Screw-worm fly outbreaks affect multiple Mexican states

The screw-worm fly (Cochliomyia hominivorax) is causing significant health and agricultural issues across various Mexican states. In Chihuahua, the outbreak has expanded to 30 municipalities, covering nearly half of the state's territory. According to Senasica, there are 137 total cases in the state, with 107 remaining active. The infestation primarily affects livestock, with 88 bovine cases, followed by equine, canine, ovine, and porcine infections.

In terms of human health, Veracruz has the widest territorial presence of human myiasis caused by the screw-worm, affecting 56 municipalities. While Chiapas has reported a higher total number of human cases (145), Veracruz accounts for 91 cases across a larger number of locations. Nationally, epidemiological reports indicate 478 confirmed cases of human myiasis during 2025 and 2026. The condition occurs when larvae invade living tissue, often starting from small wounds, and can lead to intense pain and deep tissue damage if left untreated.