FebriDx®: A Rapid Diagnostic Test for Differentiating Bacterial and Viral Aetiologies in Acute Respiratory Infections

  • Matt ShirleyEmail author
Adis Diagnostic Profile


FebriDx® is a rapid, point-of-care diagnostic test that is designed to aid in the differentiation of bacterial and viral acute respiratory infections (ARIs), thus helping to guide decisions regarding the prescription of antibiotics in the outpatient setting. FebriDx carries a CE mark for use in the EU and is also approved in several other countries, including Canada, Saudi Arabia and Singapore. It is indicated for use in patients > 2 years old with symptoms consistent with a community-acquired ARI. The test involves the use of an immunoassay on a fingerstick blood sample to provide simultaneous, qualitative measurement of elevated levels of C-reactive protein (CRP) and myxovirus resistance protein A (MxA). In two prospective, multicentre studies in patients with acute upper respiratory tract infections, FebriDx was shown to be both sensitive and specific in identifying patients with a clinically significant infection and in differentiating between infections of bacterial and viral aetiology. The test is simple, requires no additional equipment and produces actionable results in ~ 10 min. As was demonstrated in a small, retrospective analysis, FebriDx results can help guide (improve) antibiotic prescribing decisions. Reducing the unnecessary or inappropriate prescription of antibiotics for ARIs of probable viral aetiology is important for antibiotic stewardship and can also reduce the unnecessary exposure of patients to the risk of antibiotic-related adverse events. FebriDx thus represents a useful diagnostic tool in the outpatient setting.



During the peer review process, the manufacturer of FebriDx was also offered an opportunity to review this article. Changes resulting from comments received were made on the basis of scientific and editorial merit.

Compliance with Ethical Standards


The preparation of this review was not supported by any external funding.

Conflict of interest

Matt Shirley is a salaried employee of Adis International Ltd/Springer Nature, is responsible for the article content and declares no relevant conflicts of interest.


