EDWARDS COUNTY, Texas - Three new cases of New World Screwworm were detected within 24 hours, the U.S. Department of Agriculture said Sunday, bringing the total detections domestically up to 15. Two of the new cases were detected in Edwards County calves, the USDA said in a post on its Screwworm Rapid Response page, which were found in animals already inside the currently affected area.

NWS UPDATE: In the last 24 hours, 1 lamb in Crockett County, TX and 2 calves in Edwards County, TX have tested positive for New World Screwworm, bringing the total number of domestic confirmed detections to 15.@USDA has already taken action and will be starting sterile fly..

The USDA said the new Edwards County cases were anticipated, even with sterile fly dispersals underway, because it does not kill existing larvae but instead prevents future generations.