Florida using 'overwhelming force' to fight flesh-eating screwworms

Endangered Key deer are facing an infestation of screwworms in Florida.

Story highlights

  • The USDA confirmed a local infestation of New World screwworm in Key deer
  • The fly can be fatal to animals; no cases have been reported in humans or livestock

(CNN)In recent months, Florida has faced both Zika virus and hurricanes. Now, the Sunshine State must defend itself against one more natural scourge: flesh-eating worms of unknown origin.

After the US Department of Agriculture confirmed a local infestation of New World screwworm in Key deer on September 30, state Commissioner of Agriculture Adam Putnam declared an agricultural state of emergency in Monroe County, the home of Key West.
    Despite its name, the adult screwworm is actually a fly, and it typically lays its eggs in an open wound on an animal. Infected animals usually separate from their herd and, if left untreated, die in seven to 14 days from toxicity or secondary infections.
      No human or livestock cases have been reported, according to the Department of Agriculture and Consumer Services. The infestation is geographically limited to the Keys, specifically Big Pine Keys and No Name Keys.
      Along with the confirmed cases in the National Key Deer Refuge of Big Pine Keys, a few local pets and additional deer have showed signs of possible infestations over the past two months. Key deer, a subspecies of white-tailed deer, once ranged throughout the lower Keys. They are protected under the Endangered Species Act.
      Around 60 endangered Key deer have died as a result of a screwworm infestation.
      This is the first local infestation in the nation in more than three decades and the first time in 50 years Florida has seen the screwworm, Cochliomyia hominivorax.
        "While it sounds like a Halloween joke, it poses a grave threat to the last population of the subspecies of Key Deer," Putnam said. "And if it gets beyond the Keys, it represents an enormous threat to the US livestock industry, because of potential quarantines and trade barriers that could occur if it gets into the livestock population."
        The New World screwworm can harm humans and their pets, but it is relatively easy to detect and simple to treat in both, explained Putnam. Though just confirmed within the past month, he said, officials believe this local infestation possibly began as early as July. Though the origin is unknown, previous infestations have been set off by animals entering from other countries.

        'It is a horrible death'

        The adult screwworm is about the size of or just slightly larger than the common housefly. The screwworm is different in color and appearance, a Technicolor vision with orange eyes and a metallic dark blue to blue-green or gray body, according to the USDA. Three dark stripes run down its back.
        In her lifespan, the screwworm fly can produce thousands of offspring.
        Typically, the female screwworm fly mates just once in her lifetime. She lands on or near an open wound or the mucous membranes of an animal's nose, mouth or ears and there lays hundreds of eggs.
        The eggs emerge as maggots and begin to feed on the live tissue of the animal, the unwitting host to this parasite, explained Putnam. Aft