Screwworm cases in Mexico surge, nearing US border Infestations jump 53%, threatening cattle and wildlife29 August 2025 29 August 2025 2 minute read 2 minute read By: By: Global Ag Media North AmericaMexico has recorded 5,086 cases of flesh-eating screwworm in animals as of August 17, a 53% jump from the number of cases reported in July, Reuters reported, citing Mexican government data on Wednesday. The updated numbers, which have not been previously reported to the public, showed 649 currently active cases. The vast majority of cases were identified in cattle, though Mexican government data also showed infestations in dogs, horses and sheep. On Sunday, Reuters reported the first human case in the United States of travel-associated New World screwworm from an outbreak-affected country. The US Department of Agriculture is sending a team to Mexico in two weeks to verify that Mexico is following protocol to prevent screwworm's northern spread, Deputy Secretary Stephen Vaden said on Tuesday.