Evaluation of reverse transcription loop- mediated isothermal amplification assays for rapid diagnosis of pandemic influenza A/H1N1 2009 virus

Two genetic diagnosis systems using reverse transcription- loop- mediated isothermal amplification (RT- LAMP) technology were evaluated: one for detecting the HA gene of the pandemic influenza A/H1N1 2009 virus (H1pdm RT- LAMP) and the other for detecting the matrix gene of the influenza A virus (TypeA RT- LAMP). The competence of these two RT- LAMP assay kits for the diagnosis of the pandemic influenza A/H1N1 2009 virus was compared using real- time RT- PCR assays developed recently on viruses isolated and clinical specimens collected from patients with suspected infection. TypeA RT- LAMP and H1pdm RT- LAMP showed almost the same sensitivity as real- time RT- PCR for viruses isolated. The sensitivity and specificity of TypeA RT- LAMP and H1pdm RT- LAMP were 96.3% and 88.9%, respectively, for clinical specimens. Considering that the ability of the two RT- LAMP assay kits for detection of the pandemic influenza A/H1N1 2009 virus was comparable to that of the real- time RT- PCR assays, and that the assays were completed within 1 hr and did not require any expensive equipment, these two RT- LAMP assays are promising rapid diagnostic tests for the pandemic influenza A/H1N1 2009 virus at the hospital bedside.