What are viral hemorrhagic fevers (VHFs)?

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:

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.

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:

  • Body aches
  • Dizziness
  • Fatigue (extreme tiredness)
  • Fever
  • Headache
  • Rashes

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)
  • Death

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