New World screwworm parasite resurges in US livestock

The New World screwworm (Cochliomyia hominivorax) has re‑emerged in the United States, with the USDA confirming 11 cases across Texas and New Mexico. Infected animals include cattle, goats and a domestic dog, and the larvae infest open wounds, causing severe tissue damage and potentially death. Authorities are intensifying surveillance and containment, highlighting the pest as a serious threat to the beef and sheep industries.

The federal response relies on releasing sterile male flies to curb reproduction, a biological‑control method previously successful elsewhere. Veterinary and public‑health officials warn of possible spread beyond the southern states, urging heightened biosecurity at borders and in farms. European countries such as Spain are also monitoring the situation, given the parasite’s capacity to travel on imported livestock and its prior impact on human health in regions like Honduras.