#18,401
Yesterday California was reporting 236 infected herds, but that total has risen according to the latest update from the USDA to 259 (+23), while Utah's total has grown to 13.
While we've seen reports suggesting expanded testing of dairy cattle (via bulk milk testing) are in the works, so far no timeline or scope has been announced.
The CDC's count of human infections since March of this year sits at 46 (see below).
Excluded from this list are at least 4 cases confirmed by states (California & Washington), but not by the CDC, along with the 8 retrospectively detected (by serological testing) in Michigan and Colorado, along with the strongly suspected house mate in Missouri.
Considering how many other cases (symptomatic and asymptomatic) that have likely gone unreported, the true number is undoubtedly much higher.
With seasonal flu season soon upon us, concerns over co-infections with H1N1/H3N2 and H5N1 are only going to increase, since we've seen studies suggesting a High Reassortment Potential of Avian H5N1 and Human H3N2 Influenza Viruses.
Antigenic `Shift' or Reassortment
Because while rare, as any virologist will tell you. Shift happens.