Diagnosis of 2009 Pandemic Influenza A (pH1N1) and Seasonal Influenza Using Rapid Influenza Antigen Tests, San Antonio, Texas, April–June 2009

Abstract

Clinicians frequently use influenza rapid antigen tests for diagnostic testing. We tested nasal wash samples from 1 April to 7 June 2009 from 1538 patients using the QuickVue Influenza A+B (Quidel) rapid influenza antigen test and compared the results with real-time reverse transcription polymerase chain reaction (rRT-PCR) assay (gold standard). The prevalence of 2009 pandemic influenza A (pH1N1) was 1.98%, seasonal influenza type A .87%, and seasonal influenza type B 2.07%. The sensitivity and specificity of the rapid test for pH1N1 was 20% (95% CI, 8-39) and 99% (95% CI, 98-99), for seasonal influenza type A 15% (95% CI, 2-45) and 99% (95% CI, 98-99), and for influenza type B was 31% (95% CI, 9-61) and 99% (95% CI, 98-99.7). Rapid influenza antigen tests were of limited use at a time when the prevalence of pH1N1 and seasonal influenza in the United States was low. Clinicians should instead rely on clinical impression and laboratory diagnosis by rRT-PCR.

The Effect of the Rapid Antigen Test for Influenza on Clinical Practice in the Emergency Department: A Comparison of Periods before and After the 2009 H1N1 Influenza Pandemic

“…Lucas et al reported that the sensitivity and specificity for the detection of H1N1 was 20.0% and 99.0%, respectively, using the QuickVue Influenza A+B Test (Quidel), while other investigators have found its sensitivity to be higher than this value. (7)(8)(9) In one study, the Actim Influenza A&B kit (Medix Biochemica, Joensuu, Finland) has been shown to be 90.0% sensitive for the detection of influenza A virus. (10) Some small studies have shown that a positive RAT spurs changes in clinical practice.…”

Risk factors for severe outcomes among members of the United States military hospitalized with pneumonia and influenza, 2000–2012

“…During the 2009 pandemic, attack rates among military personnel measured during clusters of infection among specific military units ranged from as low as 3% [7] and as high as 70% [8]. In confined settings, such as aboard navy ships, serologic attack rates of influenza among US and foreign military crew have been estimated to be between 30–50% [9, 10].…”

Randomised controlled trial and health economic evaluation of the impact of diagnostic testing for influenza, respiratory syncytial virus and Streptococcus pneumoniae infection on the management of acute admissions in the elderly and high-risk 18- to 64-year-olds

“…l Comparison of estimates of sensitivity of POCTs for the detection of influenza A and B suggested that kits may detect influenza A more readily than influenza B -Influenza A: 81% (95% CI 64% to 91%); Influenza B: 59% (95% CI 47% to 70%). l Analyses of five studies 152,182,198 that included both adults and children and compared the Quidel POCT with PCR produced an overall pooled sensitivity of 34% (95% CI 14% to 62%) and specificity of 99% (95% CI 97% to 100%), which are much more similar to those obtained in 3WS.…”