Endangered Deer Infected With “Gory” Parasite

Image: Ianaré Sévi

Endangered key deer have a gruesome new problem: They’re infested with invasive screwworms, a species that hasn’t been seen in the United States for over 50 years.

Staff at National Key Deer Refuge recently found deer infested with maggots of New World screwworm larvae that had previously been eradicated from the US in the 1960’s. Experts are unsure how they got here.

These screwworms lay eggs in open wounds; once the maggots hatch, they feed by digging corkscrew holes (hence the name) into the flesh of their host, most commonly the head. Ouch.

screwworm-lavaScrewworm fly larvae. Image: John Kucharski

More than 40 key deer have already been euthanized after becoming infested with these parasites, and there is now a mandatory “animal health check point” surrounding the area to ensure that infested pets in vehicles do not leave the quarantine area.

Refuge manager Dan Clark told a Florida Keys News reporter, “[The deer] are in as gory of a condition as you can imagine.”

Screwworms were originally eradicated in 1966 by entomologist Edward Knipling after he released artificially sterilized screwworm males. While this worked in the US, some of the species persisted in the Caribbean Islands and in South America.

Humans can be infected the same way the flies infect animals.

secondary_screwworm_fly_cochliomyia_macellariaScrewworm fly

Key deer are a small endangered subspecies of white-tailed deer that exist only on a few small islands in the Florida Keys, with only about 800 remaining. Unfortunately, motorists incidentally kill an average of 150 of these docile deer every year.

It’s not just key deer that are being affected by these parasites. The screwworms are said to be a nightmare for farmers, as they can lose huge amounts of animals in a short amount of time. Cattle in particular are a concern, and the Florida Commissioner of Agriculture Adam Putnam has declared a state of emergency.

Thankfully, officials believe that they will be able to stop the spread and eradicate the screwworms after a period of quarantine.