There are some basic misunderstandings circulating around regarding how the CDC calculates the Wastewater Viral Activity Level (WVAL) and what it means.

Let me explain what the WVAL is and isn't.

1/

https://x.com/michael_hoerger/status/1880860632850829519

Another thread that gets it wrong.
2/

https://x.com/greg_travis/status/1880632684978085893

Influenza prevalence in the US drops suddenly the first week of each year, a trend which was observed pre-covid and has continued post-covid.

Red lines are my additions to the charts below, marking the 1st week of the year.

1/
The timing is too precise to be an effect of climate and likely reflects increased social mixing in the Thanksgiving to Christmas period, and decrease thereafter (school break may also be important).

2/

Quite an opening paragraph:

"Among the current generation...many are growing up with their mother or father confined to bed or confined to bed themselves. According to a study by ANU, long COVID is hitting up to an estimated 20% of Australians three months after...COVID..."

1/ Story from @jasemurphy in @crikey_news, here:



2/crikey.com.au/2024/12/02/lon…

Part III of what I've found in looking for evidence of long covid on the Australian workforce.

(This is the last segment of the thread. The other two can be found below, if you didn't read them you may want to start there!)

1/

https://twitter.com/MichaelSFuhrer/status/1850724318139048104

In this thread I examine some ABS survey results for workforce participation.

First, the ABS survey regularly identifies people not in the labour force, with the following possible reasons:

2/

Part II of what I've found in looking for evidence of an effect of long covid on the Australian workforce.

(if you didn't read Part I, it is below!)

1/

https://twitter.com/MichaelSFuhrer/status/1849668806131761379

In this thread, I looked at ABS survey results for workforce participation. The ABS regularly surveys the population 15 and older. The survey records reasons why employees worked fewer hours than normal.

These are the available choices:

2/

I went looking for evidence of an effect of long covid on the Australian workforce. Here’s what I found.

(this will be a long thread, in installments!)

🧵1/ Let me preface by saying that long covid is real, and an important part of the burden of disease of the novel covid-19 pandemic. We know with certainty that long covid is making work impossible for some, and for others it is debilitating enough to cause missed hours of work.

2/

If you happen to see one of these amateur estimates of covid-19 infection numbers floating around the internet, here's a handy graphic you can use to show why this is unscientific misinformation.

1/

https://x.com/michael_hoerger/status/1845695053819474252

There's a lot of obfuscation and gobbledygook in @michael_hoerger's posts.

Don't be fooled.

He's plotting *one* number, from one source of data: The CDC's Wastewater Viral Activity Level.

2/

Following up on covid-vs. flu mortality.

Let’s have a look at the US.

I’m going to explain why I think mortality rates (per year) are currently very similar (within a factor of 2) for covid and flu in the US. (I don’t expect everyone will agree!)


1/

https://x.com/MichaelSFuhrer/status/1841301332080365650

First, some raw data on deaths by cause of death (including underlying and contributing) for covid and flu over July 2023 to June 2024 (one year, including one flu season), broken out by age group.

2/

"Covid-19 isn't seasonal" is an odd claim. Here is covid-19 surveillance at emergency departments in US, averaging data for 6 northern regions (blue) and three southern regions (red).

Two waves/year with one in late summer and one in winter have occurred consistently...
1/ ...throughout the pandemic.

Summer waves (red arrows) are bigger in the south, and northern regions (blue line) tend to show relatively higher winter waves (blue arrows) compared to summer waves (red arrows).

2/

I have been thinking a lot about this tweet.

What is a "normal" flu season? What is a "weird" flu season?

1/

https://twitter.com/SolidEvidence/status/1835689340200231355

Influenza isn't all one type. There are three currently circulating flu strains in humans which cause significant disease: influenza A/H1N1, A/H3N2 and B/Victoria.

Here are detections of the three strains over time from US sentinel labs.

2/

In the six stories on COVID-19 @Hayley_Gleeson has written this year for @abcnews, a total of 19 expert sources (scientists or medical practitioners) are quoted.

10 out of 19 are members of zero-covid advocacy groups @TheWHN, @RealOzSAGE, @IndependentSage, @JohnSnowProject.

1/

https://twitter.com/abcnews/status/1838303603234127898

These zero-covid advocacy groups are discussed in this peer-reviewed article, which estimates that fewer than 1% of scientists working on COVID-19 are members of such groups.

