February 5, 2026

Today the U.S. Food and Drug Administration issued an Emergency Use Authorization (EUA) for Ivomec (ivermectin) injectable solution against New World screwworm (NWS). The agency has concluded that based on the scientific evidence available, it is reasonable to believe that Ivomec may be effective for the prevention of infestations caused by NWS larvae (myiasis) in cattle when administered within 24 hours of birth, at the time of castration, or when a wound appears,

https://www.fda.gov/animal-veterinary/cvm-updates/fda-issues-emergency-use-authorization-over-counter-injectable-drug-prevent-new-world-screwworm

Ivermectin at 200 micrograms/kg caused 100% mortality of screw-worm larvae up to 2 days old at the time of treatment with 70, 64 and 21% mortality of 3-, 4- and 5-day old larvae at the time of treatment. The residual protection from a single dose of 200 micrograms/kg was 16 to 20 days. When bull calves were treated with ivermectin at a dose of 200 micrograms/kg at the time of castration and branding, none of the 77 treated animals sustained a screw-worm strike in the scrotal area compared with 47 strikes (44%) in the 106 control cattle.

https://pubmed.ncbi.nlm.nih.gov/3840994/

U.S. Department of Agriculture Secretary Brooke Rollins on Thursday said the agency aims to increase production to 30 million sterile flies per week by the end of the summer. That figure is expected to rise to 100 million flies per week by the end of the year, Rollins added.

https://www.tpr.org/news/2026-06-05/heres-what-officials-are-doing-to-stop-the-spread-of-new-world-screwworm-in-texas