Cont: The One Covid-19 Science and Medicine Thread Part 2

[The Atheist]

I suspect most of the "close" peeps were people in the home they stayed in. Details are in the study.

I'll see if I can find it, because I agree that you'd expect a lot higher percentage of people in the same house to get it.
____________________________

Dr Sid: What's happening in Chechia?

You numbers appear to have taken a turn in the wrong direction, immediately after loosening restrictions.

Don't be America!

 

[wasapi]

Blood type and virus risk.

https://www.nj.com/coronavirus/2020...us-make-you-vulnerable-studies-say-maybe.html

I'm sorry if this topic has been posted about already. I saw this discussed on TV recently, then came upon this article. It is interesting,

 

[Skeptic Ginger]

Sweden has kept preschools and primary schools open and it has basically not seen any signs that children spread the disease to any significant degree either among themselves or to adults. Teachers and other school staff members are far more likely to infect each-other than being infected by the kids.

There has so far only been one single significant outbreak at a school where a lot of teachers were sick and one of them ended up dying, which eventually had to close prematurely for the summer due to a lack of sufficient teachers. I live fairly close to this school and it was a very exceptional event especially given the low rate of infection in this region.

Teachers are not any more likely to be infected than anyone else.

How do you know kids aren't silent spreaders?

 

[Skeptic Ginger]

Some do many don't. The FDA has been coming down a some of the hundred plus purveyors of antibody tests that haven't even applied for an emergency authorization. Many of those are crap. Some tests deployed in Japan in a large group that hasn't had Covid-19 has a positive rate of under 0.1% so at least that test had decent specificity. Sensitivity, OTOH, is harder to quantify as there are fewer known positives to test against.

Is this a separate issue than prevalence studies?

Because regardless, we don't have good prevalence studies.

 

[marting]

Is this a separate issue than prevalence studies?

Yes.

Because regardless, we don't have good prevalence studies.

I agree. They aren't that good. Selection bias looks to be an issue in the ones I've seen.

 

[William Parcher]

The link is the full pdf of the study. IIRC, the "close" was people that had spent over 15 minutes closer than 2m

With or without masks?

as well as people in the same household.

With or without masks?

 

[marting]

How do you know kids aren't silent spreaders?

The study I linked above was an antibody study. In that only 1 child under 10 of over 100 that had lived in a household with a Covid-19 case tested positive for antibodies.

That doesn't say children that are infected can't be spreaders but it does suggest children are unlikely to be infected.

 

[William Parcher]

Also of note is the study is base on close contacts of Covid-19 patients. Testing showed that 51% of the close contacts had acquired Covid-19.

With or without masks?

 

[marting]

With or without masks?

Masks were not commonly in use at the time and were not generally recommended. Study was antibody based to look back in time. Beyond that read the paper.

 

[William Parcher]

Here's an interesting study out of China (financed in part by the US NIH) that showed about half secondary transmission was from people that were pre-symptomatic.

I have an idea, but could you please describe the difference between pre-symptomatic and asymptomatic?

 

[marting]

I have an idea, but could you please describe the difference between pre-symptomatic and asymptomatic?

Everyone that becomes symptomatic was pre-symptomatic between the point of exposure and developing symptoms. This is referred to as the incubation period. Asymptomatics refer to people that were infected but have never had symptoms.

 

[Orphia Nay]

That's consistent with the Swiss study. Frankly, I was surprised by the almost non-existent transmission to children. Even in families where a person had Covid-19. There's clearly something different going on.

OTOH, for people 20 or more it seems they are all pretty susceptible to getting the bug. Even though it impacts older people far harder.

Elsewhere it's been reported that pregnant women don't transmit it to their newborns. Even when they may get it themselves. Curious.

The pre-existing health of the population/individuals is known to be a factor.

Plus, I've seen immunologists say a virus can change when it is transmitted -HEAR ME OUT - probably in the same way each time for most children. It's not as severe if they've fought it off a bit.

Blah blah blah we don't understand herd immunity, yeah.

 

[Samson]

The great majority of cases testing positive in quarantine in New Zealand are arriving from India.
Maybe 8 of about 12 a week
.

 

[casebro]

The latest from the CDC:
- the US is likely only testing 5 to 8 percent of those infected.
- 3% of US counties currently have a high transmission rate
- conditions giving a high risk of a serious case are: chronic kidney disease, serous heart disease, sickle cell disease, COPD, weakened immune system from organ transplant, type 2 diabetes, and a BMI > 30 (60% of American adults have at least 1 of these!)
......
https://www.washingtonpost.com/health/2020/06/25/coronavirus-cases-10-times-larger/

Do we know how many deaths are in the 40% without risk factors? If it's40%, then the definition of risk factors is bogus science. IF it is greater than 40%, then those are actually protective factors. Whatever the math, I don't think those risk factors are very strong. Rather than age or health, I think the big risk factor of catching it is environment. Like meat processing plants, care homes,... But no doubt the frail will have a higher death rate. But 99.4% of us are not going to die form it, only catch it. So let's get practical about living life while not catching it.

Shouldn't there be CDC Epidemiologists making tallies?

