BE

BE, 1 month ago

Presented without further comment.

https://www.nature.com/articles/s41577-019-0143-6

"The adaptive immune response to influenza virus infection is multifaceted and complex, involving antibody and cellular responses at both systemic and mucosal levels. Immune responses to natural infection with influenza virus in humans are relatively broad and long-lived, but influenza viruses can escape from these responses over time owing to their high mutation rates and antigenic flexibility."

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5291154/

"In summary, herd effects are assumed with influenza vaccine programmes, but there are few studies that quantify the herd effect of vaccination. We found low-level evidence supporting a herd effect of vaccination on influenza virus infection in contacts of vaccinated persons. Further rigorous studies are needed in order to better understand under which circumstances vaccination may prevent influenza and its complications in contacts."

BE, 1 month ago

I don't really have time today to do a deep dive write-up on these, as I often do for articles. However, if you're interested in the possibility of airborne transmission, where the science has been on this, and how far off the possibility has been(spoiler alert, 5 amino acid substitutions) these articles are a good starting point. I'm also putting them here so I can refer back to them in the future if needed.

"Influenza A viruses are transmitted via the air from the nasal respiratory epithelium of ferrets"

https://www.nature.com/articles/s41467-020-14626-0

"Airborne Transmission of Influenza A/H5N1 Virus Between Ferrets"

https://www.science.org/doi/10.1126/science.1213362

"The Potential for Respiratory Droplet–Transmissible A/H5N1 Influenza Virus to Evolve in a Mammalian Host"

https://www.science.org/doi/10.1126/science.1222526

"A comprehensive review of highly pathogenic avian influenza (HPAI) H5N1: An imminent threat at doorstep"

https://www.sciencedirect.com/science/article/pii/S1477893923000984

"The Role of Airborne Particles in the Epidemiology of Clade 2.3.4.4b H5N1 High Pathogenicity Avian Influenza Virus in Commercial Poultry Production Units"

https://www.mdpi.com/1999-4915/15/4/1002

"Influenza: Five questions on H5N1"(which I admittedly mostly found interesting because it extensively quotes Jeremy Farrar 11 years before he became the head of the WHO in 2023)

https://www.nature.com/articles/486456a

BE, 1 month ago

As pointed out by @HelenBranswell there's an early release of a paper from Iowa State with scientific details of the early part of this cattle H5N1 outbreak. To be quite honest, there's a lot in there that I can't really intelligently talk about as it's just out of my scientific comfort zone, but, I'm sure people who are more knowledgable will spring up to discuss it somewhere out there.

Some things I found interesting:

• From the cats in Texas that died "In total, >50% of the cats at that dairy became ill and died."

They were being fed milk from sick cows.

• "The HA sequences from the milk samples had 99.94% nucleotide identities with HA sequences from the cat tissues, resulting in a distinct subcluster comprising all 4 HA sequences, which clustered together with other H5N1 viruses belonging to clade 2.3.4.4b"

• "This case series differs from most previous reports of IAV infection in bovids, which indicated cattle were inapparently infected or resistant to infection (9). We describe an H5N1 strain of IAV in dairy cattle that resulted in apparent systemic illness, reduced milk production, and abundant virus shedding in milk. The magnitude of this finding is further emphasized by the high death rate (≈50%) of cats on farm premises that were fed raw colostrum and milk from affected cows; clinical disease and lesions developed that were consistent with previous reports of H5N1 infection in cats presumably derived from consuming infected wild birds (10–12). Although exposure to and consumption of dead wild birds cannot be completely ruled out for the cats described in this report, the known consumption of unpasteurized milk and colostrum from infected cows and the high amount of virus nucleic acid within the milk make milk and colostrum consumption a likely route of exposure. Therefore, our findings suggest cross-species mammal-to-mammal transmission of HPAI H5N1 virus and raise new concerns regarding the potential for virus spread within mammal populations."

• "Clinical IAV infection in cattle has been infrequently reported in the published literature. The first report occurred in Japan in 1949, where a short course of disease with pyrexia, anorexia, nasal discharge, pneumonia, and decreased lactation developed in cattle (17). In 1997, a similar condition occurred in dairy cows in southwest England leading to a sporadic drop in milk production (18), and IAV seroconversion was later associated with reduced milk yield and respiratory disease (19–21)."

