Hemorrhagic fevers are serious viral infections characterized by bleeding (hemorrhage).
Hemorrhagic fevers can be caused by many different types of virus.
Depending on the type of virus, these infections may be spread through contact with the skin or body fluids of an infected person, through the droppings or urine of infected rodents, or through insect bites or when contaminated food is eaten.
Symptoms may include fever, muscle and body aches, headache, and vomiting, as well as bleeding from the mouth, nose, or internal organs.
To confirm the diagnosis, doctors do blood tests or sometimes examine infected tissue under a microscope.
Treatment includes giving fluids and other treatments to maintain body functions.
Antiviral medications are effective against some hemorrhagic fever viruses but not against all of them.
(See also Overview of Arbovirus, Arenavirus, and Filovirus Infections.)
Several groups of viruses can cause fever and other symptoms that are accompanied by severe bleeding (hemorrhagic fever).
The viruses most often associated with hemorrhagic fever are
Filoviruses, such as Ebola and Marburg viruses, which occur mainly in parts of Central and West Africa
Arenaviruses, such as Lassa fever virus in West Africa and Junin virus in South America
Bleeding occurs because the viruses make the blood vessels leak. These infections are often fatal.
Many other viruses, including some South American arenaviruses, dengue virus, hantavirus, and yellow fever virus, can cause hemorrhagic symptoms.
Some of these viruses naturally reside in animals. Some are spread by the bite of a tick or mosquito.
