The 130th Annual Meeting of APHA

Abstract #47230

David Blythe, MD, MPH¹, Leslie D. Edwards, MHS¹, Dipti Shah, MPH¹, Julie Casani, MD, MPH¹, Karen Matthews, MD, MPH², Eileen Steinberger, MD, MS³, Mark V. Wegner, MD, MPH¹, John O. Davies-Cole, PhD, MPH⁴, LaVerne Hawkins Jones, MPH⁴, Elizabeth R. Souza⁴, Jennifer Capparella, MSPH⁴, Leslie M. Branch⁵, Denise C. Sockwell, MSPH⁵, and Lori C. Hutwagner⁶. (1) Epidemiology and Disease Control Program, Maryland Department of Health and Mental Hygiene, 201 West Preston Street, Baltimore, MD 21201, 410-767-6685, dblythe@dhmh.state.md.us, (2) Preventive Medicine Residency Program, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205, (3) Preventive Medicine Residency Program, University of Maryland, Baltimore, 660 W. Redwood Street, Baltimore, MD 21201, (4) Bureau of Epidemiology & Health Risk Assessment, District of Columbia Department of Health, 825 North Capitol St NE Suite 3137, Washington, DC 20002, (5) Virginia Department of Health, 1500 East Main Street, Richmond, VA 23219, (6) DHS/ESB, Agency for Toxic Substance and Disease Registry, 1600 Clifton Road NE, MS- E31, Atlanta, GA 30333

Introduction: ED Syndromic surveillance systems have been proposed as one method for quickly detecting unannounced biological attacks. We report results from a regional system that has been operating in the National Capitol Region since September 11, 2001.

Methods: ED logs from selected Maryland, District of Columbia, and Virginia hospitals are collected daily. Each ED visit is assigned to one of eight syndrome categories (death, sepsis, rash illness, respiratory illness, gastrointestinal illness, unspecified infection-like illness, neurological illness, and all other visits). Using techniques modified from the cumulative summation (CUSUM) aberrancy detection method, the daily proportion of each syndrome category and the daily census are evaluated to determine whether an expected threshold has been exceeded.

Results: Overall, thresholds were exceeded for 76 syndrome categories on 57 (42%) of 135 days under surveillance. Of the 76 syndrome category thresholds exceeded, 15 (20%) were for the unspecified infection-like illness category, 11 (14%) rash illnesses, 9 (12%) neurological illnesses, 6 (8%) each for the death and sepsis categories, and 5 (7%) for gastrointestinal illnesses. Eight (11%) were for the "other" category; 10 (13%) were for changes in ED census. The number of thresholds exceeded per day varied from none to three.

Conclusions: Regional ED syndromic surveillance systems can provide consistent daily information about ED visits, but depending upon the aberrancy detection methods employed, thresholds may be exceeded frequently. Further evaluation of the situations when thresholds are exceeded is needed to better characterize the utility of ED syndromic surveillance systems.

Learning Objectives: At the conclusion of this session, session participants should be able to

• List the eight syndrome categories used in the National Capitol Region emergency department (ED) surveillance system;
• Describe how the syndrome category thresholds are calculated;
• Identify how frequently thresholds are exceeded and recognize what this implies about the resources needed to operate such a surveillance system.

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.