Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Flu has disappeared worldwide during the Covid pandemic

scientificamerican.com

Post reply on HN
Print view View original

541–550 of 821 posts

Re: Flu has disappeared worldwide during the Covid pandemic

#541

Post by ryankemper »

jacobolus wrote: post #488
timr wrote: post #271

Earlier quoted context omitted.

> 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…

> Unlike Covid, kids are a significant vector of spread for influenza Kids are significant spreaders of both influenza and Covid (after school reopenings, in many countries kids become one of the top sources of inter-household Covid spread). They just tend to have mild or absent Covid symptoms and didn’t require regular testing for work etc., and therefore did not get consistently tested in most parts of the world. I…

Actually, what you're saying is untrue. The overwhelming evidence shows that children spread COVID less than adults do.

My favorite is this: https://www.nejm.org/doi/pdf/10.1056/NEJMoa2006100?articleTo...

The study isolated SARS-CoV-2 samples from every positive case, sequenced genome of virus, and tracked the mutation patterns. So, that will avoid a lot of the errors that improper qPCR usage can result in.

First things first, age and viral susceptibility:

> Of the 564 children under the age of 10 years in the targeted testing group, 38 (6.7%) tested positive, in contrast to positive test result in 1183 of 8635 persons who were 10 years of age or older (13.7%). In analyses involving participants up to 20 years of age, we observed a gradual increase with older age in the percentage who tested positive (Fig. S5).

That's more about who got it, but there's some discussion of transmission here where the senior author talks about it: https://www.sciencemuseumgroup.org.uk/blog/hunting-down-covi...

> Children under 10 are less likely to get infected than adults and if they get infected, they are less likely to get seriously ill. What is interesting is that even if children do get infected, they are less likely to transmit the disease to others than adults. We have not found a single instance of a child infecting parents.

> There is an amazing diversity in the way in which we react to the virus.

---

(I recognize I only presented one study here - there's only so much time in the day :P - but the other high-quality studies I've seen confirm this. Mechanistically it makes sense if you look at the enormous T-cell cross-reactivity in those age groups. And BTW, data on school closures for Influenza (which children seem to transmit much more readily) showed that school closures were ineffective anyway because they would just spread it more outside of school)

Re: Flu has disappeared worldwide during the Covid pandemic

#542

Post by defaultname »

clon wrote: post #510
defaultname wrote: post #443

Earlier quoted context omitted.

Each virus can only interact with certain cells of your body. COVID and influenza interact with lower respiratory cells. You have to inhale a viral load to be infected, or at least this is the consensus belief right now (and is contrary to all of the concern about fomites early on). Many cold-like viruses infect mucous membranes (you have a number over your body). A glancing touch is enough to be infected.

Do you have a reference for this? My SO still insists on washing our shopping, which, according to your information is totally unnecessary.

I'm certainly not trying to present medical information on here, and no one should change behaviors based upon what I said.

https://www.usatoday.com/story/news/nation/2020/09/08/do-you...

https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

Re: Flu has disappeared worldwide during the Covid pandemic

#543

Post by ryankemper »

majormajor wrote: post #228
ManBlanket wrote: post #198

Earlier quoted context omitted.

The first, "alternative explanation" the statistician in me wants to mention is perhaps the way influenza data is gathered has changed. "Only people who get tested for influenzalike illnesses—typically about 5 percent of individuals who fall ill—are tallied." If there were a change in the way these tests were administered, for example a blaring medical bias toward another disease, that would present a significant sam…

A bias towards testing for Covid wouldn't explain fewer cases of the flu unless those cases of the flu were coming back as Covid falsely instead of so further diagnosis was stopped. If you have a bad enough flue to seek treatment, then once you get that Covid test and it says "negative", you would move on to the next step for treatment. (Consistent with past years - nobody was getting flu tested just cause they had a…

> Seems like the simplest answer is just "actions that have reduced the spread of one disease have also reduced the spread of another, that's historically less widespread already."

This is not the simplest answer, and the evidence that the measures have really slowed spread is extremely low except in places like New Zealand and Australia which are small islands in Oceania.

---

> A bias towards testing for Covid wouldn't explain fewer cases of the flu unless those cases of the flu were coming back as Covid falsely instead of so further diagnosis was stopped.

Exactly this. I'm partial to the viral interference hypothesis, but what you don't seem to realize is that if you get infected for SARS-CoV-2 and recover in 7-14 days, you will still test PCR+ for months after. This goes into the widespread mistuning of the cycle threshold. Case in point: They tested George Floyd's corpse for COVID-19 and he was PCR+, despite having recovered from COVID-19 a couple months before. The test hit on the remnant viral debris from his long-gone infection.

