Ebolavirus and haemorrhagic syndrome

The Ebola virus is a highly virulent, single-stranded ribonucleic acid virus which affects both humans and apes and has fast become one of the world's most feared pathogens. The virus induces acute fever and death, with haemorrhagic syndrome occurring in up to 90% of patients. The known species within the genus Ebolavirus are Bundibugyo, Sudan, Zaire, Reston and Tai Forest. Although endemic in Africa, Ebola has caused worldwide anxiety due to media hype and concerns about its international spread, including through bioterrorism. The high fatality rate is attributed to unavailability of a standard treatment regimen or vaccine. The disease is frightening since it is characterised by rapid immune suppression and systemic inflammatory response, causing multi-organ and system failure, shock and often death. Currently, disease management is largely supportive, with containment efforts geared towards mitigating the spread of the virus. This review describes the classification, morphology, infective process, natural ecology, transmission, epidemic patterns, diagnosis, clinical features and immunology of Ebola, including management and epidemic containment strategies

Reclassifying bioterrorism risk: Are we preparing for the proper pathogens?

Existing classifications of potential biological weapons, acknowledge only limited important parameters of biological weapon potential. Certain pathogen factors would further influence the outcome of a potential attack in context with social and political aspects of the time and space of the attack. The importance of these factors was investigated through various attack scenarios that have been developed by the authors, and an individual score for each of these factors was calculated, based on the overall effect their variation had in the scenario outcome. A new classification score for potential biological weapons was subsequently developed, one, which drastically alters the perception of risk for certain pathogens, such as filoviruses and anthrax. This frame further allows for more accurate evaluation of the bioweapon potential of agents such as avian flu. Recognition of intervening factors and proper assessment of the actual risk might augment in proper distribution of interest and funds on relevant medical research

Epidemiology of the ebola virus: facts and hypotheses

Marburg and Ebola viruses are emerging pathogens recognized since 1967, and in 1976, when they were first identified. These viruses are the only members of the Filoviridae family. They cause severe, frequently fatal, hemorrhagic fever. Each genus includes some serotypes with the distinctive characteristics to cause high mortality rate during outbreaks. The Ebola-Zaire subtype is the most lethal variant. The epidemiology of human pathogenic filovirus is reviewed in this paper considering the most relevant facts. Primary human cases arise probably through close contact with infected primates. This point may be the key to preventing the introduction of these viruses in human populations. Once introduced in humans, the infection may spread through close contact with infected individuals or their body fluids, particularly in hospital environments. A main feature of filovirus outbreaks is the occurrence of cycles of secondary infection.

Ebola: síndrome letal / Ebola: a fatal syndrome

No other clinical entity has attached more attention now-a-day than those precipitated by the infection with a Hemorrhagic Fever Virus. Potentially caused by Arena, Bunya, Flavi, and Filoviradae, only the latter has had such a major impact throughout the world. Two major genuses have been recognized since they become evident for the first time in 1967, the single-species Marburg, and the 3-species-Ebola (E. zaire, sudan and reston). With the exception of the 2 outbreaks of E. reston (Washington, USA 1989-1993), all of them have taken place in Africa, where the virus is still hiding among the wild-life of the Tropical Rain Forest. Currently (in April 1995) the reemergence of Ebola virus has once more proven its fatality, leaving around 170 deaths in Zaire, 250 miles from its capital, Kinshasa. There is worldwide alert, sponsored by the CDC in Atlanta, the World Health Organization and the authorities in Zaire regarding its potential spreading to naive regions, in and out of Africa. The characteristic clinical picture of a viral hemorrhagic fever has no match. After a 2-21 days incubation period a viral-like illness develops. As days go by, symptoms worsen, and by the 7th day, a severe and diffuse bleeding tendency ensues. The individual's death is the most likely outcome in the great majority of cases. As a lethal virus, without an available treatment and a possible airborne-route of transmission, Ebola virus will always be considered a persistent threat to the global health

Virus ébola / Ebola virus

La familia Filoviridae esta compuesta por cuatro virus: Marburg y tres subtipos de Ebola (Ebola Zaire, Ebola Sudán y Ebola Reston). El género de los filovirus son muy similares morfológicamente y en densidad; son visualizados como partículas pleomórficas, grandes y filamentosas, frecuentemente adquieren configuraciones circulares o en U. La longitud del virión es variable (hasta 14000nm) pero el diámetro es uniforme en 80 nm. El virus consta de una nucleocápside, rodeada por una cápside helicoidal; hay un canal axial en la nucleocápside, una membrana formada por proyecciones de 10 nm, y todo el virión está cubierto por una unidad de lipoproteína derivada de la célula huésped. El genoma consta de una molécula de una cadena única de polaridad negativa de RNA que no es infeccioso por sí mismo, cuyo orden es: región 3I, nucleoproteína, proteína viral estructural, VP35, glicoproteína VP40, VP30, VP24, polimerasa (L) y región 5I