Ebola Virus Disease Outbreak Response: An Epidemiological Perspective—Cleveland, OH, October 2014

BACKGROUND: On October 15, 2014 the Centers for Disease Control and Prevention (CDC) confirmed that one of the nurses who had cared for the first confirmed Ebola Virus Disease (EVD) patient in the U.S. had tested positive for EVD and had traveled by plane to Cleveland Hopkins International Airport. In response, the Cleveland Department of Public Health (CDPH) activated their Emergency Operations Center (EOC) to begin surveillance, contact tracing, monitoring, isolation, and quarantine response activities.

METHODS: The CDPH conducted contact tracing in response to an EVD infected nurse (index case) that traveled throughout Northeast Ohio. Contact tracing was completed through several contact lists provided by the CDC. These lists included the flight manifests and other close contacts identified through interviewing the index case for community exposure and travel history. Additional contact lists were obtained for selected airport personnel. Phone interviews were conducted via standardized questionnaires. Upon completion of the questionnaires, contacts were classified into four distinct monitoring tiers based upon the level and type of exposure to the index case. These tiers were Tier 1 (Quarantine), Tier 2A (Active Monitoring), Tier 2B (Verified Self-Monitoring), and Tier 3 (Self-Monitoring). Once classified, contacts were provided with letters of acknowledgement, thermometers, symptom reporting forms, and informational resource packets via home visits. All contacts were monitored for a total of 21 days from the last date of exposure to the index case. Once monitoring was completed, all contacts received letters of release.   

RESULTS: The CDPH completed contact tracing for 22 total contacts that required monitoring within the City of Cleveland. These contacts included airline passengers, airline staff, airline cleaning staff, and bridal shop customers. The City of Cleveland had five contacts in Tier 2B and seventeen in Tier 3. The last day of monitoring for the final contact was November 3rd, 2014. After completion of the contact tracing, no contacts were found to have developed EVD. 

CONCLUSIONS: Experiences during this outbreak investigation included the challenges and successes with surveillance, contact tracing, monitoring, isolation, and quarantine response activities. Challenges included developing monitoring tiers based upon scientific evidence about the communicability of EVD and legal implications in relation to enforcement of compliance requirements. Successes included the just-in-time training for epidemiology strike team members and collaboration among public health and various supporting agencies to conduct a unified response. Experiences from this outbreak investigation will contribute to the advancement of public health knowledge.