Recently, there’s been a warning about a dangerous parasite getting dangerously close to the US. The New World Screwworm, a flesh-eating fly, was spotted less than 70 miles from the US-Mexico border. This parasite is known for attacking warm-blooded animals, including livestock and wild animals, by laying eggs in wounds or tiny openings. The larvae then burrow into flesh, creating serious and often deadly wounds.

The History and Spread of the Screwworm

The screwworm used to be a major problem in the US. Back in the day, it caused serious damage to the livestock industry. In the 1950s, efforts to eliminate it began, using sterile male flies and careful monitoring of animals. These measures worked well, and by 1966, the fly was wiped out of the US. Mexico also succeeded in eradicating the fly in the 1980s. Central American countries had similar success, with Panama declaring it eradicated by 2006. But in recent years, the fly has started to come back. After crossing the Darién Gap between Panama and Colombia in 2022, the flies have been moving north again. In July, Mexico found an infected animal in Veracruz, which is 370 miles from the US border. Then, in September, a case was confirmed in Nuevo León, less than 70 miles from Texas.

Why This Matters for the US and What’s Being Done

The USDA reports that the infected cow was moved to a feedlot in Nuevo León from a part of Mexico with active screwworm cases. The proximity to the US border is worrying, especially since the area is near a busy highway connecting Monterrey to Laredo, Texas. Texas officials are urging quick action. Texas Agriculture Commissioner Sid Miller said, “The screwworm is dangerously close,” and called for immediate use of pesticide bait to prevent an outbreak.

Authorities are advising residents and farmers in southern Texas to check their animals and pets regularly. They should look for wounds that are enlarging or draining, along with maggots or eggs around body openings like the nose, ears, or genitals. While humans can get infected, it’s rare, but still a concern. The US has temporarily stopped importing cattle, bison, and horses from Mexico to keep the parasite out. Additionally, nearly 8,000 traps have been set up across Texas, Arizona, and New Mexico. So far, thousands of samples have been tested, and none have shown signs of the screwworm.

Despite the good news so far, experts are taking the threat seriously. The close call with this parasite reminds everyone how easily these pests can cross borders and cause damage. Texas officials emphasize the need to stay vigilant and act quickly to prevent a potential outbreak that could threaten livestock, wildlife, and even humans.

Overall, this situation is a reminder of how global travel and trade can spread pests and diseases quickly. Staying alert and prepared is key to keeping our animals and communities safe from this ravenous parasite.

Inspired by

• https://arstechnica.com/health/2025/09/flesh-eating-parasite-just-70-miles-from-us-check-pets-texas-officials-say/

Sources

• conde.digital
• cnevids.com
• usda.gov