Source: The Focal Points
As New World screwworm (NWS) cases continue to spread in Texas and New Mexico, ivermectin is emerging as a potentially important tool for prevention and treatment. The USDA confirmed the first U.S. case in decades on June 3, 2026, and additional cases have since been reported in livestock and pets. Unlike ordinary fly larvae, NWS larvae invade open wounds and feed on living tissue, causing serious damage if left untreated.
Evidence from livestock studies has shown that ivermectin is highly effective against NWS. In February 2026, the FDA issued an Emergency Use Authorization for Ivomec (ivermectin) injectable solution after studies in South America demonstrated more than 97% protection against screwworm infestations. A single injection can provide 10 to 21 days of protection by killing larvae before they burrow deeper into tissue.
Published human case reports also suggest ivermectin can help treat severe NWS infestations (myiasis), particularly when larvae are difficult to remove mechanically, leading to successful recovery in documented cases.