The existing knowledge of all human Ebola outbreaks, prior to the ongoing outbreak, has been collated for the first time in a database described online in Scientific Data. The database comprises the index cases and geographic spread of secondary and imported cases, in addition to summaries of patient numbers and case fatality rates.
Ebola is a zoonotic virus — one that is transmitted from animals to humans — that has the potential to cause outbreaks of variable magnitude in human populations. The spread, magnitude and case fatality rate of an Ebola outbreak is determined by numerous factors, such as surveillance, treatment seeking, patient-contact rates and their combined effects on the dynamics of transmission. In addition, due to variability in the progression rate of Ebola, case fatality rates can differ significantly depending on a number of factors associated the quality and timing of symptomatic care.
Simon Hay and colleagues identified a total of 22 unique Ebola outbreaks, composed of 117 unique geographic transmission clusters, by extracting details of their suspected animal origin and subsequent human-to-human spread, using a range of published and non-published sources. While it is not yet possible to include the ongoing outbreaks, this database and compiled maps may be used to gain an improved understanding of the initial spread of past Ebola outbreaks and help evaluate surveillance and control guidelines for limiting the spread of future epidemics.
The authors will also continue to update this database to include the same standardised data fields for the ongoing outbreaks. Periodic updates to include any additional Ebola outbreaks will also ensure this resource has on-going relevance in Ebola spread analyses. In the meantime, the authors hope that these data will support research into ebolavirus disease epidemiology which can be brought to bear on the current outbreak.
A comprehensive database of the geographic spread of past human Ebola outbreaks