I do not understand why the Michigan findings, that a dairy worker from one of the infected dairies also worked on one of the layer farms that was infected, was never followed up on. They could have tested the worker for antibodies since they obviously knew who they were, and they could have compared the viral sequences from that dairy to the one that infected the layer farm, but they did not even though it was known from the first Texas dairy worker to be infected that humans could shed live virus once infected. They made the research line of the virus cultured from the eye swabs of that Texas dairy worker. It was well understood where the virus was coming from by the time the Utah layer flock was infected with the dairy virus, and they found multiple infected dairies in the same county. Millions of layer chickens would not have had to be depopulated if they had started testing and restricting dairy workers from working on poultry farms. Look at how many commercial layer flocks California lost, and they knew the virus was coming from the dairies. Changing clothing and even showering into a clean facility will not stop a worker shedding live virus from infecting the animals at another farm.