U.S. adds emergency screwworm treatments as cases near border

The U.S. is adding another emergency-use tool to its New World screwworm response as the parasite continues moving north in Mexico. On April 27, the Environmental Protection Agency granted USDA’s request for a Section 18 emergency exemption to import Tanidil, a Brazil-made topical powder from Elanco, for prevention and treatment of New World screwworm in livestock and other animals. APHIS says the product will be ordered, imported, relabeled, and stockpiled through the National Veterinary Stockpile, with availability expected about 90 to 100 days after the official order is placed, though some states may also need their own registrations. The same day, FDA issued an emergency use authorization for Elanco’s Negasunt Powder for multiple species, including cattle, swine, goats, sheep, horses, donkeys, hybrid equids, and captive wild and exotic mammals. (aphis.usda.gov)

Why it matters: For veterinarians, this expands the federal playbook beyond surveillance and sterile fly dispersal by adding wound-treatment options that can be deployed quickly if cases reach the U.S. FDA said there are no fully approved animal drugs for New World screwworm, and no adequate approved, available alternatives for several affected species, which helps explain the reliance on emergency pathways. CDC says the fly has not been detected in the U.S. as of May 6, 2026, but more than 171,700 animal cases and more than 1,830 human cases have been reported across Central America and Mexico, underscoring why regulators are trying to position products before domestic detection. (fda.gov)

What to watch: Watch for APHIS guidance on state registrations, distribution rules, and whether Tanidil arrives on the projected timeline as border-area surveillance and sterile insect releases continue. (aphis.usda.gov)