Re: Two more California Dairy workers confirmed to be H5N1 infected

On 12/3/2024 6:10 PM, *Hemidactylus* wrote:

RonO <rokimoto557@gmail.com> wrote:

On 12/3/2024 8:40 AM, RonO wrote:

On 12/2/2024 6:35 PM, RonO wrote:

On 12/2/2024 1:40 PM, RonO wrote:

https://www.cdc.gov/bird-flu/situation-summary/index.html
https://www.cdc.gov/bird-flu/situation-summary/mammals.html
>
I can't find any announcement, but the CDC has increased the
California numbers by 2 today (Dec. 2).  The USDA has increased the
number of herds infected to 689, but I do not know what states are
affected because they haven't updated their data sheet.  It still has
the old Nov 27 confirmed data that they put up last Friday.
>
Ron Okimoto
>

>
https://www.latimes.com/environment/story/2024-11-29/raw-farm-sales-
suspended
>
Another batch of raw milk products came up positive from the same
dairy that tested positive.  Initial bulk milk tank testing was
negative, but the farm has identify several asymptomatic positive
cows.  So the farm was infected and didn't know it.
>
https://www.cidrap.umn.edu/avian-influenza-bird-flu/california-
reports- h5n1-more-retail-raw-milk-virus-infects-2-more-dairy
>
CIDRAP notes that two more California dairy workers have been
confirmed.   California isn't announcing positives until they are
confirmed and it takes the CDC quite a while to confirm cases.  They
may still be working on the original batch of samples submitted by
California around a month ago.  I recall a news article that claimed
that 39 samples had been submitted, and the CDC has only released 30
positives and 1 that could not be confirmed.  That would mean that the
CDC is still working on 8 samples.  It could be that the article got
the numbers wrong, or I misinterpreted number of workers tested and
submitted.  California stopped announcing how many workers that they
had tested.
>
CIDRAP also claims more poultry flocks have gone down in 3 states, but
doesn't name the states or the size of the poultry flocks.  Washington
should have identified their positive dairy herds by now, and it is
pretty sad that they haven't bothered to test their dairies.
>
Ron Okimoto
>

It was actually 6 states that had poultry flocks go down.  All 6 should
be looking for their infected dairy herds to try to stop the spread.
Utah was stupid and stopped testing after they found 8 infected herds in
the same county as the infected poultry farm.  They knew that they
should have implemented contact tracing or bulk milk tank testing like
California to find all the other infected herds, but like all the other
states they went into denial.  Now another poultry farm in another Utah
county has gone down with the dairy virus.  More poultry workers are
being exposed to the virus, and it could have been prevented.  The price
of eggs is going up because of the stupid way in which the USDA and CDC
have handled this fiasco.
>
The stupidest thing is that the USDA and CDC are letting the states get
away with this stupid behavior because they keep calling the dairy
epidemic "avian influenza" when they know that it has been primarily a
dairy infection since March.
>
Dairies are spreading the virus because dairy cattle shed huge amounts
of virus, and dairy workers get infected and go to other farms
(including poultry farms) and infect the new farms.  Transport of cattle
has been limited to tested and negative animals since April, but the
virus still spreads to states that did not get cattle and poultry farms
that obviously did not get cattle.  It isn't rocket science, but the CDC
and USDA have refused to face reality since the beginning when the first
dairy worker was confirmed to be infected and was shedding live
culturable virus.
>
Ron Okimoto
>

  USDA had posted 6 more dairies (total 488), but the sample numbers go
to 508, so there are more in the que.
>
It has likely been over 2 weeks since the USDA was supposed to start
bulk milk tank testing, and those results should be coming in.  27% of
the California dairies are already known to be positive.  The raw milk
issue indicates that bulk milk tank testing can miss positive herds.  I
do not know how they are going to get around this, but they claim that
the herds should be tested on a routine basis, hopefully around once a
week, so even if they miss a herd it will likely test positive in a
couple of testings if there are infected cattle on the farm.
>

Can the cattle flu variants evolve away from the test resulting in false
negatives?
 

It can, but the current test involves 2 PCR tests.  One test has primers specific for the H5 gene.  If there are changes in the primer annealing sequences the test could fail, but the second test has a primer set specific for a different part of the H5 gene.  It is unlikely that mutations will occur in both primer set sequences.  I recall that they had two H5 specific tests instead of having one for H5 and the other for N1, so they have to do additional testing to determine if it is H5N1. They determine if it is the dairy recombinant virus by genome sequencing.
Any sequence changes in the primer sequences might alter the H designations of the virus, and it might become a new lineage, but my guess is that they would just redesign the primer sets so that they could still identify the current H5 designation.  The Missouri case had two amino acid substitutions in the H5 gene that decreased antibody binding using antibodies to the cultured H5 virus 100 fold, and they had to make a synthetic H5 gene with those amino acid substitutions in it to make antigen to detect the antibodies in the patient's blood.  They still called it H5 even though the old H5 probably would not work as a vaccine for the virus.  The original dairy virus was neutralized by the H5 vaccine strain that was available and they stockpiled a million doses of it, but the virus has mutated since then.
They need to track how the virus is changing and prepare to make a vaccine from whatever makes the jump to humans.
Ron Okimoto