Shoo Fly, Don’t Bother Me: Screwworm Infestation in Miami

screwworm Miami

Shoo Fly, Don’t Bother Me: Screwworm Infestation in Miami

Written by Sam Arner

Maggots…the word alone is enough to make your skin crawl. We often associate the word with dirt and filth, but maggots are simply the larval stage of a fly. And just like all living things, a maggot’s got to eat. Typically, maggots feed on decaying animals to help fuel growth. Although disgusting, they are a vital clean-up crew for the environment. Notice how I used the word “typically”? That is because there is recent evidence that a live tissue-eating maggot, known as the Screwworm (Cochliomyia hominivorax), has reappeared in Homestead, FL after being nearly eradicated in the 1950’s.

The Problem: Screwworms in the Florida Keys

Screwworm first re-appeared in North America on October 3rd 2016 in the Florida Keys. The infestation has mostly been found in the native Key deer population, but there were a few cases found in domestic animals. Biologists thought the problem had been contained, but as you can imagine it is hard to contain a fly.  In January of this year, a stray dog in Homestead was found with a screwworm infestation in its wounds. Since being detected, the dog has been contained and freed of the maggots, but at this point it is unknown how prevalent Screwworms are here on the mainland.

The Concern: Screwworm Infestation

The actual flies do not cause physical harm to any being, but a female fly will lay her eggs in any open wound she can find. What is unique about Screwworms are that they thrive on live tissue of “warm-blooded” animals. They show no mercy and can infest pets, wildlife, and even humans. One little scrape or cut can provide an excellent feeding ground for these critters. In America, infestation of humans is of little concern. We (hopefully) shower often enough and tend to our wounds quickly enough that the insects don’t have enough time to take up residency in our flesh. Animals, however, are a different story.

Screwworm presence in wildlife and feral animals can be difficult to detect, and the reason why this outbreak is so concerning. Not only do they pose a serious potential risk for wildlife populations, but these wild animals can provide the perfect breeding ground for this opportunistic insect. One undetected wound on our pets could put them at risk for an infestation.

Preventing Screwworm Infection

Being aware and knowing your pet is the key to preventing them from unnecessary harm. Do not let your pet roam around outside unmonitored. If one undetected wound on our pets comes in contact with a wild animal with these flesh-eating larvae or the fly itself, it could lead to a painful demise. Most importantly, know your pet inside and out! Along with regular bathing, look over your pets’ fur and skin frequently. If you detect a wound, clean it and closely monitor it. The larvae can go undetected in the beginning stages, so if you notice your pet’s wound hasn’t gotten better in a few days or worsens, do not hesitate, and take them to a vet. Early detection is key to saving our pets and helping biologists eradicate this species once and for all.

If you detect Screwworms on you, your pets, or local wildlife contact 1-800-HELP-FLA (1-800-435-7352). If you are a non-Florida resident call 850-410-3800. Anyone visiting the Florida area should check any pets before leaving to prevent further infestation.

Resources on Screwworms:

  1. http://entnemdept.ufl.edu/creatures/livestock/primary_screwworm.htm 
  2. https://www.aphis.usda.gov/aphis/ourfocus/animalhealth/nvap/vet_acred_alert
  3. https://www.cdfa.ca.gov/ahfss/animal_health/pdfs/Screwworm_Fact_Sheet.pdf

Photo Credits:

  1. Cochliomyia hominivorax: John Kucharski – Transferred from en.wikipedia to Commons. Original uploader was Ellmist from http://www.ars.usda.gov/is/graphics/photos/k7576-1.htm Image Number K7576-1
  2. Screwworm: The Mexican-American Commission for the Eradication of the Screwworm

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