Screwworm Outbreak Threatens Livestock, Raises Border Concerns

Mexico is grappling with a significant outbreak of the screwworm parasite, impacting livestock and leading to the closure of the U.S.-Mexico border. With over 13,000 cases reported, efforts are underway to contain the spread and protect the agricultural sectors in both countries from severe economic impacts.

Mexican officials reported a new case of the New World screwworm parasite Thursday evening, marking the second such incident in as many days. This outbreak has led to the closure of the U.S.-Mexico border for Mexican livestock.

The parasite surfaced in a goat located in the State of Mexico. Authorities conducted tests on 20 other animals at the same site, all of which returned negative results but received preventive treatment. Earlier, on December 31, a positive case was identified in a cow calf in Tamaulipas. Government records reveal a total of 13,106 cases since November 2024, with 671 currently active.

The disease, originating from Central America, poses a severe risk to the livestock industries of both countries. In Mexico, the highest concentrations of cases are in Chiapas, Oaxaca, Veracruz, and Yucatan. To prevent further economic fallout, the U.S. has imposed restrictions, fearing up to $1.8 billion in potential losses for Texas alone, according to the U.S. Department of Agriculture.