Epidemiology of Ebola Virus Disease in the Western Area Region of Sierra Leone, 2014-2015

Introduction

Western Area (WA) of Sierra Leone including the capital, Freetown, experienced an unprecedented outbreak of Ebola from 2014 to 2015. At the onset of the epidemic, there was little information about the epidemiology, transmission dynamics, and risk factors in urban settings as previous outbreaks were limited to rural/semi-rural settings. This study, therefore, aimed to describe the epidemiology of the outbreak and the factors which had most impact on the transmission of the epidemic and whether there were different drivers from those previously described in rural settings.

Methods

We conducted a descriptive epidemiology study in WA, Sierra Leone using secondary data from the National Ebola outbreak database. We also reviewed the Ebola situation reports, response strategy documents, and other useful documents.

Results

A total of 4,955 Ebola cases were identified between June 2014 and November 2015, although there were reports of cases occurring in WA toward end of May. All wards were affected, and Waterloo Area I (Ward 330), the capital city of Western Area Rural District, recorded the highest numbers of cases (580) and deaths (236). Majority of cases (63.4%) and deaths (66.8%) were in WA Urban District (WAU); 44 cases were imported from other provinces. Only 20% of cases had a history of contact with an Ebola case, and more than 30% were death alerts. Equal numbers of males and females were infected, and very few cases (3.2%) were health workers. Overall, transmission was through contact with infected individuals, and intense transmission occurred at the community level. In WAU, transmission was mostly between neighbors and among inhabitants of shared accommodations. The drivers of transmission included high population movement to and from WA, overcrowding, fear and lack of trust in the response, and negative community behaviors. Transmission was mostly through contact and with limited transmission through sex and breast milk.

Conclusion

The unprecedented outbreak in WA was attributed to delayed detection, inadequate preparedness and response, intense population movements, overcrowding, and unresponsive communities. Anticipation, strengthening preparedness for early detection, and swift and effective response remains critical in mitigating a potential urban explosion of similar future outbreaks.

Incident Management Systems Are Essential for Effective Coordination of Large Disease Outbreaks: Perspectives from the Coordination of the Ebola Outbreak Response in Sierra Leone

Background

Response to the 2014–2015 Ebola virus disease (EVD) outbreak in Sierra Leone overwhelmed the national capacity to contain it and necessitated a massive international response and strong coordination platform. Consequently, the Sierra Leone Government, with support of the international humanitarian community, established and implemented various models for national coordination of the outbreak. In this article, we review the strengths and limitations of the EVD outbreak response coordination systems in Sierra Leone and propose recommendations for improving coordination of similar outbreaks in the future.

Conclusion

There were two main frameworks used for the coordination of the outbreak; the Emergency Operation Center (EOC) and the National Ebola Response Center (NERC). We observed an improvement in outbreak coordination as the management mechanism evolved from the EOC to the NERC. Both coordination systems had their advantages and disadvantages; however, the NERC coordination mechanism appeared to be more robust. We identified challenges, such as competition and duplication of efforts between the numerous coordination groups, slow resource mobilization, inadequate capacity of NERC/EOC staff for health coordination, and an overtly centralized coordination and decision-making system as the main coordination challenges during the outbreak.

Recommendations

We recommend the establishment of EOCs with simple incident management system-based coordination prior to outbreaks, strong government leadership, decentralization of coordination systems, and functions to the epicenter of outbreaks, with clear demarcation of roles and responsibilities between different levels, regular training of key coordination leaders, and better community participation as methods to improve coordination of future disease outbreaks.