Texas officials are telling residents to check their pets and livestock, and insisting on immediate use of pesticide bait after officials in Mexico confirmed an infection with the flesh-eating New World Screwworm (NWS) less than 70 miles from the US border.
NWS is a horrifying parasitic fly that attacks warm-blooded animals, laying hundreds of eggs in any openings or wounds, even minute ones. The resulting larvae both look and act like screws, boring and twisting into the animal while feasting on its living flesh. The ravenous larvae create ghastly wounds that can be deadly to livestock and wild animals.
Long ago, this ferocious fly was endemic in the US and stymied the livestock industry. However, in the 1950s, eradication efforts using sterile male flies and livestock monitoring began to push the fly population southward. By around 1966, it was cleared from the US, and Mexico zapped the population in the 1980s. By 2006, it was pushed out of Central America, with Panama declaring it eradicated and holding the flies at bay at the Darién Gap at the border with Colombia. However, in 2022, the gap was breached, and the flies have been steadily moving northward.
In July, Mexican officials found an NWS case in Veracruz, 370 miles from the US border. On Sunday, Mexico’s National Service of Agro-Alimentary Health, Safety, and Quality (SENASICA) confirmed the closest NWS case so far, in Sabinas Hidalgo, located in the state of Nuevo León, less than 70 miles from the US-Mexico border.