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R E V I E W Open Access
Public health for the people: participatory
infectious disease surveillance in the digital age
Oktawia P Wójcik
1*
, John S Brownstein
1
, Rumi Chunara
1
and Michael A Johansson
2
Abstract
The 21
st
century has seen the rise of Internet-based participatory surveillance systems for infectious diseases. These
systems capture voluntarily submitted symptom data from the general public and can aggregate and communicate
that data in near real-time. We reviewed participatory surveillance systems currently running in 13 different
countries. These systems have a growing evidence base showing a high degree of accuracy and increased
sensitivity and timeliness relative to traditional healthcare-based systems. They have also proven useful for assessing
risk factors, vaccine effectiveness, and patterns of healthcare utilization while being less expensive, more flexible,
and more scalable than traditional systems. Nonetheless, they present important challenges including biases associated
with the population that chooses to participate, difficulty in adjusting for confounders, and limited specificity
because of reliance only on syndromic definitions of disease limits. Overall, participatory disease surveillance data
provides unique disease information that is not available through traditional surveillance sources.
Keywords: Dengue, Influenza-like illness, Participatory surveillance, Participatory surveillance system, Disease
surveillance, Public health
Background
Community engagement has long been an important
part of public health. In the 1850s, John Snow identified
the role of water in cholera transmission using data that
he acquired by talking with people living in a cholera
epidemic [1]. When large smallpox outbreaks diminished
as part of the smallpox eradication campaign, the World
Health Organization turned to field workers armed with
pictures of smallpox victims to survey villagers and find
cases of the disease [2]. This approach was critical for
identifying the last bastions of disease leading to small-
pox eradication [2]. In the veterinary field, a similar ef-
fort was carried out in the last stages of the Rinderpest
eradication campaign, with farmers identifying cases in
their own cattle [3]. This approach was coined “partici-
patory surveillance”, referring to the participation of the
community in disease surveillance.
In the 21
st
century, public engagement is being trans-
formed through participatory surveillance systems that
enable the public to directly report on diseases via the
Internet. These systems encourage the regular, voluntary
submission of syndromic, health-related information by
the general public using computers or smartphones.
Reported data are aggregated and visualized in near
real-time allowing immediate feedback to users and
public health agencies. This offers the opportunities to
improve disease surveillance by providing data faster
and to engage the public by communicating findings
directly via the Internet.
In this review, we describe: 1) a selection of active
participatory surveillance systems for infectious diseases
(Influenzanet, FluTracking, Reporta, Flu Near You, Dengue
na Web, and SaludBoricua), 2) their unique contribu-
tions to public health, 3) the strengths and weaknesses
of participatory surveillance systems for infectious
diseases, and 4) the future of participatory surveillance.
Active participatory surveillance systems for infectious
diseases
Internet-based participatory surveillance has only emerged
in the last decade. While there are not many systems
currently in place, there are new implementations almost
every year. The first system, de Grote Griepmeting, or
the Great Influenza Survey, was started by a group of
* Correspondence: Oktawia.P.Wojcik@gmail.com
1
Harvard Medical School and Boston Children's Hospital, 1 Autumn St.,
Boston, MA 02215, USA
Full list of author information is available at the end of the article
EMERGING THEMES
IN EPIDEMIOLOGY
© 2014 Wójcik et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain
Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article,
unless otherwise stated.
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7
http://www.ete-online.com/content/11/1/7
individuals from various institutes during the 2003/
2004 influenza season in the Netherlands and in Dutch
speaking Flanders in Belgium [4]. De Grote Griepmet-
ing was created to monitor the activity of influenza-like
illness (ILI) by collecting symptom data from voluntary
participants. Participants register, complete an intake
questionnaire containing various medical, geographic
and behavioral questions, and receive weekly emails for
reporting symptoms (or a lack thereof ) since their last
visit to the website [5] (Table 1). The incidence of ILI
among participants is determined in real time using a
syndromic case definition [5] (Table 2) and graphic
representation of the results is dynamically updated on
the system’swebsite.
