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Flu has disappeared worldwide during the Covid pandemic

scientificamerican.com

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Re: Flu has disappeared worldwide during the Covid pandemic

#391

Post by smolder »

Majromax wrote: post #349
timr wrote: post #315

Earlier quoted context omitted.

> Given the reproduction number appears as the base of an exponent, I would not consider the difference "small." The difference in measurement is small, relative to the error in measurement. Look at the error bars on the R0 estimates in that paper. Influenza runs from 1.06 to 3.4 . You are trying to make micrometer inferences from a parameter where our best estimates are measured in libraries of congress.

I'm not a clinician or public health policymaker, so I'm operating on the balance of probabilities rather than a p=0.05 standard. If you consider the influenza estimate independent of equivalent estimates for covid, then there's a substantially greater than 50% chance that influenza's R0 is meaningfully smaller than that of the flu. If the estimates are partially dependent (i.e. methodology that gives a larger estima…

Your 2nd paragraph seems to have a mistake: influenza vs flu?

Re: Flu has disappeared worldwide during the Covid pandemic

#392

Post by varajelle »

rubicon33 wrote: post #318
aarondia wrote: post #300

Earlier quoted context omitted.

This year was a great experiment in person hygiene. It was the healthiest I have ever been for a full year, no colds, stomach bugs, anything. I'm not sure which practices I'll continue, but its definitely shown me that I have wayyyy more control over my health than I previously thought. Curious what others think are the most effective continued practices. Seems like social distancing isn't super reasonable, but maybe…

You can do a LOT. I haven't been sick once in 6+ years because I do the following: 1) Almost never eat out. Home cooked meals that I've prepped / washed. This was single handedly the biggest factor that completely removed "getting sick" from my life. 2) Hand wash before touching face, or food. 3) Avoid sick people. If I hear someone coughing or sneezing, I move away from them. Call me a germ freak, I don't care, I've…

I'm also lucky to be quite healthy, almost never sick, The last time I had a flu was probably somewhere around 2010, because I was still in my second to last job, which was the only time ever I had to take a couple of sick days

But my lifestyle is quite different. When restaurants are not closed, I eat out at least twice a week. I don't often wash my hands. And touch my face all the time. I don't bother avoiding sick people because I don't think I'll get sick.

I'm the opposite of germ freak. I don't like washing my appartment and people visiting me can easily see that.

The social distancing rules had a big impact on me and the amount of social I get.

I guess I'm just lucky with my health. Or maybe my hymune system is well trained. Who knows?

Re: Flu has disappeared worldwide during the Covid pandemic

#393

Post by timr »

Majromax wrote: post #349
timr wrote: post #315

Earlier quoted context omitted.

> Given the reproduction number appears as the base of an exponent, I would not consider the difference "small." The difference in measurement is small, relative to the error in measurement. Look at the error bars on the R0 estimates in that paper. Influenza runs from 1.06 to 3.4 . You are trying to make micrometer inferences from a parameter where our best estimates are measured in libraries of congress.

I'm not a clinician or public health policymaker, so I'm operating on the balance of probabilities rather than a p=0.05 standard. If you consider the influenza estimate independent of equivalent estimates for covid, then there's a substantially greater than 50% chance that influenza's R0 is meaningfully smaller than that of the flu. If the estimates are partially dependent (i.e. methodology that gives a larger estima…

> we also have evidence in the actual observations of epidemic dynamics. Over the southern hemisphere fall of 2020 (northern hemisphere spring), covid cases increased more rapidly than influenza cases in countries that were entering their flu seasons. That's compelling-to-me evidence that covid in fact has a larger basic reproductive number

Yes, we know that SARS-CoV2 increased, and influenza went away. That's trivially observed. We don't know why flu went away.

To turn that observation around and say "Covid grew faster than flu, and therefore it has a higher R0, and therefore, the flu went away because {insert your favorite NPI} was just good enough to stop it" is begging the question.

It could just as easily be any number of other factors that you're not accounting for. There's also a number of other faulty assumptions inherent in your logic. For starters: there's no particular reason, a priori, that a person couldn't have both flu and SARS-CoV2 in the same year.

