Social Epidemiology of Undocumented Ebola Virus Transmission in Liberia: An Explanatory Sequential Mixed-Methods Study

Abstract

Introduction: Despite the high number of EVD cases recorded during the 2013-2016 Ebola outbreak in West Africa, our understanding of Ebola virus disease (EVD) epidemiology remains limited. A significant gap in the knowledge base is the prevalence and distribution of undocumented survivors. Estimating the numbers of undocumented EVD survivors, the prevalence of symptomatic and asymptomatic individuals would help correct for underreporting cases. Understanding how symptomatic Ebola cases fell outside of the containment response could bolster preparedness and reduce transmission in future outbreaks. We conducted a mixed-method study to understand the social epidemiology of undocumented Ebola infection within Montserrado and Margibi Counties, Liberia, and identify structural factors that shaped symptomatic individuals' choices to receive care at Ebola Treatment Units (ETUs). Methods: We conducted a descriptive, explanatory sequential mixed-methods study among seropositive EVD survivors identified from the PREVAIL III (Ebola Natural History Study) and assessed factors that shape symptomatic individuals' care-seeking behaviors during the 2014-2016 Ebola outbreak in Liberia. We administered a survey questionnaire to 199 seropositive participants. We also conducted in-depth interviews with a subset of 20 symptomatic seropositive participants and 15 community leaders and members of the local Ebola response structures from October to January 2021. Results: The study enrolled 199 undocumented Ebola seropositive individuals. 73.9% of these participants were symptomatic, while 26.1% were asymptomatic. The distribution of symptomatic undocumented EVD survivors was much higher in Montserrado County with 63.8% and relatively lower in Margibi County, with 36.2%. Most undocumented EVD cases preferred not to seek care at designated health facilities due to fear of adverse health outcomes and the social implication of being identified as Ebola patients. Unfunded health systems created unequal access to care and a lack of trust in the care delivery system. Community denial stemmed from rumors that were not unfounded but emerged from a long history of corruption and foreign exploitation. Conclusion: During the 2014-2016 Ebola outbreak in Liberia, symptomatic EBOV infections went undocumented. These seropositive undocumented patients preferred not to seek care at Ebola treatment centers due to fear of adverse health outcomes, distrust in the system, and social implications of the virus. More research needs to be conducted to estimate a more accurate disease burden in the West African epidemic.