The New World screwworm, a flesh-eating parasite once thought eradicated from the United States, has made a resurgence, posing a significant threat to cattle, wildlife, and pets. This outbreak, which began in Central America in 2023, has now spread to Texas and New Mexico, with 15 confirmed cases in the US as of Sunday. The larvae of this parasitic fly feed on the tissue of warm-blooded animals, including humans, but the risk to people is considered low. The infestation could raise the cost of beef, already at record highs, and has the potential to cost the southwestern US billions of dollars if not contained. The US Centers for Disease Control and Prevention (CDC) has designated the outbreak a Level 3 public health emergency, and federal and state officials are deploying sterile flies and enhanced surveillance to contain the spread. The New World screwworm, named for its unique feeding behavior, was first identified in 1933 and was successfully eradicated from the US in the 1960s using the sterile insect technique. However, the recent outbreak has been attributed to a less effective strain of sterile male flies and the movement of infected animals across borders. The US is taking several steps to stop the screwworm, including investing in fly-producing facilities, using sniffer dogs at the southern border, and temporarily halting exports of certain animals to Mexico. Despite the challenges, officials remain optimistic about containing the outbreak and preventing further damage to the livestock industry.
