1 in 5 samples of pasteurized milk had bird flu virus fragments, FDA says | 25 April 2024 | The Food and Drug Administration said Thursday that traces of the bird flu virus have been found in 1 in 5 samples of pasteurized milk, providing a more detailed picture of how much of the milk supply has been affected. The tested milk came from a nationally representative sample, with more of the positive results coming from milk in areas with infected herds of dairy cows, the FDA said. A spokesperson declined to say how many samples were tested. As of Thursday, bird flu had been detected in 33 herds in eight states: Idaho, Kansas, Michigan, New Mexico, North Carolina, South Dakota, Ohio and Texas. Richard Webby, an influenza virologist at St. Jude Children’s Research Hospital, said the number of positive samples is consistent with numbers he's reviewed from smaller sample sets.