Researchers and officials warn that sterile-fly programs alone won’t eradicate the pest unless underlying drivers—especially illicit cattle trafficking—are tackled, since human-assisted livestock movement, not wildlife migration, is driving current spread.

Efforts to boost the screwworm control program include expanding sterile-fly production, with a new facility in Mexico opened in late June and plans for another in Texas by late 2027, as irradiated sterile flies are released to prevent reproduction when they mate with wild females.

Experts caution that the outbreak could heighten broader infectious disease risks beyond screwworm, including tuberculosis, brucellosis, hoof-and-mouth disease, and bird flu, underscoring the need for enhanced wildlife disease monitoring across the Americas.

A Wildlife Conservation Society study links illegal cattle movement in Central America to the rapid spread of the screwworm, showing wildlife with infected wounds far from cattle sources and indicating the parasite is now endemic in wildlife.

Historical context shows that the 1960s eradication success relied on different cattle densities and movement patterns; today’s higher cattle density and illicit trafficking create a much tougher environment for control, making this situation distinct from past efforts.

Screwworm detections in the United States remain limited to livestock and pets (34 animals across Texas and New Mexico), while authorities deploy sterile flies to slow northward spread; eradicating it would require roughly 500 million sterile flies, far more than the current releases of about 100 million.

Future innovations could include raising only sterile males or developing better bait traps, but these require time to develop and test; in the meantime, broader disease monitoring and addressing cattle trafficking roots are essential parts of a comprehensive response.