A Texas dairy herd first reported in March that cattle had tested positive for highly pathogenic avian influenza (HPAI). Since then, the H5N1 version of the virus has spread to 299 dairy herds in 14 states, according to the Centers for Disease Control and Prevention, which has also reported more than 100 million poultry affected in 48 states. Twenty cases, all of them non-fatal, have been reported in humans this year.
What to know about the current avian influenza outbreak
