Clinical Features of and Risk Factors for Fatal Ebola Virus Disease, Moyamba District, Sierra Leone, December 2014–February 2015

The 2013-2016 outbreak of Ebola virus disease (EVD) in West Africa infected >28,000 people, including >11,000 who died, and disrupted social life in the region.We retrospectively studied clinical signs and symptoms and risk factors for fatal outcome among 31 Ebola virus-positive patients admitted to the Ebola Treatment Center in Moyamba District, Sierra Leone.We found a higher rate of bleeding manifestations than reported elsewhere during the outbreak.Significant predictors for death were shorter time from symptom onset to admission, male sex, high viral load on initial laboratory testing, severe pain, diarrhea, bloody feces, and development of other bleeding manifestations during hospitalization.These risk factors for death could be used to identify patients in need of more intensive medical support.The lack of fever in as many as one third of EVD cases may have implications for temperature-screening practices and case definitions.S ince its discovery in 1976 (1), Ebola virus has caused small sporadic outbreaks with high case-fatality rates (CFRs), mostly in rural areas in central and eastern Africa (2).The outbreak of Ebola virus disease (EVD) in West Africa that began in Guinea in December 2013 (3,4) and subsequently spread to Sierra Leone and Liberia (5) is the largest known outbreak to date: >28,000 cases and >11,000 deaths were reported (6).Weak health systems, deep-rooted traditional burial customs, high population mobility, and early spread of disease in urban areas contributed to the unprecedented extent of the epidemic (5,7,8).The high death toll among healthcare workers further undermined weak existing health systems (9).Apart from Médecins Sans Frontières and a few other organizations, the international community responded slowly (8,10).However, a turning point came with a United Nations resolution on August 8, 2014, that led to creation of UNMEER (UN Mission for Ebola Emergency Response) on September 19.Leading public health agencies predicted that the epidemic could spiral out of control and estimated that, in a worst-case scenario, 1.4 million persons could become infected (11).In response, an increasing number of international stakeholders became involved, and several countries make direct monetary contributions.The epidemic peaked in September-October 2014 in Liberia and in December 2014 in Sierra Leone and Guinea; a gradual decline in the number of new cases followed (6,8).The sporadic nature of previous Ebola outbreaks in remote areas of Africa has hampered the collection of clinical and laboratory data.In the 13 previously described outbreaks of Zaire EVD, the average CFR was 81% (1,123 deaths/1,390 cases) (12).The natural history of the 2013-2016 EVD outbreak in West Africa may vary from that in previous outbreaks.