# As Screwworm Cases Mount, U.S. Officials Ramp Up Response
The screwworm, a parasitic fly whose larvae burrow into living flesh and consume tissue, has triggered an escalating public health response across the United States. Officials have now confirmed infections in cattle, goats, and dogs, marking a serious expansion of a pest once nearly eradicated from North America.
The screwworm (Cochliomyia hominivorax) infects open wounds and sores, where females lay eggs that hatch into larvae within hours. These maggots feed on healthy tissue, causing severe pain and, if untreated, death. The infestation spreads rapidly in warm climates, making the ongoing warm weather particularly concerning for disease control.
This resurgence follows decades of successful eradication efforts. The U.S. eliminated screwworm in 1966 using the sterile insect technique, releasing millions of sterilized male flies to prevent breeding. However, the parasite persists in Central and South America, and recent cases suggest reestablishment in American livestock and pets.
U.S. Department of Agriculture officials have intensified surveillance and quarantine measures. States with confirmed cases implement strict movement restrictions on affected animals to prevent geographic spread. Veterinarians and livestock owners receive guidance on recognizing early symptoms: irritation around wounds, unusual behavior, and visible larvae in sores.
Treatment options exist but require prompt intervention. Veterinarians apply insecticides to kill larvae and manage secondary infections. However, prevention remains the priority. Farmers are advised to minimize animal injuries, maintain sanitary conditions, and report suspected cases immediately.
The outbreak underscores how quickly invasive parasites can re-establish themselves when vigilance lapses. Climate change and increased trade with endemic regions amplify reintroduction risks. Public health agencies