Asymptomatic spreading is rare

[Toocold]

If this is true, then it would be good news.

"Coronavirus patients without symptoms aren't driving the spread of the virus, World Health Organization officials said Monday, casting doubt on concerns by some researchers that the disease could be difficult to contain due to asymptomatic infections.

“From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual,” Dr. Maria Van Kerkhove, head of WHO’s emerging diseases and zoonosis unit, said at a news briefing from the United Nations agency’s Geneva headquarters. “It’s very rare.”

https://www.cnbc.com/2020/06/08/asy...GcDecD0fCOeXg62qE0GZFVr33DZ6PNGHkGxdrQNwXimI0

 

[MichaelB]

Can we please have a snippet or summary, not just a headline and link?

 

[audreyh1]

I simply do not believe that. They tried to downplay asymptomatic transmission before, but we finally find out that in fact a huge % of infected are asymptomatic. If asymptomatic persons are 50% of those infected which is certainly seems to be the case, and we already have a number of documented cases of "super spreader" events have been asymptomatic or pre-symptomatic folks at a gatherings infecting numerous others simultaneously.

And don't forget that a person is usually contagious for a day or two before they themselves come down with symptoms. At the time no one would know whether the person would become ill, or remain asymptomatic.

The article has the WHO making this statement:

Coronavirus patients without symptoms aren’t driving the spread of the virus, World Health Organization officials said Monday, casting doubt on concerns by some researchers that the disease could be difficult to contain due to asymptomatic infections.

Some people, particularly young and otherwise healthy individuals, who are infected by the coronavirus never develop symptoms or only develop mild symptoms. Others might not develop symptoms until days after they were actually infected.

Preliminary evidence from the earliest outbreaks indicated that the virus could spread from person-to-person contact, even if the carrier didn’t have symptoms. But WHO officials now say that while asymptomatic spread can occur, it is not the main way it’s being transmitted.

They just make this blanket statement claiming it's very rare. They don't show percentages or graphs or anything? So how the %$%# is it being transmitted?

Maybe not NOW while social distancing is in force and larger group gatherings are still banned. But lots of cases - for example recently in Germany - you had asymptomatic individuals driving the spread via gatherings that are still off limits. https://www.theguardian.com/world/2...es-present-fresh-challenges-as-lockdown-lifts

And in the US we had so many outbreaks like with the choir where a huge% of the group became ill, and it wasn't obvious that anyone attending was ill.

Recently numerous work places and other institutions in the US as well as many ship confined cases, have found when testing everybody, that there were many more positive cases present than indicated by symptoms.

I just can't see how the WHO can claim that an infected person without symptoms is not contagious. A Singapore study indicated otherwise - https://hub.jhu.edu/2020/05/12/gigi-gronvall-asymptomatic-spread-covid-19-immunity-passports/. https://www.ctvnews.ca/health/coron...?contactForm=true?ot=AjaxLayout?autoPlay=true

I mean we had a lot of community spread with folks not realizing they were contagious before people starting dying in nursing homes etc. How does that happen without a significant number of people being asymptomatic or very mildly symptomatic or pre-symptomatic? And then there is the fine line between someone who truly has no symptoms and who is so mildly symptomatic that they don't realize they are ill and contagious. I think we already tried to manage this via only tracking people who were ill, and it was a dismal failure just like only testing people who were very very ill or had traveled from very specific locations was a dismal failure early on.

 

[Aerides]

It's important to note:

Asymptomatic and Pre-symptomatic are not the same. And the WHO report doesn't make this distinction or share the data yet.

Asymptomatic cases - those that never have symptoms - appear to be the focus of the new info. It good news of course if they can't spread it nearly as much.

Pre-symptomatic cases - people who are infected, but in those first early days before they feel sick, are apparently known to transmit and shed the Covid virus quite well.

Please don't let anyone start thinking "if I don't feel sick I can't give it to anyone" because that's not what the report says.

