Table 1 Data Extraction

Ansaldi, F.et al.,2009 [13]

Emergency Department Syndrome Surveillance System

ED

5 syndromes including measles-like illness

Italy

Retrospective

Effective

First, the specificity and sensitivity were 94.3 and 91% respectively. Second, the two epidemic threshold breakthroughs anticipated the first notified case by 54 and 11 days. Finally, this was able to anticipate the first case notified by statutory system and virological surveillance to detect signals where low circulation of measles virus was recorded by other systems of surveillance.

6

Cashmore, A. W. et al.,2013 [14]

Public Health Real-Time Emergency Department Surveillance System (PHREDSS)

ED

Pertussis in children

Australia

Retrospective

Not Effective

First, the monitoring of ED visits with cough in children was not able to detect a potential pertussis outbreak before passive surveillance, which includes mandatory reporting from numerous sources including laboratory notification of positive tests. Finally, the RSV activity influences fluctuations in ED visits with cough among the study population.

5

Elliot, A. J. et al.,2012 [15]

Emergency Department Sentinel Syndromic Surveillance System (EDSSS)

ED

Syndromic indicators (respiratory, gastrointestinal, cardiac, acute respiratory infection, gastroenteritis and myocardial ischemia)

United Kingdom

Prospective

Effective

First, this has the potential of identifying severe outbreaks of infectious diseases. Second, the sustainability of the ED-SSS system will continue for several years. Finally, the EDSSS also had the ability to standardize the way data are collected and this can be for multiple uses.

5

Hope, K. G. et al., 2010 [16]

Emergency department syndromic surveillance

ED

Public health conditions during mass gatherings

Australia

Retrospective and Prospective

Effective (Potential)

First, this informs local health action or plays a role as a surveillance safety net for traditional surveillance systems, especially when focusing on pneumonia, meningitis, poisoning and gastrointestinal syndromes. In addition, this has a specific local utility, especially during mass gatherings or disaster response surveillance. Moreover, the ED surveillance data has informed health messages for the media and guided response planning. Finally, this has the potential to detect public health threats that require prompt intervention.

5

Lall, R. et al.,2017 [17]

New York City syndromic surveillance system (The New York City DOHMH Department of Health and Mental Hygiene syndromic surveillance system)

ED

6 use cases (synthetic cannabinoid drug use, heat-related illness, suspected meningococcal disease, medical needs after severe weather, asthma exacerbation after a building collapse, and Ebola-like illness in travelers returning from West Africa

United States

Prospective

Effective

First is the ability to adjust the sensitivity and the specificity, including or excluding keywords or phrases and ICD diagnosis codes. In addition, the surveillance for diseases such as meningitis ED visits helps in tracking unreported cases of culture-negative meningococcal diseases.

6

Muscatello, D. J. et al., 2005 [18]

Public health surveillance system

ED

Syndrome groupings (Abdominal pain Chest pain Convulsions (not clearly epilepsy), Fever (cause unspecified), Collapse/syncope/coma /delirium/ dizziness, Neuromuscular/vision problems, Gastrointestinal syndromes, Cardiovascular syndromes, Respiratory syndromes, Injury syndromes, Other syndromes (Illicit drug-related, Alcohol-related provisional diagnosis, Meningococcal infection, Other or unspecified meningitis Skin problems))

Australia

Retrospective

Effective (Complement)

First is that the ED was able to provide a more timely broad-based surveillance capability than previously available in NSW. However, this doesn’t replace the communicable disease surveillance but worked as a complement for its greater specificity.

4

Terry, W. et al., 2004 [19]

Westchester County’s Syndromic Surveillance System

ED

8 syndrome categories (fever/influenza, respiratory, vomiting, gastrointestinal illness/diarrhea, sepsis, rash, hemorrhagic events, and neurologic)

United States

Retrospective

Effective (Complement)

First, this provides baseline and timely objective data for hospital visits and will be used as a basis for future monitoring of other conditions. Second, several reportable and unusual events during a 9-month period were detected through telephone calls from ED. Finally, this also reflects the importance of disease surveillance communication with local ED staff and indicates the complementary role for syndromic surveillance systems since they are not replacing traditional ones.

6

Tsung-Shu Joseph Wu et al., 2008 [20]

Hospital emergency department-based syndromic surveillance system (ED-SSS)

ED

Fever, respiratory, skin, neurological, upper gastrointestinal (GI), lower GI, haemorrhagic, influenza-like illness (ILI), asthma, enterovirus-related infection (EVI) syndrome, and syndrome for severe illness or death

Taiwan

Retrospective

Effective

First, this can be adapted to other language and cultural environments for improving the global surveillance of infectious diseases. Second, the use of ED-SSS for surveillance of influenza-like illnesses has improved the preparedness of Taiwan’s flu pandemic. Finally, this system was not able to reveal obvious trends in all syndrome groups.

4

Ansaldi, F. et al., 2008 [21]

Emergency Department-based syndromic surveillance system

ED

5 syndromes (Influenza-like illness (ILI), Low-respiratory tract illness (LRTI), not-haemorrhagic gastroenteritis, acute hepatitis, fever-with-rash (maculo-papular or vescicular) syndrome

Italy

Retrospective

Effective (Complement)

The specificity and the sensitivity for this system are 90.3 and 72.9% respectively, and it has the ability to alert the public health institutions 2.5 days before than the local surveillance system.

