The report is the latest evidence that the outbreak in dairy herds is spreading undetected in cows, and the spillover into people at highest risk of exposure is going unnoticed.

Bird flu may be spreading undetected in humans, according to a recently released report from the Centers for Disease Control and Prevention Data posted last week in the CDC’s Morbidity and Mortality Weekly Report suggests the spread of bird flu between dairy cattle and humans has gone unchecked,

Nearly 70 people across the United States have been infected with bird flu in the last year, with officials saying the tally could be a significant undercount.