New World screwworm re-emerges in Mexico and US

The New World screwworm (Cochilomyia hominivorax) is re-emerging in Mexico and the United States, posing a significant threat to both livestock and human health. Unlike most flies, screwworm maggots feed on the living flesh of warm-blooded animals, causing extensive tissue damage and secondary infections.

Research published in the journal Emerging Infectious Diseases indicates that between April 2025 and March 2026, Mexico reported 204 human cases of infestation. While most cases involved men and affected lower limbs, at least one death was directly attributed to the parasite. Recent surveillance from Mexico’s Ministry of Health suggests human cases may exceed 500.

To combat the resurgence, companies like Agragene are developing advanced eradication methods. Using CRISPR gene editing, Agragene aims to improve upon traditional radiation-based sterile insect techniques. Their method targets specific genes to produce healthy, sterile male flies and lethal females, which could more effectively disrupt the mating cycle without compromising the insects' ability to mate.