6

Hong et al., 2022 [22]

Emergency Department-Based Syndromic Surveillance

ED

Predict the number of patients with influenza using the daily number of ED visits due to fever

Korea

Retrospective

Effective

This EWS proved to be feasible for predicting influenza cases 14 days earlier than the routine system through surveilling fever chief complaints from emergency departments.

6

Lukowsky et al., 2022 [23]

–

ED

COVID-like symptoms, influenza-like illnesses (ILIs), and non-influenza ILIs

United States

Retrospective

Effective (Adjunct)

This system was the first to monitor COVID-like symptoms rather than influenza-like illnesses. It has retrospectively suggested that COVID-19 symptoms started in October 2019 (prior to COVID-19 known community transmission).

4

Caudle, J. M. et al., 2009 [24]

Telehealth Ontario toll-free helpline

Telephone

Gastrointestinal Illness

Canada

Retrospective

Effective (Complement)

First, The Telehealth Ontario GI call complaints are a novel, timely and representative data stream that shows promise for integration in the detection of unexpected cases in a real-time syndromic surveillance system. Then, without the need to assimilate ED data from disconnected sources, as a single database, telehealth would provide effective disease surveillance. This type of surveillance can also provide reassurance that an infectious disease outbreak is not occurring. Finally, Telehealth data can serve as proxy measures for ED discharge.

5

Cooper, D. L. et al., 2006 [25]

NHS Direct Surveillance System

Telephone

Syndromes which may represent the prodromal stages of disease caused by a bio-terrorist attack, or more likely a rise in common infections

United Kingdom

Retrospective

Not Effective

First, the NHS Direct surveillance system was most suited for the detection of more widespread rises in syndromes in the community, but at the same time this was unlikely to detect an event like the cryptosporidiosis outbreak. Second, the rise in NHS direct call rates helps in improving the early warning of outbreaks by using call data. Third, when nine-tenths of cases telephoned NHS Direct (using the confidence interval method) there was a one-in-two chance of detection prior to the date officials were notified of this outbreak. Finally, after a substantial rise in call rates there is a full potential for the surveillance system to detect local outbreaks. This work provided information about the nature of syndromic data required to trigger ‘exceedances’.

6

Doroshenko, A. et al., 2005 [26]

NHS Direct syndromic surveillance

Telephone

10 syndromes (cold/influenza, cough, diarrhea, difficulty breathing, double vision, eye problems, lumps, fever, rash, and vomiting)

United Kingdom

Prospective

Effective

First the NHS direct syndromic surveillance has a representative national coverage, It has the potential to detect high-risk, large-scale events by providing near real-time data analysis. Second, this system is useful and acceptable with low marginal costs and borderline portability and flexibility. NHS direct surveillance by the majority of stakeholders was able to detect the national (England and Wales) outbreaks of ILI and increases in diarrhea and vomiting.

6

Dureab, F.et al., 2019 [27]

National electronic Disease Early Warning System (eDEWS)

Telephone

Cholera

Yemen

Retrospective

Effective

This system is sensitive. Second, it can detect and send alerts to health authorities about cholera cases under conditions of ongoing war and civil war, but the timeliness of the response needs improvement. Third, between the first response and reporting the mean time was 2.85 days. Finally, this system is not the only source of data collection of an outbreak of infectious disease, but it is important for the detection of newly emerging cases.

5

Katayama, Y. et al., 2020 [28]

–

Telephone

Seasonal influenza

Japan

Retrospective

Effective

This system showed a positive relationship between the number of telephone triages for fever and the number of patients with influenza in a large metropolitan area in Japan.

5

Katayama, Y. et al., 2021 [29]

–

Telephone

Rotavirus in pediatric patients

Japan

Retrospective

Effective

This showed that the number of pediatric patients with rotavirus incidence was positively related to the number of telephone triage symptoms in a large metropolitan area of Japan. Also, there is a high correlation between traditional surveillance data and the number predicted from the linear regression model, indicating that it would be possible to predict an epidemic of rotavirus earlier than with traditional surveillance.

5

Kavanagh, K. et al., 2012 [30]

Exception reporting system (ERS)

Telephone

Influenza-like illness (ILI)

Scotland

Prospective

Effective

First, this was able to detect exceedances in syndromes related to influenza A (H1N1v) in advance of media reporting. Second, it helps in providing useful information on trends within an area with reassurance when the exceedances are lacking in areas where outbreaks are not known to be occurring. This system is timely with a lag of one reporting day. Finally, during pandemics this system is useful to track temporal changes in the data by eye, but the alarm system is less sensitive unless upward fluctuations occur again.

4

Mostashari, F. et al.,2003 [31]

–

Ambulance

Influenza-like illness (ILI)

United States

Predictive simulation and prospective

Effective

First is the system’s sensitivity for the communitywide outbreaks of the respiratory system with a little negative alarm. Second, this system was able to track epidemics of influenza in the period 1994–1998 and prospectively 1999–2002. Third, the rate of alarms was sustainable with only five alarms not well explained at the 99% level in around 2200 days of surveillance. Fourth, this system was able to detect not only communitywide respiratory outbreaks, but also the ones caused by biologic terrorism. Lastly, the availability of the data is timely and can be categorized into syndromes. Finally, this requires so many nonspecific illnesses to occur before the detection of the event.