• "An IAV-associated drop in milk production in dairy cattle appears to have occurred during >4 distinct periods and within 3 widely separated geographic areas: 1949 in Japan (17), 1997–1998 and 2005–2006 in Europe (19,21), and 2024 in the United States (this report). The sporadic occurrence of clinical disease in dairy cattle worldwide might be the result of changes in subclinical infection rates and the presence or absence of sufficient baseline IAV antibodies in cattle to prevent infection. Milk IgG, lactoferrin, and conglutinin have also been suggested as host factors that might reduce susceptibility of bovids to IAV infection (9). Contemporary estimates of the seroprevalence of IAV antibodies in US cattle are not well described in the published literature. One retrospective serologic survey in the United States in the late 1990s showed 27% of serum samples had positive antibody titers and 31% had low-positive titers for IAV H1 subtype-specific antigen in cattle with no evidence of clinical infections (24). Antibody titers for H5 subtype-specific antigen have not been reported in US cattle."

• "The genomic sequencing and subsequent analysis of clinical samples from both bovine and feline sources provided considerable insights. The HA and NA sequences derived from both bovine milk and cat tissue samples from different Texas farms had a notable degree of similarity. Those findings strongly suggest a shared origin for the viruses detected in the dairy cattle and cat tissues. Further research, case series investigations, and surveillance data are needed to better understand and inform measures to curtail the clinical effects, shedding, and spread of HPAI viruses among mammals. Although pasteurization of commercial milk mitigates risks for transmission to humans, a 2019 US consumer study showed that 4.4% of adults consumed raw milk >1 time during the previous year (29)"

(Is anyone monitoring these people, specifically?)

• "Ingestion of feed contaminated with feces from wild birds infected with HPAI virus is presumed to be the most likely initial source of infection in the dairy farms. Although the exact source of the virus is unknown, migratory birds (Anseriformes and Charadriiformes) are likely sources because the Texas panhandle region lies in the Central Flyway, and those birds are the main natural reservoir for avian influenza viruses (30)"

• "The mode of transmission among infected cattle is also unknown; however, horizontal transmission has been suggested because disease developed in resident cattle herds in Michigan, Idaho, and Ohio farms that received infected cattle from the affected regions, and those cattle tested positive for HPAI H5N1 (33)"

• "In conclusion, we showed that dairy cattle are susceptible to infection with HPAI H5N1 virus and can shed virus in milk and, therefore, might potentially transmit infection to other mammals via unpasteurized milk. A reduction in milk production and vague systemic illness were the most commonly reported clinical signs in affected cows, but neurologic signs and death rapidly developed in affected domestic cats. HPAI virus infection should be considered in dairy cattle when an unexpected and unexplained abrupt drop in feed intake and milk production occurs and for cats when rapid onset of neurologic signs and blindness develop. The recurring nature of global HPAI H5N1 virus outbreaks and detection of spillover events in a broad host range is concerning and suggests increasing virus adaptation in mammals. Surveillance of HPAI viruses in domestic production animals, including cattle, is needed to elucidate influenza virus evolution and ecology and prevent cross-species transmission."

https://wwwnc.cdc.gov/eid/article/30/7/24-0508_article

BE, 1 month ago

There's a new article on StatNews today from @HelenBranswell with a Q&A format about what we know, and don't know, at this point about this outbreak.

https://www.statnews.com/2024/04/30/h5n1-bird-flu-virus-cows-and-risk-to-people/

Wear a mask makes an early appearance, so that's a plus. There's some discussion of asymptomatic and presymptomatic spread.

Some quotes of note:

• "The U.S. Department of Agriculture has said few tests from the respiratory tracts of infected cows have come back positive — and those that did showed there wasn’t a lot of virus present. But there is at least some evidence that H5N1 is on occasion getting deep into the respiratory tracts of cows."

• "While the contribution of respiratory transmission is still in question, there appears to be little doubt that a lot of spread is happening in milking parlors, where cows are strapped into the milking machines, and that in dairy cows, H5N1 seems to be primarily infecting mammary glands. The amount of virus in the udders of infected cows is off-the-charts high, making it easy to see how one cow’s infection soon becomes a herd’s problem."

• "Taylor noted another worry: H5N1, which is notorious for its ability to evolve, is being given a huge opportunity to adapt to bovine hosts. “The concern is if it becomes effective as a respiratory pathogen in cattle, it’s more likely to become effective as a respiratory pathogen in humans,” he said."

• "Sifford noted that cows in a herd without symptoms tested positive after cattle were moved into it from another herd whose remaining animals then went on to develop symptoms. The positive cows in the second herd haven’t developed symptoms, she said. “We are just getting underway with those studies to give us an idea of the opportunity for viremia either ahead of or after clinical signs,” she said. “So we should have more information about that in the coming weeks.”

