The circulating bird flu has become “widespread” in the Bay State, as officials believe the virus has killed 500 to 1,000 wild birds across the region. And the total number of dead birds is likely “much higher than that,

The H5N9 strain of avian influenza is much more rare than the H5N1 which has been responsible for most of the reported human cases and the first human death.

The number of bird flu cases in Central Massachusetts is relatively low, compared to a swath of the state that runs from Greater Boston to Southeastern Massachusetts. That message was delivered Wednesday during a virtual update from state health officials on the highly pathogenic avian influenza H5N1 virus.