Nucleic acid sequence-based amplification assays for rapid detection of West Nile and St. Louis encephalitis viruses.
The development and application of nucleic acid sequence-based amplification (NASBA) assays for the detection of West Nile (WN) and St. Louis encephalitis (SLE) viruses are reported. Two unique detection formats were developed for the NASBA assays: a postamplification detection step with a virus-specific internal capture probe and electrochemiluminescence (NASBA-ECL assay) and a real-time assay with 6-carboxyfluorescein-labeled virus-specific molecular beacon probes (NASBA-beacon assay). The sensitivities and specificities of these NASBA assays were compared to those of a newly described standard reverse transcription (RT)-PCR and TaqMan assays for SLE virus and to a previously published TaqMan assay for WN virus. The NASBA assays demonstrated exceptional sensitivities and specificities compared to those of virus isolation, the TaqMan assays, and standard RT-PCR, with the NASBA-beacon assay yielding results in less than 1 h. These assays should be of utility in the diagnostic laboratory to complement existing diagnostic testing methodologies and as a tool in conducting flavivirus surveillance in the United States.
Lanciotti
R S
RS
Division of Vector-Borne Infectious Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Public Health Service, U.S Department of Health and Human Services, Fort Collins, Colorado 80521, USA. rsl2@cdc.gov
Kerst
A J
AJ
D000818:Animals; D001715:Bird Diseases / Q000821:virology; D001717:Birds / Q000821:virology; D002522:Chlorocebus aethiops; D009033:Culicidae / Q000821:virology; D004665:Encephalitis Virus, St. Louis / Q000235:genetics / Q000302:isolation & purification*; D004674:Encephalitis, St. Louis / Q000821:virology*; D015335:Molecular Probes; D012367:RNA, Viral / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021161:Self-Sustained Sequence Replication / Q000379:methods*; D012680:Sensitivity and Specificity; D019914:Taq Polymerase / Q000378:metabolism; D013997:Time Factors; D014709:Vero Cells; D014901:West Nile Fever / Q000662:veterinary / Q000821:virology*; D014902:West Nile virus / Q000302:isolation & purification*
D015335:Molecular Probes; D012367:RNA, Viral; D019914:Taq Polymerase