A Current Review of Ebola Virus: Pathogenesis,Clinical Presentation,and Diagnostic Assessment

Abstract

Ebola hemorrhagic fever (EHF) is an acute viral syndrome that presents with fever and an ensuing bleeding diathesis that is marked by high mortality in human and nonhuman primates. Fatality rates are between 50% and 100%. Due to its lethal nature, this filovirus is classified as a biological class 4 pathogen. The natural reservoir of the virus is unknown. As a result, little is understood about how Ebola virus is transmitted or how it replicates in its host. Although the primary source of infection is unknown, the epidemiologic mode of transmission is well defined. A variety of tests have proven to be specific and useful for Ebola virus identification. There is no FDA-approved antiviral treatment for EHF. Incubation ranges from 2 to 21 days. Patients who are able to mount an immune response to the virus will begin to recover in 7 to 10 days and start a period of prolonged convalescence. Supportive management of infected patients is the primary method of treatment, with particular attention to maintenance of hydration, circulatory volume, blood pressure, and the provision of supplemental oxygen. Since there is no specific treatment outside of supportive management and palliative care, containment of this potentially lethal virus is paramount. In almost all outbreaks of EHF, the fatality rate among health care workers with documented infections was higher than that of non–health care workers.

Get full access to this article

View all access options for this article.

References

Arthur RR. 2002. Ebola in Africa—discoveries in the past decade. Eurosurveillance Monthly 7(3): 33-4. Available from: http://www.eurosurveillance.org/em/v07n03/v07n03.pdf. Accessed 2003 Feb 14.

Baize S, Leroy EM, Georges AJ, Georges-Courbot MC, Capron M, Bedjabaga I, Lansoud-Soukate J, Mavoungou E. 2002. Inflammatory responses in Ebola virus-infected patients. Clin Exp Immunol 128: 163-8.

Baize S, Leroy EM, Georges-Courbot MC, Capron M, Lansoud-Soukate J, Debre P, Fisher-Hoch SP, McCormick JB, Georges AJ. 1999. Defective humoral responses and extensive intravascular apoptosis are associated with fatal outcome in Ebola virus-infected patients. Nat Med 5: 423-6.

Borio L, Inglesby T, Peters CJ, Schmaljohn AL, Hughes JM, Jahrling PB, Ksiazek T, Johnson KM, Meyerhoff A, O’Toole T, and others. 2002. Hemorrhagic fever viruses as biological weapons—medical and public health management. JAMA 287: 2391-405.

Carballal G. 1996. Emerging or re-emerging viruses? Medicina-Buenos Aires 56: 97-101.

Centers for Disease Control and Prevention Special Pathogens Branch. 2002a. Ebola hemorrhagic fever table showing known cases and outbreaks, in chronological order. Available from: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebotabl.htm. Accessed 2003 Feb 11.

Centers for Disease Control and Prevention Special Pathogens Branch. 2002b. Ebola hemorrhagic fever. Available from: http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/ebola.htm.

Chen JP, Cosgriff TM. 2000. Hemorrhagic fever virus-induced changes in hemostasis and vascular biology. Blood Coagul Fibrinolysis 11: 461-83.

Collier L, Balows A, Sussman M, editors. 1998. Topley and Wilson’s microbiology and microbial infections. 9th ed. New York: Oxford University Press.

10.

Connolly BM, Steele KE, Davis KJ, Geisbert TW, Kell WM, Jaax NK, Jahrling PB. 1999. Pathogenesis of experimental Ebola virus infection in guinea pigs. J Infect Dis 179: S203-17.

11.

Dowell SF, Mukunu R, Ksiazek TG, Khan AS, Rollin PE, Peters CJ. 1999. Transmission of Ebola hemorrhagic fever: a study of risk factors in family members, Kikwit, Democratic Republic of the Congo, 1995. J Infect Dis 179: S87-91.

12.

Feldmann H, Volchkov VE, Volchkova VA, Klenk HD. 1999. The glycoproteins of Marburg and Ebola virus and their potential roles in pathogenesis. Arch Virol Suppl 15: 159-69.

13.

Franz DR, Jahrling PB, Friedlander AM, McClain DJ, Hoover DL, Bryne WR, Pavlin JA, Christopher CW, Eitzen EM. 1997. Clinical recognition and management of patients exposed to biological warfare agents. JAMA 278: 399-411.

14.