4

Schrell, S. et al.,2013 [32]

System for Information on Detection and Analysis of Risks and Threats to Health (SIDARTHa)

Ambulance

Influenza-like illness (ILI)

Spain

Retrospective

Effective (Complement)

First, sensitivity and specificity are 70/63% and 70/63% respectively. Second, is the ability to perform complement sentinel influenza surveillance. Third, the onset of the high influenza in one season was one week before. However, in the other seasons it was at the same time as the sentinel system. Third, in comparison to the weekly sentinel reporting, the daily ED report provides an earlier warning system. Finally, by using the ED Sys system, the beginning of the influenza season in season 2010–11 could be detected in near real time.

5

Ye, C. et al., 2016 [33]

Pudong Syndromic surveillance and Early Warning System (PD-SEWS)

Hospital

7 targeted syndromes (Acute respiratory and Gastrointestinal syndromes, Rash with fever, Neurological syndrome, Hemorrhagic fever, Botulism-like syndrome, Acute viral hepatitis)

China

Prospective

Effective

First, this system is sensitive. Second, this system acted as a practical tool for recording symptoms during the 41st World Exposition in Shanghai in the hospital-based enhanced syndromic surveillance. In addition, each signal which is represented as an aberration was required to be verified timely and investigated by the local staff of Center for Disease Control and Prevention, and as a result, control measures were conducted rapidly, especially when the signal seemed to lead to an outbreak.

6

Buda, S. et al., 2017 [34]

SARI (Severe Acute Respiratory Infections) surveillance system

Hospital

Acute respiratory infections, specifically influenza

Germany

Retrospective

Effective

First, the system has created a SARI baseline to be used as a starting point for the evaluation of severity of future Influenza epidemics or pandemics. Second, the EWS will allow a detailed analysis which focuses on different subgroups of patients with specific risk factors and underlying conditions. In addition, the temporal pattern of hospitalized SARI patients in sentinel data corresponded well to the course of the MAARI incidence along with the virological results of the Germen outpatient sentinel (AGI).

6

Dembek, Z. F. et al., 2004 [35]

Hospital Admissions Syndromic Surveillance statewide syndromic surveillance (HASS)

Hospital

11 syndromes (Pneumonia, hemoptysis, respiratory distress, acute neurologic illness, nontraumatic paralysis, sepsis and nontraumatic shock, fever with rash, fever of unknown cause, acute gastrointestinal illness, and possible cutaneous anthrax, and suspected illness cluster)

United States

Prospective

Effective

First, this system is considered sensitive but not totally. Second, the HASS has been successfully used to identify and investigate individual cases of relatively unusual syndromes (e.g., the detection of two cases of West Nile virus encephalitis by following up on reports of encephalitis in one hospital). However, this system was not able to detect an outbreak that was not detected by other means.

6

Dureab, F. et al., 2020 [36]

National electronic Disease Early Warning System (eDEWS)

Hospital

16 communicable diseases (later increased to 31); respiratory diseases or airborne diseases, digestive system diseases or water/food borne diseases, vector borne diseases, vaccine-preventable diseases, and all other infectious diseases such as chicken pox, brucellosis, schistosomiasis, rabies, HIV/AIDS, tuberculosis (TB), scabies and Guinea worm

Yemen

Retrospective

Effective (Complement)

First, this system is sensitive. Second, this system was the only system in Yemen that provides regular data on communicable diseases. Third, this system was able to detect changes over time since data can be supported by field investigation and laboratory testing. Fourth, this system is very useful in disease trends monitoring in Yemen. Next, this can complement the routine disease surveillance to detect potential outbreaks in a timely way. Finally, there is a challenge in the response timeliness as only 21% of all alerts were verified within the 24 hours in the year 2016.

5

Aggrawal et al., 2020 [37]

–

Hospital

22 acute diseases/syndromes (66% for acute diarrhoeal diseases, 8% for thermal event, 16% for vector-borne diseases, 8% for vaccine-preventable disease)

India

Retrospective and Prospective

Effective

First, this system enabled surveillance systems to respond and monitor risks to public health and detect diseases early. Second, the outbreaks such as gastroenteritis and varicella were confirmed and investigated, and with the implementation of interventions this has prevented additional morbidity and mortality. Finally, the web portal ensured a faster data analysis and interpretation.

5

Ang, B. C. et al., 2005 [38]

Patient Care Enhancement System (PACES)

Hospital

Gastrointestinal (GI), Fever, Respiratory, Coma, Neurological, Dermatologic-Haemorrhagic, Dermatologic-infectious

Singapore

Retrospective

Effective

First, it is sensitive. Second, by utilizing repeat consults, there was a potential to improve the signal-to-noise ratio. This has resolved the level of subunits at risk which can detect sizes of outbreaks that are difficult to achieve with community-based systems.

5

Kool, J. L. et al., 2012 [39]

Syndromic Surveillance System

Hospital

Influenza-like illness (ILI) and laboratory-confirmed influenza

Pacific island countries and territories (PICTs)

Retrospective

Effective (Complement)

First, it doesn’t replace the need for laboratories to report confirmed cases of outbreak-prone diseases such as typhoid fever, dengue, influenza, and leptospirosis. Second, it replaces the routine collection of large amounts of data in cases that this data might not be used for early warning purposes. Third, it enables public health response by control measures by the identification of outbreaks. Finally, it improves communication across borders on infectious diseases

4

Fan, S. et al., 2010 [40]

The Alberta Real Time Syndromic Surveillance Net (ARTSSN)

Public Health Records

3 goals: 1) improve upon traditional paper-based, fragmented public health surveillance using a centralized automated system; 2) enhance routine public health surveillance through effective use of existing Provincial Electronic Health Record data for earlier detection of cases, clusters, outbreaks and trends of communicable disease, injury, and environmental hazard exposure; and 3) track the effectiveness of public health interventions

Canada

Prospective

Effective

This system was very helpful in terms of providing richly integrated information on a variety of health conditions for early detection and prompt action on abnormal events such as clusters, outbreaks and trends.

