Also called: VHFs
Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.
About Hemorrhagic Fevers
Viral hemorrhagic fevers (VHFs) are a group of illnesses caused by four families of viruses. These include the Ebola and Marburg, Lassa fever, and yellow fever viruses. VHFs have common features: they affect many organs, they damage the blood vessels, and they affect the body's ability to regulate itself. Some VHFs cause mild disease, but some, like Ebola or Marburg, cause severe disease and death.
VHFs are found around the world. Specific diseases are usually limited to areas where the animals that carry them live. For example, Lassa fever is limited to rural areas of West Africa where rats and mice carry the virus.
The risk for travelers is low, but you should avoid visiting areas where there are disease outbreaks. Because there are no effective treatments for some of these viral infections, there is concern about their use in bioterrorism.
Centers for Disease Control and Prevention
It sits within Infections.
The lead U.S. institute for this subject is the National Institute of Allergy and Infectious Diseases.
When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.
Research on Hemorrhagic Fevers
502 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.
What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.
Research currently under way
- Phase 1 Challenge Study Using rDEN2delta30-7169 to Evaluate Host-Pathogen Interactions in Primary, Homotypic, and Heterotypic Dengue Virus InfectionNational Institute of Allergy and Infectious Diseases (NIAID)
- Zanamivir Treatment of Vascular Permeability in Dengue (ZAP-DENGUE)George Washington University
- A Study on a New Tetravalent Dengue Vaccine (TDV) Formulation in Healthy AdultsTakeda
- Butantan-DV Vaccine in Elderly Populations (DEN-04-IB)Butantan Institute
- Trial to Evaluate the Immunogenicity and Safety of the Co-administration of Live Attenuated Dengue and Chikungunya Vaccines Compared to Separate Administration in Adults Aged 18 to 59 Years.Butantan Institute
- A Study to Assess the Efficacy, Safety and Pharmacokinetics of EYU688 in Patients With Dengue FeverNovartis Pharmaceuticals
Research already completed
- Long-Term Safety and Antibody Persistence of TDV and the Impact of a Booster DoseTakeda
- Investigating Vector-Borne Determinants of Aedes Transmitted Arboviral Infections in Cambodia: An Observational Longitudinal Cohort Study in ChildrenNational Institute of Allergy and Infectious Diseases (NIAID)
- Long-Term Neurologic and Neurocognitive Sequelae Following Pediatric Ebola Virus in LiberiaNational Institute of Neurological Disorders and Stroke (NINDS)
- Prevalence and Incidence of Lassa Virus Infection in Southern MaliNational Institute of Allergy and Infectious Diseases (NIAID)
- Study to Evaluate the Immunogenicity and Safety of a Heterologous Vaccine Regimen Against EbolaUniversiteit Antwerpen
Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.
Where to read more
Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.
Start Here
- About Viral Hemorrhagic FeversCenters for Disease Control and Prevention
- Viral Hemorrhagic FeversMayo Foundation for Medical Education and Research
Related Issues
- Travelers' Health: Yellow FeverCenters for Disease Control and Prevention
Clinical Trials
- ClinicalTrials.gov: Hemorrhagic Fevers, ViralNational Institutes of Health
- ClinicalTrials.gov: Lassa FeverNational Institutes of Health
- ClinicalTrials.gov: Yellow FeverNational Institutes of Health
Medical subject headings
Clinicians and researchers index this subject under Hemorrhagic Fevers, Viral. These are the terms to use when searching medical literature.
This page is built from the MedlinePlus health topic record for Hemorrhagic Fevers, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.