Influenzanet: Citizens Among 10 Countries Collaborating to Monitor Influenza in Europe

Abstract

BackgroundThe wide availability of the Internet and the growth of digital communication technologies have become an important tool for epidemiological studies and health surveillance. Influenzanet is a participatory surveillance system monitoring the incidence of influenza-like illness (ILI) in Europe since 2003. It is based on data provided by volunteers who self-report their symptoms via the Internet throughout the influenza season and currently involves 10 countries.ObjectiveIn this paper, we describe the Influenzanet system and provide an overview of results from several analyses that have been performed with the collected data, which include participant representativeness analyses, data validation (comparing ILI incidence rates between Influenzanet and sentinel medical practice networks), identification of ILI risk factors, and influenza vaccine effectiveness (VE) studies previously published. Additionally, we present new VE analyses for the Netherlands, stratified by age and chronic illness and offer suggestions for further work and considerations on the continuity and sustainability of the participatory system.MethodsInfluenzanet comprises country-specific websites where residents can register to become volunteers to support influenza surveillance and have access to influenza-related information. Participants are recruited through different communication channels. Following registration, volunteers submit an intake questionnaire with their postal code and sociodemographic and medical characteristics, after which they are invited to report their symptoms via a weekly electronic newsletter reminder. Several thousands of participants have been engaged yearly in Influenzanet, with over 36,000 volunteers in the 2015-16 season alone.ResultsIn summary, for some traits and in some countries (eg, influenza vaccination rates in the Netherlands), Influenzanet participants were representative of the general population. However, for other traits, they were not (eg, participants underrepresent the youngest and oldest age groups in 7 countries). The incidence of ILI in Influenzanet was found to be closely correlated although quantitatively higher than that obtained by the sentinel medical practice networks. Various risk factors for acquiring an ILI infection were identified. The VE studies performed with Influenzanet data suggest that this surveillance system could develop into a complementary tool to measure the effectiveness of the influenza vaccine, eventually in real time.ConclusionsResults from these analyses illustrate that Influenzanet has developed into a fast and flexible monitoring system that can complement the traditional influenza surveillance performed by sentinel medical practices. The uniformity of Influenzanet allows for direct comparison of ILI rates between countries. It also has the important advantage of yielding individual data, which can be used to identify risk factors. The way in which the Influenzanet system is constructed allows the collection of data that could be extended beyond those of ILI ...

Participatory Disease Surveillance: Engaging Communities Directly in Reporting, Monitoring, and Responding to Health Threats

“…Over time this effort grew into the “Influenzanet” consortium that now includes 10 countries in Western Europe, coordinated by the ISI Foundation in Italy [18,23]. In 2006, the “FluTracking” program began in Australia and now operates as a joint initiative of Newcastle University, Hunter New England Population Health, and the Hunter Medical Research Institute [17,24].…”

Unsupervised Extraction of Epidemic Syndromes from Participatory Influenza Surveillance Self-reported Symptoms

“…The system relies on the voluntary participation of the general population 35 through a dedicated national website in each country involved in the project. Data are 36 obtained on a weekly basis through an online survey [24] where participants are invited 37 to report whether they experienced or not any of the following symptoms since their 38 last survey: fever, chills, runny or blocked nose, sneezing, sore throat, cough, shortness 39 of breath, headache, muscle/joint pain, chest pain, feeling tired or exhausted, loss of 40 appetite, coloured sputum/phlegm, watery/bloodshot eyes, nausea, vomiting, diarrhoea, 41 stomach ache, or other symptoms. Differently from most traditional surveillance 42 systems, this participatory form of online surveillance allows the collection of symptoms 43 in real time and directly from the general population, including those individuals who 44 do not seek health care assistance.…”

“…Only in recent years, some state members have 20 adopted the case definition provided by the European Center for Disease Control and 21 Prevention (ECDC) which defines an ILI case as the sudden onset of symptoms with 22 one or more systemic symptoms (fever or feverishness, malaise, headache, myalgia) plus 23 one or more respiratory symptoms (cough, sore throat, shortness of breath) [13]. 24 Nevertheless, a significant fraction of European countries still adopts their own clinical 25 case definition to compile seasonal influenza surveillance weekly reports. 26 In recent years the availability of novel data streams has given rise to a variety of 27 non-traditional approaches for monitoring seasonal influenza epidemics [14][15][16].…”

A Review on Event-Based Epidemic Surveillance Systems that Support the Arabic Language

“…They identified 11 web-based surveillance systems, including GOARN, GPHIN, MedISys , BioCaster, HealthMap, ProMED, and EpiSPIDER, which had already been reviewed by Velasco et al [3]. However, they also reviewed new systems: EpiSimS (now known as Object-oriented Platform for People in Infectious Epidemic OPPIE) [18], Google Flu Trends [19], GET WELL [20] and Influenzanet [21], which were not mentioned in [3], as can be seen in Table I. To the best of the authors' knowledge, the recent review article was carried out by Yan et al [22] and was published in October 2017. Developed systems in articles published between 2006 and 2016 were evaluated in terms of their methods, timeliness and accuracy outcomes.…”