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. 2021 Jul:108:231-236.
doi: 10.1016/j.ijid.2021.04.065. Epub 2021 Apr 24.

Use of the FebriDx point-of-care test for the exclusion of SARS-CoV-2 diagnosis in a population with acute respiratory infection during the second (COVID-19) wave in Italy

Filippo Lagi  1 , Sasha Trevisan  2 , Matteo Piccica  2 , Lucia Graziani  2 , Gregorio Basile  2 , Jessica Mencarini  1 , Beatrice Borchi  3 , Lorenzo Menicacci  2 , Micol Vaudo  2 , Valentina Scotti  4 , Alessia Fabbri  2 , Giulia Bandini  2 , Camilla Tozzetti  5 , Andrea Berni  5 , Noemi Aiezza  2 , Giulia Pestelli  6 , Valerio Turchi  6 , Alberto Moggi Pignone  2 , Loredana Poggesi  7 , Carlo Nozzoli  6 , Alessandro Morettini  4 , Gian Maria Rossolini  8 , Alessandro Bartoloni  9
Affiliations

Use of the FebriDx point-of-care test for the exclusion of SARS-CoV-2 diagnosis in a population with acute respiratory infection during the second (COVID-19) wave in Italy

Filippo Lagi et al. Int J Infect Dis. 2021 Jul.

Abstract

Objective: Evaluate the real-world accuracy of Myxovirus resistance protein A (MxA) detected by the rapid, point-of-care FebriDx test during the second-wave pandemic in Italy in patients with acute respiratory infection (ARI) and a clinical suspicion of COVID-19.

Design and methods: Prospective, observational, diagnostic accuracy study whereby hospitalized patients with ARI were consecutively enrolled in a single tertiary care center in Italy from August 1, 2020 to January 31, 2021.

Results: COVID-19 was diagnosed in 136/200 (68.0%) patients and Non-COVID-19 was diagnosed in 64/200 (32.0%) patients. COVID-19 patients were younger and had a lower Charlson comorbidity index compared to Non-COVID-19 patients (p < 0.001). Concordance between FebriDx, MxA and rt-PCR for SARS-CoV-2 (gold standard) was good (k 0.93, 95% CI 0.87-0.99). Overall sensitivity and specificity were 97.8% [95% CI 93.7-99.5] and 95.3% [95% CI 86.9%-99.0%], respectively. FebriDx demonstrated a negative predictive value of 95.3% (95% CI 86.9-99.0) for an observed disease prevalence of 68%.

Conclusions: FebriDx MxA showed high diagnostic accuracy to identify COVID-19 and could be considered as a real-time triage tool to streamline the management of suspected COVID-19 patients. FebriDx also detected bacterial etiology in Non-COVID-19 patients suggesting good performance to distinguish bacterial from viral respiratory infection.

Keywords: Accuracy; COVID-19; FebriDx; Italy; Point-of-care.

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Figures

Figure 1
Figure 1
FebriDx Result Interpretation. Left: Control (blue) and MxA (middle, red) lines (response: viral positive). Middle: Control, MxA, CRP (top, gray) lines (response: viral positive). Right: Only control line (response: negative). Myxovirus resistance protein A (MxA). C-reactive protein (CRP).
See this image and copyright information in PMC

References

    1. Clark T.W., Brendish N.J., Poole S., Naidu V.V., Mansbridge C., Norton N. Diagnostic accuracy of the FebriDx host response point-of-care test in patients hospitalised with suspected COVID-19. J Infect. 2020;81:607–613. doi: 10.1016/j.jinf.2020.06.051. - DOI - PMC - PubMed
    1. Dahler-Eriksen B.S., Lauritzen T., Lassen J.F., Lund E.D., Brandslund I. Near-patient test for C-reactive protein in general practice: assessment of clinical, organizational, and economic outcomes. Clin Chem. 1999;45:478–485. doi: 10.1093/clinchem/45.4.478. - DOI - PubMed
    1. Diao B., Wen K., Zhang J., Chen J., Han C., Chen Y. Accuracy of a nucleocapsid protein antigen rapid test in the diagnosis of SARS-CoV-2 infection. Clin Microbiol Infect. 2021;27(2):289.e1–289.e4. doi: 10.1016/j.cmi.2020.09.057. - DOI - PMC - PubMed
    1. Diederichsen H.Z., Skamling M., Diederichsen A., Grinsted P., Antonsen S., Petersen P.H. Randomised controlled trial of CRP rapid test as a guide to treatment of respiratory infections in general practice. Scand J Prim Health Care. 2000;18:39–43. doi: 10.1080/02813430050202541. - DOI - PubMed
    1. ECDC . 2020. Options for the use of rapid antigen tests for COVID-19 in the EU/EEA and the UK Key messages.