A Novel Schistosome Species Hosted by Planorbella (Helisoma) trivolvis is the Most Widespread Swimmer's Itch-causing Parasite in Michigan Inland Lakes

Authors

• D. M. Soper, University of Dallas
• T. R. Raffel, Oakland University
• J. P. Sckrabulis, Oakland University
• K. L. Froelich, Saint Joseph High School
• B. A. McPhail, University of Alberta
• M. D. Ostrowski, Oakland University
• R. L. Reimink, Freshwater Solutions LLC
• D. Romano, University of Dallas
• S. P. Rudko, Public Health Agency of Canada
• P. C. Hanington, University of Alberta

Document Type

Article

Publication Date

1-9-2023

Publication Source

Parasitology

Volume Number

150

Issue Number

1

First Page

88

Last Page

97

ISSN

00311820

E-ISSN

14698161

Abstract

Cercarial dermatitis ('swimmer's itch'; SI), characterized by small itchy bumps caused by schistosome parasites of birds and mammals, is a common problem in Michigan. Research on avian schistosomes began nearly 100 years ago in Michigan inland lakes, yet scientists are still uncovering basic biological information including the identification of local snail and parasite species that cause SI. Previous research primarily focused on lakes in the northern half of Michigan's lower peninsula, although SI occurs throughout the state. We surveyed snails and snail-borne trematodes in lakes across Michigan's lower peninsula and used quantitative polymerase chain reaction analysis of filtered water samples to identify parasites to the species level, including a recently discovered parasite species that uses the snail Planorbella (Helisoma) trivolvis as its intermediate host. Most SI mitigation efforts have focused on a parasite species hosted by the snail Lymnaea catescopium (= Stagnicola emarginata); however, lymnaeid snails and their associated schistosome species were largely restricted to northern lakes. In contrast, P. trivolvis and its associated parasite species were common in both northern and southern Michigan lakes. A third schistosome species associated with physid snails was also present at low levels in both northern and southern lakes. These results indicate that the recently discovered parasite species and its planorbid snail intermediate host may be more important drivers of Michigan SI than previously thought, possibly due to increased definitive host abundance in recent decades. These results have potentially important implications for SI mitigation and control efforts.

Keywords

eDNA, Planorbella, qPCR, Schistosoma, snail distribution, swimmer's itch, trematodes, Trichobilharzia

Recommended Citation

Published in: Parasitology, Volume 150, Issue 1, January 9, 2023, pages 88-97.