Skip to main content
×
Home

Assessment of the severity of Ebola virus disease in Sierra Leone in 2014–2015

  • J. Y. WONG (a1), W. ZHANG (a2) (a3), D. KARGBO (a4), U. HAQUE (a5) (a6), W. HU (a7), P. WU (a1), A. KAMARA (a4), Y. CHEN (a2) (a3), B. KARGBO (a4), G. E. GLASS (a5) (a6), R. YANG (a3) (a8), B. J. COWLING (a1) and C. LIU (a2) (a3)...
Summary
SUMMARY

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.

Copyright
Corresponding author
* Author for correspondence: Professor B. J. Cowling, WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam, Hong Kong Special Administrative Region, China. (Email: bcowling@hku.hk)
References
Hide All
1. World Health Organization. Ebola response roadmap. Geneva: World Health Organization, 2014 (http://www.who.int/csr/resources/publications/ebola/response-roadmap/en/). Accessed 12 March 2015.
2. World Health Organization. WHO statement on the 1st meeting of the IHR Emergency Committee on the 2014 Ebola outbreak in West Africa. Geneva: World Health Organization; 2014 (http://www.who.int/mediacentre/news/statements/2014/ebola-20140808/en/). Accessed 12 March 2015.
3. Baize S, et al. Emergence of Zaire Ebola virus disease in Guinea – preliminary Report. New England Journal of Medicine 2014; 371: 14181425.
4. Nishiura H, Chowell G. Early transmission dynamics of Ebola virus disease (EVD), West Africa, March to August 2014. Eurosurveillance 2014; 19(36).
5. World Health Organization Ebola Response Team. Ebola virus disease in West Africa – the first 9 months of the epidemic and forward projections. New England Journal of Medicine 2014; 371: 14811495.
6. Dixon MG, et al. Ebola viral disease outbreak--West Africa, 2014. Morbidity and Mortality Weekly Report 2014; 63: 548551.
7. Feldmann H, Geisbert TW. Ebola haemorrhagic fever. Lancet 2011; 377: 849–62.
8. Gire SK, et al. Genomic surveillance elucidates Ebola virus origin and transmission during the 2014 outbreak. Science 2014; 345: 13691372.
9. World Health Organization. Ebola response roadmap – citation report – 8 April 2015. Geneva: World Health Organization; 2015 (http://apps.who.int/ebola/current-situation/ebola-situation-report-8-april-2015). Accessed 9 April 2015.
10. Cowling BJ, Yu H. Ebola: worldwide dissemination risk and response priorities. Lancet 2015; 385: 79.
11. Althaus CL. Estimating the Reproduction Number of Ebola Virus (EBOV) During the 2014 Outbreak in West Africa. PLoS Currents 2014; 6.
12. Parkes-Ratanshi R, et al. Ebola outbreak response; experience and development of screening tools for viral haemorrhagic fever (VHF) in a HIV center of excellence near to VHF epicentres. PLoS ONE 2014; 9: e100333.
13. Rivers CM, et al. Modeling the impact of interventions on an epidemic of ebola in Sierra Leone and Liberia. PLoS Currents 2014; 6.
14. United Nations. UN Mission for Ebola Emergency Response (UNMEER). United Nations; 2014 (https://ebolaresponse.un.org/un-mission-ebola-emergency-response-unmeer). Accessed 12 March 2015.
15. Centers for Disease Control and Prevention. CDC Disease Detectives Using New Software Tool in Ebola Hemorrhagic Fever Outbreak. Centers for Disease Control and Prevention, 2014 (http://www.cdc.gov/media/releases/2014/p0429-new-software.html). Accessed 27 October 2015.
16. Garske T, et al. Assessing the severity of the novel influenza A/H1N1 pandemic. British Medical Association 2009; 339: b2840.
17. Yu H, et al. Human infection with avian influenza A H7N9 virus: an assessment of clinical severity. Lancet 2013; 382: 138145.
18. Greenland S. Bayesian perspectives for epidemiological research: I. Foundations and basic methods. International Journal of Epidemiology 2006; 35: 765775.
19. Brooks S, et al. Handbook of Markov Chain Monte Carlo. Boca Raton: Chapman & Hall/CRC, 2011.
20. Schieffelin JS, et al. Clinical illness and outcomes in patients with Ebola in Sierra Leone. New England Journal of Medicine 2014; 371: 20922100.
21. World Health Organization. Outbreak of Ebola haemorrhagic fever, Uganda, August 2000-January 2001. Weekly Epidemiological Record 2001; 76: 4146.
22. World Health Organization Ebola Response Team. West African Ebola epidemic after one year – slowing but not yet under control. New England Journal of Medicine 2015; 372: 584587.
23. World Health Organization Ebola Response Team. Ebola virus disease among children in West Africa. New England Journal of Medicine 2015; 372: 12741277.
24. Mupere E, Kaducu OF, Yoti Z. Ebola haemorrhagic fever among hospitalised children and adolescents in northern Uganda: epidemiologic and clinical observations. African Health Sciences 2001; 1: 6065.
25. Sadek RF, et al. Ebola hemorrhagic fever, Democratic Republic of the Congo, 1995: determinants of survival. Journal of Infectious Diseases 1999; 179 (Suppl. 1): S24–27.
26. World Health Organization. Ebola response roadmap – citation report – 24 September 2014. Geneva: World Health Organization, 2014 (http://apps.who.int/iris/bitstream/10665/134771/1/roadmapsitrep_24Sept2014_eng.pdf?ua=1). Accessed 12 March 2015.
27. Zhang WY, et al. Field labs in actiona for Ebola control in Sierra Leone. Infectious Diseases and Translational Medicine 2015; 1: 25.
28. Briand S, et al. The international Ebola emergency. New England Journal of Medicine 2014; 371: 11801183.
29. Bah EI, et al. Clinical presentation of patients with Ebola virus disease in Conakry, Guinea. New England Journal of Medicine 2015; 372: 4047.
30. Fisman D, Khoo E, Tuite A. Early epidemic dynamics of the West African 2014 ebola outbreak: estimates derived with a simple two-parameter model. PLoS Currents 2014; 6.
31. Gomes MF, et al. Assessing the international spreading risk associated with the 2014 west african ebola outbreak. PLoS Currents 2014; 6.
32. Meltzer MI, et al. Estimating the future number of cases in the Ebola epidemic – Liberia and Sierra Leone, 2014–2015. Morbidity and Mortality Weekly Report. Surveillance Summaries 2014; 63 (Suppl. 3): 114.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
  • URL: /core/journals/epidemiology-and-infection
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords:

Type Description Title
WORD
Supplementary Materials

Wong supplementary material
Tables S1-S3 and Figure S1

 Word (43 KB)
43 KB

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 16
Total number of PDF views: 62 *
Loading metrics...

Abstract views

Total abstract views: 389 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 20th November 2017. This data will be updated every 24 hours.