6

Lowe, R. et al., 2016 [41]

Prototype Early Warning System

Public Health Records

Dengue risk

Brazil

Retrospective

Effective

First, this system has the potential to be useful in public health services and its use goes beyond the mass gatherings to control potential explosive dengue epidemics. Second, the forecast model was able to detect extreme dengue incidence rates. Finally, it was able to predict high risk of dengue correctly for 57% of the microregions.

5

Nuvey, F. S. et al., 2019 [42]

Ghana’s ILI surveillance system

Public Health Records

Influenza-like illnesses (ILI)

Ghana

Retrospective

Effective (Partial)

First, this system is sensitive and representative. Second, it has suboptimal data quality. Third, in terms of timeliness, this system takes on average 10 days between the symptom onset and detection at facilities. Next, even though the positive predictive value is low, it generally conforms to other syndromic surveillance systems with broad case definitions aiming at maximizing influenza case detection. In addition, this was able to detect influenza viruses in circulation.

5

Yang, W. et al., 2011 [43]

China Infectious Disease Automated-alert and Response System (CIDARS)

Public Health Records

28 notifiable infectious diseases

China

Retrospective

Effective

First, this assists with early outbreak detection locally and connects reporting of unusual disease occurrences or potential outbreaks to CDCs throughout the country. Second, it helps in shortening the frequency of surveillance data analysis and that of the communication of outbreaks among different CDCs. Third, it reduces the workload of data collection and analyzing for epidemiologists. Finally, this might be less timely and sensitive than other outbreak detection systems that used data on pre-diagnosis of cases in hospitals, media reports or school absenteeism.

6

Zhang, H. et al., 2014 [44]

China Infectious Disease Automated-alert and Response System (CIDARS)

Public Health Records

Dengue Fever, CIDARS automatically conducts the aberration detection from the reported data in the web-based Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS).

China

Prospective

Effective

First, this system has a sensitivity and specificity of 100 and 99.8% respectively. Second, it is successful in detecting all DF outbreaks. Third, this is assisting the local public health staff in early detection of potential outbreaks. Next, it is so useful as a decision tool for the control of dengue fever and risk-management programs 5-Median time to detection of 3 days.

4

Baghdadi, Y. et al., 2019 [45]

Reactive mortality surveillance system- syndromic surveillance system SurSaUD

Public Health Records

Combines both morbidity and mortality data (all-cause mortality surveillance system)

France

Retrospective

Effective

First, this system was able to detect weeks with alarm with sensitivity and specificity of 0.96 and 0.99 respectively at the national level and for all ages. Second, it has the potential to follow and detect mortality outbreaks. Third, this is a useful tool in early evaluation of the impacts of threats on mortality and to alert decision makers to adapt control measures. Fourth, it provides weekly information and recommendations in the form of reports for decision makers. Finally, It is useful in reinforcing recommendations for control and prevention measures.

4

Guzman-Herrador, B. et al., 2016 [46]

National web-based outbreak rapid alert system (Vesuv)

Web

(1) outbreaks caused by infectious diseases that are notifiable to MSIS, (2) outbreaks suspected to be associated with food or water, (3) outbreaks of particularly severe illnesses (i.e. diseases with high mortality, high complication rate, or otherwise severe manifestations not otherwise notifiable to MSIS), (4) particularly extensive outbreaks, and (5) outbreaks in healthcare institutions *MSIS: Meldingssystem for smittsomme sykdommer (MSIS) Norwegian Surveillance System for Communicable Diseases

Norway

Prospective

Effective

This system is helpful in terms of enhancing the reporting, and facilitating the sharing, of information between authorities at local and national levels. According to the requirement of international health regulations 2005, it is considered as an important tool for event-based reporting. Finally, it is also enhancing the rapid alerts between stakeholders and the information exchange between different levels of authority.

6

Li, Z. et al., 2014 [47]

China’s infectious disease automated alert and response system

Web

Hand, foot and mouth disease (HFM)

China

Retrospective

Effective

This system has good sensitivity and specificity in the detection of HFM disease outbreaks and has a potential in the reduction of the size of outbreak. Besides, the use of this system continuously is effective in the prevention and reduction of such an outbreak in China. The sensitivity is higher for outbreaks that are large, with more than 20 cases, than for small ones. The overall specificity of the response system was (95.0% CI) and the overall mean time to detection was 2.1 days (95% CI). The mean time of detection for outbreaks with more than 20 cases is 2.7 days while it is only 1.7 days for the smaller outbreaks with less than 10 cases. Finally, the mean time from detection to reporting to the public health emergency system was 4.5 days.

4

Stikova, E. et al., 2010 [48]

An early warning system (ALERT) for priority communicable diseases

Web

Foodborne or waterborne diseases, Acute respiratory syndrome, Acute hemorrhagic fever syndrome, Other zoonotic diseases, Acute neurological syndrome, Vector-borne disease, Vaccine-preventable diseases, Influenza (A/H5 virus), Influenza (novel virus, not H5), Cholera, Yellow fever, Plague, Others

The Republic of Macedonia

Retrospective

Effective (Complement)

First, sensitivity and usefulness of this system should be increased. Second, according to their experience, the reporting units at primary health care levels are not the most appropriate for early detection notification of some epidemic-prone diseases. In addition, adding emergency departments as notification sources for some syndromes, better defining the role of the laboratory to confirm the suspicion of outbreaks, revising the list and definition of syndromes to adjust their sensitivity and specificity for detecting the targeted diseases, and strengthening data analysis through training are necessary.

