Analysis of Daily Enhanced Syndromic Surveillance in Hillsborough County, FL, 2015
Authors: Clark Charles R. , Wiese Michael 
Published: May 2017

ObjectiveEnhanced daily surveillance is used to identify reportablediseases, outbreaks, and clusters and provides situational awareness.This project examines how health care visits requiring additionalinformation are detected using enhanced syndromic surveillance andthe resources required from detection through completion.IntroductionThe Florida Department of Health in Hillsborough County (FDOH-Hillsborough) conducts enhanced syndromic surveillance on a dailybasis. The Electronic Surveillance System for the Early Notificationof Community-based Epidemics in Florida (ESSENCE-FL) is thesyndromic surveillance system used by epidemiologists within theFlorida Department of Health (FDOH). During the time of this study,ESSENCE-FL receives data from 210 of emergency departments(ED) and 33 urgent care centers (UCC) throughout the state of Florida,including 12 EDs and 3 UCCs in Hillsborough County. In 2014, theESSENCE-FL system added a feature that delivers an automaticdaily email to designated primary ESSENCE-FL users in each countycontaining all visits which have been detected by the state’s visits ofinterest (VOI) query. The email contains all visits which have beendetected by the visits of interest (VOI) query for each ESSENCE-FLusers designated county. The VOI query utilizes the combinedchief complaint and discharge diagnosis (CCDD) field of a visit forkeywords related to reportable diseases and exposures of public healthinterest. In addition to this VOI email, Hillsborough County analyzestime of arrival alerts, specialized emerging infectious disease queries,poison information center data, and volume levels of syndromes andsubsyndromes predetermined by ESSENCE-FL. A daily summaryreport of the enhanced daily surveillance analysis is then providedto area public health officials within FDOH-Hillsborough and thesurrounding counties. This study examines how visits requiringadditional investigation are detected and the resources required tocomplete the investigation.MethodsDuring the study period from July 23 through September 30, 2015,visits identified were recorded along with the time and method ofdetection. Each day this surveillance began with the review of thevisits of interest email, facility and syndrome volumes, the VOIquery, emerging infectious disease queries (MERS-CoV, Ebola virusdisease, chikungunya, etc.), time of arrival alerts, and the review ofFlorida Poison Information Center data. A daily summary report ofthe enhanced surveillance was manually created and provided byemail to public health officials. After completion of the daily analysis,facilities were contacted about any visits identified as requiringadditional investigation, such as a reportable disease or cluster ofpublic health concern. The time of the information request, receiptof the requested information, and completion of the investigation wasrecorded.ResultsAn average of 1740 visits were made each day in HillsboroughCounty in the month prior to the start of this project. During thissame time period the daily VOI email identified an average of 5.5visits per day. During the study period, an average of 7.8 visitswere detected each day during the enhanced syndromic surveillanceprotocol. The VOI email detected 6 visits per day. Overall 558 totalvisits were detected from the enhanced daily surveillance and82 percent of these visits were found in the system generated VOIemail. Of the visits identified 149 required additional investigationand 15 were determined to be associated with a reportable disease,most commonly carbon monoxide poisoning and varicella. Anaverage of 1.3 days elapsed from the time a visit occurred to the timeit was detected through surveillance. Follow-up was started within1 day of detection and completed in an average of 1.1 days. Overallthe daily enhanced syndromic surveillance data analysis required anaverage of 60 minutes of work time daily with a range of 18-144minutes.ConclusionsDuring the study period, 15 visits were found to be cases ofreportable diseases, primarily carbon monoxide poisoning andvaricella, which would have otherwise gone unreported to FDOH-Hillsborough. The enhanced surveillance process also allows for thequick detection and evaluation of diseases or conditions requiringimmediate action that may not always be reported immediately suchas meningitis or an emerging infectious disease. The enhanced dailysyndromic surveillance in Hillsborough County has been useful indetecting reportable diseases, clusters, and providing situationalawareness in a timely manner without an overwhelming burden onstaff and resources.