Seasonal variation of potential bioterrorism-related incidents

Background/Objective: Staff that provide emergency on-call services often go through periods when there is heavier call volume. The Centers for Disease Control and Prevention (CDC) Division of Preparedness and Emerging Infections (DPEI) uses Situation Reports (SITREPs) and Incident Notices (INs) to monitor all calls received in the division. This paper evaluated seasonal variation of potential-bioterrorism incidents related to unknown white powder/suspicious package, BioWatch issue and others. Methods: The authors reviewed all SITREPs/INs prepared by DPEI from January 2007-December 2009. Crosstabs and binomial logistic regression analyses were performed using SPSS 17.0. Type of incident was the dependent variable (dichotomous) and season was the independent variable (categorical). Results: Of the 123 incidents reported to DPEI, crosstab analysis showed that there was a statistically significant relationship between season and type of potential bioterrorism-related incident (p=0.003). Logistic regression models indicated that unknown white powder issues were more likely to occur in the spring season compared to fall season (OR=4.5, 95% CI 1.498-13.515, p=0.007). BioWatch issues were more likely to occur in the fall season compared to summer season (OR=5.588, 95% CI 1.872-16.685, p=0.002). Other issues were more likely to occur in the summer season compared to winter season (OR=4.400, 95% CI 1.258-15.386, p=0.020). Conclusion: In order to prepare for a particular incident or seasonal response, findings of this study may allow public health/emergency preparedness planners at all levels of government to ensure availability of manpower, financial and other resources.