Human Myiasis Resulting from Reemergence of Cochliomyia hominivorax Screwworm, Mexico, 2025–2026

The screwworm fly (Cochliomyia hominivorax) was eradicated from Mexico in 2003, but its reemergence was documented in 2025. A retrospective study recorded 202 cases of human myiasis between April 2025 and March 2026. Most cases were concentrated in southern Mexico, particularly in Chiapas state, followed by Yucatán, Oaxaca, and Quintana Roo. The majority of affected individuals were men (71.8%), with a mean age of 61.1 years. The lower limbs were most frequently involved (55.0%). Most patients (76.7%) had more than one concurrent medical condition. Six deaths were reported, with one directly attributed to screwworm myiasis. The study emphasizes the need for active clinical detection and integrated surveillance as the parasite spreads northward.