Texas confirms additional New World screwworm livestock cases 

New World screwworm cases in the United States totaled 42 as of July 29, with 41 confirmed in Texas and one in New Mexico, according to U.S. Department of Agriculture’s Animal and Plant Health Inspection Service. 

The first domestic confirmed case was reported on June 3 in Texas. Since then, the USDA has responded by releasing sterile NWS flies in areas where cases have been confirmed. The sterile insect technique is intended to reduce successful breeding and help prevent the pest from spreading. 

Officials reported that 11 cases remain active, all in Texas, where affected animals are undergoing treatment and mitigation measures. The remaining confirmed cases have been classified as inactive following response efforts. 

Recent cases 

No locally acquired human cases or wildlife cases have been reported in the United States. The most recent confirmed case was identified on July 21 in Sutton County, Texas, in a goat. 

Other recent detections include a July 18 case in a sheep in Schleicher County, Texas, which has since been classified as inactive, and a July 17 case in a bovine in Starr County, Texas. 

On July 14, officials confirmed two cases involving sheep in Pecos County, Texas. On July 13, authorities confirmed two additional cases: one in a dog in Sutton County and another in a bovine in Brewster County. 

Animal health officials continue surveillance, treatment, and mitigation efforts to prevent additional spread of the parasitic pest. NWS larvae infest living tissue in warm-blooded animals, making rapid detection and treatment important for limiting transmission. 

Lacey Vilhauer can be reached at 620-227-1871 or [email protected].