The departures come as the country battles its longest-ever outbreak of bird flu and faces the encroachment of New World screwworm, a flesh-eating pest detected among cattle in Mexico. Egg prices set records this year after bird flu wiped out millions of laying hens. Also leaving are 20%-30% of staff at one USDA lab that tests for animal disease like bird flu, a second source said. Seventy people, mostly farm workers, have contracted the virus since 2024, and further spread raises the risk that bird flu could become more transmissible to humans, experts say. The US Centers for Disease Control and Prevention says the risk to people from bird flu remains low.