title: PCR testing can be as accurate as culture for diagnosis of Ichthyophonus hoferi in Yukon River Chinook salmon Oncorhynchus tshawytscha .
abstract: We evaluated the comparability of culture and PCR tests for detecting Ichthyophonus in Yukon River Chinook salmon Oncorhynchus tshawytscha from field samples collected at 3 locations (Emmonak, Chena, and Salcha, Alaska, USA) in 2004, 2005, and 2006. Assuming diagnosis by culture as the 'true' infection status, we calculated the sensitivity (correctly identifying fish positive for Ichthyophonus), specificity (correctly identifying fish negative for Ichthyophonus), and accuracy (correctly identifying both positive and negative fish) of PCR. Regardless of sampling locations and years, sensitivity, specificity, and accuracy exceeded 90%. Estimates of infection prevalence by PCR were similar to those by culture, except for Salcha 2005, where prevalence by PCR was significantly higher than that by culture (p < 0.0001). These results show that the PCR test is comparable to the culture test for diagnosing Ichthyophonus infection.
authors.affiliation: Alaska Department of Fish and Game, Division of Commercial Fisheries, 333 Raspberry Road, Anchorage, Alaska 99518, USA.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Hamazaki
authors.forename: Eryn
authors.initials: E
authors.lastname: Kahler
authors.forename: Bonnie M
authors.initials: BM
authors.lastname: Borba
authors.forename: Tamara
authors.initials: T
authors.lastname: Burton
mesh_terms: D000818:Animals; D002170:Canada / Q000453:epidemiology; D005393:Fish Diseases / Q000469:parasitology*; D050298:Mesomycetozoea / Q000302:isolation & purification*; D050738:Mesomycetozoea Infections / Q000175:diagnosis / Q000453:epidemiology / Q000469:parasitology*; D045483:Rivers; D012474:Salmon