Viral hemorrhagic fevers

Overview

Viral hemorrhagic (hem-uh-RAJ-ik) fevers are infectious diseases that can be life-threatening. They can damage the walls of tiny blood vessels, making them leak. And they can keep the blood from clotting.

Some viral hemorrhagic fevers include:

• Crimean-Congo.
• Dengue.
• Ebola.
• Hantavirus.
• Lassa.
• Marburg.
• Yellow fever.

These diseases most often happen in tropical areas, such as Central Africa. In the United States, most people who get them have traveled to one of those areas.

There are vaccines and treatments for only a few types of viral hemorrhagic fevers. Until there are vaccines for more of them, do your best to keep from getting viral hemorrhagic fevers.

Symptoms

Symptoms of viral hemorrhagic fevers vary by disease. Mainly, early symptoms can include:

• Fever.
• Tiredness, weakness or feeling unwell.
• Muscle, bone or joint aches.
• Nausea and vomiting.
• Diarrhea.

Symptoms that can become life-threatening

Worse symptoms include:

• Bleeding under the skin, inside the body or from the mouth, eyes or ears.
• Nervous system issues.
• Coma.
• Confused thinking and not being aware of surroundings, called delirium.
• Kidney failure.
• Trouble breathing, called respiratory failure.
• Liver failure.

When to see a doctor

The best time to see a healthcare professional is before you travel to a country where you might get an infectious disease. Then you can get vaccinations and pre-travel advice for staying healthy.

If you get symptoms once you return home from your trip, talk to a healthcare professional. If possible, see one trained in international medicine or infectious diseases. Tell your care professional where you've traveled.

Causes

Viral hemorrhagic fevers are spread by contact with infected animals. The viruses that cause viral hemorrhagic fevers live in many animal hosts. Most often, the hosts include mosquitoes, ticks, rodents, nonhuman primates or bats.

How is it transmitted?

Mosquito or tick bites spread some viral hemorrhagic fevers. Infected body fluids, such as blood, saliva or semen, spread other viral hemorrhagic fevers. You can get a few types by inhaling infected rat feces or urine.

Some viral hemorrhagic fevers also can spread from person to person.

If you travel to an area where a hemorrhagic fever is common, you can be infected there but not get symptoms until after you return home. It might take from 2 to 21 days to get symptoms. It depends on the type of virus.

Risk factors

Living in or traveling to an area where a certain viral hemorrhagic fever is common raises your risk of getting infected with that virus. Other factors that can increase your risk include:

• Working with infected people.
• Killing or eating infected animals.
• Having unprotected sex with an infected person.
• Working outdoors or in rat-infested buildings.
• Being around infected blood or other body fluids.

Complications

Viral hemorrhagic fevers can cause:

• Septic shock.
• Failure in more than one organ.
• Death.

Prevention

It can be hard to prevent viral hemorrhagic fevers. If you live in, work in or travel to areas where these diseases are common, use protective barriers when working with blood or body fluids. For instance, wear gloves, gowns, eye masks and face shields. Also take care working with lab specimens and waste.

Get vaccinated

The yellow fever vaccine is mainly safe and works well. But rarely, serious side effects can happen. The yellow fever vaccine isn't for children younger than 9 months of age, pregnant people or people whose immune systems don't work well.

There's also an Ebola vaccination that protects against one type of Ebola. It's for healthcare professionals who work in areas of outbreak. Check with the Centers for Disease Control and Prevention about the countries you plan to visit. For some, you must prove that you've been vaccinated.

Watch out for mosquitoes and ticks

Do your best to stay away from mosquitoes and ticks when traveling in areas that have outbreaks of viral hemorrhagic fevers. Wear light-colored long pants and long-sleeved shirts. Or, even better, wear clothes coated with permethrin. Don't put permethrin on the skin.

Try not to be outside at dusk and dawn when mosquitoes are most active. Put mosquito repellent with a 20% to 25% concentration of DEET on your skin and clothing. If you're staying in tents or hotels, use bed nets and mosquito coils.

Guard against rodents

If you live where there are outbreaks of viral hemorrhagic fevers, take steps to keep rodents out of your home:

• Keep pet food covered and stored in rodent-proof containers.
• Store trash in rodent-proof containers. Clean the containers often.
• Get rid of garbage often.
• Make sure doors and windows have screens that fit well.
• Keep woodpiles, stacks of bricks and other materials at least 100 feet from your house.
• Mow your grass closely. Trim brush to within 100 feet of your house.