Lauren and JJ discuss a case report from 2000: myiasis in a Thoroughbred gelding in Florida. Why was this case significant, and why was a major government response necessary?

This episode includes a thorough review of myiasis caused by the new world screwworm fly (Cochliomyia hominovorax).

References:

• United States Department of Agriculture. (2025, September 3). Module 41: New World Screwworm. National Veterinary Accreditation Program Modules for Accreditation Renewal. Accessed September 14, 2025. https://www.aphis.usda.gov/nvap/training-modules
• United States Department of Agriculture Animal and Plant Health Inspection Service. (2025, August 24). New World Screwworm. Accessed September 14, 2025. USDA. https://www.aphis.usda.gov/livestock-poultry-disease/cattle/ticks/screwworm
• The Panama-United States Commission for the Eradication and Prevention of Screwworm Infestation in Livestock (COPEG). (2025). Accessed September 14, 2025. COPEG. https://www.copeg.org/en/
• United States Department of Agriculture. (2024, December 28). Pesticides to potentially use against new world screwworm. Accessed September 14, 2025. https://www.aphis.usda.gov/sites/default/files/pesticides-for-nws.pdf
• United States Centers for Disease Control and Prevention. (2025, August 27). About new world screwworm. CDC. https://www.cdc.gov/new-world-screwworm/about/index.html
• National Public Radio. (2025, August 25). The U.S. confirms its first human case of new world screwworm: what is it? NPR. Accessed September 14, 2025. https://www.npr.org/2025/08/25/nx-s1-5515487/new-world-screwworm-us-human-case
• Beck, L. (2025, September 9). Veterinarians asked to be alert for screwworm infestations. Veterinary Information Network. Accessed September 14, 2025. https://news.vin.com/default.aspx?pid=210&Id=12840615&f5=1
• Cutolo, A. A., Perrier, N., Menz, I., Thyssen, P., Silva, F. O., & Beugnet, F. (2021). Efficacy of afoxolaner (NexGard) on the treatment of myiasis caused by the new world screwworm fly Cochliomyia hominovorax (Diptera: Calliphoridae) in naturally infested dogs. Veterinary Parasitology: Regional Studies and Reports, 24(0), 100569. https://doi.org/10.1016/j.vprsr.2021.100569
• McCullough, C. (2025, May 27). USDA confirms reports of new world screwworm in the U.S. are false. RFDTV. Accessed September 14, 2025. https://www.rfdtv.com/usda-confirms-reports-of-new-world-screwworm-in-the-u-s-are-false
• Correia, T. R., Scott, F. B., Verocai, G. G., Souza, C. P., Fernandes, J. I., Melo, R. M. P. S., Vieira, V. P. C., & Ribeiro, F. A. (2010). Larvicidal efficacy of nitenpyram on the treatment of myiasis caused by Cochliomyia hominovorax (Diptera: Calliphoridae) in dogs. Veterinary Parasitology, 173(1-2), 169-172. https://doi.org/10.1016/j.vetpar.2010.06.019
• Muchiut, S., Miro, M. V., Anziani, O., Nava, S., & Lifschitz, A. (2024). Failure of doramectin and ivermectin in prevention Cochliomyia hominivorax myiasis in a subtropical region: A pharmacokinetic-pharmacodynamic study. Veterinary Parasitology, 334, 110384. https://doi.org/10.1016/j.vetpar.2024.110384
• American Veterinary Medical Association. (April 1, 2000). Screwworm turns heads in Florida. Accessed September 14, 2025. https://www.avma.org/javma-news/2000-04-15/screwworm-turns-heads-florida
• Alexander, J. L. (2006). Screwworms. Journal of the American Veterinary Medical Association, 228(3), 357-367. https://doi.org/10.2460/javma.228.3.357