Viral hemorrhagic fever (patient information)

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Overview
Viral hemorrhagic fevers (VHFs) are caused by several families of enveloped RNA viruses: filoviruses (Ebola and Marburg viruses), arenaviruses  (Lassa fever, Lujo, Guanarito, Machupo, Junin, Sabia, and Chapare viruses),  bunyaviruses (Rift Valley fever [RVF], Crimean-Congo hemorrhagic fever [CCHF],  and hantaviruses), and flaviviruses (dengue, yellow fever, Omsk hemorrhagic  fever, Kyasanur Forest disease, and Alkhurma viruses)

What are the symptoms of Viral hemorrhagic fever?
Signs and symptoms vary by disease, but in general, patients with VHF present with abrupt onset of  fever, myalgias, and prostration, followed in severe forms by coagulopathy with  a petechial rash or ecchymoses and sometimes overt bleeding. Vascular endothelial damage leads to shock and pulmonary edema, and liver injury is  common. Signs seen with specific viruses include renal failure (HFRS), ecchymoses (CCHF), hearing loss, anasarca and shock in newborns (Lassa fever),  and spontaneous abortion (Lassa and lymphocytic choriomeningitis viruses). Because the incubation period may be as long as 21 days, patients may not develop  illness until returning from travel; therefore, a thorough travel and exposure  history is critical.

What causes Viral hemorrhagic fever?
Viral hemorrhagic fevers (VHFs) are caused by several families of enveloped RNA viruses: filoviruses (Ebola and Marburg viruses), arenaviruses  (Lassa fever, Lujo, Guanarito, Machupo, Junin, Sabia, and Chapare viruses),  bunyaviruses (Rift Valley fever [RVF], Crimean-Congo hemorrhagic fever [CCHF],  and hantaviruses), and flaviviruses (dengue, yellow fever, Omsk hemorrhagic  fever, Kyasanur Forest disease, and Alkhurma viruses)

Who is at highest risk?
Some VHFs are spread person to person through direct contact with symptomatic patients, body  fluids, or cadavers or through inadequate infection control (filoviruses,  arenaviruses, CCHF virus). Zoonotic spread includes the following: Livestock via slaughter or consumption of raw milk or meat from infected animals (CCHF,  RVF, Alkhurma viruses) Bushmeat, likely via slaughter or consumption of infected animals (Ebola, Marburg  viruses) Rodent (arenaviruses, hantaviruses) via inhalation of or contact with materials  contaminated with rodent excreta Other reservoir species, such as bats (Ebola, Marburg viruses). Vectorborne transmission also occurs via mosquito (RVF virus) or tick (CCHF, Omsk, Kyasanur  Forest disease, Alkhurma viruses) bites or by crushing ticks

When to seek urgent medical care?
If you think you are developing symptoms of this disease contact your doctor

Diagnosis
US-based clinicians should notify CDC’s Viral Special Pathogens Branch immediately of any suspected cases of VHF occurring in patients residing in or requiring evacuation to the United States: 404-639-1115 or the CDC Emergency Operations Center at 770-488-7100 after hours. CDC also provides consultation for international clinicians and health ministries. Whole blood or serum may be tested for virologic (RT-PCR, antigen detection, virus isolation) and immunologic (IgM, IgG) evidence of infection. Tissue may be tested by immunohistochemistry, RT-PCR, and virus isolation. Postmortem skin biopsies fixed in formalin and blood collected within a few hours after death by cardiac puncture can be used for diagnosis. Samples should be sent for testing to a reference laboratory with biosafety level 3 and 4 capability.

Treatment options
Ribavirin is effective for treating Lassa fever, New World arenaviruses, and likely CCHF, but it is not approved by the Food and Drug Administration (FDA) for these indications. Convalescent-phase plasma is effective in treating Argentine hemorrhagic fever. Intravenous ribavirin can be obtained for compassionate use through FDA from Valeant Pharmaceuticals (Aliso Viejo, California). Requests should be initiated by the provider through FDA (301-443-1240), with simultaneous notification to Valeant: 800-548-5100, extension 5 (domestic telephone) or 949-461- 6971 (international telephone). The process is explained on FDA’s website (http://www.fda.gov/ Drugs/DevelopmentApprovalProces...External Web Site Icon).

Where to find medical care for Viral hemorrhagic fever?
Directions to Hospitals Treating Viral hemorrhagic fever

What to expect (Outlook/Prognosis)?
Hemorrhagic fever varies in severity. Severe infections with internal bleeding and fever (hemorrhagic fever) are deadly in up to half of cases.

Prevention
he risk of acquiring VHF is very low for international travelers. Travelers at increased risk for exposure include those engaging in animal research, health care workers, and others providing care for patients in the community, particularly where outbreaks of VHF are occurring. Prevention should focus on avoiding contact with host or vector species. Travelers should not visit locations where an outbreak is occurring. Contact with rodents should be avoided. Travelers should avoid contact with livestock in RVF- and CCHF-endemic areas, and they should use insecticide-treated bed nets and insect repellent to prevent vectorborne disease. Standard precautions and contact and droplet precautions for suspected VHF case-patients are recommended to avoid transmission. Direct contact should be avoided with corpses of patients suspected of having died of Ebola, Marburg, or Old World arenavirus infection. Contact with or consumption of primates, bats, and other bushmeat should be avoided. Bat-inhabited caves or mines should be avoided. Investigational vaccines exist for Argentine hemorrhagic fever and RVF; however, neither is approved by FDA or commonly available in the United States.

Possible complications

 * Coma
 * Death
 * Disseminated intravascular coagulation (DIC)
 * Kidney failure
 * Liver failure
 * Parotitis
 * Secondary bacterial infections
 * Shock