title: An immunoassay-based reverse-transcription loop-mediated isothermal amplification assay for the rapid detection of avian influenza H5N1 virus viremia.
abstract: Avian influenza virus (AIV) subtype H5N1 attracts particular consideration because it is a continuous threat to animals and public health systems. The viremia caused by AIV H5N1 infection may increase the risk of blood-borne transmission between humans. Therefore, there is a need to rapidly evaluate and implement screening measures for AIV H5N1 viremia that allows for rapid response to this potentially pandemic threat. The present report describes an immunoassay-based reverse-transcription loop-mediated isothermal amplification (immuno-RT-LAMP) assay for the rapid detection of AIV H5N1 in whole blood samples. Using PCR tubes coated with an H5 subtype monoclonal antibody, AIV H5N1 virions were specifically captured from blood samples. After a thermal lysis step, the released viral N1 gene was exponentially amplified using RT-LAMP on either a real-time PCR instrument for quantitative analysis, or in a water bath system for endpoint analysis. The detection limit of the newly developed immuno-RT-LAMP assay was as low as 1.62×10(1) 50% embryo infectious dose/mL of virus in both regular samples and simulated viremia samples. There were no cross-reactions with non-H5N1 influenza viruses or other avian viruses. The reproducibility of the assay was confirmed using intra- and inter-assay tests with variability ranging from 1.05% to 3.37%. Our results indicate that immuno-RT-LAMP is a novel, effective point-of-care virus identification solution for the rapid diagnosis and monitoring of AIV H5N1 in blood samples.
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, #61 Dai Zong Avenue, Tai'an, Shandong 271018, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Xu
authors.initials: X
authors.lastname: Yu
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, #61 Dai Zong Avenue, Tai'an, Shandong 271018, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, #61 Dai Zong Avenue, Tai'an, Shandong 271018, China. Electronic address: yxdiao@126.com.
authors.forename: Youxiang
authors.initials: Y
authors.lastname: Diao
mesh_terms: D000818:Animals; D001717:Birds; D004279:DNA, Viral / Q000097:blood* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation*; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000302:isolation & purification*; D005585:Influenza in Birds / Q000821:virology; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D014766:Viremia / Q000175:diagnosis / Q000821:virology*
chemical_list: D004279:DNA, Viral
keywords: Avian influenza virus; H5N1; Immunoassay; RT-LAMP; Viremia