US CDC launches emergency response to screwworm fly outbreak in livestock

The United States Centers for Disease Control and Prevention (CDC) has activated a Level 3 emergency response after the New World screwworm fly was detected in U.S. cattle, a goat in Texas and a dog in New Mexico – the first confirmed cases in decades. The agency is forming a team of scientists to monitor the outbreak and to work with state health departments, while the U.S. Department of Agriculture (USDA) leads the animal‑health response, overseeing livestock and wildlife monitoring and control measures.

The screwworm fly is a parasitic insect that lays eggs in open wounds of warm‑blooded animals; the hatched larvae feed on tissue and can be fatal. Infections in humans are rare but have occurred in Central and South America and once in Maryland after travel from El Salvador. The CDC advises travelers with open wounds to avoid close contact with livestock. The USDA has stated that the food supply remains safe despite the outbreak.