On Wednesday, the U.S. Department of Agriculture reported a possible case of New World meat maggot infestation in Texas.
This comes after a worm was discovered in Mexico last week, just 25 miles from the US border, as previously reported by the US Department of Agriculture. According to federal data, this was the closest infestation to the US since at least September of last year.
The potential case identified Wednesday was found in south Texas, and a sample was sent to the USDA National Veterinary Laboratory in Ames, Iowa, for confirmation, the USDA said in a social media post.
«"We have already deployed staff on the ground and are working with local partners," the USDA said.
Texas Rep. Don McLaughlin told Reuters the samples were taken from calves on a cattle ranch in La Pryora, a small community in southwest Texas located about 80 kilometers (50 miles) from the Mexican border.
«"If this case is confirmed, I will work with all local, state, and federal agencies to combat this horror," McLaughlin wrote in X.
In Mexico, a blowfly larva was discovered in a 5-year-old goat on May 28 in the state of Coahuila, bordering southwest Texas. According to the U.S. Department of Agriculture, U.S. authorities have tracked 32 cases of this parasitic fly infestation in the Mexican state, including 19 active cases.
In total, according to the USDA, at least 26,216 cases of screwworm infestations have been identified in Mexico, with more than 2,700 of them remaining active. The agency posts twice-weekly updates on new cases detected within 400 miles of the United States in Mexico, and on its New World screwworm webpage, it specifically notes that the pest is "currently absent" from the United States and that "the current risk to livestock, other animals, and people in the United States remains very low.".
However, in recent months and years, this parasite has begun appearing closer to the United States than ever before. In April, Texas Agriculture Commissioner Sid Miller announced that it had been detected in Mexico, 60 miles from the U.S. border, as CBS Texas reported at the time. Texas authorities had been warning outdoor enthusiasts about this parasite since late 2024, when the state Parks and Wildlife Department issued an alert about a blowfly recently found on a cow in southern Mexico.
Last year, the first human case of fly larvae infection was confirmed in the United States, the Department of Health and Human Services reported at the time. The case was detected in a traveler returning to Maryland from El Salvador, Department of Health and Human Services spokesman Andrew Nixon said in a statement to CBS News. Maryland health officials later reported that the person had recovered, and investigators found no evidence of transmission to other people or animals.
The New World screwworm is a parasitic fly that feeds on warm-blooded animals and humans. It lays eggs in open wounds or orifices, such as the eyes, ears, nose, or mouth. After hatching, the larvae can feed on living tissue or flesh, according to the Centers for Disease Control and Prevention (CDC). The parasitic fly is typically found in South America and parts of the Caribbean, but over the past three years, it has been detected further north, in Central America and Mexico, according to the CDC.