Ebola virus disease

Ebola virus disease
Name	Ebola virus disease
Field	Virology, Infectious disease
Symptoms	Fever, hemorrhage, vomiting, diarrhea, shock
Complications	Multi-organ failure, coagulopathy, secondary infections
Onset	2–21 days after exposure
Causes	Filoviridae viruses (Ebolavirus species)
Prevention	Vaccination, infection control, personal protective equipment
Treatment	Supportive care, antiviral monoclonal antibodies, experimental therapies
Deaths	Varies by outbreak; up to ~90% case fatality historically

Ebola virus disease Ebola virus disease is an acute, severe, often fatal illness caused by viruses of the family Filoviridae. It presents with systemic febrile syndrome, multi-organ involvement, and variable hemorrhagic manifestations; outbreaks have major public health, humanitarian, and economic impacts. Research into pathogenesis, vaccines, and therapeutics has involved institutions and initiatives across World Health Organization, Centers for Disease Control and Prevention, United States Food and Drug Administration, and numerous academic centers.

Overview

Ebola virus disease is caused by several species within the genus Ebolavirus, including agents first described after an outbreak near the Ebola River; other named species have emerged in Democratic Republic of the Congo, Sudan, and Reston incidents. Clinical severity ranges from mild illness to fatal hemorrhagic fever; historical case fatality rates differ by outbreak, healthcare infrastructure, and available countermeasures. International responses have included deployment by Médecins Sans Frontières, coordination by United Nations agencies, and research partnerships with institutions such as National Institutes of Health and pharmaceutical companies.

Virology and Pathogenesis

Ebolaviruses are filamentous, enveloped, negative-sense single-stranded RNA viruses in the family Filoviridae. The viral genome encodes proteins including glycoprotein (GP), nucleoprotein (NP), and VP35/VP24, which mediate immune evasion and replication; GP is the primary antigenic target in vaccine design led by groups at Walter Reed Army Institute of Research and vaccine developers like Merck & Co.. Host entry involves GP interaction with cellular receptors, macropinocytosis, and endosomal fusion; subsequent dysregulation of innate immunity, endothelial dysfunction, and coagulation cascade activation produce clinical disease. Pathogenesis studies reference models used at Pasteur Institute and Rockefeller University and postmortem findings coordinated with pathology departments at institutions such as Johns Hopkins University.

Transmission and Epidemiology

Transmission occurs via direct contact with blood, secretions, organs, or bodily fluids of infected persons and through exposure to contaminated surfaces and materials; zoonotic spillover events implicate reservoir hosts such as certain bat species studied by teams from Smithsonian Institution and Woods Hole Oceanographic Institution collaborations. Nosocomial amplification has been documented in settings lacking infection prevention controls; outbreaks in Guinea, Sierra Leone, and Liberia (2013–2016) illustrated rapid urban propagation and international spread to locations including United Kingdom, Spain, and United States. Surveillance and contact tracing organized under Africa Centres for Disease Control and Prevention and national public health agencies shape outbreak response; travel screening and airport measures were implemented by agencies like European Centre for Disease Prevention and Control.

Clinical Presentation and Diagnosis

Initial symptoms mimic other tropical febrile illnesses described in regions like West Africa and include sudden onset fever, fatigue, myalgia, and headache; progression may lead to vomiting, diarrhea, abdominal pain, and hemorrhagic signs. Laboratory abnormalities include leukopenia, thrombocytopenia, elevated transaminases, and coagulopathy; definitive diagnosis relies on nucleic acid amplification tests performed in biosafety level facilities at laboratories such as those in the Global Outbreak Alert and Response Network. Point-of-care antigen detection and serologic assays used by field teams from Médecins Sans Frontières and national reference labs assist triage. Differential diagnoses involve diseases treated at centers like Centers for Disease Control and Prevention reference lists, including Lassa fever, malaria, and yellow fever.

Prevention and Treatment

Prevention strategies emphasize vaccination, personal protective equipment, safe burial practices, and community engagement coordinated by agencies such as World Health Organization and nongovernmental organizations like Red Cross and Red Crescent Movement. Licensed vaccine candidates, including viral-vectored immunizations developed by groups at Merck & Co. and trialled in ring-vaccination studies in collaboration with London School of Hygiene & Tropical Medicine, have demonstrated efficacy. Therapeutic advances include monoclonal antibody cocktails authorized by regulatory agencies such as United States Food and Drug Administration and antivirals researched at National Institutes of Health. Supportive care—fluid resuscitation, electrolyte management, hemodynamic support, and treatment of co-infections—provided at treatment centers modeled on protocols from World Health Organization and Doctors Without Borders improves outcomes.

History and Outbreaks

Ebolaviruses were first recognized following a 1976 outbreak near the Ebola River in Zaire (now Democratic Republic of the Congo), with simultaneous occurrences in Sudan. Subsequent notable outbreaks include the 1995 Kikwit episode, recurrent episodes in Democratic Republic of the Congo, and the large 2013–2016 epidemic centered in Guinea, Sierra Leone, and Liberia that prompted international emergency declarations by World Health Organization and responses by United Nations peacekeeping and humanitarian missions. More recent outbreaks in eastern Democratic Republic of the Congo engaged response efforts by African Union partners and clinical trials overseen by entities such as Wellcome Trust. The history of Ebola research and policy intersects with global health governance, biosafety developments at Centers for Disease Control and Prevention, and legal frameworks for outbreak reporting under International Health Regulations.

Category:Viral diseases