Re: Flu has disappeared worldwide during the Covid pandemic

#394

Post by treeman79 »

timr wrote: post #271
Majromax wrote: post #237

This should not come as a surprise, and it was largely predictable from the outset. The flu has a base reproduction number (R0) less than 2 ( https://www.vdh.virginia.gov/coronavirus/2020/12/07/covid-19... ). Covid has an R0 in the vicinity of 2.5 ( https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena... ). In the meantime, public health measures like masking and distancing will work against both viruses. If…

> This should not come as a surprise, and it was largely predictable from the outset....the flu has a base reproduction number (R0) less than 2....Covid has an R0 in the vicinity of 2.5....In the meantime, public health measures like masking and distancing will work against both viruses....there's really no need for conspiracy theorizing. Assuming that this is due to "masking and distancing" and the small difference…

Having school age kids means constant illness at home. Not usually severe, but annoying.

Was one nice perk having kids at home. 9 months of no illness.

6 weeks after going back family had Covid. No it’s back in the routine of mild illness at least monthly.

Re: Flu has disappeared worldwide during the Covid pandemic

#395

Post by bigbillheck »

jMyles wrote: post #62
paviva wrote: post #55

An alternative explanation is that of "viral interference"[1,2], i.e., the most transmissible virus boosting up viral immunity in the population, and precluding transmission of the less transmissible/fit virus [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5489283/ [2]: https://www.thelancet.com/journals/lanmic/article/PIIS2666-5...

It's strange to call this an "alternative explanation", since it's the one that expert infectious disease researchers, nearly without exception, are pointing to. The (let's face it, silly) notion that masks and distancing suppressed all respiratory pathogens except one is a theory with very little traction, and which will almost certainly not stand up to serious scrutiny.

> The (let's face it, silly) notion that masks and distancing suppressed all respiratory pathogens except one is a theory with very little tracti

Are you familiar with the concept of "R0" and that one virus may be more transmissible than another?

Flu has an R0 of about 1.5, and whatever covid's is, it's higher (last I saw was 2.5).

If we postulate that masking and distancing and similar measures act to reduce these numbers across the board, say by 0.6, that brings flu down to 0.9 and covid to 1.9. Outbreaks don't tend to stay around when their R0 is below 1, which would explain why there's hardly any flu this year and plenty of covid.

Source: I was trained as a mathematical biologist and did a bunch of work with compartmental models: https://en.wikipedia.org/wiki/Compartmental_models_in_epidem...

In this admittedly over-simplified model, beta is (per wiki) "the average number of contacts per person per time, multiplied by the probability of disease transmission in a contact between a susceptible and an infectious subject".

Social distancing reduces the average number of contacts, masking reduces the probability of transmission, and both act to reduce beta. You reduce beta, you reduce R0, you win.

Re: Flu has disappeared worldwide during the Covid pandemic

#396

Post by im3w1l »

samatman wrote: post #354
Majromax wrote: post #308

Earlier quoted context omitted.

> and the small difference in R0 is crude thinking. Given the reproduction number appears as the base of an exponent, I would not consider the difference "small." If influenza has a typical R0 of about 2, reducing contacts by 50% would make its growth non-exponential. If covid has a typical R0 of about 2.5, doing the same would require a further 20% reduction of contacts, to 40% of baseline rather than 50%. Since pop…

Small but important correction: nothing can make epidemiological spread non-exponential. Driving base reproduction below one additional infection per infected patient means the exponent is less than one, so the incidence of the disease rapidly decreases. This decrease is also exponential by definition: infection is simply an exponential process, and an exponential equation doesn't stop being what it is when the expon…

At a super fundamental level, epidemics take place on a social graph. In a well connected graph spread will be exponential, but depending on graph shape it could be something else.

In particular you could imagine that if people never venture outside their own block that the social network is an euclidean graph. In an ideal case where people are evenly spaced in the plane and only interact with neighbors, the disease would spread as a circle expanding outwards, so total infections would be proportional to ~ t^2, and current infections ~ t.

Re: Flu has disappeared worldwide during the Covid pandemic

#397

Post by andreygrehov »

ceejayoz wrote: post #380
andreygrehov wrote: post #360

Earlier quoted context omitted.

I read the Reuters fact-check article. In fact, there are no facts. It says that the publication has been retracted, but from what I can see, that's not true. CDC's current response on masks is positive, however their initial response was negative. Same for WHO. All in all, Reuters rely on a single source – Nature. Nature.com is indeed a legitimate source, however the article is massive, so I can't say for sure if re…

> It says that the publication has been retracted, but from what I can see, that's not true. I'm sorry, you'll base your beliefs on an article in "Medical Hypotheses", but conclude that Reuters is making up an Elsevier spokesperson? I thought "quoting Reuters is fine"; now they're fake news?

