New World screwworm cases remain under control in the United States, with just five active infections being monitored as federal and state authorities continue an aggressive campaign to keep the parasite from becoming established, according to the U.S. Department of Agriculture.
Agriculture Secretary Brooke Rollins shared an update on social media this week, noting progress since the first U.S. detection more than two months ago. “Really proud of this work. The numbers speak for themselves,” she wrote.
Rollins said the department had prepared for the threat since the start of the administration, despite warnings from critics that the pest could spread quickly through the nation’s cattle herd. She said the United States has recorded 45 total cases since the outbreak began, and all affected animals have recovered.
New World screwworm cases drop amid sterile fly releases
USDA officials attribute the decline in active New World screwworm cases to a sustained response that includes releasing more than 600 million sterile flies to break the pest’s reproductive cycle. The agency has also carried out more than 1,000 drone flights to identify and map release sites, and has observed and cleared more than 56,000 wildlife animals through ongoing surveillance.
Federal officials report no confirmed infections in wild or feral animals in the United States, a key marker because established wildlife transmission can complicate eradication efforts.
While conditions domestically have improved, officials say the situation in Mexico remains a concern. Texas Agriculture Commissioner Sid Miller said authorities there are responding to a growing number of infections.
“They’re just exploding the number of screwworm cases that they’ve got,” Miller said, adding that officials have reported hundreds of human cases and about 2,000 active infections overall. “We need to help them out because the more cases they have, the more likely they’re going to infest us.”
Miller said Texas is expanding surveillance as USDA prepares to reopen cattle trade with Mexico. Additional monitoring traps are being placed near cruise ship terminals in Corpus Christi and Galveston to detect any flies that may arrive from the Caribbean or Mexico’s Yucatán Peninsula. “I thought it would be a good idea to put them around those cruise ship terminals in Corpus Christi and Galveston in case we get any flies that are hitchhiking back up from the Caribbean or that Cancún area,” he said.
Federal and state agencies say continued surveillance, sterile fly releases, and coordination with Mexico will remain central to preventing New World screwworm from reestablishing in the United States.