Syndromic Surveillance for Influenzalike Illness

Abstract

Emergency department data are currently being used by several syndromic surveillance systems to identify outbreaks of natural or man-made illnesses, and preliminary results suggest that regular outbreaks might be detected earlier with such data than with traditional reporting. This article summarizes a retrospective study of 5 influenza seasons in Ottawa,Canada; time-series analysis was used to look for an association between consultation to the emergency department for influenzalike illness and the isolation of influenza virus in the community. The population studied included both children and adults consulting to 3 local hospitals. In 4 seasons, visits to the emergency department involving children younger than 5 years consulting mainly for fever and for respiratory symptoms peaked 1 to 4 weeks before the isolation of influenza virus in the community. If monitored regularly for the presence of key symptoms, pediatric hospitals might be efficient and cost-effective sentinels of influenza and of other infectious diseases.

Syndromic Surveillance for Influenza in the Emergency Department–A Systematic Review

“…The most frequently used data were chief complaint or ED presentation [9], [10], [11], [12], [13], [14], [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38], [39], [40], [41] and preliminary or discharge diagnosis codes [8], [9], [11], [16], [17], [18], [22], [23], [26], [27], [32], [33], [38], [39], [41], [42]. Other creative data used to capture influenza activity included free text analysis of the entire ED medical record, [37] Google flu trends, [25] calls to teletriage and help lines, [16], [25], [38] ambulance dispatch calls, [19], [20], [21], [30], [31], [32] case reports of H1N1 in the media, [8] ED census/”saturation”/length-of-s...…”

“…The observed syndromic cases based on ED data were in some cases linked to objective, confirmatory data, such as culture and other laboratory results, [8], [10], [11], [12], [14], [15], [16], [17], [18], [19], [20], [21], [24], [25], [27], [30], [31], [32], [33], [34], [35], [37], [41] and in some cases to traditional regional and national surveillance databases [9], [13], [16], [17], [22], [25], [26], [27], [29], [40], [43], historic data [44] and pneumonia and influenza weekly mortality data [12], [14].…”

Validity and timeliness of syndromic influenza surveillance during the autumn/winter wave of A (H1N1) influenza 2009: results of emergency medical dispatch, ambulance and emergency department data from three European regions

“…However, other approaches are available that directly control for seasonality, day-of-the-week effects and other influencing factors such as public holidays or vacation time, and may advisably be applied in the future to increase validity and timeliness [11,45]. Additionally, it seems to be worth incorporating the monitoring of age-group specific ILI cases, especially those of children, to enhance the performance of the approach [6,46]. Given the low daily case numbers of respiratory syndrome or ILI cases in the analysed data sets, however, the stratification in age groups in this case may not lead to valid results.…”

“…Given the low daily case numbers of respiratory syndrome or ILI cases in the analysed data sets, however, the stratification in age groups in this case may not lead to valid results. A weekly analysis may be possible and may solve the issue of too low case numbers [46]. For the identification of public health-relevant aberrations in EMS data, future work should also focus on the definition of alert criteria, for example, a definition of the number of consecutive days with significant aberrations in case numbers that lead to a response decision [39,47].…”

ED syndromic surveillance for novel H1N1 spring 2009

“…Examples of such groupings include Influenza-Like-Illness (ILI), Respiratory and Gastrointestinal syndromes(1; 2). Syndromic surveillance also relies on many pre-diagnostic data sources such as as over-the-counter pharmaceutical sales, school or work absenteeism, calls to health care hot-lines and visits to health care providers to identify potential disease outbreaks (3-5).…”