The idea of Internet-based participatory ILI surveillance
spread quickly and the model was adopted by other
European countries [6]: Portugal (Gripenet started in
2005 [7]), Italy (Influweb started in 2007 [8]), United
Kingdom (Flusurvey started in 2009 [9]), Sweden
(Influensakoll started in 2011), France (Grippenet started
in 2012), and Spain (Gripenet started in 2012 [5]). These
systems have been supported by private individuals,
numerous national agencies and foundations, as well
as the European Commission and are now collectively
called Influenzanet. Collaboration between these sys-
tems has led to standardization of collection and ana-
lytical methods which allows comparability between
countries.
A similar participatory ILI surveillance system, Flu-
Tracking, was launched in Australia in 2006 as a joint pro-
ject between the University of Newcastle and Hunter New
England Health [10]. FluTracking started with a focus on
south-eastern Australia, but expanded nationally in 2007
[11]. Like Influenzanet, participants are asked to report
weekly and data is published online as a map and a news-
letter at the end of each week. FluTracking also focuses on
examining the yearly effectiveness of the influenza vaccine
using its data [12].
Based on Portugal’s Gripenet, Reporta was launched in
2009 in Mexico to track respiratory disease, including
ILI. The system was initially created in the Mathematical
Visualization Laboratory with funding from the Institute
of Science and Technology of Mexico and the Center
for Complexity of Science at the National Autonomous
University of Mexico [13]. Like the other systems,
Reporta collects symptom data from residents on a
weekly basis and the website displays data in real-time
together with other important news and information
about influenza and public health in Mexico.
Flu Near You is a U.S. based system developed by
HealthMap at Boston Children’s Hospital, the Skoll Global
Threats Fund, and the American Public Health Associ-
ation (APHA) and launched in 2011 [14]. Flu Near You
allows individuals to register using its website, mobile
application or Facebook. Like the other systems, Flu
Near You targets ILI and collects data on a weekly basis,
which it publishes in real time, while offering a user
interface to compare its data with data from Centers for
Table 1 List of symptoms collected by Influenza-like
Illness (ILI) tracking systems: Influenzanet, FluTracking,
Reporta and Flu Near You
Symptom Influenzanet
a
FluTracking Reporta Flu Near
You
Fever ✓✓✓✓
Cough ✓✓✓✓
Sore throat ✓✓✓
Shortness of breath ✓✓✓
Chills/night sweats ✓✓
Fatigue ✓✓
Nausea/vomiting ✓✓✓
Diarrhea ✓✓✓
Body aches/Muscle
pain
✓✓✓
Headache ✓✓✓
Runny or blocked
nose
✓✓
Sneezing ✓
Chest pain ✓
Loss of appetite ✓
Colored sputum/
phlegm
✓
Watery/bloodshot
eyes
✓
Stomach ache ✓
Irritation ✓
Joint pain ✓
Weakness ✓
a
Influenzanet has an extensive symptom questionnaire and not all of the
information collected by this questionnaire is listed in Table 1. A complete list
of questions can be obtained from the “Methods”section of influenzanet.eu.
Table 2 Influenza-like Illness (ILI) definitions for
Influenzanet, FluTracking, Reporta and Flu Near You/
SaludBoricua
Participatory
surveillance system
Influenza-like illness definition
Influenzanet Sudden onset of symptoms AND at least one
of the following: fever and/or chills, feeling
tired or exhausted, headache, muscle pain;
AND at least one of the following: cough, sore
throat, shortness of breath
FluTracking Fever AND cough
Reporta Fever AND at least one of the following: cough
or sore throat
Flu Near You/
SaludBoricua
Fever AND at least one of the following: cough
or sore throat
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7 Page 2 of 7
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Disease Control and Prevention (CDC) sentinel influenza
network and Google Flu Trends. Additionally, Flu Near
You also hosts a “Vacci n e Finde r”which allows individuals
to identify local sources for influenza vaccination [14].
