The Impact of a Case of Ebola Virus Disease on Emergency Department Visits in Metropolitan Dallas-Fort Worth, TX, July, 2013-July, 2015: An Interrupted Time Series Analysis.

Background: The first Ebola virus disease (EVD) case in the United States (US) was confirmed September 30, 2014 in a man 45 years old. This event created considerable media attention and there was fear of an EVD outbreak in the US.

Methods: This study examined whether emergency department (ED) visits changed in metropolitan Dallas-Fort Worth--, Texas (DFW) after this EVD case was confirmed. Using Texas Health Services Region 2/3 syndromic surveillance data and focusing on DFW, interrupted time series analyses were conducted using segmented regression models with autoregressive errors for overall ED visits and rates of several chief complaints, including fever with gastrointestinal distress (FGI). Date of fatal case confirmation was the "event."

Results: Results indicated the event was highly significant for ED visits overall (P<0.05) and for the rate of FGI visits (P<0.0001). An immediate increase in total ED visits of 1,023 visits per day (95% CI: 797.0, 1,252.8) was observed, equivalent to 11.8% (95% CI: 9.2%, 14.4%) increase ED visits overall. Visits and the rate of FGI visits in DFW increased significantly immediately after confirmation of the EVD case and remained elevated for several months even adjusting for seasonality both within symptom specific chief complaints as well as overall.

Conclusions: These results have implications for ED surge capacity as well as for public health messaging in the wake of a public health emergency.