Viral hemorrhagic fevers (VHFs) are a group of febrile illnesses caused by RNA viruses from several viral families. These infectious viruses lead to a potentially lethal disease syndrome characterized by fever, malaise, vomiting, mucosal and gastrointestinal bleeding, edema, and hypotension. The four viral families known to cause VHF disease in humans naturally reside in an animal reservoir host or arthropod vector. This volume presents the most current information on each virus. It examines the fevers caused by these viruses, their mechanisms for spreading, their molecular pathogenesis, host pathogen immune interactions, and detection, treatment, and prevention.