title: Assessment of the severity of Ebola virus disease in Sierra Leone in 2014-2015.
abstract: The current Ebola virus disease (EVD) epidemic in West Africa is unprecedented in scale, and Sierra Leone is the most severely affected country. The case fatality risk (CFR) and hospitalization fatality risk (HFR) were used to characterize the severity of infections in confirmed and probable EVD cases in Sierra Leone. Proportional hazards regression models were used to investigate factors associated with the risk of death in EVD cases. In total, there were 17 318 EVD cases reported in Sierra Leone from 23 May 2014 to 31 January 2015. Of the probable and confirmed EVD cases with a reported final outcome, a total of 2536 deaths and 886 recoveries were reported. CFR and HFR estimates were 74·2% [95% credibility interval (CrI) 72·6-75·5] and 68·9% (95% CrI 66·2-71·6), respectively. Risks of death were higher in the youngest (0-4 years) and oldest (⩾60 years) age groups, and in the calendar month of October 2014. Sex and occupational status did not significantly affect the mortality of EVD. The CFR and HFR estimates of EVD were very high in Sierra Leone.
authors.affiliation: WHO Collaborating Centre for Infectious Disease Epidemiology and Control,School of Public Health, Li Ka Shing Faculty of Medicine,The University of Hong Kong,Hong Kong Special Administrative Region,China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Wong
authors.affiliation: Beijing Institute of Disease Control and Prevention,Beijing,China.
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Ministry of Health and Sanitation,Freetown,Sierra Leone.
authors.forename: D
authors.initials: D
authors.lastname: Kargbo
authors.affiliation: Emerging Pathogens Institute,University of Florida,Gainesville,FL,USA.
authors.forename: U
authors.initials: U
authors.lastname: Haque
authors.affiliation: School of Public Health and Social Work,Queensland University of Technology,Brisbane,Australia.
authors.forename: W
authors.initials: W
authors.lastname: Hu
authors.affiliation: WHO Collaborating Centre for Infectious Disease Epidemiology and Control,School of Public Health, Li Ka Shing Faculty of Medicine,The University of Hong Kong,Hong Kong Special Administrative Region,China.
authors.forename: P
authors.initials: P
authors.lastname: Wu
authors.affiliation: Ministry of Health and Sanitation,Freetown,Sierra Leone.
authors.forename: A
authors.initials: A
authors.lastname: Kamara
authors.affiliation: Beijing Institute of Disease Control and Prevention,Beijing,China.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Ministry of Health and Sanitation,Freetown,Sierra Leone.
authors.forename: B
authors.initials: B
authors.lastname: Kargbo
authors.affiliation: Emerging Pathogens Institute,University of Florida,Gainesville,FL,USA.
authors.forename: G E
authors.initials: GE
authors.lastname: Glass
authors.affiliation: China Mobile Laboratory Response Team for Ebola in Sierra Leone,Freetown,Sierra Leone.
authors.forename: R
authors.initials: R
authors.lastname: Yang
authors.affiliation: WHO Collaborating Centre for Infectious Disease Epidemiology and Control,School of Public Health, Li Ka Shing Faculty of Medicine,The University of Hong Kong,Hong Kong Special Administrative Region,China.
authors.forename: B J
authors.initials: BJ
authors.lastname: Cowling
authors.affiliation: Beijing Institute of Disease Control and Prevention,Beijing,China.
authors.forename: C
authors.initials: C
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D029043:Ebolavirus / Q000502:physiology*; D058872:Epidemics; D005260:Female; D019142:Hemorrhagic Fever, Ebola / Q000401:mortality* / Q000821:virology; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012720:Severity of Illness Index; D012807:Sierra Leone / Q000453:epidemiology; D055815:Young Adult
keywords: Death; Ebola virus; severity