A worrying outbreak of screwworm, a parasitic fly larva that burrows into open wounds on livestock, has seen cases rise in the US. Twelve animal cases have been confirmed so far, a significant increase from the first case detected in a calf in south Texas on 3 June.
The growing number of infections has alarmed agricultural experts, who warn that a wider outbreak could have serious consequences for the Texas beef industry. Of the 12 reported cases, 11 remain active and one is inactive, according to an update issued last Thursday by the US Department of Agriculture’s animal and plant health inspection service.
The infected animals include cattle, goats, sheep, and one dog. The screwworm is a fly larva that feeds on living tissue, and its re-emergence and rapid spread have raised concerns that the parasite is making a comeback at a time when beef prices are at record highs.
USDA officials are urging animal owners to watch for signs of screwworm infection, including draining or enlarging wounds, maggots or egg masses, unusual discomfort, and lesions around the nose, ears, genitals or umbilical area. Suspected cases should be reported immediately to help contain the spread of the parasite, the USDA said.
Despite the outbreak still being restricted to Texas and New Mexico, Pennsylvania’s agriculture department has issued a precautionary quarantine order. The order imposes stricter controls on the import of susceptible livestock from affected areas, requiring veterinary inspections and health documentation.