The New World screwworm's spread into the United States

In May 2025 the US suspended imports of live cattle from Mexico for 15 days to review the joint strategy against the screwworm,^[7] and in July barred them again.^[8] In August federal officials confirmed the first US case in years, in Maryland.^[9] Texas Gov. Greg Abbott issued a statewide disaster declaration in January 2026 to prepare,^[10] and in June the US Department of Agriculture confirmed the first case in South Texas, in Zavala County.^[11][12] Within weeks the USDA counted 16 cases,^[13] counties in the Rio Grande Valley declared disasters,^[14][15] and the outbreak slowed the movement of rescued pets out of Texas shelters.^[2]

The Food and Drug Administration granted emergency authorizations for more drugs to prevent and treat infestations.^[16] At the end of August, Mexican cattle imports resumed after the long shutdown, part of the Trump administration's effort to lower near-record beef prices,^[3][4] though Texas imposed stricter movement rules on some Mexican cattle.^[17] The USDA lifted quarantines on some infested zones in Texas in September,^[18][19] but in October new cases were confirmed in New Mexico, where officials set an infested zone and released sterile flies, and in an elk in Texas.^[6][20] In late October, screwworm was detected in a dog in Arizona and in El Paso County, Texas.^[21] In November, the USDA said it would begin hiring for more than 200 positions at a sterile fly production facility being built near the Texas border.^[22]