Diagnostic performance of the Sofia® influenza A+B fluorescent immunoassay in adult outpatients in Northern Taiwan

Abstract

To evaluate the diagnostic performance of the Sofia influenza A+B fluorescent immunoassay (Sofia FIA), we performed a prospective study at the Chang Gung Memorial Hospital in Taiwan from January 2012 to December 2013. Patients who presented at out-patient clinics or the emergency department with influenza-like illness were included. Upper respiratory tract specimens were collected from oropharynx or nasopharynx. Performance of the Sofia FIA was compared to that of the Formosa One Sure Flu A/B Rapid Test. A Real-time reverse transcriptase-polymerase chain reaction assay (RT-PCR) and/or virus culture were used as reference standards. Of the 109 enrolled patients, the sensitivity, specificity, positive, and negative predictive values of the Sofia FIA to detect influenza A virus were 82%, 89%, 77%, and 89%, respectively. These parameters were 100% when the samples were from nasopharynx. The positive predictive value for influenza B virus detection was 29%. The sensitivity of the Sofia FIA for detection of influenza A virus was 93% between days 2 and 4 after onset of symptoms. For specimens with low viral loads (RT-PCR cycle threshold between 30 and 34.9), the sensitivity of The Sofia FIA was 83% (10/12). The Sofia FIA performed effectively in detecting influenza A virus infection. With nasopharyngeal samples, the performance was comparable to RT-PCR. Although influenza viral load typically decreases with time, the Sofia FIA was sensitive enough to identify influenza infecting patients presenting after several days of illness. However, a high false positive rate limits the assay's usefulness to identify influenza B virus infection.

Diagnostic Accuracy of the Quidel Sofia Rapid Influenza Fluorescent Immunoassay in Patients with Influenza-like Illness: A Systematic Review and Meta-analysis

“…26 The sensitivity for each type of specimens was 72% and 100% in influenza A, and 71% and 100% in influenza B, respectively. 26 In the other study, the sensitivities of the Quidel Sofia rapid influenza FIA with saliva specimens were comparable to the sensitivities of tests with NP swabs specimens. 27 The sensitivity of the test with the NP swabs samples was significantly higher than that of the saliva samples for influenza A (74.2% vs. 59.2%, P=0.014) and similar between two samples in influenza B (75.9% vs. 65.5%, P=0.387).…”

“…26,27 One study compared the results of testing throat and NP swabs specimens. 26 The sensitivity for each type of specimens was 72% and 100% in influenza A, and 71% and 100% in influenza B, respectively. 26 In the other study, the sensitivities of the Quidel Sofia rapid influenza FIA with saliva specimens were comparable to the sensitivities of tests with NP swabs specimens.…”

“…With quantitative synthesis, seventeen studies were included in our final analysis. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Table 1 summarizes the features of the included studies. For influenza A, we identified seventeen studies comprising 8,334 participants.…”

Akut Solunum Yolu Enfeksiyonu Olan Hastalarda Hızlı İnfluenza Tanı Testi ile İnfluenza A ve B Antijenlerinin Araştırılması

“…Ceyhan ve ark.20 2011 yılında yaptıkları çalışmada hastaların %34,1 oranında influenza A pozitifliği, Yang ve ark. 21…”

Diagnostic Accuracy of the Quidel Sofia Rapid Influenza Fluorescent Immunoassay in Patients with Influenza-like illness: A Systematic Review and Meta-analysis

“…1. With quantitative synthesis, seventeen studies were included in our nal analysis [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Table 1 summarizes the features of the included studies.…”