Viral hemorrhagic fever (patient information)

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Viral hemorrhagic fever
Overview
What are the symptoms?
What are the causes?
Who is at highest risk?
When to seek urgent medical care?
Diagnosis
Treatment options
Where to find medical care for Viral hemorrhagic fever?
What to expect (Outlook/Prognosis)?
Possible complications
Prevention
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Viral hemorrhagic fevers (VHF) 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 may vary according to the disease, but in general, patients with VHF present with:

• Abrupt onset of fever
• Myalgias
• Prostration
• Coagulopathy with:

• Petechial rash
• Ecchymoses, sometimes with overt bleeding

• Vascular endothelial damage may lead to:

• Shock,
• Pulmonary edema
• Liver injury

Signs seen with specific viruses may include:

• Renal failure (HFRS)
• Ecchymoses (CCHF)
• Hearing loss
• Anasarca
• 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, including:

• Filoviruses, such asEbola and Marburg viruses
• Arenaviruses, such as Lassa fever, Lujo, Guanarito, Machupo, Junin, Sabia, and Chapare viruses
• Bunyaviruses, such as Rift Valley fever (RVF), Crimean-Congo hemorrhagic fever (CCHF
• Hantaviruses
• Flaviviruses, such as dengue, yellow fever, Omsk hemorrhagic fever, Kyasanur Forest disease, and Alkhurma viruses

Who is at highest risk?

Some VHFs are spread on person to person basis, through direct contact with symptomatic patients, body fluids, cadavers or through inadequate infection control measures (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 or contact with contaminated materials.
• 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. Common symptoms of Viral hemorrhagic fever include:

• Fever
• Bleeding, through body orificies, such as: mouth, eyes, or ears
• Fatigue
• Dizziness
• Muscle pain
• Weakness
• Exhaustion
• Seizures
• Kidney problems

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 the following tests:

• Immunohistochemistry
• RT-PCR
• 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.

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

The 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
• 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 vector borne disease
• Direct contact should be avoided with corpses of patients suspected of having died of Ebola, Marburg, or Old World arenavirus infection

• Standard precautions and contact and droplet precautions for suspected VHF case-patients are recommended to avoid transmission
• 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

Sources

http://wwwnc.cdc.gov/travel/yellowbook/2012/chapter-3-infectious-diseases-related-to-travel/viral-hemorrhagic-fevers.htm Template:WSTemplate:WH