A Concerned Scientist @BE@qoto.org

Statnews.com's update today with a few interesting tidbits again:

https://www.statnews.com/2024/04/26/h5n1-bird-flu-usda-cattle-testing-order-more-limited/

"farmers only have to test up to 30 animals in a given group. The guidance does not say how farmers should determine which 30 animals to test in larger groups that are being readied to be moved. The USDA did not respond to STAT’s questions about the rationale for the 30-animal cap."

"Under the new rules, cows that are to be moved between states must have samples collected and tested no more than a week prior to transport. A licensed or accredited veterinarian has to collect the samples — between 3 and 10 milliliters of milk per animal taken from each of the four teats. That’s very important, the USDA noted, because there have been reports of infected animals having virus in only one teat.

A strange feature of H5N1’s jump from birds into cows is that the virus seems to have developed an affinity for mammary tissue. Samples from sick cows show the highest levels of virus not in their noses but in their milk, suggesting that udders seem to be where H5N1 migrates to or infects."

"The USDA order does not apply to beef cattle or non-lactating dairy cattle, including calves, due to their lower risk profile, according to the guidance. But influenza researchers told STAT that not enough yet is known about the risks to non-lactating animals to leave them out."

34 herds in 9 states now confirmed:

https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections/livestock

But almost certainly far more widespread.

"On Friday, the FDA issued an update saying that tests of several samples of retail powdered infant and toddler formula were negative, indicating no presence of H5N1 viral fragments or whole virus. It provided no details on the quantity tested."

"At this time, there have been no reported cases of H5N1-positive dairy cattle exhibiting any signs of neurological disease in the U.S."

I'm going to dump a few more articles that I've been reading here today. These ones are specifically related to previous mammal to mammal spread of H5N1, presented roughly in chronological order starting in 2004.

"Avian Influenza H5N1 in Tigers and Leopards"

https://wwwnc.cdc.gov/eid/article/10/12/04-0759_article

"Probable Tiger-to-Tiger Transmission of Avian Influenza H5N1"

https://wwwnc.cdc.gov/eid/article/11/5/05-0007_article

(Transmission route not determined, but they had stopped being fed raw chicken)

"H5N1 pathogenesis studies in mammalian models"

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5858902/

(Interesting tidbit - "Notably, conjunctivitis and other ocular complications following influenza virus infection in humans are most frequently associated with the H7 subtype, but have been documented rarely during H5N1 virus infection (Belser et al., 2009a). Furthermore, the presence of SA on the corneal surface and linkage of ocular and respiratory tract tissues by the nasolacrimal ducts identifies the ocular system as both a potential site of replication as well as a route of entry to establish a respiratory infection (Kumlin et al., 2008). Although H5N1 viruses do not demonstrate a particular tropism for this tissue, ocular inoculation (with or without prior corneal scarification) of mice with H5N1 viruses resulted in a systemic infection, with infectious virus recovered from the lungs, brain, and eye of mice p.i. (Belser et al., 2009b; Sun et al., 2009). Selected H5N1 viruses were capable of mounting a lethal infection by this route, albeit with a 2–3 delay in mortality compared with i.n. inoculation (Belser et al., 2009b).")

"Highly pathogenic avian influenza A(H5N1) virus infection in farmed minks, Spain, October 2022"

https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2023.28.3.2300001

"Highly Pathogenic Avian Influenza A(H5N1) Virus Outbreak in New England Seals, United States"

https://wwwnc.cdc.gov/eid/article/29/4/22-1538_article

"Mass Mortality of Sea Lions Caused by Highly Pathogenic Avian Influenza A(H5N1) Virus"

https://wwwnc.cdc.gov/eid/article/29/12/23-0192_article

"Highly pathogenic avian influenza A (H5N1) in marine mammals and seabirds in Peru"

https://www.nature.com/articles/s41467-023-41182-0

New H5N1 info today from stat, although not from Helen Branswell this time.

https://www.statnews.com/2024/04/25/h5n1-bird-flu-cows-outbreak-likely-widespread/

I think this paints a pretty good picture of where we're at, in terms of the extent of the outbreak in dairy herds.