1

Ganeshkumar et al., 2022 [49]

Digital syndromic surveillance system

Web

17 syndromes; Fever, Fever with cough, Dysentery, Diarrhoea, Bites, Heat related illness, Injuries, Drowning, Conjunctivitis, Cutaneous lesions, Acute Jaundice Syndrome, Botulism like syndrome and Unusual syndrome

India

Retrospective

Effective

This system is highly feasible in LMICs given its adaptability and affordability. Through an open-source software, epidemiologists had real-time access to surveillance data of mass gathering events with prompt reporting to higher authorities.

5

Pinto, A. et al., 2005 [50]

EWS

Internet

Acute flaccid paralysis, Acute jaundice syndrome, Acute respiratory infection, Acute watery diarrhoea, Bloody diarrhoea Injuries, Malaria Neonatal tetanus, Severe malnutrition, Suspected measles, Suspected meningitis, Unexplained fever

Darfur

Retrospective

Effective

First, this system sets up a rumor-verification process to increase the sensitivity and the timeliness of the EWS. This EWS is useful for detecting outbreaks and monitoring the number of consultations that are required to trigger actions. Next, The Crude Mortality Rate (CMR) is a key indicator of an emergency in a crisis setting. However, other indicators should be considered such as surveys, grave counting, and daily interviews. Finally, the computer application developed and installed at the state level was a simple tool to enhance surveillance capacities at the peripheral level, improve timeliness in outbreak detection and to facilitate information exchange and feedback through the production of automatic reports.

5

Zeldenrust, M. E. et al., 2008 [51]

ProMED-mail; the Program for Monitoring Emerging Diseases

Internet

Emerging diseases involving humans, animals and plants around the world

Netherlands

Retrospective

Effective (limited)

First, this is sensitive but not very specific. Second, it has a limited but real added value than the other sources. In addition, ProMed-mail is considered as the only source of information about a VPD outbreak (Vaccine preventable disease).

4

Witkop et al., 2009 [52]

Electronic Surveillance System for the Early Notification of Community-Based Epidemics (ESSENCE) Version II

Internet

Influenza-like illness (ILI)

United States

Retrospective

Not Effective but useful

First, this system has inadequate sensitivity and poor positive predictive value of (71.4%) and (31.8%) respectively. Second, this has a lack of timeliness (1–3-day delay). Third, it is useful in monitoring local influenza seasons and determining syndromic baselines. Finally, this is not the early warning system for an emerging infectious disease and didn’t detect the outbreak soon enough to establish prevention and control measures that might have slowed the spread of the infection.

5

Betancourt, J. A. et al., 2007 [53]

Electronic Surveilance System for the Early Notification of Community-based Epidemics (ESSENCE)

Internet

Syndrome groups: respiratory, upper gastrointestinal (GI), lower GI, fever, hemorrhagic illness, infectious rash, neurological, and coma or sudden death

United States

Retrospective

Effective

First, this system has a high sensitivity and specificity with a range of sensitivity for the syndromic groups of 65.7, and 89% for respiratory disease and GI diseases respectively. In addition, the specificity ranged from 95.5 to 96% for all MTFs. Finally, the data used by the ESSENCE reflects the types of patient visits to these facilities with a high level of accuracy.

6

Carneiro, H. A. and Mylonakis, E., 2009 [54]

Google Flu Trends

Internet

Influenza

United States

Retrospective

Effective

First, this system is sensitive. Second, it has shown great promise as a timely and robust surveillance system. Next, this is best for diseases with higher prevalence, and it performs better in developed countries because for this system to perform well, it needs a large population of Web search users. Moreover, Google flu trends and possibly GT makes it possible to track the infectious diseases activity faster than the conventional systems. Finally, this was able to estimate Influenza levels 1–2 weeks earlier than published CDC reports.

5

Dion, M. et al., 2015 [55]

Global Public Health Intelligence Network (GPHIN)

Internet

Communicable disease outbreaks, potential chemical and radio nuclear hazards

Canada

Retrospective

Effective

First, this has an efficacy in detecting new illnesses. Second, the adoption of big data in the system has increased the capacity to detect international infectious disease outbreaks. In addition to early detection this system has proven to be effective in monitoring. Moreover, what is meant by big data is the large datasets provided by sources such as social media or newspapers which requires a powerful computational method to reveal trends, patterns or the predictive likelihood of events.

4

Samaras, L. et al., 2021 [56]

–

Internet

Measles

The largest countries of Europe (France -Germany - UK -Spain)

Retrospective

Effective

First, measles cases estimation using Google trends helps in producing acceptable results and predicts outbreaks at least two months in advance. Second, the overall prediction model shows statistically significant correlation between measles cases and predictive values. Third, in terms of time, volume and overall spread, measles can be predicted and estimated. Fourth, countries with relatively low impact of measles had major differences and deviation so alternative models were used to improve the results. Fifth, the ECDC publishes a report monthly that includes data on measles 2–3 months prior to the month of the report announcement. Next, the previously stated countries with low activity of measles show less efficient predictions, such as Spain and UK.