For a more detailed take by another doc:

https://twitter.com/x/status/1270069131652427776

 

[audreyh1]

During the pre-symptomatic period there is no practical distinction between an asymptomatic person and one who eventually goes on to develop symptoms. And then there are the very mildly symptomatic folks who have no idea that they are sick, or no clue that it could be the virus. So what is the point of de-emphasizing asymptomatic spread if it can only be known well after the fact that someone is truly asymptomatic, whereas a pre-symptomatic or very mildly symptomatic person can spread the virus? Very slippery slope IMO.

I see from your twitter link:

Some modeling studies suggest 40-60% of spread is from people when they didn’t have symptoms.

And that is the point. WHEN they didn't have symptoms.

And the WHO is still gathering data?

"There's significant transmission by people not showing symptoms," Stephen Morse, an epidemiologist at Columbia University, previously told Business Insider. Even some of WHO's own research suggests many coronavirus patients who are initially asymptomatic eventually fall ill.

"Some modeling studies suggest 40-60% of spread is from people when they didn't have symptoms," Ashish Jha, the director of the Harvard Global Health Institute, said on Twitter. "It may be there isn't a lot of asymptomatic spread but plenty of pre-symptomatic spread. Would be helpful to get the full report they are referencing."

WHO said that kind of robust data just isn't available yet.
....
More research and data are needed to “truly answer” the question of whether the coronavirus can spread widely through asymptomatic carriers, Van Kerkhove added.

https://www.businessinsider.com/who...-2020-6?utm_source=feedly&utm_medium=referral

Oh great! Go ahead and make the assertion without "truly answering" the question.

And another gem from the WHO:

When we actually go back and we say how many of them were truly asymptomatic, we find out that many have really mild disease," Van Kerkhove said.

OK - so a lot of the people we thought were truly asymptomatic, really did have mild disease. So I suppose that lumps them in with the more contagious folks. But gosh, who can figure out if they are truly symptomatic or not, until sometime after the fact when it's too late! Is the real story that most "asymptomatic" folks really aren't? You just couldn't get more confusing.

I liked this twitter response:

Joshua Uy MD @joshuy · 52m
Replying to @ashishkjha and @WHO

What in the world would be the clinical utility of pontificating between pre symptomatic and asymptomatic patients with COVID?

Exactly!

 

[2017ish]

As demonstrated by our recent and imminent travels (by car and air), my wife and I are far from being overly concerned with this virus, but WHO has screwed up enough that I'd like a better source....

 

[Montecfo]

During the pre-symptomatic period there is no practical distinction between an asymptomatic person and one who eventually goes on to develop symptoms. And then there are the very mildly symptomatic folks who have no idea that they are sick, or no clue that it could be the virus. So what is the point of de-emphasizing asymptomatic spread if it can only be known well after the fact that someone is truly asymptomatic, whereas a pre-symptomatic or very mildly symptomatic person can spread the virus? Very slippery slope IMO.

I see from your twitter link:

And that is the point. WHEN they didn't have symptoms.

And the WHO is still gathering data?

https://www.businessinsider.com/who...-2020-6?utm_source=feedly&utm_medium=referral

Oh great! Go ahead and make the assertion without "truly answering" the question.

And another gem from the WHO:
OK - so a lot of the people we thought were truly asymptomatic, really did have mild disease. So I suppose that lumps them in with the more contagious folks. But gosh, who can figure out if they are truly symptomatic or not, until sometime after the fact when it's too late! Is the real story that most "asymptomatic" folks really aren't? You just couldn't get more confusing.

Excellent points!

You know, the pundits have demanded that we "follow the science" as if the "science" has presented a single, consistent message.

This story is relatively useless as you point out, but it also contradicts the earlier "science". Same with masks, virus transmission on surfaces, appropriate social distance etc.

I think the scientists have largely failed us, unfortunately.

 

[Gumby]

Science is a process for increasing knowledge. It proceeds in fits and starts, has sometimes gaping holes, and occasionally goes down blind alleys and has to double back. The knowledge gained is always subject to revision as better data and/or methodologies are discovered. If you want perfect revealed truth, you're better off sticking with religion.

