SREL Reprint #3765

Otterly diverse - A high diversity of Dracunculus species (Spirurida: Dracunculoidea) in North American river otters (Lontra canadensis)

Michael J. Yabsley1,2,3, Kayla B. Garrett1,2, Alec T. Thompson1,3, Erin K. Box1, Madeline R. Giner1,
Ellen Haynes1, Heather Barron4, Renata M. Schneider5, Sarah M. Coker1, James C. Beasley2,6,
Ernest J. Borchert2,6, Renn Tumlison7, Allison Surf7, Casey G. Dukes1,8, Colleen Olfenbuttel8,
Justin D. Brown9, Liandrie Swanepoel1, and Christopher A. Cleveland1,3

1Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine,
University of Georgia, Athens, GA, 30602, USA
2Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
3Center for Ecology of Infectious Diseases, Athens, GA, 30602, USA
4Clinic for the Rehabilitation of Wildlife, Sanibel, FL, 33957, USA
5South Florida Wildlife Center, Fort Lauderdale, FL, USA
6Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA
7Applied Science and Technology, Henderson State University, Arkadelphia, AR, 71999, USA
8North Carolina Wildlife Resources Commission, NCSU Centennial Campus,
1751 Varsity Drive, Raleigh, NC, 27606, USA
9Department of Veterinary and Biomedical Sciences, Pennsylvania State University,
University Park, PA, 16802, USA

Abstract: The genus Dracunculus contains numerous species of subcutaneous parasites of mammals and reptiles. In North America, there are at least three mammal-infecting species of Dracunculus. Reports of Dracunculus infections have been reported from river otters (Lontra canadensis) since the early 1900s; however, little is known about the species infecting otters or their ecology. Most reports of Dracunculus do not have a definitive species identified because females, the most common sex found due to their larger size and location in the extremities of the host, lack distinguishing morphological characteristics, and few studies have used molecular methods to confirm identifications. Thus, outside of Ontario, Canada, where both D. insignis and D. lutrae have been confirmed in otters, the species of Dracunculus in river otters is unknown. In the current study, molecular characterization of nematodes from river otters revealed a high diversity of Dracunculus species. In addition to confirming D. insignis infections, two new clades were detected. One clade was a novel species in any host and the other was a clade previously detected in Virginia opossums (Didelphis virginiana) from the USA and a domestic dog from Spain. No infections with D. lutrae were detected and neither new lineage was genetically similar to D. jaguape, which was recently described from a neotropical otter (Lontra longicaudis) from Argentina. These data also indicate that Dracunculus spp. infections in otters are widespread throughout Eastern North America. Currently the life cycles for most of the Dracunculus spp. infecting otters are unknown. Studies on the diversity, life cycle, and natural history of Dracunculidae parasites in wildlife are important because the related parasite, D. medinensis (human Guinea worm) is the subject of an international eradication campaign and there are increasing reports of these parasites in new geographic locations and new hosts, including new species in humans and domestic dogs.

Keywords: Guinea worm; Mustelid; North America; Subcutaneous parasite; Wildlife

SREL Reprint #3765

Yabsley, M. J., K. B. Garrett, A. T. Thompson, E. K. Box, M. R. Giner, E. Haynes, H. Barron, R. M. Schneider, S. M. Coker, J. C. Beasley, E. J. Borchert, R. Tumlison, A. Surf, C. G. Dukes, C. Olfenbuttel, J. D. Brown, L. Swanepoel, and C. A. Cleveland. 2024. Otterly diverse - A high diversity of Dracunculus species (Spirurida: Dracunculoidea) in North American river otters (Lontra canadensis). International Journal for Parasitology: Parasites and Wildlife 23(100922).

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).