Evaluation of multiple test methods for the detection of the novel 2009 influenza A (H1N1) during the New York City outbreak.
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.


METHODS
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.
Ginocchio
Christine C
CC
Department of Pathology and Laboratory Medicine, North Shore-Long Island Jewish Health System, Lake Success, NY 11042, USA. cginocch@nshs.edu
Zhang
Frank
F
Manji
Ryhana
R
Arora
Suman
S
Bornfreund
Mark
M
Falk
Leon
L
Lotlikar
Madhavi
M
Kowerska
Margaret
M
Becker
George
G
Korologos
Diamanto
D
de Geronimo
Marcella
M
Crawford
James M
JM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification*; D007251:Influenza, Human / Q000175:diagnosis* / Q000453:epidemiology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009519:New York City / Q000453:epidemiology; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D055815:Young Adult
D011933:Reagent Kits, Diagnostic