Investigation of the Ecological Origins of Schistosome Cercarial Dermatitis, with Emphasis on the Intermediate Snail Hosts of Schistosomatidae Trematodes, at Higgins Lake in Roscommon County, Michigan
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Authors
Nyman, Patrick M.
Issue Date
1998
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
The biologist Cort discovered the relationship between nonhuman schistosomes
and the skin ailment known as schistosome cercarial dermatitis in 1928 at the University
of Michigan Biological Station. These digenetic trematodes cause an allergic
sensitization reaction in people who come into contact with the cercarial stage in lakes
throughout the United States. The parasites cycle between a definitive host, including
waterfowl and some mammals, and an intennediate aquatic snail host. The objective of
this study was to explore the ecological root of schistosome cercarial dennatitis at
Higgins Lake in Roscommon County, Michigan. The focus was the acquisition of
information regarding the intermediate hosts in the lake. New potential hosts were
identified and previously known hosts were examined for incidences of infection. Seven
species of snails were encountered that belong to three families known to host nonhuman
schistosomes, two of which were proven to harbor the parasite. Distribution of both
Stagnicola emarginata (Say) and Physella (Costatella) integra integra morph walkeri
(Crandall), with an emphasis on geographic dispersal, depth ranges, densities at different
locations, and shell length, was analyzed with relation to schistosome infection. Both
species were found at numerous locations. P. integra was found associated only with
shallow depths less than 0.6 meters, while S. emarginata was found at all depths
explored, 0.3 to 0.9 meters. Larger shell lengths in S. emarginata had higher incidences
of infection than did those with shorter shells.
Description
iv, 36 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.