 

[Rianne]

I'm reading/hearing about "mild symptoms." Define that. Does that mean you're not sick enough to be hospitalized, go on ventilators? Mild symptoms can last weeks/months. Taking from several articles, interviews and podcasts...mild isn't a brief cold that goes away in a week. Some have bouts of cough, extreme lethargy, difficulty concentrating and other symptoms that go beyond what I consider "mild symptoms." These are not symptoms that require hospitalization but interfere with living normally.

 

[Aerides]

seeing a lot more chatter on twitter (from medical blue check types) that the WHO announcement was possibly incorrect, incomplete, and they are already walking it back and throwing out new numbers...bleh

 

[audreyh1]

I'm reading/hearing about "mild symptoms." Define that. Does that mean you're not sick enough to be hospitalized, go on ventilators? Mild symptoms can last weeks/months. Taking from several articles, interviews and podcasts...mild isn't a brief cold that goes away in a week. Some have bouts of cough, extreme lethargy, difficulty concentrating and other symptoms that go beyond what I consider "mild symptoms." These are not symptoms that require hospitalization but interfere with living normally.

Yes, from what I’ve read over the months, the mild symptoms is a huge range from barely noticeable to really miserable and long, but not hospitalized. The Chinese included pneumonia in their “mild” symptoms.

What I found so upsetting is that no data were given, in fact the WHO admitted that more study is needed. Yet there is a strong assertion that asymptomatic people don’t cause spread, and oh by the way, most asymptomatic folks really aren’t. Incredibly poor and unclear communication on a very critical issue.

With no data provided, that doesn’t sound like a scientific approach, and since the WHO is supposed to help public health policy, how is the above supposed to inform public health policy? They are asserting that contact tracers only need to pay attention to folks with symptoms. And they don’t clarify on presymptomatic folks, so practically speaking it’s useless. I think it’s been clearly established that folks are contagious for at least a day or two before symptoms, so ignoring that issue seems very dangerous to me. Tracers might figure out some things well after the fact, but at the time of contact they don’t know who will end up being asymptomatic. And, IMO, it is way too easy for very mild symptoms to be overlooked/misinterpreted. And we also know that symptoms are highly variable, so pinning down on symptoms alone seems impossible, which is why we came to be so dependent on testing for the virus.

 

[Montecfo]

Science is a process for increasing knowledge. It proceeds in fits and starts, has sometimes gaping holes, and occasionally goes down blind alleys and has to double back. The knowledge gained is always subject to revision as better data and/or methodologies are discovered. If you want perfect revealed truth, you're better off sticking with religion.

No misunderstanding at all. But not everything scientists and other experts say is actually science, it may well be mere opinion or viewpoint with its own agenda. How else do you explain all the contradictory pronouncements?

Just bad science?

 

[audreyh1]

seeing a lot more chatter on twitter (from medical blue check types) that the WHO announcement was possibly incorrect, incomplete, and they are already walking it back and throwing out new numbers...bleh

A lot found here. https://www.washingtonpost.com/news...-experts-doubt-that/5ede874a88e0fa32f82355d4/

But key experts in the United States say the WHO's conclusion presents some big problems.

It's not that asymptomatic people don’t spread the virus — but that contact tracing is simply bad at detecting it, they argue. The studies cited by WHO relied on only a small number of people in China who claimed to have gotten sick from someone who had symptoms – which is not exactly a rigorous scientific experiment.

They also worry that their findings will lead to confusion. There's a difference between people who truly never showed symptoms of coronavirus and people who were “pre-symptomatic," who had not yet developed symptoms but eventually would. Then, of course, there are “low-symptomatic” people who are experiencing effects of coronavirus so mild they might not be noticed.

Andy Slavitt, former head of the Centers for Medicare and Medicaid Services, said that in an email exchange with the WHO, the organization admitted to him it can't distinguish between asymptomatic and pre-symptomatic people.

Whoa!

A big policy pronouncement based on a small number of people studied in China?

