Re: Dairy cattle mortality in California

On 10/13/2024 9:49 AM, RonO wrote:

Second attempt to post:
 https://www.newsweek.com/disturbing-footage-reveals-bird-flu-infected- cattle-dumped-roadside-1967813
 As noted in previous posts the California strain of the dairy influenza virus has a higher mortality rate among cattle than the initial virus. Apparently dead cattle are piling up and not being disposed of in a biosecure manner.
 The esimate is that there are over 1,100 dairy herds in California and 100 have already been confirmed to be infected with more herds detected by California health officials and already submitted for verification.
 20% of the dairy herd in the US is in California (over a million cattle).  The mortality rate was initially 2%, but around 15% of the infected cattle are dying in California.  Initially around 10% of the herd was infected at any one time, but now 50% of the herd is found to be infected in some cases.
 Ron Okimoto
 

https://evrimagaci.org/tpg/california-confronts-bird-flu-cases-among-dairy-workers-45706
This article claims that California has been contact tracing since the start in late August.  After the first couple weeks the first claims were that they thought that they had isolated the infected herds to around half a dozen because they shared workers between the farms, but the contacts obviously exploded out of those first half dozen and now they likely have over a 100 infected dairy herds identified some of them before the cattle showed symptoms.
The claim is that there is still no evidence for human to human transmission, but that hasn't been true since late July.  A Texas study released their data before peer review.
https://www.cidrap.umn.edu/avian-influenza-bird-flu/previously-undetected-h5n1-avian-flu-cases-farmworkers-revealed-new-report
They released this data in late July, but the CDC has never incorporated the data into the known human infections.  What they found was they tested 14 dairy workers from two farms and two of the dairy workers from one of the farms had antibodies to H5 indicating that they had been infected by the dairy virus.  One of those workers only had contact with other dairy workers, and did not have contact with cattle (cafeteria worker).  Their submitted publication indicated that this was evidence for human to human transmission (worker infected by dairy cattle, and one worker infected that did not have contact with cattle).
The initial Texas data indicated that around 10% of a herd was infected (showed symptoms), but when these researchers tested 39 milk samples from the two farms they found 64% of the samples had H5N1 virus.  This is closer to the 50% infection rate that California is experiencing, but the mortality in Texas was only 2% while it is 10 to 15% of infected animals in California.  So going by symptoms under estimated the rate of infection in Texas herds.  They should have implemented testing like they have in California, and they would have had a better estimate of the actual infection rate.
One of the authors of this paper is quoted in the news article.
QUOTE:
"I am very confident there are more people being infected than we know about," senior author Gregory Gray, MD, MPH, a UTMB infectious disease researcher, told NPR. "Largely, that's because our surveillance has been so poor."
END QUOTE:
It should be noted that the CDC never changed their minds, and surveillance continues to be poor (except in California where they implemented contact tracing) for the rest of the nation.
Ron Okimoto