Viral hemorrhagic fever

Viral hemorrhagic fevers (VHFs) are a group of severe, life-threatening infectious diseases caused by several distinct families of RNA viruses, including Filoviridae (Ebola, Marburg), Arenaviridae (Lassa fever, Argentine hemorrhagic fever), Bunyavirales (Crimean-Congo hemorrhagic fever, Hantavirus), and Flaviviridae (Dengue hemorrhagic fever, Yellow fever). These diseases are characterized by damage to the vascular system, leading to increased vascular permeability, coagulation abnormalities, and in severe cases, widespread hemorrhaging. VHFs are primarily zoonotic, transmitted to humans through contact with infected animals, arthropod vectors (ticks, mosquitoes), or person-to-person spread via infected body fluids. The clinical presentation typically begins with nonspecific symptoms including high fever, fatigue, myalgia, headache, and dizziness, progressing to more severe manifestations such as bleeding from mucous membranes, petechiae, ecchymoses, internal hemorrhaging, hypotension, and multi-organ failure. The vascular endothelium, liver, spleen, and hematopoietic system are particularly affected. Thrombocytopenia, disseminated intravascular coagulation (DIC), and shock are common complications in advanced disease. Case fatality rates vary widely depending on the specific virus, ranging from less than 1% to up to 90% (as seen in some Ebola outbreaks). Treatment is largely supportive, including fluid and electrolyte management, blood product transfusion, and hemodynamic support. Ribavirin has demonstrated efficacy against certain arenaviruses and bunyaviruses (e.g., Lassa fever, Crimean-Congo hemorrhagic fever). Monoclonal antibody therapies (such as Inmazeb for Ebola) have been developed for specific VHFs. Vaccines exist for Yellow fever (widely available) and Ebola (rVSV-ZEBOV), while vaccines for other VHFs remain in development. Prevention strategies focus on vector control, infection control measures, and avoiding contact with reservoir hosts.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Viral hemorrhagic fever