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In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

reuters.com

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Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#561

Post by Symmetry »

greedo wrote: post #470
Symmetry wrote: post #353

Earlier quoted context omitted.

It depends. If you're not going to develop symptoms for another 14 days then yeah, you're not infectious. But for a few days before symptom onset you become just as infectious as you will be after symptom onset - which is one of the things that makes this virus hard to stop. A low initial dose doesn't seem to affect the course of the infection much, though. For a sufficiently low dose either none of the viruses find…

I'm very confused by this as I understand that asymptomatic patients are infectious. How does this square with your second sentence?

So, it looks like most asymptomatic infections later become infectious. Basically every person who gets symptoms had a multi-day asymptomatic infectious period they went through. SARS-CoV-2 does a better job than most of avoiding the automatic immune system because its large genome lets it encode a bunch of proteins that aren't for making new viruses but rather screwing with the immune system in ways that let it reach high numbers before the immune system catches on. Every virus that can actually make you sick does this but SARS-CoV-2 seems better than most. But frequently you're able to fight off the infection at a later point before the part of the automatic immune system reaction that makes you feel sick kicks into play but after you're got a chance to infect other people.

The normal course of the automatic immune system wiping out an invading pathogen without you noticing is that it happens immediately without you noticing and you never get a chance to infect anyone. But if that doesn't happen for COVID-19 or influenza or most things there'll be a time period after infection but before you notice anything where you're infectious. For COVID-19 this period is particularly infectious compared to the flu or SARS-1 or most things. It might be that flu and other coronaviruses tend to people who are infected enough to transmit the virus but never go on to develop symptoms. I don't know in that case.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#562

Post by freeflight »

One of the more interesting differences between US prison populations and others is that smoking tobacco is way more prevalent:

> Estimated smoking prevalence among inmates was approximately 50% in 2003–2004, compared to 21% among noninstitutionalized adults. [0]

Which might play a major role in the spread and the actual severity of COVID-19 as French researchers are speculating that nicotine could be responsible for blocking the ACE2 receptors that COVID-19 uses to get into cells, which could explain why there's such a low incidence of tobacco smokers among patients, far below what should be expected [1].

There's nothing really concrete yet, for now they want to experiment with nicotine patches as treatment.

But in that context, prison populations could make for an interesting control group: Maybe the prevalence of smoking is what keeps the virus less severe, due to reduced viral load reaching cells, and thus fewer carriers are symptomatic?

[0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5100810/

[1] https://www.qeios.com/read/article/574

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#564

Post by nradov »

igravious wrote: post #531
GuB-42 wrote: post #403

Earlier quoted context omitted.

Here is for Europe if you are interested. There are charts for excess morality by country, by age, and by year. https://www.euromomo.eu/ There is a very noticeable spike in the worst hit countries: Italy, Spain, France, Belgium, Netherlands and the UK. The cumulative excess deaths for all Europe in the last two months matches the COVID-19 reported deaths (around 100000).

> The cumulative excess deaths for all Europe in the last two months matches the COVID-19 reported deaths (around 100000). Where's the noticeable spike for Ireland? Where's the spike for Portugal? Where's the spike for Luxembourg? Where's the data for the rest of Germany outside of Hesse and Berlin? Where's the spike for Austria? (And this is not a criticism of them, but they only track Western Europe by the looks of…

Malta is also considered part of Europe, south of Italy.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#565

Post by gridlockd »

KaiserPro wrote: post #560
gridlockd wrote: post #540

Earlier quoted context omitted.

I'm trying to figure out what tests they used. PCR is very specific but only works reliably in the early stages and generally has a high false negative rate. Antibody tests only work after several days of infection, but some of them are not very specific to SARS-CoV2 and therefore have a high false positive rate. So you really need use both tests, but you can't just OR the results together, because then a faulty anti…

> but only works reliably in the early stages No, it only works if there is enough virus to be detected. If you are infected, you will have a high enough count to be detected. Each type of PCR test is highly selective. The point of them is that they can differentiate between many types of virus, depending on how its setup. > Antibody tests only work after several days of infection Yes. Depending on the type of test,…

In principle yes, but The PCR test is usually a throat swab, where detectable amounts often disappear after a few days, even in severely symptomatic cases.

This is the reason why China started to accept clinical diagnosis like chest scans, causing a sudden big spike in cases.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#566

Post by icegreentea2 »

darkerside wrote: post #414
icegreentea2 wrote: post #384

Earlier quoted context omitted.

