Syndromic Surveillance in Public Health Practice, New York City
Figure 1. Trends in emergency department visits for fever and respiratory syndromes, New York City, November 1, 2001–November 14, 2002. Plots show the daily ratio of syndrome visits to other (noninfectious disease) visits. diamonds, citywide signal; triangles, spatial signal by hospital; circles, spatial signal by patient’s home zip code; , influenza A; , influenza B isolates (weekly number identified in New York City residents by World Health Organization collaborating laboratories).