Dengue na Web was the first system to target non-
respiratory diseases. It was launched in 2011 to monitor
dengue activity in the city of Salvador de Bahia, Brazil.
Inspired by the Gripenet project, Dengue Na Web was
developed by the Federal University of Bahia with sup-
port from various state and federal entities [15]. Dengue
na Web offers real-time maps of participant reports
along with educational materials and international news
about dengue research.
In November 2012, SaludBoricua, an expanded version
of the Flu Near You system, was launched in Puerto
Rico. While the reporting mechanisms and data display
are virtually identical to Flu Near You, SaludBoricua
is unique among the other systems because instead of
targeting a single disease, it targets three different
acute febrile illnesses: influenza, dengue and leptospir-
osis [16].
While system design and objectives vary across these
systems, they all include a registration process which
collects varying amounts of background data and weekly
email prompts to encourage reporting of symptoms expe-
rienced that week (Table 1). Symptom data is processed in
real-time using syndromic definitions (Table 2) and is
displayed, generally in the form of maps or timelines, on
the system’s website communicating the information
back to the public. Many of the sites also provide public
health news or information about the diseases that they
target.
Unique contributions to public health
Several of the participatory surveillance systems de-
scribed above have already demonstrated their accuracy
and sensitivity, their ability to provide more timely mea-
sures of disease activity, and their usefulness for ad-
dressing public health challenges such as identifying
risk groups, assessing burden of illness and evaluating
vaccination coverage and effectiveness, and informing
disease transmission models [4-8,10,17-19].
Accuracy and sensitivity
After the first season of ILI surveillance in the Netherlands
(2003/2004), de Grote Griepmeting data were compared
to the official ILI data collected by the Dutch Sentinel
Practice Network of physicians [4]. The timing of the
ILI epidemic closely matched the official data, peaking
the same week. This initial observation was later repli-
cated by comparing Gripenet in Portugal and de Grote
Griepmeting in the Netherlands and Belgium to sentinel
physician networks for the 2006/2007 influenza season
[7]. The ILI incidence rate among Gripenet and de
Grote Griepmeting participants was also closely corre-
lated with ILI incidence data from the European Influ-
enza Surveillance Scheme (EISS)). These observations
have proven to be robust over time as well. A compari-
sonofdatafromfiveseasonsofdeGroteGriepmeting
with the Dutch Sentinel Practice Network data found
that Pearson correlations for each seasonal epidemic
ranged from 0.69 to 0.90 [17].
Australian data collected by FluTracking from 2007 to
2009 were compared temporally with laboratory influ-
enza antigen test data as well as ILI reports from emer-
gency departments [20]. All three systems detected
peak incidence concordantly, with no more than a week
difference between them. This finding suggests that all
systems are monitoring the same condition. In the UK,
Flusurvey data also are highly correlated with the ILI
incidence estimates reported by the Health Protection
Agency (Pearson correlation: 0.71; 95% Confidence
Interval: 0.44-0.87) [9]. The 2012/2013 influenza season
data collected by Flu Near You for the United States has
been compared with data collected by the CDC’s sentinel
influenza network and Google Flu Trends [21]. While Flu
Near You data followed the curve of the CDC data closely,
data for more years and more participants are needed to
verify these preliminary findings.
These studies have also identified the high sensitivity
of participatory surveillance. The main difference between
ILI incidence in de Grote Griepmeting versus sentinel
surveillance was the amplitude; de Grote Griepmeting
incidence rate was 10 times higher throughout the en-
tire observation period [4]. This was again found to be
true in Belgium and Portugal, though the degree varied
by country [7]. Importantly, the definition for ILI was
the same for all three countries in the participatory sur-
veillance system, but not in the EISS system, making a
true ILI comparison between the Netherlands, Belgium
and Portugal challenging. One of the reasons for this
differenceinthemagnitudebetweenthesystemsmay
be country-specific variations in the likelihood of going
to the physician. Nonetheless, this finding suggests that
ILI incidence rates observed in participatory surveil-
lance systems may be closer to the true incidence of ILI
in these populations [7].
