Health officials have confirmed 31 human cases of H5N1 bird flu in the U.S., primarily among farmworkers. Investigations into a recent Missouri case show no evidence of human-to-human transmission. There are concerns about exposure risks as bird flu spreads among livestock. The CDC continues to assess the situation amidst rising infections predominantly in California and Washington state, urging caution among those in contact with infected animals. Most cases have been mild, but health officials remain vigilant as environmental factors and migratory patterns may affect future spread.