Nope. Reuters is still a great source of truth. In fact, Reuters is my favorite publication agency. But, it doesn't mean they are saint and won't ever bullshit.

> I'm sorry, you'll base your beliefs on an article in "Medical Hypotheses".

I haven't made any conclusions yet. I'm still analyzing. Both you and Reuters try to belittle the significance of an entity based on its name or the titles of their publications. While it's possible that the publication is pure crap, "belittling" is one of those crappy techniques one can rely on to defend their arguments.

Re: Flu has disappeared worldwide during the Covid pandemic

#398

Post by joshgel »

timr wrote: post #294
joshgel wrote: post #284

Earlier quoted context omitted.

2 was published in Feb 2020, so not sure how helpful that is... 1 is not normalized data. It does not account for testing frequency. These percentages are of tests using BioFire. My hospital, for example, does not use BioFire to test for SARS-CoV-2 and so we end up running BioFire much, much less frequently than during a normal year. Anecdotally non-COVID respiratory infections in hospitalized patients have decreased…

> 2 was published in Feb 2020, so not sure how helpful that is... It's a meta-analysis of many other papers. The estimates for the other ILIs have not changed significantly in 2020. Again, this is nitpicking that misses the forest for the trees: the differences in estimated R0 between these viruses is not so precise as to be useful for claiming the effectiveness of something like "masks and distancing". > 1 is not no…

In the paper associated with 1 it says:

The FilmArray RP test utilization rate (TUR) metric is defined as the non-normalized number of RP patient test results generated each week across the Trend sites (computed as a centered 3-week moving average). To calculate the pathogen detection rate (as displayed in Figure 2 [second data view] and on the Trend website), we compute the rate for each organism at each institution as a centered 3-week moving average. To adjust for the capacity differences between sites, a national aggregate is calculated as the unweighted average of individual site rates. Only data from sites contributing more than 30 tests per week is included to avoid noise from small numbers of tests. Because the calculation of pathogen detection rate includes results from patients with multiple detections, the detection rate for all organisms can, in theory, add up to greater than one. In practice, this does not occur.

These are rates. This does not account for testing frequency. If they only tested 1 person in the United States tomorrow, and they had rhino/entero, the graph would show 100% (obviously it wouldn't and they won't only test 1 person). That means that if testing decreased, because for example there were less patients with symptomatic viral infections, but the % positive stayed the same, the chart would not appear to change, even though there were fewer cases...

paper: https://publichealth.jmir.org/2018/3/e59/

Re: Flu has disappeared worldwide during the Covid pandemic

#399

Post by tempestn »

allturtles wrote: post #330
rubicon33 wrote: post #318

Earlier quoted context omitted.

You can do a LOT. I haven't been sick once in 6+ years because I do the following: 1) Almost never eat out. Home cooked meals that I've prepped / washed. This was single handedly the biggest factor that completely removed "getting sick" from my life. 2) Hand wash before touching face, or food. 3) Avoid sick people. If I hear someone coughing or sneezing, I move away from them. Call me a germ freak, I don't care, I've…

4) Don't have children.

Don't know why you're downvoted; this is true. You can personally avoid opportunities for exposure all you want, but your 2-8ish year old kids will get colds regularly from daycare/school, and then will give them to you. I also didn't get sick from March-September 2020. Then schools re-opened here, and I was sick within 3 weeks, and then again a couple months later. And that's even with all the extra sanatization and distancing they were trying to do at school.

Re: Flu has disappeared worldwide during the Covid pandemic

#400

Post by kevin_thibedeau »

MeinBlutIstBlau wrote: post #363
Majromax wrote: post #237

This should not come as a surprise, and it was largely predictable from the outset. The flu has a base reproduction number (R0) less than 2 ( https://www.vdh.virginia.gov/coronavirus/2020/12/07/covid-19... ). Covid has an R0 in the vicinity of 2.5 ( https://www.cdc.gov/coronavirus/2019-ncov/hcp/planning-scena... ). In the meantime, public health measures like masking and distancing will work against both viruses. If…

How can you explain people getting covid but not the flu when nothing changed when places started opening up? It sounds more like poor data reporting more than anything else and I will take that to my grave.

The CDC doesn't accurately measure flu deaths. It's largely done by assessing death certificate data rather than positively identifying a flu infection. Deaths by pneumonia during the designated flu season months are counted in the tally of annual flu deaths. It is very likely that a portion of deaths attributed to COV19 over the winter were in fact from flu.
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