  1. 1.
    Renati S, Linder JA. Necessity of office visits for acute respiratory infections in primary care. Fam Pract. 2016;33(3):312–7.CrossRefGoogle Scholar
  2. 2.
    Caliendo AM, Gilbert DN, Ginocchio CC, et al. Better tests, better care: improved diagnostics for infectious diseases. Clin Infect Dis. 2013;57(Suppl 3):S139–70.CrossRefGoogle Scholar
  3. 3.
    Cole A. GPs feel pressurised to prescribe unnecessary antibiotics, survey finds. BMJ. 2014;349:g5238.CrossRefGoogle Scholar
  4. 4.
    Fleming-Dutra KE, Hersh AL, Shapiro DJ, et al. Prevalence of inappropriate antibiotic prescriptions among US ambulatory care visits, 2010–2011. JAMA. 2016;315(17):1864–73.CrossRefGoogle Scholar
  5. 5.
    Gulliford MC, Dregan A, Moore MV, et al. Continued high rates of antibiotic prescribing to adults with respiratory tract infection: survey of 568 UK general practices. BMJ Open. 2014;4(10):e006245.CrossRefGoogle Scholar
  6. 6.
    Harbarth S, Samore MH. Antimicrobial resistance determinants and future control. Emerg Infect Dis. 2005;11(6):794–801.CrossRefGoogle Scholar
  7. 7.
    van de Sande-Bruinsma N, Grundmann H, Verloo D, et al. Antimicrobial drug use and resistance in Europe. Emerg Infect Dis. 2008;14(11):1722–30.CrossRefGoogle Scholar
  8. 8.
    World Health Organization. Antibiotic resistance; 2018. Accessed 20 Sep 2019.
  9. 9.
    Shehab N, Patel PR, Srinivasan A, et al. Emergency department visits for antibiotic-associated adverse events. Clin Infect Dis. 2008;47(6):735–43.CrossRefGoogle Scholar
  10. 10.
    Tandan M, Vellinga A, Bruyndonckx R, et al. Adverse effects of amoxicillin for acute lower respiratory tract infection in primary care: secondary and subgroup analysis of a randomised clinical trial. Antibiotics. 2017;6(4):36.CrossRefGoogle Scholar
  11. 11.
    US Centers for Disease Control and Prevention. Antibiotic use in the United States, 2017: progress and opportunities; 2017. Accessed 20 Sep 2019.
  12. 12.
    Beck JN, Suppes SL, Smith CR, et al. Cost and potential avoidability of antibiotic-associated adverse drug reactions in children. J Pediatr Infect Dis Soc. 2019;8(1):66–8.CrossRefGoogle Scholar
  13. 13.
    McGowan JE Jr. Economic impact of antimicrobial resistance. Emerg Infect Dis. 2001;7(2):286–92.CrossRefGoogle Scholar
  14. 14.
    Cosgrove SE, Carmeli Y. The impact of antimicrobial resistance on health and economic outcomes. Clin Infect Dis. 2003;36(11):1433–7.CrossRefGoogle Scholar
  15. 15.
    Rodrigues CMC, Groves H. Community-acquired pneumonia in children: the challenges of microbiological diagnosis. J Clin Microbiol. 2018;56(3):article e01318-17, 1–9.Google Scholar
  16. 16.
    RPS Diagnostics. FebriDx®: product brochure; 2018. Accessed 20 Sep 2019.
  17. 17.
    RPS Diagnostics. FebriDx® receives updated CE mark to allow incorporation of all-in-one test format [media release]. 31 Oct 2018.
  18. 18.
    RPS Diagnostics. FebriDx®; 2019. Accessed 20 Sep 2019.
  19. 19.
    RPS Diagnostics. FebriDx®: quick reference guide; 2018. Accessed 20 Sep 2019.
  20. 20.
    Okamura JM, Miyagi JM, Terada K, et al. Potential clinical applications of C-reactive protein. J Clin Lab Anal. 1990;4(3):231–5.CrossRefGoogle Scholar
  21. 21.
    Young B, Gleeson M, Cripps AW. C-reactive protein: a critical review. Pathology. 1991;23(2):118–24.CrossRefGoogle Scholar
  22. 22.
    Pepys MB, Hirschfield GM. C-reactive protein: a critical update. J Clin Investig. 2003;111(12):1805–12.CrossRefGoogle Scholar
  23. 23.
    Sproston NR, Ashworth JJ. Role of C-reactive protein at sites of inflammation and infection. Front Immunol. 2018;9:754.CrossRefGoogle Scholar
  24. 24.
    Bray C, Bell LN, Liang H, et al. Erythrocyte sedimentation rate and C-reactive protein measurements and their relevance in clinical medicine. WMJ. 2016;115(6):317–21.PubMedGoogle Scholar
  25. 25.
    Falk G, Fahey T. C-reactive protein and community-acquired pneumonia in ambulatory care: systematic review of diagnostic accuracy studies. Fam Pract. 2009;26(1):10–21.CrossRefGoogle Scholar
  26. 26.
    Le Bel J, Hausfater P, Chenevier-Gobeaux C, et al. Diagnostic accuracy of C-reactive protein and procalcitonin in suspected community-acquired pneumonia adults visiting emergency department and having a systematic thoracic CT scan. Crit Care. 2015;19(366):1–12.Google Scholar
  27. 27.
    Haller O, Kochs G. Human MxA protein: an interferon-induced dynamin-like GTPase with broad antiviral activity. J Interferon Cytokine Res. 2011;31(1):79–87.CrossRefGoogle Scholar
