have helped all that much. This could also mean the heat & humidity is not going to save rest of the northern hemisphere either.

 

[TheTalkingMule]

Note that NYC PFR is now about 0.18%.

Isn't NYC 10,344 / 8,700,000 or .119%?

 

[Doggydogworld]

Maybe you should have?:

"The researchers used a rapid antibody test for the study. The FDA allows such tests for public health surveillance to gain greater clarity on actual infection rates. The test's accuracy was further assessed at a lab at Stanford University, using blood samples that were positive and negative for COVID-19.

In addition to Sood and Simon, other authors and institutions contributing to the study include Peggy Ebner of the Keck School; Daniel Eichner of the Sports Medicine Research & Testing Laboratory; Jeffrey Reynolds of LRW Group; Eran Bendavid and Jay Bhattacharya of Stanford University School of Medicine."

I'm going to assume they are using the same statistical "methods" they used from their last study in Santa Clara, until shown otherwise (I don't see their paper - why not provide the link in the press release?). Which means we should probably view their multiplier as a modest overestimate, until the analysis is complete and the specificity of the test is properly understood. A modest overestimate would likely put things in line with what we assume the prevalence to be.

Apparently these guys are undeterred by last week's fiasco. Maybe this time they confirmed the positives with ELISA testing?

Lead researcher is Nareej Sood, who was listed as a co-author on the Stanford paper. He's written other papers with Bhattacharya, e.g. "Does Health Insurance Make You Fat?", but I don't know if he shares Bhattacharya's absurd 0.01% IFR belief.

This study used the same test as Stanford. They say they used a consumer research database from LCW to get a random sample of ~1000 people. That sounds a lot better than running ads on Facebook, but we have no details. No raw results in the press release, just their estimates which I assume include "adjustments".

 

[Darkfox021]

Isn't NYC 10,344 / 8,700,000 or .119%?

I've got 12,712 deaths with a population of 8.4 million, but my deaths are a day or two outdated.

PFR of .15%

 

[bkp_duke]

LA County of Public Health and USC have issued a press release on the first round of antibody studies conducted by USC in Los Angeles.

Here is a summary of results:

"Based on results of the first round of testing, the research team estimates that approximately 4.1% of the county's adult population has antibody to the virus. Adjusting this estimate for statistical margin of error implies about 2.8% to 5.6% of the county's adult population has antibody to the virus- which translates to approximately 221,000 to 442,000 adults in the county who have had the infection. That estimate is 28 to 55 times higher than the 7,994 confirmed cases of COVID-19 reported to the county by the time of the study in early April. The number of COVID-related deaths in the county has now surpassed 600.​

"We haven't known the true extent of COVID-19 infections in our community because we have only tested people with symptoms, and the availability of tests has been limited," said lead investigator Neeraj Sood, a USC professor of public policy at USC Price School for Public Policy and senior fellow at USC Schaeffer Center for Health Policy and Economics. "The estimates also suggest that we might have to recalibrate disease prediction models and rethink public health strategies." Press Release:USC-LA County Study: Early Results of Antibody Testing Suggest Number of COVID-19 Infections Far Exceeds Number of Confirmed Cases in Los Angeles County
​

More info in the release for anyone interested (I haven't reviewed in detail yet).

So they are publishing the statistically massaged data . . . but not the raw data?

Color me skeptical until I can see the ACTUAL RAW DATA myself.

This smells of more Stanford-esque funny business.

 

[Doggydogworld]

I've got 12,712 deaths with a population of 8.4 million, but my deaths are a day or two outdated.

PFR of .15%

NYC Health shows 9101 confirmed and 4582 probable through 4/19. That's 0.11% PFR for confirmed only and 0.16% PFR for confirmed+probable.

 

[Norbert]

I've got 12,712 deaths with a population of 8.4 million, but my deaths are a day or two outdated.

PFR of .15%

COVID-19: Data - NYC Health

9,101 + 4,582 = 13,683 deaths
13,683 / 8.4 million = 0.163% mortality in New York City, as of April 20, 2:30pm.

EDIT: A common assumption is that even with "probable deaths", there is still an undercounting of deaths.

 

[byeLT4]

Just wondering.... Has any version of the flu, or better yet, any known Coronavirus, ever been tested with as many asymptomatic cases as Covid19?

Update on my county in Texas of 92k people (from yesterday, no data yet today)-

95 cases
54 recovered... ?
40 active
1 deceased

Testing has slowed considerably from my understanding.

 

[deonb]

One of the most pessimistic takes I've read on Covid in India.

'Herd Immunity Is the Only Lasting Solution to the Coronavirus', Says Leading Epidemiologist

The initial 21 days lockdown was extended by 19 more days. Doesn't seem to have helped all that much. This could also mean the heat & humidity is not going to save rest of the northern hemisphere either.

Herd immunity is the only lasting solution to any virus... Ok, a few exceptions like SARS-1 and Smallpox but for the majority of them.

Where in the article do they say the lockdown haven't "helped all that much"?