Timeliness
Thenearreal-timeavailabilityofdataiscurrentlya
major strength of participatory surveillance systems. All
healthcare-based surveillance systems can be slow be-
cause of persons waiting to seek treatment. While elec-
tronic health records will change this, additional delays
occur due to manual reporting at various administrative
levels within systems. Further delays occur in laboratory-
based systems, which depend on sample collection and
testing prior to notification. In participatory surveillance,
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7 Page 3 of 7
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there may be very little delay because those who are sick
can report their symptoms directly to the system and
their information can be assessed, aggregated and visu-
alized almost instantly. This gain in time between the
onset of disease and its reporting is a considerable
advantage of participatory surveillance systems because
it increases the possibility of detecting warning signals
before traditional healthcare-based systems, though
this is conditional on maintaining a sufficiently high
rate of participation.
Some of the participatory surveillance systems have
also demonstrated that the ILI signal is slightly earlier
than in traditional surveillance systems. This has been
exemplified by the need to lag their data in order to
strengthen associations with traditionally collected data.
While five seasons of de Grote Griepmeting data corre-
lated well with the Dutch Sentinel Practice Network
data, the correlation was strongest with a one week lag,
suggesting that de Grote Griepmeting may detect changes
in ILI incidence one week earlier than the traditional sen-
tinel network [17]. Similarly, in Italy and Australia, Influ-
web and Flutracking data captured the H1N1 pandemic
peak one week before the sentinel physician network
[8,10]. A possible explanation for the earlier signal in both
of these examples is that a sick individual does not go to
the doctor on the first day of illness, but many participants
in de Grote Griepmeting and Influweb report illness on
the same day that they started feeling sick.
Addressing public health questions
Surveillance data is used to address important questions
related to control and prevention activities, such as iden-
tifying risk groups and monitoring intervention effective-
ness. Here participatory surveillance also has much to
offer. Influenzanet, for example, has consistently shown
that public transportation does not increase the risk of
developing ILI relative to driving a car, riding a bicycle
or walking as a primary mode of transportation [5]. This
result has been observed in the majority of the partici-
pating countries (the Netherlands, Portugal, Italy, United
Kingdom, Sweden, France, and Spain) for all the seasons
the systems have been in operation.
The UK Flusurvey data were used to estimate the
effectiveness of the 2010/2011 influenza season vaccine
[22]. Vaccination was associated with reduced ILI inci-
dence, with an estimated vaccine effectiveness of 52%
(95% CIs, 27%-68%) [22]. It was also associated with
reduced absenteeism, especially for those between 25–64
years of age, with 4.1% of the vaccinated participants
reporting taking time off work compared to 11.6% of the
unvaccinated. Furthermore, vaccinated absentees were
away from work for a significantly shorter period of time
compared to the unvaccinated persons.
FluTracking data have also been used to estimate vac-
cine effectiveness [23]. Vaccine effectiveness was estimated
to vary substantially across different years, from approxi-
mately 21% in 2007 and 23% in 2008 to essentially 0% in
2009, most likely due to the appearance of H1N1. As with
estimates from other surveillance systems, these estimates
may be sensitive to system-specific biases including par-
ticipation bias, small sample size, and the fact that not all
ILI cases are influenza.
In addition, FluTracking data have been used to
explore vaccination coverage in participants, including
specifically those with patient contact [24]. By the end of
2009, 28% of FluTracking participants and 41% of those
who worked face-to-face with patients had received the
pandemic vaccine. FluTracking was able to monitor this
as it changed, with coverage increasing to 65% of partici-
pants and 78% of persons with patient contact by the
end of 2010.