6

El-Khatib, Z. et al., 2019 [57]

Syndrome-Based Surveillance System (SbSS) for Infectious Diseases Among Asylum Seekers

Staff

13 syndromes (rash with fever, rash without fever, acute upper respiratory tract infection, acute lower respiratory tract infection, meningitis or encephalitis, fever and bleeding, non-bloody gastroenteritis or watery diarrhea, bloody diarrhea, acute jaundice, skin, soft tissue, or bone abnormalities, acute flaccid paralysis, high fever with no other signs, and unexplained death

Austria

Retrospective

Effective

First, this system has high sensitivity and low specificity. Second, the SbSS is considered as a reliable method for public health surveillance that is used in different contexts. Third, it supports suitable public health responses and timely information. Finally, this system was reliable at identifying and controlling the spread of infectious disease among the asylum-seeking population from September 2015 onward.

5

Flamand, C. et al., 2008 [58]

Syndromic Surveillance System (SOS Medecins)

Staff

Seasonal outbreaks and unusual events

France

Retrospective

Effective (Complement)

First, this system is highly sensitive. Second, this system is used to assess large episodes of illnesses that do not require hospital admissions or an etiological agent identification. Third, this system has advantages such as timeliness and diagnostic specificity. Next, it has many purposes such as disease patterns monitoring to detect outbreaks and providing timely and detailed information to health authorities. Also, it helps in informing the clinicians of the conditions that are prevalent in the community along with supplementing the current infectious disease surveillance. In addition, it has the potential to show the importance of an early signal to increase the GP’s awareness of the need to bring any unusual events to the attention of the surveillance. This reinforces the links between clinicians and institutions in charge of health security. It helps in the estimation of a heat wave’s health impact to provide data to politicians to make decisions. Finally, it reassures health authorities that an outbreak has not occurred because of a public health alert, such as the potentially dangerous food consumption in a large part of the population of that area.

6

Leining et al., 2022 [12]

Syndromic Surveillance

Staff

Runny nose / congestion/ sneezing

Achy muscles/joints Anxiety

Headache Depression

Cough—productive

Stomach pain/cramping Sore throat

Cough—non-productive Injury/Skin wounds Malaise/Fatigue/Tired

Fever

Nausea Rash

Diarrhea

Animal or insect bites Vomiting

United States

Cross-sectional

Effective

Although the system did not detect a specific outbreak, it successfully surveilled prodromal manifestations among Hurricane Harvey evacuees. Efficiency, effectiveness, acceptability and being user-friendly are its key strengths.

6

Jones, N. F. and Marshall, R., 2004 [59]

Electronic general-practitioner-based syndromic surveillance system (GPSURV)

Staff

3 acute infectious-disease syndromes (gastroenteritis, influenza-like illness, and skin and subcutaneous tissue infection)

New Zealand

Retrospective

Effective

First, it monitors the incidence of acute syndromes as successfully as the manual systems by using the standardized clinical-term data from general-practice clinics that are selected. Second, the provision of feedback for reports appears to have a positive effect on data quality but is limited at the same time. Third, the algorithm that was used for the classification of follow-up visits is probably working effectively. Finally, the number of physicians reporting the increase in compliance during the pilot study was higher than number reporting decreases for all conditions.

4

Merali, S. et al., 2020 [60]

Modified Community-based surveillance (CBS)

Staff

Animal-related events, Suspected rabies and other animal bites Unexpected animal deaths, Vaccine-preventable diseases, Suspected measles, Suspected yellow fever, Acute flaccid paralysis, Suspected meningitis, Chickenpox, Foodborne illnesses, Other infectious diseases (Acute hemorrhagic conjunctivitis, Malaria, Skin diseases, Suspected cholera Infectious arthritis, Adverse event following immunization)

Ghana

Retrospective

Effective

First, this is a highly sensitive system. Second, it has an attempt to incorporate a one-health approach at the community level. Third, it is useful in the detection of diverse public health events that might be missed by routine surveillance systems. Fourth, this system was able to detect about 26% of all suspected vaccine-preventable cases from the implementing districts through routine disease surveillance. The one-health approach can address the urgent ongoing or potential health threats at the human animal nexus at sub-national, national, regional, or global levels and this requires balance and collaboration among multiple relevant sectors and disciplines. In addition, both the event-based surveillance and one health are complementary. The one health can enhance the EBS by providing a platform for coordinating surveillance and information sharing across all relevant sectors. It enhances the One-health by rapid detection of a wide range of events between humans, animals and the environment including zoonotic diseases.

3

Murray, K. O. et al., 2009 [61]

Emerging Disease Syndromic Surveillance

Staff

Fever, vomiting, diarrhea, sore throat, cough, runny nose, rash, and communicable respiratory diseases (influenza or common cold)

United States

Prospective

Effective

This was successful in confirming the acute gastroenteritis outbreak and became a critical tool in monitoring the course of the outbreak. During the surveillance period, they were able to identify a steady increase in reporting of respiratory symptoms.

3

Randrianasolo, L. et al., 2010 [62]

Sentinel syndromic-based surveillance system

Staff

Circulating arboviruses (changes in fever frequency during fever-associated diagnoses and changes in diarrheal frequency)

Madagascar

Retrospective

Effective (Complement)

First, this showed the feasibility of implementing syndrome surveillance in a developing country at low cost with good cooperation by SGPs (daily data transfer rate estimated to 89%) and a minimum of effort by staff. Then, this system was able to detect by the use of plot peaks in febrile syndromes, including which disease among influenza, malaria or arboviruses was the most potential cause.

