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The North Shore--Long Island Jewish Health System Laboratories serve 15 hospitals and affiliated regional physician practices in the New York City metropolitan area, with virus testing performed at a central reference laboratory. The influenza A pandemic (H1N1) 2009 outbreak began in this area on April 24, 2009, and within weeks respiratory virus testing increased 7.5 times. In response, laboratory and client service workforces were increased, physical plant buildout was completed, testing paradigms were converted from routine screening tests and viral culture to a high-capacity molecular assay for respiratory viruses, laboratory information system interfaces were built, and same-day epidemiologic reports were produced. Daily review by leadership of data from emergency rooms, hospital facilities, and the Health System Laboratories enabled real-time management of unfolding events. The ability of System laboratories to rapidly increase to high-volume comprehensive diagnostics, including influenza A subtyping, provided key epidemiologic information for local and state public health departments. [ABSTRACT FROM AUTHOR]

Abstract: Background: In response to the novel influenza A H1N1 outbreak in the NY City area, 6090 patient samples were submitted over a 5-week period for a total of 14,114 viral diagnostic tests, including rapid antigen, direct immunofluorescence (DFA), viral culture and PCR. Little was known about the performance of the assays for the detection of novel H1N1 in the background of seasonal H1N1, H3N2 and other circulating respiratory viruses. In addition, subtyping influenza A became critical for the identification of high risk and/or hospitalized patients with novel H1N1 infection and for monitoring the spread of the outbreak. Study design: This study analyzed the performances of the BinaxNOW Influenza A&B test (BinaxNOW), the 3M Rapid Detection Flu A+B test (3MA+B), direct immunofluorescence, R-Mix culture and the Luminex xTAG Respiratory Virus Panel (RVP) for the detection of seasonal influenza, novel H1N1 and other respiratory viruses. RVP was also evaluated for its ability to differentiate seasonal H1N1, H3N2 and novel H1N1. Results: The sensitivities, specificities, PPVs and NPVs for the detection of novel H1N1, determined by comparing all four-test methods, were: rapid antigen: 17.8%, 93.6%, 77.4%, 47.9%; DFA: 46.7%, 94.5%, 91.3%, 58.9%; R-Mix culture: 88.9%, 100%, 100%, 87.9%; RVP: 97.8%, 100%, 100%, 97.3%. The individual sensitivities of BinaxNOW and 3MA+B as compared to R-Mix culture for the detection of novel H1N1 were 9.6% and 40%, respectively. All unsubtypeable influenza A specimens identified by RVP and tested with the CDC novel H1N1 specific RT-PCR assay were confirmed to be novel H1N1. Conclusions: Rapid antigen tests, DFA, R-Mix culture and the xTAG RVP test all detected the novel H1N1 strain, but with highly varied sensitivity. The RVP test provided the best diagnostic option as RVP demonstrated superior sensitivity for the detection of all influenza strains, including the novel H1N1, provided accurate influenza A subtyping and identified a significant number of additional respiratory pathogens. [Copyright &y& Elsevier]