Viral hemorrhagic fever

Viral hemorrhagic fevers (VHFs) are a diverse group of infectious diseases. "Viral" refers to a virus being the etiologic factor (as opposed to, for instance, a parasite or a bacterium), "hemorrhagic" as in "bleeding-associated," and "fever" meaning an unusually high body temperature. Indeed, bleeding and fever are typically the most prevalent and severe symptoms of VHFs.

There are five known families of (RNA) viruses known to cause hemorrhagic fever: Arenaviridae, Filoviridae, Flaviviridae, Hantaviridae, and Rhabdoviridae. Some VHFs are considered mild, such as nephropathia epidemica (caused by a hantavirus), while others tend to be debilitating or even lethal, such as ebola fever (caused by a filovirus). All VHFs have the potential to result in hypotension, high fever, and death.

Both humans and non-human animals can be infected. VHFs are often zoonoses, meaning they can be transmitted from wild animals to human populations; for instance, the Lassa arenavirus is spread by mice.