5

Ratnayake, R. et al., 2016 [63]

Community Event–Based Surveillance for Ebola Virus Disease (CEBS)

Staff

Ebola virus disease- CEBS was designed to supplement the national surveillance system by training community members to identify, within their own communities, unsafe burials and persons with signs and symptoms compatible with EVD infection.

Sierra Leone

Retrospective

Effective

First, it is highly sensitive. Second, the CEBS detected cases were more rapidly identified than by the national surveillance system. The CEBS system is capable of quickly finding cases, especially those with no identified epidemiological links. This helps in making the system capable in the detection of early stages of new infectious disease outbreaks or to rapidly identify the spread of disease to new geographic areas. Then, the CEBS was effective in generating alerts for, and was able to detect, a third of all EVD cases found in the districts.

5

Weng, T. C. et al., 2015 [64]

School-Based Syndromic Surveillance System (SID-SSS)

Staff

5 syndrome groups (most common pediatric); enterovirus, influenza, conjunctivitis, diarrhea, and others (chicken pox, scabies, and head louse infection)

Taiwan

Retrospective

Effective (Complement)

First, this system completely replaces the ED-SSS, but the two systems complement each other. Second, it has the ability to detect timely signals for common pediatric infectious diseases. Third, it has a role in being the first line of alert at the beginning stage of pandemics. Through identifying the secondary cases at schools and families (clusters) this has helped in estimating the transmissibility caused by different strains within the same type/subtype/genotype of Enteroviruses of influenza viruses. Enterovirus and influenza-like illnesses were the most reported syndrome groups with (77.6 and 15.8% among a total of 19,334 cases, respectively). The pre-diagnostic data reported from the SID-SSS offered a 1–2-week advance in detecting the peaks of EVI and ILI, indicating a marked improvement from the hospital-based surveillance system.

5

Lai et al., 2021 [65]

Sentinel syndromic surveillance system

Staff

Daily counts of ‘total’ and ‘cough’ absence reports

United Kingdom

Retrospective

Effective (Complement)

This system gathered school absenteeism data which has supported tracking community morbidity such as for COVID-19, and other respiratory and gastrointestinal infections.

5

Yang et al., 2022 [66]

“Xiao Lian Xing” (XLX), SSS based app

Staff versus technology

Daily and weekly absenteeism and fever rates

China

Prospective

Effective with less capacity

This system highlighted that utilization of information technology to record school absenteeism has better “simplicity, cost-effectiveness, data quality, sensitivity, and timeliness metrics over manual approaches (by school staff). (completeness of 100% versus 86.7%, respectively)

6

Groeneveld, G. H. et al., 2017 [67]

ICARES: a real-time automated detection- ICARES (Integrated Crisis Alert and Response System)

Staff

Infectious diseases (respiratory tract infection, hepatitis and encephalitis/meningitis)

Netherlands

Prospective

Effective (Complement)

First, this is a specific system. It is considered as the first flexible automated, real-time cluster detection system for infectious diseases based on information from the hospitals and general practitioners. Then, this system has the ability to detect and follow small regional clusters in real time and can handle any diseases that are registered by first line physicians.

6

Lami et al. 2021 [68]

Syndromic surveillance system

Staff

Common acute and infectious conditions, chronic conditions, and trauma and injuries

Iraq

Prospective

Effective (Complement)

This system provided assistance to health staff to monitor common infectious diseases during mass gathering events where combining fever and cough syndromic surveillance data alerted health staff of the rise in influenza-like illness.

6

Das, D. et al.,2015 [69]

–

Drugs

Influenza-like Illness (cough and influenza medications) and gastrointestinal illness (major brand and generic antidiarrheal)

United States

Retrospective and Prospective

Effective (Adjunct)

First, this is not as sensitive as ED systems. Second, this system has found that the antidiarrheal medication sales for diseases such as Norovirus and influenza were more sensitive than for other illnesses caused by rotavirus. Third, this is more useful in large-scale illness trends. Fourth, for other indications of citywide illness this played a role as an adjunct. In addition, the ILI sales were not able to provide an earlier warning than the ED system of communitywide influenza. Last, GI medications didn’t increase during late winter as ED diarrheal visits. Finally, the sales of citywide OTC medications can provide indications of a communitywide illness such as the annual influenza epidemic.

6

Dong, X.et al.,2017 [70]

Over-The-Counter (OTC) drug sales, Hospital and School-based influenza-like illness (ILI) and Baidu search queries

Drugs

Influenza-like illness (ILI)

China

Retrospective

Effective (Complement)

First, there was a very strong correlation between the research for terms on the Baidu Internet; for example, fever and laboratory-confirmed influenza activity obtained during 2013–14 period of reporting. However, the correlation was moderate among other influenza syndromic surveillance systems. Finally, using this type of data together with traditional laboratory surveillance can provide more timely and sensitive information about current influenza activity.

6

van Benthem, B. H. and van Vliet, J. A., 2008 [71]

The Netherlands’ Infectious diseases Surveillance Information System (ISIS)

Lab

Test results of all microorganisms and Trends in antimicrobial resistance

Netherlands

Prospective

Not Effective

This ISIS system was not considered suitable as an early warning since other systems were better in detecting outbreaks.

4

Bijkerk, P. et al., 2017 [72]

Netherlands Early Warning Committee

Records + Internet

All infectious diseases that can potentially threaten Dutch public health

Netherlands

Retrospective

Effective

First, this system is sensitive. Second, it provides background and preliminary outbreak information. Third, there are only 2% of the potentially relevant threats by using the ECDC RT Report and ProMed-mail. Fourth, they showed that to detect threats internationally by the weekly report, it is enough to screen the ECDC Round Table Report and ProMed-mail. Finally, these ECDC RT reports and ProMED-MAIL were the most complete and timely sources for the identification of infectious diseases threats. This combination between the two sources has resulted in 169 (95%) timely reported threats with only six missed threats and three threats not detected in a timely manner.

