A Concerned Scientist @BE@qoto.org

Had to pull up an old post here for an unfortunate update.

We went back to this guy because we had another roofing job that we needed done and he was our first call. He said he was happy to take it on and scheduled us for almost a month ago now. He tore a ligament in his knee on the job before ours, unfortunately. These things happen.

However, while rehabbing that, in and out of doctor’s offices, etc. he got “sick” again. Checked in with him this morning to see how he was doing, as he’d tentatively scheduled us for next week and he had a heart attack yesterday.

I think this article from Scientific American does a great job of laying out some of the reasons these documents are important.

https://www.scientificamerican.com/article/a-fight-about-viruses-in-the-air-is-finally-over-now-its-time-for-healthy/

"The operative phrase here is “through the air.” It’s plain language that anyone can understand, and this switch from jargon such as “airborne” and “aerosol” may finally clear the way for researchers to get funding to study better, real-life ways to protect people from a range of infectious diseases.

And just maybe governments, retailers, school authorities and others can now start to get solid information about ways they can clean indoor air. While it is going to take more than a wordy WHO statement to persuade gym owners that fogged-up windows mean too many people are huffing out potentially infectious air, the new wording does provide a better explanation of why it’s gross and unhealthy."

...

"This should clear the way for funding more and better research on the transmission of infectious diseases—not just COVID, but influenza, respiratory syncytial virus (RSV) and viruses that cause the common cold. That, in turn, should give managers of schools, retailers, airports and other public spaces the information they need to help keep air and surfacers cleaner. Because if people understand the physics of disease transmission, they can find ways to safely keep schools, shops and restaurants open during outbreaks and epidemics with better practices in ventilation, air and surface cleaning and foot traffic control."

...

"“It’s now respectable to do this research,” Jiménez said. “People can get funding to do some research about indoor air and engineering systems. They are stepping into fields that they really wouldn’t work on before. So you see some encouraging changes.”"

The paper has some salient, and interesting facts. It's always amazing to me what research comes out of these types of situations, and what assumptions that were made previously don't hold up to scrutiny.

"Here we evaluate the expression of IAV receptors in situ in the mammary gland, respiratory114 tract and cerebrum of cattle, which typically has been considered less susceptible to IAV115 infection5 . Strikingly, was the finding that both the human- (SA-α2,6) and the duck receptors116 (SA-α2,3-Gal-β1,3) were highly expressed in the mammary glands, whereas no expression of117 the chicken receptor (SA-α2,3-Gal-β1,4) was detected. A previous study showed that co-expression118 of both the human- and avian receptors can enhance the receptor binding of H5N1119 isolated from ducks (clade 2.1.1) in vitro23. Combined these findings support the hypothesis120 that the high viral load seen in milk from cows infected by HPAI H5N1 virus belonging to121 clade 2.3.4.4b are due to local viral replication, because these viruses have high affinity for this122 receptor24. Additionally, the avian receptor has been found to be highly expressed in the human123 cornea and conjunctiva25 which may explain the report that conjunctivitis was the dominating124 clinical sign of a person presumably infected by dairy cows in Texas 7."

"The transmission route(s) and the pathogenesis of H5N1 in cows remain unclear,126 and it’s not known if the virus enters the mammary gland by an ascending infection or127
systemically by the blood supply.

...

Suggestions by the USDA that only some udder quarters may be133 involved in infection does, however, argue against a viremic source27."

"The investigation of the IAV receptor distribution in the respiratory tract also135
revealed some novel findings. In the upper respiratory tract and upper part of the lower136 respiratory tract (trachea, bronchi, and bronchioles), the chicken receptor (SA-α2,3-Gal-β1,4)137 was expressed on the surface of the respiratory epithelium, whereas a lack of - or very limited138 expression - of the human and duck receptors was detected. This pattern is the opposite to what139 we found in the mammary gland. The lack of expression of the human receptor in the upper140 respiratory tract of cattle contrasts with findings in humans25,28 and swine22,25 and supports the141 perception that bovines are highly resistant to infection with influenza A viruses of human and142
swine origin when exposed by the respiratory route1,29. In the lung alveolar cells, however, all143 three receptors were abundantly expressed, similar to what has been found in pigs and144
humans22,25,28."

After a peaceful weekend in the woods and some reflection, I decided I am not going to live blog all of the articles that come out about H5N1 any further. I think a lot of it is distraction. That said, I would still like to keep up on the science, and I'm sure other people would, too.

So here's a new story on an article discussing how cows might be a "mixing vessel" for influenza that digs into the receptor types. It "found that tissue from the mammary gland contains abundant receptors of the kind to which avian flu viruses like H5N1 can attach. But brain and respiratory tract tissues contained far fewer of this type of receptor."

https://www.statnews.com/2024/05/06/bird-flu-spread-study-of-h5n1-virus-infection-in-cows/

https://www.biorxiv.org/content/10.1101/2024.05.03.592326v1.full.pdf+html

"Human IAVs24 preferentially bind SA-α2,6 (human receptor), whereas avian IAVs have a preference for α2,325
(avian receptor). The avian receptor can further be divided into two receptors: IAVs isolated26 from chickens generally bind more tightly to SA-α2,3-Gal-β1,4 (chicken receptor), whereas27 IAVs isolated from duck to SA-α2,3-Gal-β1,3 (duck receptor). We found all receptors were28 expressed, to a different degree, in the mammary gland, respiratory tract, and cerebrum of beef29
and/or dairy cattle. The duck and human IAV receptors were widely expressed in the bovine30 mammary gland, whereas the chicken receptor dominated the respiratory tract. In general, only31 a low expression of IAV receptors was observed in the neurons of the cerebrum. These results32 provide a mechanistic rationale for the high levels of H5N1 virus reported in infected bovine33
milk and show cattle have the potential to act as a mixing vessel for novel IAV generation."