title: Evaluation of Nucleic Acid Preservation Cards for West Nile Virus Testing in Dead Birds.
abstract: The California West Nile virus (WNV) Dead Bird Surveillance Program (DBSP) is an important component of WNV surveillance in the state. We evaluated FTA™ and RNASound™ cards as an alternative method for sampling dead birds for WNV molecular testing as these cards allow for more cost effective, rapid, and safer diagnostic sampling than the shipment of bird carcasses. To evaluate accuracy of results among avian sampling regimes, Reverse-Transcription Polymerase Chain Reaction (RT-PCR) results from FTA™ and RNASound™ cards were compared with results from kidney tissue, brain tissue, or oral swabs in lysis buffer in 2012-2013. In addition, RT-PCR results were compared with results from oral swabs tested by rapid antigen tests (RAMP™ and VecTOR™). While test results from the cards were not as sensitive as kidney tissue testing, they were more likely to provide accurate results than rapid antigen tests, and detected WNV in corvids as well as in other passerines, raptors, and waterfowl. Overall, WNV RT-PCR cycle threshold (Ct) scores from the cards were higher than those from tissue testing, but both card products displayed high sensitivity and specificity. American Crow samples provided the highest sensitivity. The cards also proved to be easier and more convenient vehicles for collecting and shipping samples, and in 2014 our program launched use of RNASound™ cards in the DBSP. Both FTA™ and RNASound™ products displayed 96% agreement with tissue results and are an adequate alternative sampling method for WNV dead bird testing.
authors.affiliation: California Department of Public Health, Vector-Borne Disease Section, 850 Marina Bay Parkway, Richmond, California, United States of America.
authors.forename: Leslie
authors.initials: L
authors.lastname: Foss
authors.affiliation: Davis Arbovirus Research and Training Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, 3331 VetMed3A, University of California Davis, Davis, California, United States of America.
authors.forename: William K
authors.initials: WK
authors.lastname: Reisen
authors.affiliation: Davis Arbovirus Research and Training Laboratory, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, 3331 VetMed3A, University of California Davis, Davis, California, United States of America.
authors.forename: Ying
authors.initials: Y
authors.lastname: Fang
authors.affiliation: California Department of Public Health, Vector-Borne Disease Section, 1616 Capitol Avenue, MS-7307, P.O. Box 997377, Sacramento, California, United States of America.
authors.forename: Vicki
authors.initials: V
authors.lastname: Kramer
authors.affiliation: California Department of Public Health, Vector-Borne Disease Section, 850 Marina Bay Parkway, Richmond, California, United States of America.
authors.forename: Kerry
authors.initials: K
authors.lastname: Padgett
mesh_terms: D000818:Animals; D001715:Bird Diseases / Q000453:epidemiology / Q000821:virology*; D001717:Birds; D002140:California / Q000453:epidemiology; D062486:Public Health Surveillance; D012367:RNA, Viral; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014901:West Nile Fever / Q000662:veterinary*; D014902:West Nile virus / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D012367:RNA, Viral