Screwworm outbreaks reported in Hidalgo and Querétaro, Mexico

Health authorities in Mexico are monitoring the spread of the screwworm (gusano barrenador), caused by the larvae of the fly Cochliomyia hominivorax.

In Hidalgo, the Health Secretariat is observing two men from Atotonilco el Grande and Tianguistengo for probable human cases. As of September, the state has recorded 24 confirmed human cases across various municipalities, including Tenango de Doria and Tlanchinol, with no reported deaths. The infestation can cause myiasis, where larvae feed on living tissue in wounds or natural cavities, leading to intense pain and tissue destruction.

In Querétaro, Secretary of Agricultural Development Rosendo Anaya Aguilar reported 55 active cases. The state has surpassed 1,000 cumulative cases across different species, primarily affecting cattle and, to a lesser extent, dogs. The highest incidence is concentrated in the Sierra Gorda region, where livestock grazing in pastures has increased exposure to the flies.