Predicting Ebola Severity: A Clinical Prioritization Score for Ebola Virus Disease

Background: despite the notoriety of ebola virus disease (evd) as one of the world’s most deadly infections,evd has a wide range of outcomes,where asymptomatic infection may be almost as common as fatality. with increasingly sensitive evd diagnosis,there is a need for more accurate prognostic tools that objectively stratify clinical severity to better allocate limited resources and identify those most in need of intensive treatment. methods/principal findings: this retrospective cohort study analyses the clinical characteristics of 158 evd(+) patients at the goal-mathaska ebola treatment centre,sierra leone. the prognostic potential of each characteristic was assessed and incorporated into a statistically weighted disease score. the mortality rate among evd(+) patients was 60.8% and highest in those aged <5 or >25 years (p<0.05). death was significantly associated with malaria co-infection (or = 2.5,p = 0.01). however,this observation was abrogated after adjustment to ebola viral load (p = 0.1),potentially indicating a pathologic synergy between the infections. similarly,referral-time interacted with viral load,and adjustment revealed referral-time as a significant determinant of mortality,thus quantifying the benefits of early reporting as a 12% mortality risk reduction per day (p = 0.012). disorientation was the strongest unadjusted predictor of death (or = 13.1,p = 0.014) followed by hiccups,diarrhoea,conjunctivitis,dyspnoea and myalgia. including these characteristics in multivariate prognostic scores,we obtained a 91% and 97% ability to discriminate death at or after triage respectively (area under roc curve). conclusions/significance: this study proposes highly predictive and easy-to-use prognostic tools,which stratify the risk of evd mortality at or after evd triage. © 2017 hartley et al.