The U.S. Department of Agriculture has confirmed a case of New World screwworm in a 3-week-old calf in Zavala County, Texas, sparking concerns about the parasitic fly’s potential impact on livestock and human health.
The confirmation comes after a sample was sent to the USDA’s National Veterinary Services Laboratories in Ames, Iowa, for testing, following a report of a possible case in southern Texas. Rep. Don McLaughlin of Texas has vowed to work with local, state, and federal agencies to combat the issue.
New World Screwworm Outbreak
The New World screwworm is a parasitic fly that feeds on warm-blooded animals and people, laying its eggs in open wounds or orifices, which can then eat living tissue or flesh once they hatch. The screwworm is typically found in South America and parts of the Caribbean but has been detected in Central America and Mexico over the last three years.
The USDA has been tracking the screwworm’s spread in Mexico, with at least 26,216 cases identified and upward of 2,700 remaining active. The department shares updates twice a week on any new cases found within 400 miles of the U.S. in Mexico.
Texas officials have warned outdoor enthusiasts about the parasite since late 2024, and last year, the first case of a New World screwworm infestation in a human was confirmed in the U.S. in a traveler who had returned to Maryland from El Salvador.
Implications and Response
The confirmation of the screwworm case in Texas has significant implications for the livestock industry and public health. The USDA has activated personnel on the ground and is working with local partners to combat the issue.
The case highlights the need for continued vigilance and cooperation between federal, state, and local agencies to prevent the spread of the screwworm and protect animal and human health. As the screwworm continues to spread northward, its impact on the U.S. could be significant, emphasizing the importance of monitoring and response efforts.
