Case definitions

The table below outlines the case definitions used by the surveillance networks in EuroFlu.
For a discussion of the different case definitions used in Europe, please see: Aguilera JF et al. Heterogeneous case definitions used for the surveillance of influenza in Europe. European Journal of Epidemiology 2003: 18(8): 733-736.

Surveillance networks Influenza-like illness Acute respiratory infection
Belgium Sudden onset of fever, with respiratory symptoms and systemic symptoms Common cold, (rhino-)pharyngitis, tonsilitis, sinusitis, acute otitis media, laryngitis, (laryngo-)tracheitis, bronchitis, bronchiolotis, (broncho)pneumonia.
Czech Republic No case definition
Cyprus Sudden onset of fever (38.5°C) of at least 2 days duration, symptoms from the upper respiratory system, weakness, muscular pains, and headache.
Denmark Sudden onset of disease with fever, myalgia and symptoms of respiratory infection
England No case definition
Estonia Clinical picture compatible with influenza, e.g. sudden onset of disease, cough, fever > 38°C, muscular pain and/or headache.
France Sudden onset of respiratory symptoms with infection context (fever, headaches), in the absence of other diagnosis
Germany Acute pharyngitis, acute bronchitis or pneumonia, with or without fever
Greece Acute onset of illness, cough, fever >38ºC, muscle ache and/or headache.
Ireland Sudden onset of symptoms with a temperature of 38C or more in the absence of any other disease with at least 2 of the following: headache, myalgia, sore throat, dry cough
Italy Sudden onset of symptoms, with temperature >38C, plus at least 1 systemic symptom and at least 1 respiratory symptom
Latvia Every illness characterized by sudden onset of fever (>38C) with respiratory symptoms (dry cough and sore throat), headache and/or myalgia
Lithuania Sudden onset of fever (> 38°C ), cough, myalgia and/or headache. Sudden onset of respiratory symptoms rhino-pharyngitis, pharyngitis, sinusitis, tonsilitis, laryngitis, tracheitis, epiglottitis included.
Luxembourg Sudden onset of fever (> or equal to 38C), myalgia and respiratory symptoms (e.g. cough or pharyngitis). No case definition
Malta Fever (>38°C) with cough and headache and/or muscular pain
The Netherlands Pel criteria 1
Northern Ireland An acute respiratory illness accompanied by variable fever and myalgia
Norway A patient with clear general symptoms, primarily acute fever >38C, headache, muscle ache, and in addition a dry cough
Poland No case definition
Portugal ICHPPC-2-D definition2

Every illness characterized by sudden onset, fever, myalgia and respiratory symptoms (cough, coryza).

Common cold, rhinitis, rhino-pharyngitis, tonsilitis, sinusitis, otitis media, laryngitis, tracheitis, bronchitis, bronchiolotis, pneumonia and broncho-pneumonia.
Scotland No case definition No case definition
Slovak Republic Sudden onset and fever with (1) at least 1 respiratory symptoms; cough, rhinitis, sore throat, and (2) at least 1 general symptoms: headache, joint ache, chills, malaise
Slovenia Sudden onset of fever (>38C) with general weakness, muscle and joint pain, dry cough and symptoms of upper respiratory tract affection No case definition
Spain ICHPPC-2-D case definition2
Sweden No case definition
Switzerland Respiratory illness with fever >38C, myalgia, general pain, chills, anorexia. (optional symptoms are: cough, rhinitis and arthralgia)
Wales Upper respiratory tract symptoms, fever, chills, myalgia, cough

1: Pel criteria An acute onset (i.e. at most a prodromal stage of three to four days), accompanied by a rise in rectal temperature of >38C, and at least 1 of the following symptoms: cough, coryza, sore throat, frontal headache, retrosternal pain, myalgia.

2: International Classification of Health Problems in Primary Care
ILI: at least one of the following characteristics:

  1. Influenza virus culture positive or serological evidence of influenza virus infection
  2. Context of influenza epidemic, plus 4 of the criteria in 3.
  3. 6 of the following criteria: sudden onset (within 12 hours), cough, fever, chills, prostration and weakness, myalgia or general pain, rhinitis, pharyngitis, contact with a case.

Last updated: 12 December 2005 for technical correspondence only. System design copyright 1996-2013 Quad Logic ©
Home Page