How to treat Ebola virus infections? A lesson from the field.

The reported case fatality ratios (CFR) of Ebola virus disease (EVD) have been as high as 90% in previous outbreaks. While the cumulative CFR among patients medically evacuated and treated in Western countries was inferior to 20%, it peaked to approximately 75% between September and December 2014 in West Africa, thereafter decreasing to less than 40% (May 2015) without current evidence of major virus mutations capable to alter virus pathogenicity over the course of the epidemic. Therefore, the observed diminution of CFR is likely to reflect improvement of EVD patient care. Here, we summarize major lessons learned, that is, progresses and knowledge gaps, about the clinical management of patients in West African settings during the 2014-2016 outbreak.