The USDA says a New World screwworm was detected in Mexico’s Coahuila state in a 5-year-old goat only 25 miles from the U.S. border—the closest it has been to U.S. soil since at least last September. Officials have tracked dozens of cases across the state, whi
A 5-year-old goat in Mexico’s Coahuila state became the latest checkpoint in a widening sweep of a parasite that can turn open wounds into something far more dangerous.
The U.S. Department of Agriculture says a New World screwworm was detected there on Thursday—about 25 miles from the United States border. USDA data shows this is the closest the pest has been to U.S. soil since at least last September.
Coahuila borders southwestern Texas, and the USDA says federal officials have tracked 32 cases of the parasitic fly throughout the Mexican state, including 19 active cases. Across Mexico overall, at least 26,216 screwworm cases have been identified, and upward of 2,700 remain active, the USDA said.
The USDA updates twice a week when new cases are found within 400 miles of the U.S. in Mexico. On a webpage dedicated to the New World screwworm. the department notes that the pest “is not currently present” stateside and that “the current risk to livestock. other animals. and people in the United States remains very low.”.
Still, the pattern has been moving closer.
In April. Texas Agriculture Commissioner Sid Miller announced it had been found at a location in Mexico that was 60 miles from the U.S. border. Texas officials have been warning outdoor enthusiasts about the parasite since late 2024. after the Texas Parks and Wildlife Department issued an advisory saying the screwworm had recently been detected in a cow in southern Mexico.
The anxiety isn’t limited to animals. Last year, the U.S. Department of Health and Human Services confirmed the first case of a New World screwworm infestation in a human in the United States. The case was detected in a traveler who had returned to Maryland from El Salvador. according to an HHS spokesperson. Andrew Nixon. Maryland health officials later said the person had recovered. and investigators did not find evidence of transmission to other people or animals.
The New World screwworm is a parasitic fly that feeds on warm-blooded animals and people. It lays its eggs in open wounds or orifices like the eyes, ears, nose, or mouth. When the eggs hatch, the larvae can eat living tissue or flesh. The Centers for Disease Control and Prevention says the screwworm is typically found in South America and parts of the Caribbean. but it has been detected farther north in Central America and Mexico over the last three years. according to the CDC.
What makes this latest detection so closely watched is the distance. Once, the border line was a far boundary on a map. Now. USDA says. federal tracking is reaching territory where the pest is showing up within the same narrow band of proximity that has already brought public warnings and reinforced federal reassurance: the risk to the U.S. remains very low, even as the closest sightings keep shrinking the gap.
USDA New World screwworm flesh-eating screwworm Mexico Coahuila U.S. border Texas livestock safety parasitic fly Centers for Disease Control and Prevention human case Maryland Sid Miller
25 miles?? That’s basically next door, so why are they saying risk is “very low” lol
So it’s a fly and it attacks wounds? Sounds like something that would spread way faster than “twice a week” updates. I’m not convinced.
Wait I thought screwworm already was in Texas? Like I swear I saw a post last year about it being in a cow, so now it’s “not present”?? Maybe they mean not close enough for healthcare or something.
The USDA says “not currently present” and “risk remains very low” but it’s moving closer from Mexico like… okay but what does “very low” even mean when there are 19 active cases. Also if it can mess up livestock wounds then you’d think they’d do more than an advisory for outdoors people. This just feels like they’re waiting for it to pop up here before caring.