Public concern for exposure to agents of bioterrorism leading to emergency department visits in New Jersey, 2001

Abstract

Study objectives: Media coverage after the September 11, 2001, attacks included warnings about possible bioterrorism. Concerns increased in New Jersey after several Trenton postal workers were diagnosed with anthrax on October 12, 2001. Patients presented to New Jersey emergency departments (EDs) with concerns of possible exposure (CE visits). Our objective is to determine the volume of CE visits during that time at 15 New Jersey EDs.Methods: We performed a retrospective analysis of a computerized database of ED visits. The setting was 15 New Jersey EDs within a 55-mile radius of Trenton, with annual ED volumes from 20,000 to 65,000. The participants were consecutive patients treated by emergency physicians from August 11, 2001, to December 11, 2001. We determined the number of CE visits to selected EDs by counting visits having the following International Classification of Diseases, Ninth Revision descriptors: “Feared Complaint–No Diagnosis” and “Screening for Infectious Disease.” We calculated rates of CE visits for all hospitals and for Trenton versus non-Trenton hospitals as a percentage of ED visits for the following 4 periods in 2001: 1 month before September 11, 1 month after September 11, 1 month after October 12, and the second month after October 12. We used χ2 analysis to test for statistical significance, with α set at .01 to account for multiple comparisons.Results: For the 4 periods, there were 225,403 total ED visits, of which 657 were CE visits. The rates of CE visits for the 4 periods were 0.06%, 0.06%, 0.92%, and 0.10%, respectively. Using the first period as the baseline, only the third period showed a statistically significant increased rate of CE visits (0.92%, P<.001). For the peak third period, the rate was significantly increased for the 2 Trenton hospitals, 1.81%, versus 0.82% for the 13 non-Trenton hospitals (P<.001).Conclusion: We found an increase in CE visits in the 1-month period after the identification of a Trenton postal facility as an exposure site, whereas there was no increase in the month after September 11, 2001. During the peak month, there was a greater increase in the Trenton EDs than in other EDs in the state.