Viral hemorrhagic fevers

Last updated: May 26, 2021

Summarytoggle arrow icon

Viral hemorrhagic fevers (VHFs) are a group of viral infections caused by viruses from five different families: Arenaviridae, Bunyaviridae, Filoviridae, Flaviviridae, and Paramyxoviridae. The most well-known VHFs are Lassa fever, Hantavirus syndromes, Ebola virus disease, Dengue hemorrhagic fever, and yellow fever. Transmission of VHFs occurs via contact with their animal or insect reservoirs or vectors (e.g., rodents, mosquitoes, ticks). Human-to-human transmission is also possible, e.g., via bodily fluids. VHFs predominantly occur in tropical and subtropical regions. Clinical features of VHFs vary but often include an initial nonspecific flu-like illness that progresses to multisystem hemorrhage. VHFs are diagnosed via antibody detection (e.g., IgG, IgM), PCR, or immunohistochemistry. Treatment is typically supportive, but antivirals may be used in some cases (e.g., ribavirin in Lassa fever). Case fatality rates vary greatly between VHFs but can be up to 90%. Vaccines are licensed internationally for yellow fever only, so prevention primarily consists of infection control measures.

Etiologytoggle arrow icon

Overviewtoggle arrow icon

Overview of common viral hemorrhagic fevers
Family Virus Disease(s) Geography Transmission

Incubation period

Case fatality rate



Lassa virus

Lassa fever

  • West Africa (e.g., Liberia, Sierra Leone, Guinea) [1]
  • Ingestion/inhalation of rodent urine or droppings from reservoir hosts of the virus: the multimammate rat
  • Contact with bodily fluids of other infected animals or humans
  • 1–21 days
  • Only ∼ 1% of infections are fatal
  • Mortality rate in those requiring hospitalization: 15–20%
  • None internationally licensed


Hantaviruses (especially Sin Nombre virus for HCPS)

Hantavirus cardiopulmonary syndrome (HCPS)

  • North and South America [2]
  • Contact with infected rodent reservoir hosts or ingestion/inhalation of their blood, urine, droppings, or saliva
  • 1 –8 weeks
  • 35–45% in severe cases (bilateral infiltrates on chest x-ray)
  • Mild cases are not fatal.
  • None internationally licensed
Hemorrhagic fever with renal syndrome (HFRS)
  • Asia, Korea, Russia, Europe
  • Highest annual incidence in China [3]
  • Contact with infected rodent reservoir hosts or ingestion/inhalation of their urine, droppings, or saliva
  • Up to 15% [4]
Nairoviridae Crimean Congo hemorrhagic fever virus Crimean-Congo hemorrhagic fever
  • Southeastern Europe, Africa, Middle East, Asia [5]
  • 1–13 days
  • Up to 80% [6]
  • None internationally licensed [6]
Phenuiviridae Rift valley fever virus Rift valley fever
  • Eastern and Southern Africa (e.g., Kenya, Tanzania, Somalia)
  • Sporadic cases also reported throughout Africa and the Middle East [7]
  • Contact with infected livestock (i.e., bodily fluids)
  • Mosquito bites
  • 2–6 days
  • None internationally licensed

Ebola virus

Ebola virus disease

  • Sub-Saharan Africa [8][9]
  • Contact with bodily fluids of infected people, nonhuman primates (e.g., gorillas, chimpanzees, monkeys), or fruit bats
  • Direct contact with fomites increases the likelihood of nosocomial spread.
  • 2–21 days
Marburg virus Marburg hemorrhagic fever
  • Africa (e.g., Uganda, Zimbabwe, the Democratic Republic of the Congo) [10]
  • Contact with the reservoir host of the virus, the African fruit bat
  • Contact with bodily fluids of infected individuals or animals
  • 5–10 days
  • 25–90%
  • None internationally licensed
Flaviviridae Dengue virus Dengue hemorrhagic fever
  • Worldwide in tropical regions of Central and South America, the Caribbean, Africa, and Asia [11]
  • Mosquito bites
  • 4–10 days
  • 2–5% [12]
Yellow fever virus Yellow fever
  • Tropical regions of South America and sub-Saharan Africa [13]
  • Mosquito bites
  • 3–6 days
  • 30–60% of those who develop severe infection (The vast majority of infections are asymptomatic or very mild.)

Clinical featurestoggle arrow icon

Clinical features of VHFs vary depending on which virus is involved. Onset may be acute (e.g., Ebola virus disease) or insidious (e.g., Lassa fever) and often includes the following:

Diagnosticstoggle arrow icon

Treatmenttoggle arrow icon

Aspirin and NSAIDs should be avoided in VHFs because they are associated with an increased risk of bleeding!

Preventiontoggle arrow icon


  • See “Vaccine” in “Overview of viral hemorrhagic fevers” above.

