Phys.org California dairy virus

https://phys.org/news/2024-09-bird-flu-outbreaks-california-dairy.html
This Phys.org article has the most information on the Calif. situation. It was written earlier this week and has the old number of 34 infected herds (it was actually 36 listed at the USDA site) but now 6 more herds were added yesterday so the situation is even worse than they describe in this article.
California is doing a better job of detecting herds at this time than other states because they claim to be tracing contacts and testing herds that share workers and equipment with infected herds.  That seems to be the reason that they are detecting so many herds, and they are detecting them before the herds show signs of infection.  It has been known for a long time that dairy workers were likely spreading the virus from farm to farm, but the USDA and CDC have been in deep denial, and refused to do contact tracing to demonstrate that they were wrong.
This article claims that Calif. has evidence that cattle were illicitly brought back into Calif. from Idaho, but that doesn't make sense because the virus is closest in sequence to Colorado, and Idaho was infected before Colorado.  The Colorado virus is most closely related to the virus isolated from a Michigan dairy worker, so Colorado likely was infected from Michigan (my guess the Colorado virus was transmitted by a migrant infected dairy worker from Michigan because Michigan should not have been exporting cattle at that time due to USDA restrictions).  It will all be worked out once they do a phylogenetic assay of all the infected states.
They still are refusing to test dairy workers, but they are trying to quarantine the farms and not allowing workers to move from an infected farm to other farms.
Ron Okimoto