The sensitivity of PCR tests to SAR-COV-2 varies over time from time to infection. I think the the OP is overestimating how narrow this window is though. It's not like you need to test within a few days or a week to be positive - it's just that viral load is maximum for only a few days (roughly the +/-3 days around onset of symptoms). Even after the viral load in the upper respiratory tract drops off, there's still l…

Depending on the nature of the virus and how the PCR test works with it, I couldn't rule out that it could be much longer than that. Virii are not my area, but there are bacterial diseases that result in positive PCR years after infection. Disclaimer: microbiology is also not my area.

Yes, it all depends on how the agent infects the body and how the immune system is able to clear it. Our belief (based on how other coronaviruses behave) is that the body is pretty good at clearing it out, and that the virus doesn't really have a mechanism for forming a reservoir within the body.

The expectation is that PCR negative is roughly correlated with fighting off the disease in the short term, and basically perfectly correlated in the long term.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#567

Post by heisenbit »

ivanhoe wrote: post #52

I've read that asymptomatic carriers are though to be less infectious than those with symptoms because of the lower concentration of virus in the saliva. Also, many virologists mentioned in recent texts that the initial concentration of the virus you receive can affect how sick you'll get - the more viruses you're exposed to, the faster they can invade the body and the more severe it will get. Can those two facts be…

Prof. Dr. Drosten (inventor of Covid-19 test) said in the interview below that there is a study which shows asymptomatic adult shed as much virus as symptomatic ones. He also said there is no good study on how many viruses are shed by kids.

https://tvthek.orf.at/profile/Additional-Content/1670/Langfa...

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#568

Post by sharken »

wegs wrote: post #538
sharken wrote: post #236

Earlier quoted context omitted.

We are quite a lot of people that fear the operation will be successful but the patient is dead with the Corona actions being taken. Case in point, 26.5 million americans have sought unemployment benefits ( https://vastuullisuusuutiset.fi/en/weben/women-bear-brunt-of... ). The deaths in New York are quite telling for who is at risk, see https://www.statista.com/statistics/1109867/coronavirus-deat... . Over 90% of the…

That's an accurate argument for why it'd be nice if COVID19 would be not serious. Wishful thinking doesn't make it not serious. Deaths are telling for who is dead, not for who is at risk of lung damage, compromised immune system, or other consequences.

It's all in the eye of the beholder:

Africa have registered 1,297 deaths with a population of 1.2 billion (https://www.africanews.com/2020/04/24/coronavirus-in-africa-...).

Given the fact that 8.8 million die yearly, i'd say that for Africa this disease can be classified as 'not serious'.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#569

Post by Retric »

_-___________-_ wrote: post #521
Retric wrote: post #418

Earlier quoted context omitted.

South Korea had a very rapid decline post peak. 1062 cases on 2/29 to 114 cases on 3/11. With an average of just under 10 cases per day for the last week. Also, the number I have seen was ~1% of cases where asymptotic for 14 days. https://hub.jhu.edu/2020/03/09/coronavirus-incubation-period...

Do note that rapid decline in the day-to-day increase of case numbers is not necessarily indicative of rapid decline in transmission rate. Transmission rate could have declined gradually over the course of a week or more, and the rapid decline in day-to-day increase of case numbers could have just been detection catching up with existing infections.

Their daily testing was reasonably consistent over that time period. So, their is some wiggle room, but it’s at minimum a 80% drop over 2 weeks. Compared to the US where daily numbers are steady for weeks with the last two days having the greatest number of detected cases.

Re: In 4 US state prisons, 3,300 inmates test positive, 96% without symptoms

#570

Post by dima_medvedev »

sandworm101 wrote: post #146
ivanhoe wrote: post #52

I've read that asymptomatic carriers are though to be less infectious than those with symptoms because of the lower concentration of virus in the saliva. Also, many virologists mentioned in recent texts that the initial concentration of the virus you receive can affect how sick you'll get - the more viruses you're exposed to, the faster they can invade the body and the more severe it will get. Can those two facts be…

>> Also, many virologists mentioned in recent texts that the initial concentration of the virus you receive can affect how sick you'll get - the more viruses you're exposed to, the faster they can invade the body and the more severe it will get. That is basic infections 101. When you are exposed to any dangerous virus a race starts between the virus and your immune system. If the virus starts out only infecting a han…

There's already a comment above pointing out that it might be the initial infection location plays big role. Seems very likely that poor ventilation (in e.g. medical facilities) is main cause of severe cases.

Also, the virus is replicating exponentially only if it can reach many uninfected cells. It takes ~10 hours for an infected cell to start producing virus. Not sure whether non-specific immune system can somehow "contain" virus, would be great to learn about that.

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