Prevention [14][20][21]

  • Avoid contact with blood, body fluids, or tissue from infected reservoirs or humans
  • Avoid travel to endemic areas
  • In suspected cases
    • Immediate notification of local health authorities and the CDC of any suspected cases of VHF
    • Strict isolation of infected patients and their contacts with disinfection and sterilization measures
    • Wear appropriate personal protective equipment (e.g., impermeable gown, gloves, respiratory protection, rubber boots).

Reportable disease [22]

  • Probable, suspected, or confirmed cases of VHFs are notifiable conditions to local and state health authorities, as well as the CDC National Notifiable Disease Surveillance System.

Hantavirus infectiontoggle arrow icon

There are two notable syndromes that can develop from a hantavirus infection: hantavirus cardiopulmonary syndrome (HCPS) and hemorrhagic fever with renal syndrome (HFRS)

Referencestoggle arrow icon

  1. CDC - Viral Hemorrhagic Fevers. Updated: June 24, 2019. Accessed: March 26, 2021.
  2. Cobo F. Viruses Causing Hemorrhagic Fever. Safety Laboratory Procedures.. The open virology journal. 2016; 10: p.1-9.doi: 10.2174/1874357901610010001 . | Open in Read by QxMD
  3. CDC - Hantavirus. Updated: March 11, 2020. Accessed: March 26, 2021.
  4. CDC - Hemorrhagic Fever with Renal Syndrome (HFRS). Updated: January 18, 2017. Accessed: March 26, 2021.
  5. CDC - Hantavirus Pulmonary Syndrome (HPS). Updated: January 1, 2015. Accessed: March 26, 2021.
  6. CDC - Lassa Fever - Treatment. Updated: March 25, 2014. Accessed: March 26, 2021.
  7. CDC - Ebola (Ebola Virus Disease) - Prevention and Vaccine. Updated: February 26, 2021. Accessed: March 26, 2021.
  8. $Infection Control for Viral Haemorrhagic Fevers.
  9. CDC - National Notifiable Diseases Surveillance System (NNDSS). Updated: January 1, 2017. Accessed: March 26, 2021.
  10. CDC - Lassa Fever. Updated: January 31, 2019. Accessed: March 26, 2021.
  11. CDC - Hantaviruses. Updated: August 29, 2012. Accessed: March 26, 2021.
  12. Avšič-Županc T, Saksida A, Korva M. Hantavirus infections. Clinical Microbiology and Infection. 2019; 21: p.e6-e16.doi: 10.1111/1469-0691.12291 . | Open in Read by QxMD
  13. Jonsson CB, Figueiredo LT, Vapalahti O. A global perspective on hantavirus ecology, epidemiology, and disease.. Clin Microbiol Rev. 2010; 23 (2): p.412-41.doi: 10.1128/CMR.00062-09 . | Open in Read by QxMD
  14. Mertens M, Schmidt K, Ozkul A, Groschup MH. The impact of Crimean-Congo hemorrhagic fever virus on public health.. Antiviral Res. 2013; 98 (2): p.248-60.doi: 10.1016/j.antiviral.2013.02.007 . | Open in Read by QxMD
  15. Dowall SD, Carroll MW, Hewson R. Development of vaccines against Crimean-Congo haemorrhagic fever virus.. Vaccine. 2017; 35 (44): p.6015-6023.doi: 10.1016/j.vaccine.2017.05.031 . | Open in Read by QxMD
  16. CDC - Rift Valley Fever (RVF). Updated: February 25, 2020. Accessed: March 26, 2021.
  17. 2014-2016 Ebola Outbreak in West Africa. Updated: March 8, 2019. Accessed: March 26, 2021.
  18. CDC - Ebola (Ebola Virus Disease) - Case Counts. Updated: February 19, 2020. Accessed: March 26, 2021.
  19. CDC - Marburg hemorrhagic fever (Marburg HF). Updated: December 3, 2014. Accessed: March 26, 2021.
  20. Guzman MG, Halstead SB, Artsob H, et al. Dengue: a continuing global threat. Nature Reviews Microbiology. 2010; 8 (S12): p.S7-S16.doi: 10.1038/nrmicro2460 . | Open in Read by QxMD
  21. Moraes GH, de Fátima Duarte E, Duarte EC. Determinants of mortality from severe dengue in Brazil: a population-based case-control study.. Am J Trop Med Hyg. 2013; 88 (4): p.670-6.doi: 10.4269/ajtmh.11-0774 . | Open in Read by QxMD
  22. CDC - Yellow Fever. Updated: September 14, 2018. Accessed: March 26, 2021.
  23. CDC - Hantavirus - Diagnostics. Updated: March 11, 2020. Accessed: March 26, 2021.
  24. CDC - Hantavirus - Diagnosis & Treatment. Updated: August 29, 2012. Accessed: March 26, 2021.
  25. Moreli ML, Marques-Silva AC, Pimentel VA, da Costa VG. Effectiveness of the ribavirin in treatment of hantavirus infections in the Americas and Eurasia: a meta-analysis.. Virusdisease. 2014; 25 (3): p.385-9.doi: 10.1007/s13337-014-0219-7 . | Open in Read by QxMD

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