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Post by mhbruin on Apr 21, 2020 14:30:14 GMT -8
Here are a few highlights from an interesting article: The USC report estimates that 4 percent of Los Angeles County residents have COVID-19 antibodies, meaning they either had an active infection or have recovered. Experts suspect that people who've had the virus can't immediately become infected a second time, although it's unclear how long the protection lasts. If "roughly 4 percent of adults have been infected, it means the remaining 96 percent are still susceptible to this disease," Sood said. He estimated that 60 percent of the public would need COVID-19 antibodies for what's known as herd immunity to kick in, meaning enough people in a community have a level of immunity that makes it more difficult for infectious diseases to spread. "Just because you're antibody-positive doesn't necessarily mean you're immune," said Joel Baines, a virologist and professor of pathobiological sciences at Louisiana State University. "That's a very dangerous conclusion." Only time — perhaps a year or more, experts predict — will be able to determine whether immunity lasts several weeks, several months, several years or even a lifetime. But the USC data do offer some reassuring news: COVID-19 death rates may be lower than expected. When experts factor in those additional cases, the mortality rate plummets to less than 0.2 percent. That's because there are more patients overall, making the number of people who've died a smaller percentage of cases in total. What can coronavirus antibody tests actually tell us? |
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Post by andyh64000 on Apr 21, 2020 14:45:39 GMT -8
Here are a few highlights from an interesting article: The USC report estimates that 4 percent of Los Angeles County residents have COVID-19 antibodies, meaning they either had an active infection or have recovered. Experts suspect that people who've had the virus can't immediately become infected a second time, although it's unclear how long the protection lasts. If "roughly 4 percent of adults have been infected, it means the remaining 96 percent are still susceptible to this disease," Sood said. He estimated that 60 percent of the public would need COVID-19 antibodies for what's known as herd immunity to kick in, meaning enough people in a community have a level of immunity that makes it more difficult for infectious diseases to spread. "Just because you're antibody-positive doesn't necessarily mean you're immune," said Joel Baines, a virologist and professor of pathobiological sciences at Louisiana State University. "That's a very dangerous conclusion." Only time — perhaps a year or more, experts predict — will be able to determine whether immunity lasts several weeks, several months, several years or even a lifetime. But the USC data do offer some reassuring news: COVID-19 death rates may be lower than expected. When experts factor in those additional cases, the mortality rate plummets to less than 0.2 percent. That's because there are more patients overall, making the number of people who've died a smaller percentage of cases in total. What can coronavirus antibody tests actually tell us?I don't think we can calculate a mortality rate yet since so many people are still sick. In California 35K people are sick and 1300 have died but the real denominator is how many people have recovered right? |
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DrJ
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Post by DrJ on Apr 21, 2020 14:52:22 GMT -8
We also don’t know if the sample is representative.
I don’t think this or a similar study in Santa Clara were random; people who volunteer may do so because they had elevated concerns due to symptoms or exposure.
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Post by mhbruin on Apr 21, 2020 15:41:02 GMT -8
LA County said they picked subjects to create a representative sample. They will be repeating this.
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DrJ
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Post by DrJ on Apr 21, 2020 15:59:22 GMT -8
The LA was recruited from a database and conducted at drive through sites. The database is representative of population but the actual test subjects were volunteers who responded and got to the test sites.
I think we all believe that with very little testing the number of cases is far higher than those verified. Question is really how much.
We need more of this!
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Post by sagobob on Apr 21, 2020 16:06:00 GMT -8
Then was the virus present in the population prior to the "explosion" of cases? Maybe it had to cook for awhile before boiling over the pot? Answers seem to prompt more questions.
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DrJ
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Post by DrJ on Apr 21, 2020 16:32:24 GMT -8
No one believes that the virus was present in large amounts before this current outbreak (meaning this January) because the virus spreads so rapidly and is a new virus. The first confirmed cases in the US was in Jan and the first death in February. The first community spread case was confirmed in February as well.
Testing was very late and inadequate so that case was only confirmed after about a week.
So the infection was spreading rapidly until the stay at home orders and this 2-4% likely represents those weeks from late January to mid March.