One such study will be taking place in the high-containment laboratories at Kansas State University’s Center of Excellence for Emerging and Zoonotic Animal Diseases. Director Jürgen Richt said his group already has the necessary approvals and hopes to begin the research in mid-May."

• "Some uninfected cows will be housed with the infected animals to see whether they contract the virus, Richt said."

• "As to whether infected cows that have no symptoms are shedding virus in their milk, the evidence of viral traces in commercially purchased milk brings that question to the forefront. Farmers are supposed to discard milk from infected cows, which reportedly looks odd — yellowish and unusually thick. But PCR testing of commercially sold pasteurized milk has shown a substantial portion of samples were positive for RNA from H5N1, indicating the presence of either viral fragments or dead viruses. (The FDA said last week about one in five samples purchased in a cross-country survey tested positive.) So either some farmers aren’t following the recommendation, or some milk isn’t noticeably altered, or some cows that aren’t known to be sick are shedding the virus in their milk."

• "Kuiken is a bit pessimistic about whether, once the virus has found its way into a herd, transmission can be stopped: “You can’t not milk. And you probably can’t milk so well as to prevent cow-to-cow spread. I don’t think you can do it.” "

• "The CDC recommends that people working with or around cattle suspected or confirmed to be infected with H5N1 wear gloves, disposable fluid-resistant coveralls, vented safety goggles or a face shield, and an N95 respirator."

I would like to add to this that the CDC has recommendations for backyard flock owners since 2022 and I have yet to hear of anyone following it, even after bird flu has been found in their area. Recommendations, such as an N95, safety goggles and head to toe PPE, are pointless if no one follows them, or knows about them to begin with.

https://www.cdc.gov/flu/avianflu/h5/backyardflockowners.htm

• "Kuiken said the setup of many milking parlors is almost tailor-made to put workers in contact with viruses being shed in milk. That’s because there is typically a well — think of the area under the hoist in the garage where your car gets repaired — where workers are located while cows are being milked.

“So the milk worker is standing in a depressed area, and therefore his eyes are about at knee level — a little bit higher, maybe — with the cow. So very good for being inoculated, for eye infection,” he said."

• "Cook is also concerned about the possibility that the high pressure hoses that are used to spray down the parlors after milking may be aerosolizing virus that has fallen to the floor, making it easier for cows — and humans —to breathe in. He and other colleagues at the University of Wisconsin have begun deploying air monitoring devices into the milking parlors of affected farms to investigate the extent to which they can find genetic evidence of the virus in the air."

• "Farmers, who mostly haven’t been willing to have their cows tested, haven’t been keen to have their workers tested either."

Look, I know a lot of people are mad at the CDC about this, but, they can't raid farms and force people to test for a virus. I would sincerely like everyone who is calling for this to think it all the way through.

• "The World Health Organization appears to be concerned about the possibility of undetected human cases. Maria Van Kerkhove, acting head of the department of epidemic and pandemic preparedness, told STAT she’d like to see, among other things, studies looking for antibodies to H5N1 in the blood of farm workers and people who’ve been in contact with farm workers, to determine if there have been unreported cases and possibly even spread from those individuals to others."

People who don't want the CDC to test their workers for an active infection are really going to love the idea of the WHO coming in and testing their blood, right?

BE, 29 days ago

New article from StatNews again today, this time titled "Pasteurization inactivates H5N1 bird flu in milk, new FDA and academic studies confirm"

https://www.statnews.com/2024/05/01/bird-flu-pasteurization-inactivates-h5n1-in-milk/

I think the take home message in the article is:

"On Wednesday, the agency reported results from testing of a further 201 products, which included cottage cheese and sour cream, in addition to milk. Any PCR-positive samples were then injected into embryonated chicken eggs, to see whether any active virus could be grown — the gold standard test for assessing the viability of an influenza virus. None of the samples produced viable, replicating virus, Prater said."

"In addition, several samples of retail powdered infant formula as well as other powdered milk products. All PCR results from these products were negative. The agency did not disclose when it plans to make its full analysis, including which products were purchased from which states, available to the public."

"Bolstering the FDA’s data, academic researchers at the Ohio State University and St. Jude Children’s Research Hospital told STAT Tuesday night that their own study of 58 PCR-positive milk samples taken from Texas, Kansas, and eight other states in the Midwest also failed to turn up any evidence that H5N1 can survive the pasteurization process."

