Surveillance implemented as mandatory, weekly assay of bulk milk samples identified ten incident cases of bovine influenza H5N1 in the state of Colorado.  This allows regulators and farmers to quarantine their herds until viral shedding ceases within a few weeks without evident mortality in uncomplicated cases.

The fact that Colorado is able to identify a number of incident cases suggests that infection is more widespread than the herds previously identified by the presence of clinical signs in twelve other states.

USDA-APHIS will allow interstate movement of lactating cows if three consecutive weekly bulk milk samples are negative.  This is relatively ineffective since heifers can theoretically transmit the infection and only herd operators wishing to move cows to other states are required to sample milk.

Knowing that a herd is infected can prevent infection of workers since they can be supplied with PPE and undergo training and supervision in the use of face shields or goggles.