I think it's important not to overstate what this means. Most likely, the kid had some other upper respiratory tract infection with the symptoms coming from that and the H5 may well have been an incidental finding, especially since they have likely already recovered based on the timeframe I'm aware of. One potential theory is exposure to wild bird droppings. Due to the circumstances of the case, we may never find out exactly what the child came in contact with.

Alameda county's original PR: https://health.alamedacountyca.gov/wp-content/uploads/2024/1...