Rapid-Test Sensitivity for Novel Swine-Origin Influenza A (H1N1) Virus in Humans

Abstract

Faix et al. (Aug. 13 issue)¹ highlight the moderate sensitivity of rapid antigen tests as compared with reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assays in detecting the 2009 pandemic influenza A (H1N1) virus in infected patients. We found that the antigen tests had poor sensitivity to the virus when used in a subgroup of 21 patients in the Australian intensive care cohort with severe 2009 influenza A (H1N1) virus infection and acute lung injury that required mechanical ventilation.² In these patients, rapid antigen tests (QuickVue A+B, Quidel) were performed on swabs from the nose and throat, and influenza type-specific immunofluorescent antigen assays (Chemicon, Millipore) were performed on bronchoscopic specimens. In all 21 patients, RT-PCR testing (AusDiagnostics), performed on specimens from both the upper and lower respiratory tracts, had been used to confirm infection with the virus.