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New World Screwworm: What You Need To Know

By Craig Payne

Dr. Payne is a member of Missouri’s New World Screwworm Joint Working Group, which was assembled in preparation for the potential re-emergence of NWS in the U.S. Led by State Veterinarian Steve Strubberg, the working group comprises representatives from USDA, Missouri Department of Agriculture, University of Missouri Extension, Missouri Department of Conservation and Missouri Department of Health and Senior Services.

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service confirmed the presence of New World screwworm in the United States on June 3. Larvae were identified in the umbilical area of a 3-week-old calf in Zavala County, Texas. Current information on confirmed cases can be found on the USDA APHIS website.

New World screwworm is the larval stage (maggot) of the blowfly Cochliomyia hominivorax. Unlike most other blowfly larvae, which feed on necrotic tissue, NWS larvae feed on living tissue of warm-blooded animals.

While New World screwworm poses a health threat to cattle and other animal species, USDA emphasizes that the U.S. food supply remains safe. Screwworms do not infest meat or other food products. Any evidence of screwworm infestation in an animal would be identified during inspection, and any contaminated product from an affected animal would not be allowed to enter the food supply.

USDA and Texas animal health officials have initiated response activities consistent with the New World Screwworm Response Playbook. These actions include establishing a 20-kilometer (12.4-mile) infested zone around the detection, implementing quarantines and movement controls, increasing surveillance and trapping, deploying response personnel, and expanding sterile fly release efforts in the affected area. Early recognition of NWS by animal owners and rapid reporting will be essential for limiting the spread.

Source : missouri.edu

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