title: Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.
abstract: Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent "head to head" re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US).
authors.affiliation: Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Roellig
authors.affiliation: Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Yoder
authors.affiliation: Parasitology Laboratory, Division of Infectious Disease, Wadsworth Center, New York State Department of Health, Albany, New York, United States of America.
authors.forename: Susan
authors.initials: S
authors.lastname: Madison-Antenucci
authors.affiliation: Minnesota Department of Health, St. Paul, Minnesota, United States of America.
authors.forename: Trisha J
authors.initials: TJ
authors.lastname: Robinson
authors.affiliation: Communicable Disease Division, Wisconsin State Laboratory of Hygiene, Madison, Wisconsin, United States of America.
authors.forename: Tam T
authors.initials: TT
authors.lastname: Van
authors.affiliation: Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Collier
authors.affiliation: Minnesota Department of Health, St. Paul, Minnesota, United States of America.
authors.forename: Dave
authors.initials: D
authors.lastname: Boxrud
authors.affiliation: Communicable Disease Division, Wisconsin State Laboratory of Hygiene, Madison, Wisconsin, United States of America.
authors.forename: Timothy
authors.initials: T
authors.lastname: Monson
authors.affiliation: Kentucky Division of Laboratory Services, Frankfort, Kentucky, United States of America.
authors.forename: Leigh Ann
authors.initials: LA
authors.lastname: Bates
authors.affiliation: Biostatistics and Information Management Office, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Anna J
authors.initials: AJ
authors.lastname: Blackstock
authors.affiliation: Association of Public Health Laboratories, Silver Spring, Maryland, United States of America.
authors.forename: Shari
authors.initials: S
authors.lastname: Shea
authors.affiliation: Association of Public Health Laboratories, Silver Spring, Maryland, United States of America.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Larson
authors.affiliation: Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Lihua
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Waterborne Disease Prevention Branch, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
authors.forename: Michael
authors.initials: M
authors.lastname: Beach
mesh_terms: D000293:Adolescent; D000328:Adult; D000953:Antigens, Protozoan / Q000032:analysis*; D001681:Biological Assay / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003457:Cryptosporidiosis / Q000175:diagnosis* / Q000469:parasitology; D003458:Cryptosporidium / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology*; D005260:Female; D019085:Fluorescent Antibody Technique, Direct / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D062486:Public Health Surveillance; D055815:Young Adult
chemical_list: D000953:Antigens, Protozoan