Test Characteristics of Commercial Influenza Assays for Detecting Pandemic Influenza a (H1n1) in Children

Abstract

We assessed the test characteristics of 2 influenza antigen tests, a rapid immunoassay and a direct fluorescence antibody (DFA) assay, in detecting pandemic influenza A (H1N1) in children up to 18 years of age, using polymerase chain reaction as the standard. The sensitivities of BinaxNOW (59.6%) and direct fluorescence antibody (57.3%) were similar. The specificity of each test was >99%.

Performance characteristics of a rapid immunochromatographic assay for detection of pandemic influenza A (H1N1) virus in children

“…Sensitivity of Influenzatop® was higher when performed between 24 and 48 h post onset of symptoms compared to 74.2% (95% CI, 62-84.2) with QuickVue® [8]. Sensitivity of Influenzatop® was about 7% points higher contrasted to that estimated for direct fluorescence antibody assay (57.3%) in pediatric patients presenting with ILI [14]. In a large study assessing multiple tests, sensitivities of BinaxNOW® and 3MA + B® as compared to R-Mix culture for the detection of pandemic (H1N1) 2009 virus were 9.6% and 40%, respectively.…”

“…When comparing Influenzatop® to that of QuickVue Influenza A + B® and BinaxNOW Influenza A&B® assessed in previous studies, performance of Influenzatop® appears comparable in general but higher when employed between 24 and 48 h post onset of symptoms [3,8,14]. Especially when employed between 24 and 48 h after onset of symptoms, Influenzatop® can be a valuable asset in the management of pediatric H1N1 patients.…”

“…This divergence from test characteristics observed in our study may be due to variation of performance of rapid influenza detection tests by virus subtype. Sensitivity of rapid tests has indeed been reported to be poorer for the nonhuman pandemic (H1N1) 2009 viruses [6,8,14,15,17].…”

Diagnostic Methods of Influenza a From Clinical Specimens: A Critical Review of Literature

“…Similarly, recent studies reported that the sensitivity values of rapid detection kits for influenza A are higher in younger patients. However, some studies have also reported lower sensitivities for samples from younger patients (≤10 years) than the ones older (10-18 years) (Sandora et al 2010). The clinical sensitivity and specificity of a rapid influenza diagnostic test also differ greatly during periods of low prevalence, by region, influenza subtype and risk population (Dale et al 2008).…”

“…The detection of Influenza A or B antigen is performed by staining with the cell monolayer with fluorescent monoclonal antibodies (Mills et al 1989). Due to the need to produce more rapid results, some sensitivity may be lost using SVC (Sandora et al 2010). Additionally, the commercially available R-Mix cells and R-Mix Too (Diagnostic Hybrids, Athens, OH, USA), have shown the advantage of influenza virus identification within 1-2 days of inoculation.…”