What are viral hemorrhagic fevers (VHFs)?
VHFs are a group of infectious diseases caused by viruses. These infections can damage the blood vessels and cause dangerous bleeding in organs throughout the body.
While some VHFs can cause mild illness, others can be very serious, even deadly. There are several VHF diseases and variations, including:
- Ebola virus disease (EVD), also known as Ebola hemorrhagic fever
- Hantavirus pulmonary syndrome
- Lassa fever
- Marburg hemorrhagic fever
- Yellow fever
How common are viral hemorrhagic fevers (VHFs)?
Each VHF virus exists only in geographic areas where its host species lives. Most VHF viruses do not occur naturally in the US, except for Hantaviruses. These are spread by rodents. In the US, these rodents include the deer mouse, white-footed mouse, the cotton rat and the rice rat.
When people travel to other countries, they can bring viral diseases back to their home countries. During an outbreak of Ebola virus disease (EVD) that affected more than 28,000 people in West Africa, doctors diagnosed 11 cases of the disease in the U.S.
Symptoms and Causes
What causes viral hemorrhagic fevers (VHFs)?
Viruses cause VHFs. These viruses occur naturally in some animals and insects. The viruses usually infect people through contact with fluids or excretions from animals or other people infected with the disease.
What are the symptoms of a viral hemorrhagic fever (VHF)?
Symptoms of VHFs vary depending on the disease. Early in the illness, they often include:
In severe cases, VHFs can cause symptoms that include:
- Bleeding from the eyes, ears or mouth
- Difficulty breathing
- Coma (a prolonged and deep unconscious state)
- Internal bleeding
- Organ failure
- Shock (a condition where the organs do not receive enough blood or oxygen)
What are the risk factors for viral hemorrhagic fevers (VHFs)?
People at higher risk for VHFs include those who:
- Have direct contact with natural hosts of VHF viruses including mosquitoes, ticks or rodents
- Have close contact with infected people
- Travel to developing countries
Diagnosis and Tests
How are viral hemorrhagic fevers (VHFs) diagnosed?
Doctors diagnose VHFs with blood and urine tests. These tests allow a doctor to examine a sample of blood or urine to see if it contains proteins and antibodies associated with VHFs. Because these diseases can spread through contact with infected blood and urine, your doctor will take many precautions during these tests.
Management and Treatment
How are viral hemorrhagic fevers (VHFs) managed or treated?
There are no treatments specifically for VHFs. Doctors treat them similarly to other viral illnesses. In some cases, doctors use antiviral drugs to prevent complications associated with some of the viruses.
Treatment usually involves managing the symptoms of the disease and varies according to the virus involved. It often includes fluids for hydration, delivered intravenously (through a needle inserted into a vein) or orally (by mouth).
What complications are associated with viral hemorrhagic fevers (VHFs)?
Severe cases of VHFs can cause life-threatening complications including:
Can viral hemorrhagic fevers (VHFs) be prevented?
Yellow fever is the only VHF with a vaccine for prevention. Research is underway on developing vaccines for other VHFs. To reduce your risk of being infected, avoid:
- Travel to areas with VHF outbreaks
- Mosquito and tick bites by wearing protective clothing and suggested insecticides when traveling internationally
- Contact with rodents and their secretions
- Contact with people who are sick after traveling to a developing country
- Direct contact with human blood and body fluids. Use proper protective gear.
Outlook / Prognosis
What is the prognosis (outlook) for people with viral hemorrhagic fevers (VHFs)?
The outlook for people with a VHF varies according to the specific disease.
When should I call the doctor if I have or think I have a viral hemorrhagic fever (VHF)?
Contact your doctor if you experience the signs and symptoms of VHFs. It is important to seek medical attention quickly to avoid spreading the disease. Tell your doctor if you have recently traveled internationally.
What questions should I ask my doctor if I have or think I have a viral hemorrhagic fever (VHF)?
- How serious is my condition?
- Are there other conditions that could be causing my symptoms?
- What can I do to avoid infecting others?
- What are my treatment options?
When can I go back to my regular activities if I have been diagnosed with a viral hemorrhagic fever (VHF)?
Healing times for VHFs vary according to the disease and its severity. Your doctor will tell you when you can return to your usual activities.