洛杉矶检测显示4.1%的成人已有新冠抗体

s
sbtelf
楼主 (北美华人网)
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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

Los Angeles (April 20, 2020) - USC and the Los Angeles County Department of Public Health (Public Health) today released preliminary results from a collaborative scientific study that suggests infections from the new coronavirus are far more widespread - and the fatality rate much lower - in L.A. County than previously thought.The results are from the first round of an ongoing study by USC researchers and Public Health officials. They will be conducting antibody testing over time on a series of representative samples of adults to determine the scope and spread of the pandemic across the county.

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."

The results have important implications for public health efforts to control the local epidemic.

"These results indicate that many persons may have been unknowingly infected and at risk of transmitting the virus to others," said Dr. Barbara Ferrer, director of the L.A. County Department of Public Health. "These findings underscore the importance of expanded polymerase chain reaction (PCR) testing to diagnose those with infection so they can be isolated and quarantined, while also maintaining the broad social distancing interventions."

The antibody test is helpful for identifying past infection, but a PCR test is required to diagnose current infection.

"Though the results indicate a lower risk of death among those with infection than was previously thought, the number of COVID-related deaths each day continues to mount, highlighting the need for continued vigorous prevention and control efforts," said Dr. Paul Simon, chief science officer at L.A. County Department of Public Health and co-lead on the study.

The study's results have not yet been peer reviewed by other scientists. The researchers plan to test new groups of participants every few weeks in coming months to gauge the pandemic's trajectory in the region.

About the study With help from medical students from the Keck School of Medicine of USC, USC researchers and Public Health officials conducted drive-through antibody testing April 10th and 11th at six sites. Participants were recruited via a proprietary database that is representative of the county population. The database is maintained by LRW Group, a market research firm.

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.

The study was supported with funding from USC Schwarzenegger Institute, USC Lusk Center, USC President's Office, Jedel Foundation, LRW Group, Soap Box Sample, and several individual donors.
More information

A recent Q&A with Neeraj Sood on antibody testing can be found here.
See the Los Angeles County's April 16, 2020,Health Advisory SARS-CoV2 Serology Advisoryfor clarification on antibody testing.
B-roll and photos from the April 10-11, 2020 antibody testing conducted in Los Angeles can be found here.
To learn more about the L.A. County Department of Public Health and the work they do, visit the following sites and pages:

L.A. County Channel:http://bit.ly/CountyChannel
Online: http://publichealth.lacounty.gov/
Facebook: https://www.facebook.com/countyofla/
Twitter: https://twitter.com/LAPublicHealth
YouTube: https://www.youtube.com/LAPublicHealth

http://publichealth.lacounty.gov/phcommon/public/media/mediapubhpdetail.cfm?prid=2328
O
Orogenes
楼下觉得新冠病毒的真实死亡率是多少?
c
computer101
读完了这个report全文,目前感觉可信度挺高的,按这个说法真实死亡率确实也就1%甚至更低,只是测试量决定了目前观测到的死亡率非常高
童童童鞋
算算纽约...该解封了
s
sbtelf
目前为止,各个地方都报道有百分之好几的感染率了,都有错的可能性太低了
e
erniuth
不全面测试没到100倍实际感染就已经不错了。。。
t
tiaodashen
十天增长一个数量级,山鸡过两个星期就群免了
h
honeymustard
所以就是没有疫苗和药的大号流感?😢
弹指芳华
至少说明这个病毒对绝大部分人的影响非常小。
x
xizzhu
荷兰 Santa Clara JoCo 然后是LA 数据惊人的一致啊~~
M
MM1mm3
这么说 川普是对的啊 大号流感
C
Confuse
至少说明这个病毒对绝大部分人的影响非常小。
弹指芳华 发表于 4/20/2020 6:58:40 PM

问题是大家都感染,1%也是很恐怖的数字。还不要说一会变异一下。
A
ArizonaGreenTea
据说武汉的检出率是0.07% 大家相信么
缺德舅舅
How reliable are the antibody tests? Premier Biotech, the manufacturer of the test that USC and L.A. County are using, tested blood from COVID-19-positive patients with a 90 to 95% accuracy rate. The company also tested 371 COVID-19-negative patients, with only two false positives. We also validated these tests in a small sample at a lab at Stanford University. When we do our analysis, we will also adjust for false positives and false negatives. 假阳率大概是0.5%
s
sisi12
据说武汉的检出率是0.07% 大家相信么

ArizonaGreenTea 发表于 4/20/2020 7:16:43 PM

信不信有什么关系呢?对我们抗疫没啥意义。居家隔离标准都不一样,没有可比性
m
minijing

信不信有什么关系呢?对我们抗疫没啥意义。居家隔离标准都不一样,没有可比性

sisi12 发表于 4/20/2020 7:19:26 PM

同意,是不是大号流感事实都是不管就会挤兑医疗系统,已经好几个地方验证了
w
wyz4632
不是说60%才能群体免疫吗 还有很长一段距离啊
l
luckyhusky
如果LA是这个概率的话,NYC很可能全民免疫了啊……
缺德舅舅

同意,是不是大号流感事实都是不管就会挤兑医疗系统,已经好几个地方验证了

minijing 发表于 4/20/2020 7:23:43 PM


是不是大号流感还是完全不一样的。比如说意大利,现在他们可能觉得如果当初没有lockdown,医院的病人会是现在的10倍20倍。
但如果是大号流感,即使他们没有lockdown任其发展,医院的病人或许只会是现在的1.5倍、2倍。

大号流感情况下,热带国家完全不需要lockdown,天气自然会帮他们flatten the curve,印度现在就可以赶快解封了。

其实大多数国家防疫都不怎么样,但是只有少数几个国家地区医疗被击穿。或许说明死亡率太低,想要医疗被击穿,需要的条件比较苛刻,比如天气和人口密度。
2
2sigma
对无症状者连流感都不算,但对重症患者不死也脱层皮。看来抗病毒全靠基因彩票了。
正版凤姐
据说武汉的检出率是0.07% 大家相信么

ArizonaGreenTea 发表于 4/20/2020 7:16:43 PM

提都不要提CCP那p
r
ranran
目前为止,各个地方都报道有百分之好几的感染率了,都有错的可能性太低了
sbtelf 发表于 4/20/2020 6:23:41 PM

如果用的抗体试剂盒特异性不够高,也能得出这样的结论。

实际上,罗斯福号和公主号都测的很多,完全无症状者并没有那么高比例