Jahrling PB, Geisbert TW, Dalgard DW, Johnson ED, Ksiazek TG, Hall WC, Peters CJ. 1990. Preliminary report: isolation of Ebola virus from monkeys imported to USA. Lancet 335: 502-5.

15.

Klenk HD, Feldmann H. 2001. Symposium on Marburg and Ebola viruses. Virus Res 80: 117-23.

16.

Klenk HD, Slenczka W, Feldmann H. 1995. Marburg and Ebola viruses. Available from: http://www.bocklabs.wisc.edu/eov-ebola.html. Accessed 2003 Feb 14.

17.

Ksiazek TG, Rollin PE, Williams AJ, Bressler DS, Martin ML, Swanepoel R, Burt FJ, Leman PA, Khan AS, Rowe AK, and others. 1999. Clinical virology of Ebola hemorrhagic fever (EHF): virus, virus antigen, and IgG and IgM antibody findings among EHF patients in Kikwit, Democratic Republic of the Congo, 1995. J Infect Dis 179(1 Suppl): S177-87.

18.

Ksiazek TG, West CP, Rollin PE, Jahrling PB, Peters CJ. 1999. ELISA for the detection of antibodies to Ebola viruses. J Infect Dis 179(1 Suppl): S192-8.

19.

Outbreak of Ebola hemorrhagic fever Uganda, August 2000-January 2001. MMWR Morb Mortal Wkly Rep 50(5): 73-7.

20.

Peters CJ, Jahrling PB, Khan AS. 1996. Patients infected with high-hazard viruses: scientific basis for infection control. Arch Virol Suppl 11: 141-68.

21.

Peters CJ, LeDuc JW. 1999. An introduction to Ebola: the virus and the disease. J Infect Dis 179(1 Suppl): ix-xvi.

22.

Rodriguez LL, De Roo A, Guimard Y, Trappier SG, Sanchez A, Bressler D, Williams AJ, Rowe AK, Bertolli J, Khan AS, and others. 1999. Persistence and genetic stability of Ebola virus during the outbreak in Kikwit, Democratic Republic of the Congo, 1995. J Infect Dis 179(1 Suppl): S170-6.

23.

Roels TH, Bloom AS, Buffington J, Muhungu GL, MacKenzie WR, Khan AS, Ndambi R, Noah DL, Rolka HR, Peters CJ, and others. 1999. Ebola hemorrhagic fever, Kikwit, Democratic Republic of the Congo, 1995: risk factors for patients without a reported exposure. J Infect Dis 179: S92-7.

24.

Rowe AK, Bertolli J, Khan AS, Mukunu R, Muyembe-Tamfum JJ, Bressler D, Williams AJ, Peters CJ, Rodriguez L, Feldmann H, and others. 1999. Clinical, virologic, and immunologic followup of convalescent Ebola hemorrhagic fever patients and their household contacts, Kikwit, Democratic Republic of the Congo. Commission de Lutte contre les Epidemies a Kikwit. J Infect Dis 179(1 Suppl): S28-35.

25.

Schou S, Hansen AK. 2000. Marburg and Ebola virus infections in laboratory non-human primates: a literature review. Comp Med 50: 108-23.

26.

Villinger F, Rollin PE, Brar SS, Chikkala NF, Winter J, Sundstrom JB, Zaki SR, Swanepoel R, Ansari AA, Peters CJ. 1999. Markedly elevated levels of interferon (IFN)-gamma, IFN-alpha, interleukin (IL)-2, IL-10, and tumor necrosis factor-alpha associated with fatal Ebola virus infection. J Infect Dis 179(1 Suppl): S188-91.

27.

World Health Organization. 1997. WHO recommended guidelines for epidemic preparedness and response: Ebola haemorrhagic fever (EHF). Available from: http://www.who.int/emc-documents/haem_fevers/docs/whoemcdis977E.pdf. Accessed 2003 Feb 14.

28.

World Health Organization. 2000. Ebola haemorrhagic fever (Fact Sheet No. 103). Available from: http://www.who.int/inf-fs/en/fact103.html. Accessed 2003 Feb 14.

29.

Zaki SR, Shieh WJ, Greer PW, Goldsmith CS, Ferebee T, Katshitshi J, Tshioko FK, Bwaka MA, Swanepoel R, Calain P, and others. 1999. A novel immunohistochemical assay for the detection of Ebola virus in skin: implications for diagnosis, spread, and surveillance of Ebola hemorrhagic fever. Commission de Lutte contre les Epidemies a Kikwit. J Infect Dis 179(1 Suppl): S36-47.