Mexico intensifies fight against gusano barrenador parasite

Mexico is confronting a rapid expansion of the gusano barrenador (Cochliomyia hominivorax) infestation that now affects livestock and has produced a surge in human miasis cases across 24 states. By early July 2026, 489 confirmed human cases and three deaths were reported, with new cases emerging in Yucatán, Quintana Roo, Chiapas, Guerrero, Jalisco, San Luis Potosí, Veracruz and Zacatecas.

The federal government is scaling up control measures. President Claudia Sheinbaum announced plans to produce a new sterile‑fly strain at the Chiapas facility, mirroring a technology developed in the United States, and to begin weekly releases of up to five million sterile flies in Tamaulipas, later expanding northward. The aim is to double productivity over the older strain and facilitate the reopening of the U.S. cattle export corridor.

Regional officials have also acted. In Chihuahua, legislator Arturo Medina demanded an immediate sanitary cordon, intensified zoosanitary surveillance, and criminal investigations after the first local case was confirmed in Parral. Hidalgo’s Copriseh completed a census of 889 residents in 13 at‑risk municipalities and provided education to prevent miasis. Across the country, multi‑disciplinary brigades have conducted treatments, fumigations and outreach to protect both cattle and companion animals.