Flesh-eating New World Screwworms have invaded Arizona, becoming the third U.S. state affected after New Mexico and Texas. Since the flies re-entered the country in June, 74 animal cases have been confirmed. The parasites lay hundreds of eggs in wounds or moist orifices of animals; the resulting maggots — resembling screws — bore into living flesh, causing severe and sometimes fatal damage.
The flies were eradicated from the U.S. in the 1960s via sterile male fly releases and contained for decades by a biological barrier at the Darién Gap between Panama and Colombia. That barrier was breached in 2022, allowing the pests to migrate north through Central America.
While primarily a livestock threat, screwworms also endanger wildlife, domestic pets, and humans. Mexico’s Ministry of Health reports 806 human cases and nine deaths since the reemergence, underscoring the growing public health risk.
Source: Ars Technica · Summarized by HeadlinesBriefing