2/

sciencedirect.com/science/articl…

Oh good lord, this is absolutely hilarious and devastating news for the copromancers.

Here's how CDC aggregates its wastewater data.

TL;dr, it's a Z-score of variation around a baseline of last 12 months' data from each site.

1/
cdc.gov/nwss/about-dat…
In simple terms, "high" or "low" means high/low compared to the average of the last 12 months!

***By design*** it is impossible to use the data to compare the size of waves that are >12 months apart, or to calculate absolute numbers of infections.

2/

I thought I’d provide my thinking on this set of polls.

To start, I’ll say I was heartened by the polite and constructive engagement!

The thread got more than a dozen replies and >300 votes. (I re-posted on the blue site: 2 likes and 0 comments ☹.)

1/

https://x.com/MichaelSFuhrer/status/1833328190200414240

https://twitter.com/MichaelSFuhrer/status/1833328190200414240

My personal calculus:

I think annual boosters are probably quite effective against onward transmission, probably 50% (a combination of VE|infection and VE|symptomatic which affects onward transmission).
2/

Really good article about the body of work from @zalaly using electronic health records to study post-acute symptoms of covid in the US Veterans Health Administration.

Mirrors many of the criticisms I've made of these studies over the years.

1/undark.org/2024/07/25/lon… "At best, the studies are detecting health problems...when people with poor baseline health experience a severe infection of any kind, said @anders_hviid. At worst, the findings simply reflect bias...picking up on symptoms that are not caused by Covid-19 at all."

2/

"Conservative estimates suggest that over 200 million SARS-CoV-2 infected individuals worldwide will develop persistent symptoms of COVID-19" (C. Yang and S.J. Tebutt)

Tracking down the origin of that number led me to an absolute gem of a figure...

thelancet.com/journals/lanep…
C. Yang and S.J. Tebutt cite Ref 1 as the source.

Ref 1 is another paper by the same authors and isn't the actual source of the 200 million figure. Sloppy referencing!

(But well done slipping in a self-reference 👍)

frontiersin.org/journals/immun…

Top-level result here is that covid is 1.35 times [95% CI, 1.10-1.66] more deadly than influenza in this cohort (VA patients hospitalized due to covid or influenza).

To me that means covid ~ influenza.

Moreover...

1/

https://twitter.com/zalaly/status/1790809011031351597

Around 44% of those hospitalized for influenza had been vaccinated this season. While that's lower than the average vaccination for this age cohort (most >65) of around 54% (quite possibly because the vaccine works!)

But...

2/

A new study out on neurologic sequelae following covid-19 or influenza hospitalization using a large electronic health record database.

Interesting to compare this study to the recent study using VA database - a thread.

1/

neurology.org/doi/10.1212/WN… I wrote a lot about the VA study here.


Here's the rate of new neurological diagnoses after covid-19 (red) or influenza (blue) hospitalization in the VA study:

2/

https://twitter.com/MichaelSFuhrer/status/1746654964473332063

Does covid infection cause psychiatric and neurologic disorders?

A tale of two studies, and an interesting story about how science works!

Time for a long weekend thread.

1/

First, this study published last year in Nature Medicine.



The study examined electronic health records of the US Department of Veterans Health Care System (VHA).

2/nature.com/articles/s4159…

Immunity gap update.

Flu and RSV hospitalizations have peaked in the US. How does this season compare to previous?

Thread.

1/ RSV first. Overall, RSV hospitalizations are down a little this year compared to last but still higher than pre-pandemic.

2/

In testimony before the US Senate yesterday, Dr. Ziyad Al-Aly (@zalaly) is quoted as saying “The burden of disease and disability in Long Covid is on par with heart disease and cancer”.

I think this statement is provably false.

Thread.

1/🧵

https://twitter.com/luckytran/status/1748037164913267006

The basis of the statement appears to be a study on which Dr. Al-Aly is the lead author, “Postacute sequelae of COVID-19 at 2 years”.

The abstract is below.

2/

nature.com/articles/s4159…

I’d like to revisit this study by @zalaly’s group.

I want to tackle one issue in particular:

Does the study provide evidence that those hospitalized for COVID-19 had worse *long-term* health outcomes compared to those hospitalized for influenza?

1/🧵
thelancet.com/journals/lanin…
I discussed the same study previously here:

2/🧵

https://twitter.com/MichaelSFuhrer/status/1735803629498671599