4

van den Wijngaard, C. et al., 2008 [73]

Syndromic Surveillance System

Records + Lab

Emerging respiratory diseases

Netherlands

Retrospective

Effective

First, earliest syndrome elevations were observed in absenteeism data, followed by hospital data (+1 week), pharmacy/general practitioner consultations (+2 weeks), and deaths/laboratory submissions (test requests) (+3 weeks). We are confident in concluding that the GP, hospital, laboratory submission, and mortality syndromes do reflect pathogen activity sufficiently for use in syndromic surveillance. Second, using seasonal terms as an addition, they observed that for the absenteeism and, to a lesser extent, the pharmacy registry, the associations between the respiratory syndromes and the pathogen counts might be biased to some extent. Finally, they find that using data from multiple registries together has an advantage so that signal detection can be made more specific by focusing on signals that occur concurrently in > 1 data source.

4

van den Wijngaard, C. C.et al., 2010 [74]

–

Records + Staff

Lower Respiratory Infections

Netherlands

Predictive simulation

Effective (Complement)

First, the sensitivity for local outbreaks was reduced by using data with relatively low coverage levels. Methods other than space-time statistics are more appropriate to generate useful information for such data sources with low coverage in the public health practice. Second, this can detect local LRI-outbreaks in a timely manner. Third, Internet based ILI monitoring along with virological self-sampling increases the microbiological base for interpreting syndromic surveillance. Fourth, the age stratification syndromic surveillance with a multivariate space-time can facilitate the quick interpretation of clusters by revealing the affected age groups. Next, hospital -based syndromic surveillance could be helpful in detecting local LRI-outbreaks. Finally, syndromic surveillance might be most valuable for outbreaks due to uncommon or novel pathogens like SARS outbreak.

5

Weirong Yan et al., 2013 [75]

ISSC project - An integrated surveillance system for infectious disease in rural China:

Records + Staff

10 targeted symptoms (Cough, Sore throat, Fever, Headache, Diarrhea Vomiting/nausea, Rash, Mucocutaneous hemorrhage, Convulsions, and Disturbance of consciousness)

China

Retrospective

Effective (Complement)

First, this system helps in the early detection of infectious disease epidemics as it provides near real time syndromic data collection, interactive visualization, and automated aberration detection. Second, it has the potential for identifying the change of disease patterns within the community.

6

Schenkel, K. et al., 2006 [76]

Enhanced Surveillane of Infectious Diseases

Enhanced surveillance

Accelerate and sensitise the pre-existing surveillance system for infectious diseases

Germany

Prospective

Effective

First, the delay of the notified transmitted data from the community to the federal level was reduced up to one day from three days. Second, it had the ability to detect the World Cup-related Norovirus outbreak. Third, the transformation from weekly to daily implementation was considered as a successful strategy. Next, it had the ability to intensify communication and action-oriented cooperation between players in the German public health system, In addition, this benefited the routine infectious disease surveillance in Germany.

6

White, P. et al., 2017 [77]

Mass gathering enhanced surveillance system

Enhanced surveillance

Acute fever and rash Watery diarrhoea, Non-watery diarrhoea, Influenza-like illness, Prolonged fever, Chikungunya-like illness, Dengue-like illness, Acute flaccid paralysis, Neonatal tetanus, Fever and jaundice, Acute fever and neurological symptoms Foodborne diseases

Samoa

Retrospective

Effective

First, this system is sensitive. Second, it is performed well in terms of providing vital disease early warning and health security assurance. Moreover, it had the potential of enhanced surveillance to be sustained when it is integrated from mass gathering surveillance into long-term surveillance.

4

Paul White et al., 2018 [78]

Enhanced syndromic surveillance system for mass gatherings

Enhanced surveillance

8 syndromes (Acute fever and rash, Watery diarrhoea, Non-watery diarrhea, Influenza-like illness, Prolonged fever, Fever and jaundice, Heat-related illness, Foodborne disease syndrome)

Federated States of Micronesia

Retrospective

Effective

First, this system is sensitive and specific. Second, introduction of the web-based system greatly improved the timeliness of data entry along with the analysis and SitRep dissemination, assuring the Games organizers that communicable disease would not adversely impact the Games. In addition, this has demonstrated the need for a good planning and preparation of at least 12 months to test the web-based surveillance tools, and to test methods for timely manual data collection. Finally, this system helped in understanding the importance of adequate staff resourcing to address staff fatigue due to intense daily operation of the surveillance for multiple weeks.

3

C. J. WILLIAMS,K. et al., 2009 [79]

–

Enhanced surveillance

Strengthen and augment the existing surveillance structures (SurvNet); measles, scarlet fever, chickenpox, hand foot and mouth disease, erythema infectiosum, legionellosis, Norovirus, gastroenteritis, pertussis and Salmonella.

Germany

Retrospective

Effective

First, syndromic surveillance may not be the best response to infectious disease surveillance at international events. Second, the surveillance of satisfactory events can be achieved through temporary adaptations of an existing routine infectious disease surveillance. Third, this has improved the timeliness and detection of relevant events without requiring extra sources. Finally, this has offered a chance to try out accelerated routine reporting.

6