USDA says screwworm case no threat to farm sector Cattle industry on alert as parasite spreads in Mexico27 August 2025 27 August 2025 3 minute read 3 minute read By: By: Global Ag Media North AmericaThe human case of screwworm reported this week by US health officials is the country's only one so far this year and poses no risk to the farm sector, Reuters reported, citing a US Department of Agriculture (USDA) official on Tuesday. Following Vaden's comments, the USDA released a statement late on Tuesday, saying the CDC has been leading the response to the human case. The release did not clarify when the agency learned of the human case or initiated its surveillance. The release also said the risk to US public health from the human case is very low and that there have been previous travel-associated human cases of screwworm. The USDA has not detected screwworm in livestock or other animals since 2017, the release said.