Healthcare-seeking behavior has been monitored in all
Influenzanet countries. In the 2006/2007 season, 25% of
all participants with ILI in the Netherlands, 45% of all
participants with ILI in Portugal and 76% of all partici-
pants with ILI in Belgium visited a healthcare profes-
sional [7]. Specifically in Italy, 55% of participants who
reported ILI symptoms phoned a physician while only
4% visited a physician [8], suggesting that almost half of
all ILI cases have no contact with healthcare profes-
sionals and only a very small proportion are available for
potential testing. Data from the UK Flusurvey during the
2009 H1N1 influenza epidemic showed that adults were
50% less likely to get medical attention than children
[18]. This data allowed the authors to estimate that there
were 1.1 million symptomatic influenza cases, a number
40% greater than the Health Protection Agency’s estimate
of 780,000 cases (based on ILI physician consultations
and internet- and telephone-based National Pandemic
Flu Service). This estimate implies a 35% lower case fatality
rate than previously estimated, as case fatality rates are
dependent on the total number of cases detected.
Strengths and weaknesses of participatory surveillance
systems for infectious diseases
As discussed, participatory surveillance systems can be
more sensitive and timely than traditional systems. In
addition, these systems are independent from healthcare-
seeking behavior biases and are less costly, more flexible
and more scalable than tradition healthcare-based surveil-
lance. However, participatory surveillance systems also
offer unique challenges: there may be biases associated
with the population that chooses to participate, adjusting
for confounders may be complicated, reliance only on syn-
dromic definitions of disease limits their specificity, and
ensuring consistent participation is difficult.
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7 Page 4 of 7
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Traditional healthcare-based surveillance systems rely
on sick people seeking medical care (Figure 1). Many
people do not seek care for a variety of reasons, some
related to disease severity, but others related to socio-
demographic differences which introduce inherent biases
[25,26]. These systems also require that the symptoms
are attributed to the correct etiology, often aided by
seeking laboratory confirmation, and that the relevant
information is reported to the system [27]. Taking this
entire process into consideration, it is easy to see why
the number of cases reported in traditional healthcare-
based surveillance methods is an underestimation of the
true disease burden in the population. This is precisely
where participatory surveillance systems can be used as
an additional, supplemental data source to have a more
comprehensive estimate of disease burden.
From a technical point of view, data collection in
participatory surveillance systems is also easier and more
streamlined than in traditional healthcare-based surveil-
lance systems as it can be accomplished via a simple
Internet-based form that is readily accessible from many
locations. This also decreases the costs associated with
operating a participatory surveillance system. Having all
aspects of the system integrated, including participant
recruitment, questionnaires, case definitions, analysis of
the data and presentation of the results, increases the
system’s flexibility. This means that almost any or all of
the components of the system can be changed without
disturbing the system’s overall functionality.
Scalability is another technical strength associated
with participatory surveillance systems. The amount of
resources (time, computation, finances and personnel)
needed to expand or change a participatory surveil-
lance system is minimal in comparison to those needed
to expand a healthcare-based surveillance system, as
no additional personnel or specific training of existing
personnel is needed.
At the same time participatory surveillance systems
have limitations, including participant populations that
may not be representative of the general population. A
majority of participants are women [9,17,20,28]. Chil-
dren and the elderly tend to be underrepresented as the
elderly and young are the least likely age groups to use
the Internet [4,8,11,17,18,22,23,28]. However, Flusurvey
was able to show that its participants were similar to
the general population in terms of risk group status
(diabetes, asthma, other chronic lung disease, immune-
compromised, chronic heart disease, other chronic dis-
eases and pregnancy), with the exception of the 0–14
age group [9]. Asthma and diabetes rates in participants
and the general population have also been shown to be
similar in the Netherlands [4] and Belgium [29]. And
most of the systems have evolved mechanisms to include
more children and elderly, by allowing participants to also
report for other members of their household. In 2007,
FluTracking expanded to include everyone 12 years or
older not just those over the age of 18. FluTracking also
allows participants to report on behalf of household
members of any age [11]. For Flu Near You, any resi-
dents of the US or Canada 13 years of age or older can
register and participants can report on their own health
as well as the health of household members of any age
[14]. Dengue na Web also allows participants to register
household members who can either report for them-
selves or have the registering participant report for
them [15].
