The Natural History of Acute Ebola Virus Disease Among Patients Managed in Five Ebola Treatment Units in West Africa: A Retrospective Cohort Study

International Medical Corps and Brown University analyzed clinical care data from Ebola virus-positive patients admitted to five Ebola treatment units in West Africa over a one-year period from 2014 to 2015 to investigate EVD symptoms and the Ebola virus cycle threshold values in patients from the time the illness started to the time they recovered or died. This retrospective cohort study found that the youngest (under five) and oldest (45 and older) patients were less likely to survive Ebola virus (EBOV) infection. During the first week of illness, dyspnea and tachycardia were associated with increased mortality. Dyspnea, bleeding and diarrhea at any point during the illness course were associated with increased mortality. In addition, higher levels of virus in the blood at the time patients sought treatment, as well as higher virus levels over the duration of their illness, were associated with lower survival. These findings provide important insight into the progression of EVD over time and will help clinicians and other health workers to identify and design interventions for subgroups of patients who are more likely to die from EBOV infection.