  28. 28.
    Chieux V, Hober D, Chehadeh W, et al. MxA protein in capillary blood of children with viral infections. J Med Virol. 1999;59(4):547–51.CrossRefGoogle Scholar
  29. 29.
    Engelmann I, Dubos F, Lobert P-E, et al. Diagnosis of viral infections using myxovirus resistance protein A (MxA). Pediatrics. 2015;135(4):e985–93.CrossRefGoogle Scholar
  30. 30.
    Halminen M, Ilonen J, Julkunen I, et al. Expression of MxA protein in blood lymphocytes discriminates between viral and bacterial infections in febrile children. Pediatr Res. 1997;41(5):647–50.CrossRefGoogle Scholar
  31. 31.
    Nakabayashi M, Adachi Y, Itazawa T, et al. MxA-based recognition of viral illness in febrile children by a whole blood assay. Pediatr Res. 2006;60(6):770–4.CrossRefGoogle Scholar
  32. 32.
    Zav’yalov VP, Hämäläinen-Laanaya H, Korpela TK, et al. Interferon-inducible myxovirus resistance proteins: potential biomarkers for differentiating viral from bacterial infections. Clin Chem. 2019;65(6):739–50.CrossRefGoogle Scholar
  33. 33.
    Sambursky R, Shapiro N. Evaluation of a combined MxA and CRP point-of-care immunoassay to identify viral and/or bacterial immune response in patients with acute febrile respiratory infection. Eur Clin Respir J. 2015;2:28245.CrossRefGoogle Scholar
  34. 34.
    Self WH, Rosen J, Sharp SC, et al. Diagnostic accuracy of FebriDx: a rapid test to detect immune responses to viral and bacterial upper respiratory infections. J Clin Med. 2017;6(10):1–16.CrossRefGoogle Scholar
  35. 35.
    Shapiro NI, Self WH, Rosen J, et al. A prospective, multi-centre US clinical trial to determine accuracy of FebriDx point-of-care testing for acute upper respiratory infections with and without a confirmed fever. Ann Med. 2018;50(5):420–9.CrossRefGoogle Scholar
  36. 36.
    Jain S, Self WH, Wunderink RG, et al. Community-acquired pneumonia requiring hospitalization among U.S. adults. N Engl J Med. 2015;373(5):415–27.CrossRefGoogle Scholar
  37. 37.
    Lingard H, Zehetmayer S, Maier M. Bacterial superinfection in upper respiratory tract infections estimated by increases in CRP values: a diagnostic follow-up in primary care. Scand J Prim Health Care. 2008;26(4):211–5.CrossRefGoogle Scholar
  38. 38.
    Mäkelä MJ, Puhakka T, Ruuskanen O, et al. Viruses and bacteria in the etiology of the common cold. J Clin Microbiol. 1998;36(2):539–42.PubMedPubMedCentralGoogle Scholar
  39. 39.
    Davidson M. FebriDx point-of-care testing to guide antibiotic therapy for acute respiratory tract infection in UK primary care: a retrospective outcome analysis. J Infect Dis Prev Med. 2017;5(3):1000165.Google Scholar
  40. 40.
    Dellit TH, Owens RC, McGowan JE Jr, et al. Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America guidelines for developing an institutional program to enhance antimicrobial stewardship. Clin Infect Dis. 2007;44(2):159–77.CrossRefGoogle Scholar
  41. 41.
    National Institute for Health and Care Excellence (NICE). Pneumonia in adults: diagnosis and management; 2014. Accessed 20 Sep 2019.
  42. 42.
    Srugo I, Klein A, Stein M, et al. Validation of a novel assay to distinguish bacterial and viral infections. Pediatrics. 2017. Scholar
  43. 43.
    Stein M, Lipman-Arens S, Oved K, et al. A novel host-protein assay outperforms routine parameters for distinguishing between bacterial and viral lower respiratory tract infections. Diagn Microbiol Infect Dis. 2018;90(3):206–13.CrossRefGoogle Scholar
  44. 44.
    van Houten CB, de Groot JAH, Klein A, et al. A host-protein based assay to differentiate between bacterial and viral infections in preschool children (OPPORTUNITY): a double-blind, multicentre, validation study. Lancet Infect Dis. 2017;17(4):431–40.CrossRefGoogle Scholar
  45. 45.
    Harris AM, Hicks LA, Qaseem A. Appropriate antibiotic use for acute respiratory tract infection in adults: advice for high-value care from the American College of Physicians and the Centers for Disease Control and Prevention. Ann Intern Med. 2016;164(6):425–34.CrossRefGoogle Scholar
  46. 46.
    Hofer U. The cost of antimicrobial resistance. Nat Rev Microbiol. 2019;17(1):3.CrossRefGoogle Scholar

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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Springer NatureAucklandNew Zealand

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