A flesh-eating parasite has returned to Florida

Screwworm larvae

Screwworm larvae

BIG PINE KEY, Fla. (AP) — An agricultural emergency has been declared in the Florida Keys over a fly larvae infestation threatening endangered deer found only in the island chain.

In a statement Monday, Agriculture Commissioner Adam Putnam said the discovery of New World screwworm in the National Key Deer Refuge “sends shivers down every rancher’s spine.” Screwworm feed on the animals’ flesh, and infestations can be fatal to livestock and pets.

Refuge manager Dan Clark says about 40 of the 3-feet-tall Key deer have had to be euthanized over the last month due to the screwworm infestation.

To stop the infestation from spreading north, officials have established an animal health check point on the only road leading from the Keys. Putnam’s office says sterile flies will be released to eradicate the area’s screwworm fly population.

The adults lay eggs in open wounds, and the hatched larvae burrow, corkscrew-like, through flesh. Screwworms ate their way into livestock, dogs, deer, and even humans in the U.S. until they were wiped out in 1982, in one of the most successful national eradication campaigns ever.

The source of Florida’s current screwworm infestation is still unknown, but some are speculating it’s Cuba. The island nation still has screwworms. It’s conceivable an adult fly could be blown over on the right wind, but that hadn’t happened before in 30 years. What has changed recently are thawing relations between the U.S. and Cuba.