 

[Chuckanut]

Announcements from various scientific studies are like the latest update to one's phone or computer. Unless you want to be on the bleeding edge, wait a few days or weeks for others to put the new findings to the test.

 

[audreyh1]

No misunderstanding at all. But not everything scientists and other experts say is actually science, it may well be mere opinion or viewpoint with its own agenda. How else do you explain all the contradictory pronouncements?

Just bad science?

I think he means there are always going to be contradictory studies and results, as science is messy and it can take a while to uncover and rediscover the truth.

But experts giving their opinion for whatever motivation is not itself science without giving a reference to the studies they base it on, so that just muddies the waters.

There are even papers where the conclusions are in no way justified by the data presented in the paper. That can be called bad science. So you really have to be able to see the data.

 

[Gumby]

Very well stated, Audrey. Those who need incontrovertible, immutable truth -- right now -- are likely to be disappointed with scientists and the scientific method. It is said patience is a virtue.

 

[Rianne]

Very well stated, Audrey. Those who need incontrovertible, immutable truth -- right now -- are likely to be disappointed with scientists and the scientific method. It is said patience is a virtue.

+1 We have to live in the here and now with many unknowns. I'm sticking to the precautions I've taken since mid March. The noise will not change my opinion about keeping safe and free of this virus (hopefully).

 

[Red Badger]

As demonstrated by our recent and imminent travels (by car and air), my wife and I are far from being overly concerned with this virus, but WHO has screwed up enough that I'd like a better source....

+1.

Our county of ~1M souls has to date; 4652 cases / 142 deaths. C-19 has not kept me home. I go to the hardware and grocery store most everyday after my long walk.

I don't trust the guidance from WHO, CDC, NIH, etc. They are all just doing OJT, IMHO. What I trust is the US, state, and county data. It tells me that severe illness is rare and death is very remote - even for the elderly. We continue to travel while practicing common sense hygiene, and we are very happy to be able to dine out again.

 

[Montecfo]

Very well stated, Audrey. Those who need incontrovertible, immutable truth -- right now -- are likely to be disappointed with scientists and the scientific method. It is said patience is a virtue.

Forget anything that can be called "truth". Science doesn't do that. But entreaties that we must "follow the science" when there appears to be so much that is deemed false (even within a few days or a week, and then reverses again) seems wrong-headed to say the least.

 

[Winemaker]

+1.

Our county of ~1M souls has to date; 4652 cases / 142 deaths. C-19 has not kept me home. I go to the hardware and grocery store most everyday after my long walk.

I don't trust the guidance from WHO, CDC, NIH, etc. They are all just doing OJT, IMHO. What I trust is the US, state, and county data. It tells me that severe illness is rare and death is very remote - even for the elderly. We continue to travel while practicing common sense hygiene, and we are very happy to be able to dine out again.

+10

 

[MissMolly]

And now W.H.O is clarifying that they didn't mean what they said, or at least, not what was reported They are saying it is a major unknown.

https://www.cnn.com/2020/06/09/health/who-coronavirus-asymptomatic-spread-bn/index.html

Others such as Liam Smeeth, professor of clinical epidemiology at the London School of Hygiene and Tropical Medicine says "The best scientific studies to date suggest that up to half of cases became infected from asymptomatic or pre-symptomatic people."

 

[audreyh1]

Good article, thanks.

 

[Montecfo]

Hours later, they have now walked it back.

"Following the science" in this instance requires a great deal of agility.

 

[audreyh1]

Hours later, they have now walked it back.

"Following the science" in this instance requires a great deal of agility.

I don’t think you can describe what happened over the past two days as following any science. More like miscommunications and misreporting and considerable confusion.

 

[Sunset]

I don’t think you can describe what happened over the past two days as following any science. More like miscommunications and misreporting and considerable confusion.

+1
I saw on the news, the woman who said "it" , was simply answering a question, and talking about a very small specific study (or two). Now that she realizes how people ran with the story, she was back on the news to say people took the wrong message and she was not saying any official WHO policy/decision.