BE, 28 days ago

Catching up on my reading today and there's 4 new articles from StatNews.com that fit in this thread.

First, making the case for expanded wastewater surveillance:

https://www.statnews.com/2024/05/01/h5n1-bird-flu-hospital-wastewater-surveillance/

@HelenBranswell with another article about the USDA obfuscating data by labeling genomic sequences with simply "USA" and "2024":

https://www.statnews.com/2024/05/02/bird-flu-in-cows-h5n1-virus-changes-missing-data/

This one discusses a preprint

"The authors suggest the spillover event that started the spread in cattle may have happened in early December. The first detection that something was amiss with some cattle herds in the Texas panhandle dates to late January, but it took until March 25 before USDA confirmed the presence of H5N1 in a Texas herd."

https://www.biorxiv.org/content/10.1101/2024.05.01.591751v1.full.pdf+html

"Our genomic analysis
and epidemiological investigation showed that a reassortment event in wild bird populations preceded a5
single wild bird-to-cattle transmission episode. The movement of asymptomatic cattle has likely played a
role in the spread of HPAI within the United States dairy herd. Some molecular markers in virus populations
were detected at low frequency that may lead to changes in transmission efficiency and phenotype after evolution in dairy cattle. Continued transmission of H5N1 HPAI within dairy cattle increases the risk for
infection and subsequent spread of the virus to human populations."

The politics of public health is the topic of the next one, which is depressing:

https://www.statnews.com/2024/05/02/bird-flu-testing-dairy-state-politics-in-congress/

"Republican lawmakers have one big message on the avian flu outbreak in cows: Calm down."

No comment from me as I couldn't even get through it without having to take a walk.

And, finally, a little more info about the preprint paper from above and the recent data dump from the USDA:

https://www.statnews.com/2024/05/02/bird-flu-virus-in-cows-four-months-before-h5n1-outbreak-confirmed/

""These data support a single introduction event from wild bird origin virus into cattle, likely followed by limited local circulation for approximately 4 months prior to confirmation by USDA,” the authors wrote."

"In the last few years, H5N1 has spread from wild birds to a variety of carnivorous mammals, including foxes, bears, and seals, but in each of those instances, the virus has hit a dead end. The outbreak in dairy cows represents one of the first times that this bird flu virus has demonstrated the ability to efficiently transmit between mammals, said Thomas Mettenleiter, a virologist who served as the director of the Friedrich Loeffler Institut — Germany’s leading animal disease research center — from 1996 until he stepped down last year. The other instance was a number of outbreaks at mink farms in Spain and Finland in 2022 and 2023, respectively."

BE, 27 days ago

Another article from @HelenBranswell today. This time with an interesting Q&A with the head of the CDC's influenza division.

https://www.statnews.com/2024/05/03/bird-flu-why-h5n1-keeping-awake-cdc-top-flu-scientist/

"It sounds like your team that was ready to go didn’t go. And it sounds like from what you’re telling me that CDC is very much in the back seat on this one. That it’s the states or local authorities who are running this.

They have the authority, right? CDC does not have the authority to go into a state. We have to have an invite from state public health.

Have any states invited CDC in?

No. Not officially yet. We’re speaking to these partners if not once a day, more than that."

"There has been a single human case in Texas. Has anybody done serology testing around that individual? That would be an obvious place to start, would it not?

I don’t know that that was consented to. You have to have consent from people to follow up. Certainly it was something that was on our radar for what we would like to have and request, but to my knowledge, serology was not performed. (A report on the case published Friday in the New England Journal of Medicine confirmed Dugan’s belief. The infected person and his contacts would not consent to have blood drawn.)"

BE, 23 days ago

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."

BE, 23 days ago

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."

BE, 11 days ago

I haven't said anything in this thread for a while, because I just don't think there's been a whole lot to say. People really seem to have dug themselves into "Pandemic Incoming" and "Slurp All That Raw Milk" camps pretty quickly. I guess we did learn something from COVID!

Anyway, I thought AJ Leonardi had a pretty spot on short article on the subject today.

https://www.easychair.info/p/let-them-eat-viruses

BE, 10 days ago

There's a new paper out today discussing airborne transmission of H5N1 among ferrets. The paper itself is quite good, on a first read, however, the press release states that this is the first time H5N1 has been shown to do so, yet above you can find another paper showing exactly this in 2020.

