Use of Syndromic Surveillance for the Early Detection of and Response to Illness Associated with Chemical Exposures in Florida

BACKGROUND: Chemical incidents are a serious public health concern in Florida.  The State Emergency Response Commission for Hazardous Materials reported a total of 1,576 incidents in Florida for 2010.  Most chemical incidents that occur do not result in exposures to the general public, workers, or first responders, but some do, and may result in minor to severe symptoms or injuries.  Early identification of exposures to hazardous chemicals through syndromic surveillance, and the use of this surveillance following an incident can help minimize adverse health effects.  The Chemical Disease Surveillance Program (CDSP), located within the Florida Department of Health, performs surveillance and investigation activities related to chemical exposures. 

METHODS: The CDSP uses the Electronic Surveillance System for the Early Notification of Community-based Epidemics (ESSENCE) system, which allows for near-real time access to emergency department (ED) data and call data from the Florida Poison Information Center Network (FPICN).  Substance-specific queries are used to search ED chief complaints and discharge diagnoses for terms related to chemical exposures (e.g., “ammonia”, “chlorine”, “chemical”, etc.).  Potential exposures may also be identified by searching chief complaints for common chemical exposure symptoms (e.g., “shortness of breath”, “cough”, “burns”, etc.).  FPICN queries in ESSENCE use pre-existing substance categories for more common chemicals and product specific codes for chemicals less commonly reported. FPICN also records health effects for all exposure calls, and potential chemical exposures may be identified by searching health effects for common chemical exposure symptoms.  Methods for identification of chemical incidents also involve review of State Watch Office alerts and media reports in near-real time.  

RESULTS: Surveillance efforts to identify exposures to chemical substances have resulted in timely follow-up by county health department (CHD) staff.  Initial follow-up has involved the review of reports from FPICN, medical record review for exposures identified in ED data, or patient contact to determine specifics of the incident.  In some instances, an epidemiologic investigation, including active case finding and incident-specific questionnaires and interviews were warranted.  Efforts during surveillance and follow-up have provided valuable information for monthly reports that are distributed to partners, which include federal, state, and local agencies.  In addition, this process has led to the development and use of protocols for the identification and follow-up of chemical incidents.   

CONCLUSIONS: Use of syndromic surveillance methods helps to identify chemical incidents that affect the public.  Early identification and notification of potential incidents to CHDs benefits the residents and visitors of Florida by providing timely follow-up.