Re: Flu has disappeared worldwide during the Covid pandemic

#545

Post by ryankemper »

ineedasername wrote: post #526
tshaddox wrote: post #218

Earlier quoted context omitted.

If a large portion of the people who contracted COVID are removed from the set of people who could have potentially exposed me to the flu, doesn't that decrease the likelihood of me contracting the flu regardless of whether I contracted COVID?

Removing those people removes, relatively, an extremely small portion of the population. You are removing roughly 10% of the population in the U.S., or 2% worldwide. This does not explain the magnitude of the decrease observed for the flu. Is it that hard to believe that not being around other people limits the chance of getting sick from other people?

> You are removing roughly 10% of the population in the U.S., or 2% worldwide.

These numbers seem way too low if you're talking about the prevalence of people that have been exposed to SARS-CoV-2.

Re: Flu has disappeared worldwide during the Covid pandemic

#546

Post by zackees »

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…

The problem with this logic is the presumption that wearing masks was a widespread phenomenon. As someone who traveled a lot this year I can assure you that there a many states and areas that mostly ignored the lockdowns happening in the city areas.

For these places, we would expect the flu to continue on as normal. Instead it’s disappeared.

How strange.

Re: Flu has disappeared worldwide during the Covid pandemic

#547

Post by ryankemper »

addicted wrote: post #70
jMyles wrote: post #62

Earlier quoted context omitted.

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.

There’s nothing silly about a novel virus having greater abilities to overcome barriers when compared to other pathogens that humans have had years decades and centuries to develop defenses again. At the end of the day it’s likely gonna be the result of a combination of all these factors.

> There’s nothing silly about a novel virus having greater abilities to overcome barriers when compared to other pathogens that humans have had years decades and centuries to develop defenses again.

This isn't really quite accurate though. Before SARS-CoV-2 ever emerged, our immune systems already had defenses against it. This is because of the already-extant circulating hCoVs.

This is why something like 80% of blood samples taken before SARS-CoV-2 emerged showed T-cell cross-reactivity. From the perspective of our immune system, it was never a "novel" virus. It was novel to scientists and politicians but not to the human immune system.

Re: Flu has disappeared worldwide during the Covid pandemic

#548

Post by 0x445442 »

gorbachev wrote: post #262

I was just commenting to a co-worker my entire family hasn't been sick since the pandemic started. That is very unusual for a family with young children. No flu, no stomach viruses, absolutely nothing for more than a year now. Thankfully no covid-19 either.

Due to T-Cell immunity, a max of 20% of the population was ever going to catch the CV19 version of the flu anyway. Its obvious at this point the reaction was extremely disproportional to the risk.

Re: Flu has disappeared worldwide during the Covid pandemic

#549

Post by galangalalgol »

jampekka wrote: post #529
galangalalgol wrote: post #518

Earlier quoted context omitted.

The normal flu can be pretty bad. In 2018 the spike in total deaths in TX and surrounding states were between a third and a half of the covid spike in those regions. Masks might have been a good idea in 2018 and I hope they become part of our culture at least when you think you might be coming down with something. You know, that first day of a cold when you are telling yourself its allergies or drainage. Shutting dow…

How about a culture and social support system where you can just stay home and rest if you feel something's up? Probably a lot more efficient than a mask, and would probably help with lots of other problems as well.

But sometimes it is allergies, and you feel fine and want to get some work done. Masks aren't a big deal, I forget I have mine on, and I wear it all day. Maybe some people have more difficulty? If I vwas in construction or something more physical vthan typing I might vfeel differently.

Re: Flu has disappeared worldwide during the Covid pandemic

#550

Post by rubicon33 »

tehlike wrote: post #475
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…

I don't think your anecdata proves anything but your own experience. 1. I eat out a lot, including junk food every now and then. 2. Of course I hand wash, but i would not say "before touching face" per-se, but as often as you'd normally expect (restroom breaks, before preparing food and/or eating, after coming from outside). 3. I don't really run away from sick people. I simply am indifferent. I still never get sick,…

Yes well, I would hope if you've learned nothing during this pandemic it's that there is no one-size-fits-all immune system. Some 20 year olds are dying from COVID, others are barely noticing they have symptoms.

All suggestions are de facto "anecdata". What works for me, may not work for you. I used to get "food poisoning" once a year or so, but haven't ever since I stopped eating out. That you are more resilient to whatever food born illnesses I was encountering, does not invalidate my own experience.

Post reply on HN