Award Date


Degree Type


Degree Name

Master of Public Health (MPH)


Health Sciences

First Committee Member

Mark Buttner

Second Committee Member

Patricia Cruz

Third Committee Member

Shawn Gerstenberger

Fourth Committee Member

Vernon Hodge

Number of Pages



Cercarial dermatitis, commonly known as swimmer's itch, is caused by penetration of larvae of the schistosome,Trichobilharzia, into the dermis and epidermis layers of the skin. Symptoms are characterized by painful swelling and itching at the site of penetration. The normal hosts for the life cycle of the schistosome are aquatic birds and aquatic snails. The most frequently used method of detection forTrichobilharziais microscopy. With increases in the occurrence of cercarial dermatitis outbreaks in freshwater in the Southwestern United States, it is becoming increasingly important to develop and standardize a molecular method for rapid detection that can assist health professionals and those who monitor public freshwater recreation systems. Therefore, the objective of this study was to develop a genus-specific real-time polymerase chain reaction (PCR) assay for the detection ofTrichobilharziaparasites in public freshwater systems. A literature search was completed to gather existing published material, and the DNA sequence database was searched to design and test potential primers and probes. The PCR assay primers and probes were developed, tested and optimized and used successfully to detect reference strains ofTrichobilharziaspecies. The method was then used to test for the presence ofTrichobilharziaschistosomes in surface grab samples and aquatic snails collected from Lake Mohave (AZ-NV). None of the water or snail samples tested with the primers and probes resulted in amplification. While the field collected samples did not yield any positive PCR results, it remains important to understand temporal and spatial patterns ofTrichobilharziaprevalence in order to provide a better understanding of risks for exposure periods during the year.


Microbiological assay; Polymerase chain reaction; Schistosomatidae; Skin—Parasites; Swimmer's itch


Environmental Health | Environmental Health and Protection | Microbiology | Occupational Health and Industrial Hygiene

File Format


Degree Grantor

University of Nevada, Las Vegas




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