Participatory surveillance also has limitations about
how much data can be collected from participants. The
more complicated and long the survey becomes for par-
ticipants the less likely they are to contribute informa-
tion to the system [30]. This is particularly important
for identifying and adjusting for potential confounders
and risk factors, including but not limited to chronic
illnesses, pregnancy and immune status. The more
Figure 1 Comparison between traditional healthcare surveillance and participatory surveillance.
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7 Page 5 of 7
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information that is available, the more accurate the
estimates of burden can be.
Participatory surveillance systems are inherently syn-
dromic as none of the systems incorporate any labora-
tory testing. They thus depend heavily on the syndrome
definitions and reporting behavior. A number of differ-
ent ILI definitions are in use by surveillance systems in
general, and that is also true of the participatory systems.
While no definitions are right or wrong, it is vital for
them to be clearly defined and analyzed. It is also pos-
sible to use other, complementary data sources to bolster
participatory surveillance data, for example using more
detailed data to estimate the probability of reporting ILI
symptoms given that a person has influenza [31].
There are other issues related to participation, which
is critical to all functions of participatory surveillance.
All systems have found that recruiting and maintaining
participants is a substantial challenge. Reporting fidelity
is quite variable, with some participants reporting only
once or twice, others sporadically over time, and many
every week [8,9,17,18]. Participation rates also relate to
illness; first-time participants are more likely to be sick
than repeat participants. Limited access to internet may
also limit participation. However, even in places with
limited internet access, internet-based surveillance sys-
tems show promise [32].
The future of participatory surveillance
Participatory surveillance is a quickly growing and
evolving field. One of the key aspects that needs to be
addressed for participatory surveillance systems to gain
greater acceptance and credibility in the field of public
health is data validation. This can be accomplished by
comparison to traditional surveillance systems, as is
already being done, or by laboratory testing of biological
samples from participants reporting symptoms.
In addition to collecting disease data, participatory
surveillance systems are improving awareness of the
infectious diseases they monitor. However, these systems
have the potential to go beyond that and increase a lay-
person’s knowledge of public health and its importance
for society. Communicating this kind of information
effectively could result in a greater appreciation and
understanding of public health in the general population.
A large number of consistent users who are geo-
graphically dispersed and of diverse age and risk groups
are needed for participatory surveillance systems to
work optimally. Systems need to continue recruiting
new members and expanding to areas where the
general population is not well represented so that they
collect and disseminate the best information possible.
Ideally, participatory surveillance systems should be
integrated into healthcare-based systems to supplement
data obtained from traditional sources because they
can provide information about people who do not seek
healthcare, data that is not otherwise available.
Integration with traditional healthcare-based surveil-
lance systems is also important from a system’ssustain-
ability perspective. Although participatory surveillance
systems are low-cost in comparison with traditional
systems, they are not free and need active support to
continue. Besides integration with an already existing
traditional healthcare-based system, there are different
revenue sources that can be used to support participatory
surveillance systems. These sources include advertising on
the system’s webpage, and non-profit or corporate spon-
sorships. Before deciding on what financial support to
accept, it is important to understand and anticipate how
various funding sources will be perceived by the public
and whether the system’s reputation will be altered based
on what organization provides the support.
Currently, healthcare-based surveillance systems rely
on obligatory reporting of diseases in a one-way system
where information feeds into an institutional reporting
hierarchy. This classical paradigm requires revision for a
better fit with today’s technological and societal ad-
vancements. Participatory surveillance systems promote
the exchange of information between people and public
health professionals, with the potential to spark a new
level of engagement in an individual’saswellasacom-
munity’s health.
