Control of swimmer's itch in Michigan: past, present and future

TitleControl of swimmer's itch in Michigan: past, present and future
Publication TypeJournal Article
Year of Publication1988
AuthorsBlankespoor HD, Reimink RL
JournalThe Michigan Riparian
Pagination10, 19

The association between a type of dermatitis known as swimmer's itch and the free-living stage of certain digenetic trematodes (nonhuman schistosomes) was delineated in 1928 by Cort at the University of Michigan Biological Station. Following his discovery, studies on swimmer's itch have continued at the Biological Station until the present time. In 1939, the State of Michigan initiated a control program that included the application of copper sulfate to many of the larger recreational lakes. It was assumed that this molluscicide would reduce the prevalence and incidence of swimmer's itch by interrupting the life cycle of the parasite in the snail intermediate hosts. Unfortunately, swimmer's itch continues to be a problem in Michigan despite more than a half century of control efforts. In addition, environmental concerns about the accumulation of this toxic substance in our aquatic ecosystems are being expressed more frequently. In 1985, Blankespoor initiated a new concept in controlling swimmer's itch by treating the definitive hosts with an antihelminthic drug, Praziquantel. Based on four years of research on Big and Little Glen Lakes, the authors have concluded that controlling swimmer's itch with Praziquantel is more effective, less expensive and has no detrimental effects on the environment. In 1990, the program will be expanded to include three additional lakes in Leelanau County.