Regardless, it's worth a read if you're trying to keep up on the science.

https://www.nature.com/articles/s41467-024-48475-y

BE, 6 days ago

For whatever reason there seems to be a lot of H5N1 science in the news today. Since I haven't been keeping up, here's a bit of a summary of what I've seen.

When the FDA tested milk samples from stores, the original numbers to come out were kind of vague. Eventually they released them all and 20.2% of 297 samples, from 17 states encompassing dairy from 132 processing locations in 17 states were positive for H5N1.

https://www.fda.gov/food/alerts-advisories-safety-information/updates-highly-pathogenic-avian-influenza-hpai#testing

This answered a lot of my early questions. I'd even reached out to an acquaintance who was a purchaser at a grocery chain to try to figure out how milk travelled around the country, but now we have some details. To me, this means the outbreak is a lot bigger than 51 herds in 9 states, which, to be fair, was obvious. But, now that we're talking bigger numbers, let's zoom out to the whole country. There's upwards of 10 million dairy cows in the US. While I am not talking about H5N1 being everywhere, I think the possibility exists that we are saying that millions of cows may have been/are infected.

I posted elsewhere today that what we know of in terms of spread is mammal to mammal transmission amongst herds of cattle. I do think that accounts for 51 herd in 9 states. However, if we're talking millions of cows, and I'm not sure that we are, we just haven't tested enough to know, then we're likely talking about birds spreading H5N1 across state lines from herd to herd. Unproven, but, keep it on your radar.

Next up, raw milk and pasteurization. Researchers from the Texas A&M Veterinary Medical Diagnostic Laboratory obtained cow’s milk samples from an affected herd in New Mexico.

https://www.nejm.org/doi/full/10.1056/NEJMc2405495#t1

First up, they "orally inoculated" mice with the raw milk. The mice were sick on day 1, and all lived until day 4 at which point they were euthanized and tested. Infection seems to have set in in the pharynx, and led to systemic illness. I don't think that's a surprise, but there you have it. Further, infections were found in the mammary glands, despite the fact that the mice were not lactating. So, similar to cows and their milk, we seem to have an influenza virus with an affinity for mammary glands.

Next, while they are clear that their bench top experiments do not exactly replicate commercial pasteurization processes, they tested heating the milk to 63C and 72C for a variety of times.

All longer times, 5, 10, 20 and 30 minutes at 63C led to no live virus above detection limits.

At 72C, times of 5 seconds and 10 seconds led to detectable amounts of live virus, but 15 seconds did not.

Further tests at 72C for 15, 20 and 30 seconds were inoculated into embryonated chicken eggs or Madin–Darby canine kidney cells for virus detection. These samples showed "educed virus titers by more than 4.5 log units but did not completely inactivate the virus."

One thing I want to highlight here is this:

"The stability of HPAI A(H5N1) virus in cow’s milk stored at 4°C is another important question. For milk sample NM#93, we detected a decline of only two log units over 5 weeks. HPAI A(H5N1) virus may therefore remain infectious for several weeks in raw milk kept at 4°C."

I've leaned towards believing that H5N1 wouldn't survive long term in milk, but, that's why I try to avoid prognosticating as much as I'm able to. I was apparently wrong about that.

So what does all of that mean for milk at the store? I don't know! We'd have to establish an infectious oral dose to know whether what could remain after pasteurization, and refrigeration, is significant.

I have other thoughts, but, that's enough of a novel for now!

BE, 6 days ago

@samhainnight

If, and this is still an if to me, high temperature short time pasteurization really is the standard, then what I found was the procedure there is "heat the milk to between 72°C to 74°C for 15 to 20 seconds."

If that's what's being done currently, then this seems to show that it brings the amount of detectable virus below detection limits, but, there is enough live virus to replicate when inoculated into chicken eggs.

From there, it does still go down further when refrigerated over time, but also does not go away.

Between the two, is that enough to make certain that it's not enough to make people sick? I don't know, and I don't know if there's a known infectious dose that we could go off of to do that calculation.

BE, 1 month ago

@pvonhellermannn

This is a really salient point that I don't hear a lot of people making. My wife teaches high school, and anecdotally, a couple years ago she would always say that the kids didn't question climate change at all. They all understood. Now they often say it doesn't exist, or it's a hoax. She went from being optimistic about "the kids" to totally dismayed.

BE, 1 month ago

There's a pretty good article today on Vox about this. I distinctly remember the author being on NPR shooting down immunity debt once, because she interrupted the host mid-introduction when she said "post-pandemic" to say "mid-pandemic" and I had so much hope. Then she said something wishy-washy about masks and suggested washing your hands better. But, that was at least a couple years ago and not a lot of people were actively shooting down immunity debt, so good for her.

