1409. Hospital-acquired Ebola Virus Disease: Probability of Emergence and Secondary Case Estimation Based on Healthcare Contact in a Tertiary University Medical Center in Lyon, France
Session: Poster Abstract Session: HAI: Outbreaks
Friday, October 28, 2016
Room: Poster Hall
Background: The potential spread of nosocomial Ebola virus disease (EVD) in non-outbreak areas is not known. The objective of this study was to use detailed contact data on patients and healthcare workers (HCW) to estimate the occurrence of secondary incident cases (SIC) after hospitalization of an index case.

Methods: Contact data were collected through radio frequency identification devices over a period of 5 days in an acute care geriatric unit. Patients and HCW were equipped with these devices for quantification and description of contact patterns during hospital care. A “susceptible-exposed-infected” model was investigated under different conditions, including control measures, to estimate emergence probability of EVD and the number of SIC.

Results: Probable SIC occurrence ranged from 7% to 67% by transmission probability without control measures. A plateau around 67% was observed. Emergence probability was proportional to the time exposed to undiagnosed patients or patients with nonspecific symptoms, and was 14%, 25% and 35% for exposures lasting 1, 2 and 3 days, respectively. Nurses were at higher risk of nosocomial EVD than physicians because of more frequent contacts.

Conclusion: These results indicate that the risk of nosocomial EVD in non-outbreak areas might be substantial if no preventive measures are implemented to address the admission of asymptomatic patients or those with mild symptoms. Among HCW, nurses are at highest risk of EVD. HCW education for appropriate infection control measures remains the key determinant of EVD control to prevent hospital outbreaks.

Philippe Vanhems, MD, PhD, Innovative Clinical Research Network in VACcinology (iREIVAC), Lyon, France; Infection Control and Epidemiology Unit, Edouard Herriot Hospital, Hospices Civils de Lyon, Lyon, France; International Center for Infectiology Research (CIRI), Laboratory of Emerging Pathogens, UCBL1, Lyon, France, Rose Von Raesfeldt, MSc, Service de Biostatistiques, Lyon, France, René Ecochard, MD, PhD, Service de Biostatistique, Lyon, France and Nicolas Voirin, PhD, Hospices Civils de Lyon, Hygiène Epidémiologie et Prévention, Epidémiologie et Biomarqueurs de l'infection, Lyon, France


P. Vanhems, None

R. Von Raesfeldt, None

R. Ecochard, None

N. Voirin, None

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