Worms that burrow through flesh like corkscrews and which were thought to have been eradicated in the United States are now back in Florida, confirmed the United States Department of Agriculture’s Animal and Plant Health Inspection Service.

Flesh-eating screwworms have been found on three endangered Key deer, according to Florida's Department of Agriculture and Consumer Services. There have been no human or livestock cases since they were eradicated from the US in 1982, and they've been gone from Florida even longer.

The adult screwworm fly (Cochliomyia hominivorax) lays its eggs in open wounds, and the hatched larvae burrow through flesh like a wine bottle opener through cork.

“This foreign animal disease poses a grave threat to wildlife, livestock and domestic pets in Florida. Though rare, it can even infect humans,” Florida Commissioner of Agriculture Adam H. Putnam said. “We've eradicated this from Florida before, and we'll do it again. We will work with our partners on the federal, state and local level to protect our residents, animals and wildlife by eliminating the screwworm from Florida. The public's assistance is crucial to the success of this eradication program.”

It’s still unknown how these screwworms arrived in Florida, but, according to The Atlantic, some are speculating it’s a repercussion from increased trading with Cuba.

Earlier this month, federal officials already kicked off efforts to stop the spread of the screwworm fly by releasing sterilized males, Newsweek reported. After these flesh-eating creatures mate with female flies, they will not be able to lay more viable eggs, because they only breed once during their life cycle.

This strategy worked to eradicate the fly from the United States in the 1950s and 1960s.

“The screwworm is a potentially devastating animal disease that sends shivers down every rancher's spine. It's been more than five decades since the screwworm last infested Florida, and I've grown up hearing the horror stories from the last occurrence,” Putnam said.

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