Anyway, onto the article today. Overall it's good. It details some risks, what to do, recommends reverse osmosis as your best bet. There's a lot of good info here.

What do I hate? This:

"While their health risks are concerning — and scientists still have a lot to learn about them — it can be helpful to think of PFAS in the context of some other common toxins, says Ducatman. If you had “the choice between smoking a pack [of cigarettes] a day or being in one of those high-PFAS populations,” he says, “high-PFAS population is way safer.”"

I really don't know why anyone feels the need to compare every health threat to smoking a pack a day. Like, what is this? 1985?

Avoid PFAs wherever you can.

https://www.vox.com/even-better/24135052/pfas-forever-chemicals-health-testing-exposure

BE, 12 days ago

I know I say this often, but, ubiquitous is the right word for PFAs.

https://truthout.org/articles/forever-chemicals-ubiquitous-in-water-atmosphere-in-great-lakes-basin/

"The levels of PFAS in precipitation did not correlate with whether or not an area in the Great Lakes Basin was heavily industrialized, lead author Chunjie Xia, a postdoctoral associate at Indiana University, told The Hill.

“The levels in precipitation don’t depend on the population,” said Xia. “They are similar in Chicago, which is heavily populated, and at Eagle Harbor, Michigan, where there’s maybe 500 people living in a 25-kilometer radius.”

“That tells us the levels are ubiquitous,” he said."

https://pubs.acs.org/doi/10.1021/acs.est.3c10098

BE, 10 days ago

Fantastic article today from ProPublica on 3M and PFAs in everyone's blood. I know I've mostly focused on DuPont here, but they're not the only ones with blame. I once briefly partnered with 3M on a project and I found them to be the most objectionable company I ever worked with. Much like DuPont, they knew how toxic it was, going back to at least the 70's. They knew what they were doing, and they chose profits.

"Rats that had more fish meal in their diets, she discovered, tended to have higher levels of PFOS, suggesting that the chemical had spread through the food chain and perhaps through water. In male lab rats, PFOS levels rose with age, indicating that the chemical accumulated in the body. But, curiously, in female rats the levels sometimes fell. Hansen was unsettled when toxicology reports indicated why: Mother rats seemed to be offloading the chemical to their pups. Exposure to PFOS could begin before birth.

Another study confirmed that Scotchban and Scotchgard were sources of the chemical. PFOS wasn’t an official ingredient in either product, but both ­contained other fluorochemicals that, the study showed, broke down into PFOS in the bodies of lab rats. Hansen and her team ultimately found PFOS in eagles, chickens, rabbits, cows, pigs and other animals. They also found 14 ­additional fluorochemicals in human blood, including several produced by 3M. Some were present in wastewater from a 3M factory."

https://www.propublica.org/article/3m-forever-chemicals-pfas-pfos-inside-story

BE, 1 month ago

I have done you all a disfavor by putting these two documents in the same thread, but what's done is done. I'm going to try to make this clear.

These are NOT the same documents. One is about only COVID:

https://iris.who.int/bitstream/handle/10665/376346/9789240090576-eng.pdf

One mentions COVID, but is about ANY airborne pathogen:

https://iris.who.int/bitstream/handle/10665/376496/9789240089181-eng.pdf

All day every day I see people taking quotes from the second one and talking about how absurd it is to say that about COVID, and every time I look, the document's not actually talking about COVID where they quoted from.

I know this won't stop any of it. It's far from a perfect document and that could be discussed. There's plenty there to disagree with, but, I'd say 90% of the discussion about it that I've seen to date has been uninformed and/or disingenuous.

BE, 22 days ago

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.”"

BE, 8 days ago

I'm going way back to my first real post on Mastodon here. I've mentioned my wife's best friend quite a few times over the last couple of years.

I had another post about her when she asked about COVID precautions, and then refused. She went to Japan a few months back, unmasked, of course.

So, she calls my wife tonight and starts with "I'm wearing a heart monitor."

Long story short, after listening to her whole story of doctors visits, she has PEM. Her doctors haven't quite gotten there yet.

My wife went ahead and said that was pretty common after COVID, and she said, "Oh come on. I've only had it four times. Some people have had it way more often than me."

She has no clue, despite our best attempts.

BE, 8 days ago

@rjblaskiewicz

Very true, and a lesson I am firmly aware that I'm working on. I have a hard time with that one!