Clinical usefulness of a rapid molecular assay, ID NOW™ influenza A & B 2, in adults

• Published in: Journal of Infection and Chemotherapy Vol. 27; no. 3; pp. 450 - 454
• Main Authors: Mitamura, Keiko, Yamazaki, Masahiko, Ichikawa, Masataka, Yasumi, Yuki, Shiozaki, Ken, Tokushima, Masahiko, Abe, Takashi, Kawakami, Chiharu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.03.2021; Elsevier BV
• Subjects: Adult; Chlorophenols; Humans; ID NOW Influenza A & B 2; Influenza; Influenza A virus; Influenza B virus; Influenza, Human; Rapid antigen detection test; Rapid molecular assay; Sensitivity and Specificity; ID NOW Influenza A & B 2; Rapid molecular assay; Rapid antigen detection test; Influenza
• ISSN: 1341-321X; 1437-7780; 1437-7780
• DOI: 10.1016/j.jiac.2020.10.009

ID NOW™ Influenza A & B 2 (ID NOW 2) is a rapid molecular assay that combines two characteristics, namely the rapidness of rapid antigen detection test (RADT) and the high sensitivity of molecular assay. The clinical performance of ID NOW 2 compared with real-time RT-PCR was evaluated in adults. The sensitivity of ID NOW 2 over multiple seasons from 2016/2017 to 2019/2020 was 97.3% (95% CI: 90.7–99.7) for Type A, 100% (95% CI: 81.9–100) for Type B, and 97.8% (95% CI: 92.2–99.7) for influenza (Type A + Type B), and it was significantly higher than the sensitivity of RADT, which was 80.0% (95% CI: 69.2–88.4) for Type A, 73.3% (95% CI: 44.9–92.2) for Type B, and 78.9% (95% CI: 69.0–86.8) for influenza. The sensitivity of RADT tended to be lower in patients in the particularly early period, within 12 h from disease onset; however, the sensitivity of ID NOW 2 remained high, increasing the difference between the sensitivity of RADT and ID NOW 2. The viral loads were low within 12 h from onset, and it was considered this affected the sensitivity of RADT due to its low analytical sensitivity. The specificity of ID NOW 2 was 98% or greater in all groups. Since ID NOW 2 has a high sensitivity and specificity in adults, it is anticipated to be used in clinical practice, particularly in patients who require early and accurate diagnosis.