Competing interests
The authors declared that they have no competing interests.
Authors’contributions
OPW, JSB, RC, and MAJ participated in the conceptualization of the review
and helped to draft the manuscript. All authors read and approved the final
manuscript.
Acknowledgements
This work was supported by the Centers for Disease Control and Prevention
Innovation Fund [200-2012-M-52884]; Skoll Global Threats Fund; and the
National Institutes of Health [5R01LM010812-04 to J.S.B.].
Author details
1
Harvard Medical School and Boston Children's Hospital, 1 Autumn St.,
Boston, MA 02215, USA.
2
Centers for Disease Control and Prevention, San
Juan, Puerto Rico, USA.
Received: 1 April 2014 Accepted: 9 June 2014
Published: 20 June 2014
References
1. Paneth N: Assessing the contributions of John Snow to epidemiology:
150 years after removal of the broad street pump handle. Epidemiology
2004, 15:514–516.
2. Fenner F, Henderson DA, Arita I, Jezek Z, Ladnyi ID: World Health
Organization: Smallpox and Its Eradication. [http://apps.who.int/iris/handle/
10665/39485]
3. Mariner JC, House JA, Mebus CA, Sollod AE, Chibeu D, Jones BA, Roeder PL,
Admassu B, van’t Klooster GGM: Rinderpest eradication: appropriate
technology and social innovations. Science 2012, 337:1309–1312.
4. Marquet RL, Bartelds AIM, Van Noort SP, Koppeschaar CE, Paget J, Schellevis
FG, van der Zee J: Internet-based monitoring of influenza-like illness (ILI)
in the general population of the Netherlands during the 2003–2004
influenza season. BMC Public Health 2006, 6:242.
Wójcik et al. Emerging Themes in Epidemiology 2014, 11:7 Page 6 of 7
http://www.ete-online.com/content/11/1/7
5. Influenzanet: http://www.influenzanet.eu/en/method/.
6. Paolotti D, Carnahan A, Colizza V, Eames K, Edmunds J, Gomes G,
Koppeschaar C, Rehn M, Smallenburg R, Turbelin C, Van Noort S, Vespignani
A: Web-based participatory surveillance of infectious diseases: the
Influenzanet participatory surveillance experience. Clin Microbiol Infect
2014, 20:17–21.
7. Van Noort SP, Muehlen M, Rebelo De Andrade H, Koppeschaar C, Lima
Lourenço JM, Gomes MGM: Gripenet: an internet-based system to
monitor influenza-like illness uniformly across Europe. Euro Surveill 2007,
12:E5–E6.
8. Paolotti D, Gioannini C, Colizza V, Vespignani A: Internet-based monitoring
system for influenza-like illness: H1N1 surveillance in Italy. In 3rd
International ICST Conference on Electronic Healthcare for the 21st century.
Morocco: Casablanca; 2010.
9. Tilston NL, Eames KTD, Paolotti D, Ealden T, Edmunds WJ: Internet-based
surveillance of Influenza-like-illness in the UK during the 2009 H1N1
influenza pandemic. BMC Public Health 2010, 10:650.
10. Parrella A, Dalton CB, Pearce R, Litt JCB, Stocks N: ASPREN surveillance
system for influenza-like illness - A comparison with FluTracking and the
National Notifiable Diseases Surveillance System. Aust Fam Physician 2009,
38:932–936.
11. Dalton C, Durrheim D, Fejsa J, Francis L, Carlson S, d’Espaignet ET, Tuyl F:
Flutracking: a weekly Australian community online survey of influenza-
like illness in 2006, 2007 and 2008. Commun Dis Intell 2009, 33:316–322.
