Syndromic Surveillance in Public Health Practice, New York City

TLDR

The New York City Department of Health and Mental Hygiene operates a syndromic surveillance system that monitors emergency department visits to detect disease outbreaks early. Chief‑complaint data are electronically transmitted daily to the department and analyzed for temporal and spatial aberrations in respiratory, fever, diarrhea, and vomiting syndromes, with statistically significant signals investigated for public‑health relevance. During its first year (Nov 15 2001–Nov 14 2002), the system captured 2.5 million visits from 39 EDs (≈75 % of annual visits), and most respiratory and fever signals coincided with peak influenza activity while 83 % of diarrhea and 88 % of vomiting signals aligned with suspected norovirus and rotavirus transmission.

Abstract

The New York City Department of Health and Mental Hygiene has established a syndromic surveillance system that monitors emergency department visits to detect disease outbreaks early. Routinely collected chief complaint information is transmitted electronically to the health department daily and analyzed for temporal and spatial aberrations. Respiratory, fever, diarrhea, and vomiting are the key syndromes analyzed. Statistically significant aberrations or "signals" are investigated to determine their public health importance. In the first year of operation (November 15, 2001, to November 14, 2002), 2.5 million visits were reported from 39 participating emergency departments, covering an estimated 75% of annual visits. Most signals for the respiratory and fever syndromes (64% and 95%, respectively) occurred during periods of peak influenza A and B activity. Eighty-three percent of the signals for diarrhea and 88% of the signals for vomiting occurred during periods of suspected norovirus and rotavirus transmission.