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Post by andyh64000 on Apr 21, 2020 17:35:13 GMT -8
Then was the virus present in the population prior to the "explosion" of cases? Maybe it had to cook for awhile before boiling over the pot? Answers seem to prompt more questions. I think it actually shows that the virus spreads very quickly and it hasn't been around very long. |
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Post by sagobob on Apr 21, 2020 18:37:21 GMT -8
When the number of people who did not present symptoms or only had a mild and undocumented (at the time) case of Covid-19 are added to the total number of already confirmed cases, the death rate will drop. To me this presents a problem, that of people saying, ah it really isn't/wasn't THAT bad so let's drop the masks and kick start the economy.
The second wave of the 1918 H1N1 flu pandemic was deadlier than the first. Currently With Covid-19, no highly effective treatment or vaccine exists, so could the scene be set for another deadly second wave?
I guess we'll learn something if new cases in FL, GA & TX spike up again?
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DrJ
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Post by DrJ on Apr 21, 2020 20:11:39 GMT -8
And the mortality rate is dramatically impacted by the availability of medical resources. In California we have avoided medical resources from becoming overstretched due to public health orders being implemented early.
Another thing to factor is the number of deaths which may not have been attributed to COVID due to limited testing. We don't know enough about this virus to fully understand its lethality fully.
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Post by Born2BBruin on Apr 21, 2020 21:45:48 GMT -8
No one believes that the virus was present in large amounts before this current outbreak (meaning this January) because the virus spreads so rapidly and is a new virus. The first confirmed cases in the US was in Jan and the first death in February. The first community spread case was confirmed in February as well. Testing was very late and inadequate so that case was only confirmed after about a week. So the infection was spreading rapidly until the stay at home orders and this 2-4% likely represents those weeks from late January to mid March. L.A. Times now reporting first deaths occurred in NoCal on Feb. 6 and 17; still in February but much earlier than the previously supposed first death in Kirkland on 2/29. L.A. Times - Autopsies Confirm Coronavirus Deaths in Early February |
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DrJ
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Post by DrJ on Apr 21, 2020 21:56:04 GMT -8
Interesting - they must not have been diagnosed until later?
I recall the first community spread case was from Solano County and was transferred from a hospital there to UC Davis Med and tests finally came back onFeb 26.
To me that was a clear signal - the virus is spreading among the population and we don't know where it came from or to whom it has spread. We had ridiculously few rests available at that time and the patient had the symptoms in hospital for almost a week but,could not get a test because there was no known vector. Ridiculously ill-prepared and this was at the time of the 15 soon to be 5 soon to be zero nonsense coming from Cheeto. No recognition of the potential threat
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Post by sagobob on Apr 22, 2020 5:31:19 GMT -8
According to an article in this mornings NYT Santa Clara County officials said that autopsies of two people who died at their homes on Feb. 6 and Feb. 17 showed that the individuals were infected with the virus. The presence of the disease Covid-19 was determined by tissue samples and was confirmed by the Centers for Disease Control and Prevention, county health officials said in a statement.
The individuals who died in February did not have any known travel histories that would have exposed them to the virus, which first appeared in China. They are presumed to have contracted the virus in the community, she said.
The newly reported deaths suggest that the coronavirus may have been spreading in California much earlier than was previously known, said Dr. Jeffrey V. Smith, the Santa Clara county executive and a medical doctor. All it takes is people who are asymptomatic and shedding. I hope they're trying to find out who visited them and when.
So if you back those dates up to account for exposure, infection and death, the Covid-19 virus was here in January, or maybe even earlier?
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DrJ
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Post by DrJ on Apr 22, 2020 6:11:04 GMT -8
Those would be just before the Solano County confirmed case of community spread who was admitted to hospital on February 19 with symptoms. At that point they figured that the virus had been spreading for a matter of weeks before a case was detected, so I think that is consistent but maybe a little earlier in January. It was spreading among Americans well before the so-called China travel "ban" in February.
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DrJ
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Post by DrJ on Apr 22, 2020 13:17:40 GMT -8
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