When the first four New World screwworm cases in the United States in 60 years were reported in Texas, members of the American Association of Veterinary Parasitologists were already together at their annual conference.
Dr. Andy Moorhead, associate professor of parasitology at the NC State College of Veterinary Medicine, was there in his role as president of the association and says, though the experts there were concerned, no one was caught off-guard.
“We’d been watching it inch closer and closer, but I guess while we weren’t exactly surprised that it jumped over, we hoped on some level it wouldn’t happen,” says Moorhead, noting that infestations have been moving northward from Central America since 2023. “Dealing with an outbreak is very different from dealing with prevention.”
Most parasitic flies lay eggs in carrion, naturally eliminating carcasses, but the New World screwworm lays eggs in open wounds or body openings of live warm-blooded animals. The resulting larvae then feed on living tissue, causing painful wounds, but a screwworm infection usually is fatal only if it goes untreated, Moorhead says.
As of Monday, 15 cases had been reported in or near Texas affecting cattle, two goats, two sheep and one dog.
The good news, he says, is the parasite is not novel and has been eradicated in the United States before so officials already know what to do.
Source : ncsu.edu