Use of Electronic Surveillance System for the Early Notification of Community-Based Epidemics during a Dengue Outbreak - CHANGE presenting author

BACKGROUND:  Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE) is a web-based, automated tool available to public health agencies throughout Florida. Participating emergency department (ED) data are characterized into syndromes and disease indicators generate statistical alerts accessible by registered users.   At the end of July 2013, an astute physician reported a cluster of patients presenting with flu-like symptoms, headache and rash to an ED in Martin County, FL. Ultimately, two epicenters of autochthonous dengue transmission were identified. In neighboring St. Lucie County, ESSENCE queries were already programmed to alert for possible missed reportable conditions based on symptom groups or specific words, including dengue. Additional queries were created to capture specific diagnoses to more effectively direct active surveillance efforts. A retrospective review focused on identification of undetected cases was completed utilizing these updated ESSENCE queries. 

METHODS: In addition to viral syndrome or flu-like illness, thrombocytopenia and leukopenia were noted on the index cases’ discharge summaries. An ESSENCE query string was created to search for these more dengue- specific terms. Later, the search was expanded to include permutations for the spelling of “dengue” with the symptom grouping of fever, rash, headache, and joint pain.   Using all the above queries in combination, Florida Department of Health- St. Lucie County’s Epidemiology Program was able to identify approximately 300 St. Lucie County residents who matched the search parameters during 1 May 2013- 30 Sep 2013. The majority of these were quickly eliminated if only one maladjustment was documented i.e. only headache or arthritis, etc. which required very little time outside of routine surveillance. Approximately 60 entries warranted further investigation accomplished through medical records reviews where available (which could take several weeks due to ED records request processes) and phone calls to a select few for additional details.  

RESULTS:  Three possible cases were identified using this retrospective ESSENCE review and investigation. Of these three, one was confirmed as part of the autochthonous cluster, the second was an imported case from Puerto Rico, and the third had exposure risks and signs of illness consistent with dengue but tested negative.      

CONCLUSIONS:  Utilization of ESSENCE allowed for the identification of potentially unreported dengue cases, enhanced active case finding, and allowed for more timely notification in directing public health and mosquito control efforts. ESSENCE is easily customizable, can be programmed to capture local idiosyncrasies and can bolster situational awareness during daily surveillance or outbreaks.