 

[The Atheist]

I think otherwise. At least in the USA. There's been a big shift towards the younger crowd out having fun at bars. Older folks are still being cautious for the most part. Very different from the early days where a lot of the cases were older people who probably get a more serious case, spread it more easily, and didn't know the consequences at the time.

Now they do. Fewer going to church. Singing in choirs, or playing bingo indoors.

I hope you're right, because if USA is anything like NZ was when masks were advised, the least likely people to wear them were the worst age demographic.

Maybe 25% less deaths between the two known effective agents.

There's going to be a lot more cases, though, so I'm the other way - I'll be surprised if deaths don't surpass the earlier totals.

Give it a couple of weeks and we'll know.

The great majority of cases testing positive in quarantine in New Zealand are arriving from India.
Maybe 8 of about 12 a week
.

Yeah, I was shocked to see that.

Given the number who got through without testing - or are now refusing to be tested - if it breaks out in the community, it'll be in Mt Roskill first.

Or where I live - 30% in the area are Indians.

 

[novaphile]

The great majority of cases testing positive in quarantine in New Zealand are arriving from India.
Maybe 8 of about 12 a week
.

Tell me about it.

We're expecting more new cases, purely because we're still repatriating people from India.

 

[Skeptic Ginger]

The study I linked above was an antibody study. In that only 1 child under 10 of over 100 that had lived in a household with a Covid-19 case tested positive for antibodies.

That doesn't say children that are infected can't be spreaders but it does suggest children are unlikely to be infected.

Way too small/limited to be considered more than anecdotal evidence.

A few minutes searching for prevalence of COVID 19 in kids turns up a study of a couple thousand kids who were diagnosed with the virus and they tend to have mild or asymptomatic cases. All the reports suggest kids are indeed susceptible to the virus.

CDC COVID 19: Information for Pediatric Healthcare Providers

There have been multiple reports to date of children with asymptomatic SARS-CoV-2 infection.3,6,14,15 In one study, up to 13% of pediatric cases with SARS-CoV-2 infection were asymptomatic.16 The prevalence of asymptomatic SARS-CoV-2 infection and duration of pre-symptomatic infection in children are not well understood, as asymptomatic individuals are not routinely tested.

CDC MMWR: Coronavirus Disease 2019 in Children — United States, February 12–April 2, 2020

Among all 2,572 COVID-19 cases in children aged <18 years, the median age was 11 years (range 0–17 years). Nearly one third of reported pediatric cases (813; 32%) occurred in children aged 15–17 years, followed by those in children aged 10–14 years (682; 27%). Among younger children, 398 (15%) occurred in children aged <1 year, 291 (11%) in children aged 1–4 years, and 388 (15%) in children aged 5–9 years. Among 2,490 pediatric COVID-19 cases for which sex was known, 1,408 (57%) occurred in males; among cases in adults aged ≥18 years for which sex was known, 53% (75,450 of 143,414) were in males. Among 184 (7.2%) cases in children aged <18 years with known exposure information, 16 (9%) were associated with travel and 168 (91%) had exposure to a COVID-19 patient in the household or community. ... Discussion
Among 149,082 U.S. cases of COVID-19 reported as of April 2, 2020, for which age was known, 2,572 (1.7%) occurred in patients aged <18 years. In comparison, persons aged <18 years account for 22% of the U.S. population (3).

Those are cases that were diagnosed because they came to the attention of a health care provider. And this was during the time the CDC was discouraging testing of mild or asymptomatic cases unless there was a known exposure. We know from the cases in WA State that the virus was being spread for weeks before it was recognized. Because there was a shortage of tests, we still were told not to test people who were mildly ill if they didn't have a known exposure.

And even if only 2% of kids were getting infected (and we know it's more than that) that still represents a significant reservoir of disease.

Epidemiology of COVID-19 Among Children in China

CONCLUSIONS: Children of all ages appeared susceptible to COVID-19, and there was no significant sex difference. Although clinical manifestations of children’s COVID-19 cases were generally less severe than those of adult patients, young children, particularly infants, were vulnerable to infection. The distribution of children’s COVID-19 cases varied with time and space, and most of the cases were concentrated in Hubei province and surrounding areas.

A lot of people who would love to send kids back to school are willing to believe they are not a problem in the spread of this virus. There are lots of rationales why kids are immune before it has even been established that they are. The evidence we do have suggests they are not immune.

 

[Skeptic Ginger]

The pre-existing health of the population/individuals is known to be a factor.

Plus, I've seen immunologists say a virus can change when it is transmitted -HEAR ME OUT - probably in the same way each time for most children. It's not as severe if they've fought it off a bit.

Blah blah blah we don't understand herd immunity, yeah.

All viruses mutate. Not all mutations are significant.

So far the mutations seen in COVID 19 have not been significant. There is a suggestion one clade might be more infectious than the other clades. I'm not sure if that has been established yet. But this virus is not going through any major changes.

 

[Arcade22]

How do you know kids aren't silent spreaders?

Because teachers are not at any increased risk of being infected.

 

[Orphia Nay]

All viruses mutate. Not all mutations are significant.

So far the mutations seen in COVID 19 have not been significant. There is a suggestion one clade might be more infectious than the other clades. I'm not sure if that has been established yet. But this virus is not going through any major changes.

And as I said, 80% of cases are mild.