title: Clinical and Analytical Evaluation of a Single-Vial Stool Collection Device with Formalin-Free Fixative for Improved Processing and Comprehensive Detection of Gastrointestinal Parasites.
abstract: Microscopic examination of feces is a standard laboratory method for diagnosing gastrointestinal parasite infections. In North America, the ovum and parasite (O&P) examination is typically performed using stool that is chemically fixed in polyvinyl alcohol (PVA) and formalin, after which the stool is concentrated by filtration to enhance sensitivity. Mini Parasep solvent-free (SF) tubes allow collection and concentration within a single collection vial. The goal of the study was to determine whether consolidated processing and concentration with the Parasep tubes using an alcohol-based fixative (Alcorfix) provide O&P examinations equivalent to or better than those done by processing of PVA-formalin-fixed stool using a SpinCon concentration device. Parasep tubes revealed filtration performance equivalent to that of the SpinCon concentration device using PVA-formalin-fixed stool containing protozoa. Specimens cocollected in Parasep tubes containing PVA-formalin and Alcorfix revealed comparable morphology and staining for various protozoa. Alcorfix effectively fixed live Cryptosporidium and microsporidia such that morphology and staining were conserved for modified acid-fast and modified trichrome stains. A work flow analysis revealed significant time savings for batches of 10 or 30 O&P specimens in tubes with Alcorfix compared to the amount of time that it took to analyze the same number of specimens in tubes with PVA-formalin. The direct hands-on time savings with Mini Parasep tubes were 17 min and 41 s and 32 min and 1 s for batches of 10 and 30 specimens, respectively. Parasep tubes containing Alcorfix provide significant work flow advantages to laboratories that process medium to high volumes of O&P specimens by streamlining processing and converting to a single tube. These improvements in work flow, reduction of the amount of formalin used in the laboratory, and equivalent microscopy results are attractive advancements in O&P testing for North American diagnostic parasitology laboratories.
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Brianne A
authors.initials: BA
authors.lastname: Couturier
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Ryan
authors.initials: R
authors.lastname: Jensen
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Nora
authors.initials: N
authors.lastname: Arias
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Heffron
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Elyse
authors.initials: E
authors.lastname: Gubler
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Case
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Gowans
authors.affiliation: ARUP Laboratories, Institute for Clinical and Experimental Pathology, Salt Lake City, Utah, USA Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, USA marc.couturier@aruplab.com.
authors.forename: Marc Roger
authors.initials: MR
authors.lastname: Couturier
mesh_terms: D000818:Animals; D005243:Feces / Q000469:parasitology*; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000175:diagnosis*; D008853:Microscopy; D009656:North America; D010271:Parasites / Q000302:isolation & purification*; D010274:Parasitology / Q000379:methods; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000379:methods*; D013997:Time Factors; D057188:Workflow