Potential Case of New World Screwworm Detected in South Texas

<p>The New World screwworm, a type of fly that feeds on wounds, may have been detected in South Texas. The sample is currently being tested at the National Veterinary Services Laboratories in Iowa.</p><p>The Department of Agriculture announced on June 3, 2026, that personnel have been activated on the ground to address the situation. A potential case was identified following reports of the screwworm being found in a goat in Coahuila, Mexico, and a separate case involving a dog in Tamaulipas, Mexico. As of Monday, the USDA is tracking 1,981 active animal cases in the U.S.</p><p>In response to the outbreak in Mexico, which has been ongoing, Secretary of Agriculture Brooke Rollins had previously shut down livestock trade across the southern border in July 2025. There was one confirmed U.S. case last year involving an individual who returned to Maryland after traveling to El Salvador.</p><p>The adult screwworm flies are similar in size to houseflies, characterized by orange eyes and a metallic blue or green body with three dark stripes. While primarily found in South America and parts of the Caribbean, the screwworm has been reported in Central America and Mexico over the past three years. The CDC has noted that while the outbreak mainly affects livestock, wildlife, and pets, there have also been human cases.</p><p>The CDC reports that screwworm maggots can cause painful wounds, and if not treated promptly, infestations can lead to serious tissue damage or death. To prevent infestations, the CDC advises keeping open wounds clean and covered, wearing protective clothing, and using EPA-registered insect repellents.</p><p>The USDA is actively tracking any new cases of screwworm within 400 miles of the U.S. border, with updates provided every Tuesday and Thursday.</p>