12. FluTracking. http://www.flutracking.net/Info/About.
13. Reporta. http://reporta.c3.org.mx/.
14. Flu Near You. https://flunearyou.org/.
15. Dengue na Web. http://www.denguenaweb.org.
16. SaludBoricua. http://saludboricua.org.
17. Friesema IHM, Koppeschaar CE, Donker GA, Dijkstra F, Van Noort SP,
Smallenburg R, van der Hoek W, van der Sande MAB: Internet-based
monitoring of influenza-like illness in the general population: experience
of five influenza seasons in The Netherlands. Vaccine 2009, 27:6353–6357.
18. Brooks-Pollock E, Tilston N, Edmunds WJ, Eames KTD: Using an online
survey of healthcare-seeking behaviour to estimate the magnitude and
severity of the 2009 H1N1v influenza epidemic in England. BMC Infect Dis
2011, 11:68.
19. Van Noort SP, Águas R, Ballesteros S, Gomes MGM: The role of weather on
the relation between influenza and influenza-like illness. J Theor Biol
2012, 298:131–137.
20. Carlson SJ, Dalton CB, Durrheim DN, Fejsa J: Online Flutracking survey of
influenza-like illness during pandemic (H1N1) 2009, Australia. Emerg Infect Dis
2010, 16:1960–1962.
21. Butler D: When Google got flu wrong. Nature 2013, 494:155–156.
22. Eames KTD, Brooks-Pollock E, Paolotti D, Perosa M, Gioannini C, Edmunds
WJ: Rapid assessment of influenza vaccine effectiveness: analysis of an
internet-based cohort. Epidemiol Infect 2012, 140:1309–1315.
23. Carlson SJ, Durrheim DN, Dalton CB: Flutracking provides a measure of
field influenza vaccine effectiveness, Australia, 2007–2009. Vaccine 2010,
28:6809–6810.
24. Dalton CB, Carlson SJ, Butler MT, Feisa J, Elvidge E, Durrheim DN:
Flutracking weekly online community survey of influenza-like illness
annual report, 2010. Commun Dis Intell Q Rep 2011, 35:288–293.
25. Redondo-Sendino A, Guallar-Castillón P, Banegas JR, Rodríguez-Artalejo F:
Gender differences in the utilization of health-care services among the
older adult population of Spain. BMC Public Health 2006, 6:155.
26. Uiters E, Devillé W, Foets M, Spreeuwenberg P, Groenewegen PP:
Differences between immigrant and non-immigrant groups in the use of
primary medical care; a systematic review. BMC Health Serv Res 2009, 9:76.
27. Novick L, Morrow C, Mays G: Public Health Administration: Principles for
Population-Based Management. Sudbury, MA, USA: Jones & Bartlett Learning;
2008.
28. Debin M, Turbelin C, Blanchon T, Bonmarin I, Falchi A, Hanslik T, Levy-Bruhl
D, Poletto C, Colizza V: Evaluating the feasibility and participants’
representativeness of an online nationwide surveillance system for
influenza in France. PLoS One 2013, 8:e73675.
29. Vandendijck Y, Faes C, Hens N: Eight years of the Great Influenza Survey
to monitor influenza-like illness in Flanders. PLoS One 2013, 8:e64156.
30. Sinkowitz-Cochran RL: Survey design: To ask or not to ask? That is the
question. Clin Infect Dis 2013, 56:1159–1164.
31. Patterson-Lomba O, Van vNoort S, Cowling BJ, Wallinga J, Gomes MGM,
Lipsitch M, Goldstein E: Utilizing syndromic surveillance data for
estimating levels of influenza circulation. Am J Epidemiol 2014,
179:1394–1401.
32. Gluskin RT, Johansson MA, Santillana M, Brownstein JS: Evaluation of Internet-
based dengue query data: Google Dengue Trends. PLoS Negl Trop Dis 2014,
8:e2713.
doi:10.1186/1742-7622-11-7
Cite this article as: Wójcik et al.:Public health for the people:
participatory infectious disease surveillance in the digital age. Emerging
Themes in Epidemiology 2014 11:7.
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