Symptoms and causes

Symptoms

Signs and symptoms of viral hemorrhagic fevers vary by disease. In general, initial symptoms may include:

  • High fever
  • Fatigue
  • Dizziness
  • Muscle, bone or joint aches
  • Weakness

Symptoms can become life-threatening

Severe cases of some types of viral hemorrhagic fevers may cause bleeding, but people rarely die of blood loss. Bleeding may occur:

  • Under the skin
  • In internal organs
  • From the mouth, eyes or ears

Other signs and symptoms of severe infections can include:

  • Shock
  • Nervous system malfunctions
  • Coma
  • Delirium
  • Kidney failure
  • Respiratory fever
  • Liver failure
  • Sepsis

When to see a doctor

The best time to see a doctor is before you travel to a developing country to ensure you've received any available vaccinations and pre-travel advice for staying healthy.

If you develop signs and symptoms once you return home, consult a doctor, preferably one who focuses on international medicine or infectious diseases. A specialist may be able to recognize and treat your illness faster. Be sure to let your doctor know what areas you've visited.

Causes

The viruses that cause viral hemorrhagic fevers live naturally in a variety of animal and insect hosts — most commonly mosquitoes, ticks, rodents or bats.

Each of these hosts typically lives in a specific geographic area, so each particular disease usually occurs only where that virus's host normally lives. Some viral hemorrhagic fevers also can be transmitted from person to person, and can spread if an infected person travels from one area to another.

How is it transmitted?

The route of transmission varies by specific virus. Some viral hemorrhagic fevers are spread by mosquito or tick bites. Others are transmitted by contact with infected blood or semen. A few varieties can be inhaled from infected rat feces or urine.

If you travel to an area where a particular hemorrhagic fever is common, you may become infected there and then develop symptoms after you return home. It can take up to 21 days for symptoms to develop.

Risk factors

Simply living in or traveling to an area where a particular viral hemorrhagic fever is common will increase your risk of becoming infected with that particular virus. Several other factors can increase your risk even more, including:

  • Working with the sick
  • Slaughtering infected animals
  • Sharing needles to use intravenous drugs
  • Having unprotected sex
  • Working outdoors or in rat-infested buildings

Complications

Viral hemorrhagic fevers can damage your:

  • Brain
  • Eyes
  • Heart
  • Kidneys
  • Liver
  • Lungs
  • Spleen

In some cases, the damage is severe enough to cause death.

Feb. 24, 2016
References
  1. AskMayoExpert. Viral hemorrhagic fevers. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2015.
  2. Viral hemorrhagic fevers. Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/vhf.htm. Accessed Dec. 18, 2015.
  3. Knust B. Viral hemorrhagic fevers. 2016 Yellow Book. Centers for Disease Control and Prevention. http://wwwnc.cdc.gov/travel/yellowbook/2016/infectious-diseases-related-to-travel/viral-hemorrhagic-fevers. Accessed Dec. 18, 2015.
  4. Grey MR, et al. Viral hemorrhagic fevers. In: The Bioterrorism Sourcebook. New York, NY: McGraw-Hill; 2006. http://www.accessmedicine.com. Accessed Dec. 18, 2015.
  5. Clean up rodent food sources and nesting sites. Centers for Disease Control and Prevention. http://www.cdc.gov/rodents/prevent_infestations/clean_up.html. Accessed Dec. 18, 2015.