Influenzanet, or Gripenet, is a syndromic surveillance system that monitors the activity of influenza-like_illness (ILI) with the help of volunteers via the Internet. This innovative surveillance system is based on the voluntary online participation of the population who, on a weekly basis, respond to an internet questionnaire about flu symptoms.

During the winter 2003/2004 season, the Netherlands and Belgium launched the first Influenzanet - The Great Influenza Survey - which attracted over 30,000 participants in the first year[1]. The Dutch Great Influenza Survey has been carried out yearly in the Netherlands and Belgium, since then. In Portugal it was implemented in the 2005/2006 season, the Gripenet; followed by the Italian Fluweb in 2008. With the threat of a new pandemic influenza, in 2009, three other countries joined this project, with the Gripenet Brasil, in Brasil; Reporta in Mexico; and the Fluweb in the United Kingdom.

How it works

edit
 
ILI Incidence curves generated by the Influenzanet, in the 2008-2009 flu season, in Portugal, The Netherlands and Belgium. Source: Gripenet

influenzanet

Any resident of the participating countries can register by completing an online application form containing various medical, geographic, and behavioural questions. Every week, during the flu season, participants are asked to select from a list of symptoms the ones they have experienced since their previous visit to the website. Participation is stimulated by email newsletters, online educational materials, competitions and presentations, and other educational activities of ILI on a given day, divided by the number of active participants on that day.

A case of ILI is defined based on a set of reported symptoms: acute onset of fever of >=38ºC, plus muscle pain, plus one of the following: cough, sore throat, and/or chest pain. The daily incidence of ILI is determined by the number of participants with an onset.

The results of the influenzanet closely matches the official EISS data [2].

References

edit
  1. ^ Marquet, Richard L.; Bartelds, Aad IM; Van Noort, Sander P.; Koppeschaar, Carl E.; Paget, John; Schellevis, François G.; Van Der Zee, Jouke (01 July 2006). "Internet-based monitoring of influenza-like illness (ILI) in the general population of the Netherlands during the 2003–2004 influenza season". BMC Public Health. 6 (242): 242. doi:10.1186/1471-2458-6-242. PMC 1609118. PMID 17018161. {{cite journal}}: Check date values in: |date= (help)CS1 maint: date and year (link) CS1 maint: unflagged free DOI (link)
  2. ^ van Noort, S (01 July 2007). "Gripenet: an internet-based system to monitor influenza-like illness uniformly across Europe". Eurosurveillance. 12 (7). {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)CS1 maint: date and year (link)