Cambodia, where an older H5N1 clade circulates in poultry, has now reported 18 human cases since early 2023.
Testing of 167 samples from 27 states included different cheeses, including aged varieties made from raw milk, butter, ice cream, and milk.
Like two recent 2.3.4.4b viruses, the subtype from the Texas patient is of moderate risk for both future emergence and public health impact.
One patient had conjunctivitis in one eye, and the other had longer-lasting flulike symptoms.
In related developments, Colorado's governor recently extended an emergency declaration that frees up more resources to battle the outbreaks.
Nipah virus, which has a high fatality rate, is a top target for countermeasure development.
The girl's illness marks Cambodia's ninth H5N1 case of the year.
The latest confirmations also include more wild birds and small mammals from Weld County, a Colorado hit hard by dairy cow and poultry outbreaks.
Cattle herds in Colorado and South Dakota are the latest to be infected in the H5N1 avian flu outbreak.
The investigators also cultured infectious H5N1 virus from milk and cattle samples taken from 2 Texas dairy farms.
