Performance of influenza case definitions for influenza community surveillance: based on the French influenza surveillance network GROG, 2009-2014

Abstract

International case definitions recommended by the Centers for Disease Control and Prevention (CDC), the European Centre for Disease Prevention and Control (ECDC), and the World Health Organization (WHO) are commonly used for influenza surveillance. We evaluated clinical factors associated with the laboratory-confirmed diagnosis of influenza and the performance of these influenza case definitions by using a complete dataset of 14,994 patients with acute respiratory infection (ARI) from whom a specimen was collected between August 2009 and April 2014 by the Groupes Régionaux d'Observation de la Grippe (GROG), a French national influenza surveillance network. Cough and fever ≥ 39 °C most accurately predicted an influenza infection in all age groups. Several other symptoms were associated with an increased risk of influenza (headache, weakness, myalgia, coryza) or decreased risk (adenopathy, pharyngitis, shortness of breath, otitis/otalgia, bronchitis/ bronchiolitis), but not throughout all age groups. The WHO case definition for influenza-like illness (ILI) had the highest specificity with 21.4%, while the ECDC ILI case definition had the highest sensitivity with 96.1%. The diagnosis among children younger than 5 years remains challenging. The study compared the performance of clinical influenza definitions based on outpatient surveillance and will contribute to improving the comparability of data shared at international level.

DOI: 10.2807/1560-7917.ES.2017.22.14.30504

Cite this paper

@inproceedings{Casalegno2017PerformanceOI, title={Performance of influenza case definitions for influenza community surveillance: based on the French influenza surveillance network GROG, 2009-2014}, author={Jean-sebastien Casalegno and Daniel Eibach and Martine Valette and Vincent Enouf and Isabelle Daviaud and Sylvie Behillil and Astrid Vabret and Jean Claude Soulary and Mehdi Benchaib and Jean Marie Cohen and Sylvie van der Werf and Anne Mosnier and B. Lina}, booktitle={Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin}, year={2017} }