"They collected 150 commercial milk products from around the Midwest, representing dairy processing plants in 10 different states, including some where herds have tested positive for H5N1. Genetic testing found viral RNA in 58 samples, he told STAT."

For me, personally, this is both good and bad news.

On the one hand, the continuing drip of information saying that this has been going on longer than we knew, and is pretty widespread, means that the milk is almost certainly safe. At least, not acutely bad. If, for instance, as I have seen speculated(not on Mastodon), 50% of people would die from drinking contaminated milk we'd know. Agreed? Let's put that idea away.

Small sample size, but:

"The team that produced that data — the St. Jude and OSU groups — told STAT that it has so far analyzed four samples of store-bought milk that had tested positive via PCR for H5N1 genetic material. “We’ve done the viral growth assays to see if we can recover any virus from them and we can’t,” Webby said."

On the other hand, every mammal infection is another chance for a dangerous mutation. Just 5 amino acids, right? We've, hopefully, learned this lesson from COVID variants.

Now, what does 39% of samples testing positive in this case mean? I don't know! My first thought was that there's 64,155 dairy farms in the US, so near 25,000 must have infections, but, I realized I was making two big assumptions. One, milk from the Midwest is representative of the whole supply. Two, 150 was a significant sample size.

The FDA is now saying their testing found ~20% positive, but no information on where those samples came from, or how many they tested. Come on FDA!

I think it does suggest it's a lot more widespread than we previously knew. If this is the case, I think it's important that we now have genetic evidence of bird to cow, and then back to bird. Beyond the movement of cattle, this would be a way that you could see rapid spread across the nation.

I think the fact that early cases were said to have yellowed, viscous milk perhaps slowed the response. It's time(past time) to move to more mandatory testing given the newer information of asymptomatic infections.

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.

Pro tip:

This applies to H5N1, too. The fire hose of bad science right now is crazy and all of the same COVID grifters are latching on trying to use "the next pandemic" to support their views on COVID.

Lots of absolutely well meaning people in my timeline right now are sharing stuff from people they've spent the last 4 years saying were unreliable.

Likewise, lots of "here's who you should listen to" followed by stuff from people saying the opposite on both the COVID and H5N1 fronts right now.

Being the "first" to put something up, or mashing the boost button just because something supports what you believe isn't as helpful as taking the time to critically think about it first.

I know saying this is pointless against the volume of bad science, but, try to think about it anyway.

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

An article from today about the possibility of this H5N1 spread being similar to the spread of contagious mastitis in cows. It's from the perspective of the industry.

https://www.agri-pulse.com/articles/20994-usda-working-to-provide-answers-on-h5n1-in-dairy

I also read way more about contagious mastitis than I ever wanted to, but, if anyone is interested this article was a good review.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7649072/

@HelenBranswell on top of it again today. Lots of good tidbits in this one.

https://www.statnews.com/2024/04/24/h5n1-bird-flu-usda-orders-dairy-cow-testing/

"an animal to test negative for the virus before it can be moved across state lines"

"farms that move cattle across state lines and have animals that test positive for H5N1 or any influenza A virus will be required to open their books to investigators, so they can trace movement of cattle from infected herds"

"The order currently applies to lactating dairy cows but could be expanded if necessary"

"He sidestepped questions about where the positive milk samples were purchased and what percentage of samples contained traces of the virus when tested by PCR — polymerase chain reaction testing — saying that the agency has an analysis of its work that will be made public “very shortly.”"

"There was some support offered for the oft-repeated claim that pasteurization would kill the virus in milk from by Jeanne Marrazzo, the new NIAID director. She said that some NIAID-funded researchers had also found PCR-positive milk in samples bought from stores, but that when the researchers tried to grow virus from those samples, they could not.

“The results that those investigators got indicated that the PCR-positive material was not alive,” Marrazzo said, though she warned that work was done on a small number of samples and needs to be confirmed by the larger FDA effort."

"Watson confirmed that USDA has met some resistance from farmers who they’ve suspected of having infected cows. Farmers have been told they must discard any milk produced by cows that are infected with H5N1 virus, though it’s not clear if or how that recommendation is being enforced."

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."