Viral Hemorrhagic Fever

Aka: Viral Hemorrhagic Fever, Hemorrhagic Fever Syndrome

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II. Pathophysiology

  1. Natural host species (e.g. animal carcasses, infected bats) are specific to certain geographic regions
    1. Natural outbreaks typically start in these regions
    2. However, person to person spread may occur in new regions if patients travel
      1. Responsible for most cases in humans
  2. Transmission
    1. Natural exposure to body fluids
    2. Bioterrorism exposure to aerosolized infectious agent
  3. Pathogenesis
    1. All Viral Hemorrhagic Fevers result in vascular endothelial damage
      1. Results in Flushing, edema, Petechiae, Ecchymosis, Hemorrhage and shock

III. Causes

  1. Background
    1. Four families of lipid-enveloped single-stranded RNA Viruses
  2. Arena Virus (Arenaviridae, Rodent Reservoir)
    1. Lassa Fever
    2. Junin
    3. Machupo
    4. Lujo
    5. Sabia
    6. Chapare
  3. Bunyavirus (Bunyaviridae)
    1. Rift Valley Fever
    2. Crimean Congo Hemorrhagic FeverVirus
    3. Hantavirus Hemorrhagic Fever
  4. Flavivirus (Flaviviridae)
    1. Yellow Fever
    2. Dengue Fever
    3. Omsk Hemorrhagic Fever
    4. Kyasanur Forest Disease
  5. Filovirus (Filoviridae, Bat Reservoir)
    1. Ebola Virus
    2. Marburg Hemorrhagic Fever

IV. Findings

  1. Incubation: 2-21 days
  2. Non-specific symptoms (initial phase)
    1. Fever
    2. Headache
    3. Myalgias
    4. Arthralgias
    5. Rash
  3. Gastrointestinal symptoms (second phase)
    1. Abdominal Pain
    2. Vomiting
    3. Diarrhea
  4. Bleeding
    1. Conjunctival Injection
    2. Mucosal Bleeding (gums, Gastrointestinal Tract)
    3. Hemoptysis
    4. Epistaxis
    5. Hemoptysis
    6. Bloody Diarrhea
    7. Petechiae, Purpura and Ecchymosis
  5. Other late findings
    1. Shock with Multisystem organ failure
    2. Encephalitis

V. Diagnosis: Hemorrhagic Fever Syndrome (WHO)

  1. Fever <3 weeks AND
  2. Severely ill patient AND
  3. Two hemorrhagic findings (without known host predisposing factors)
    1. Hemorrhagic or Purpuric rash
    2. Epistaxis
    3. Hematemesis
    4. Hemoptysis
    5. Blood in stools

VI. Labs

  1. Diagnostic specimens are sent to specialized labs (e.g. CDC or U.S. Army Medical Research Institute of Infectious Diseases)

VII. Complications

  1. Multiorgan Failure
    1. Hepatic Failure
    2. Renal Failure
  2. Hemorrhagic Shock
  3. Septic Shock

VIII. Management: General

  1. See Specific causes
  2. Strict patient isolation
  3. Supportive care
  4. Antiviral management
    1. Ribavirin (see below)
    2. Monoclonal Antibody treatments have been developed for several hemorrhagic fevers
      1. See Ebola
  5. Personal Protective Equipment for care givers
    1. Transmission from the body fluids (percutaneous, mucosal contact) is common at the end stages of the disease
    2. See Personal Protection Equipment for protection against Viral Hemorrhagic Fevers
    3. See Donning and Doffing PPE
  6. Disinfection with dilute bleach
    1. Use 1:10 bleach solution to disinfect bodies and excretions
    2. Use 1:100 bleach solutions to disinfect surfaces, equipment, bedding and reusable PPE

IX. Management: Ribavirin (Virazole)

  1. Indications
    1. Lassa Fever
    2. Arenaviridae
    3. Bunyaviridae
    4. May be used in other Viral Hemorrhagic Fevers (e.g. ebola)
  2. Ribavirin Protocol
    1. Load 30 mg/kg (up to 2 g) IV
    2. Then 16 mg/kg (up to 1 g) IV every g hours for 4 days
    3. Then 8 mg/kg (up to 500 mg) IV every 8 hours for 6 days

X. References

  1. Black, Martin, DeVos (2018) Crit Dec Emerg Med 32(8): 3-12
  2. Charbonnet and Mace (2023) Crit Dec Emerg Med 37(4): 4-10
  3. Gladwin (2014) Clinical Microbiology, MedMaster, Miami, p.306-7, 398
  4. Rathjen (2021) Am Fam Physician 104(4): 376-85 [PubMed]

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