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fredag 4 mars 2011

Afrikan Ebolavirus aiheuttaa verenvuotokuumetta. Filippiinien Reston Ebolavirus ei.

  • LÄHDE 1.
Dr Heinz Feldmann MD a b, Thomas W Geisbert PhD cEbola haemorrhagic fever
The Lancet, Volume 377, Issue 9768, Pages 849 - 862, 5 March 2011
doi:10.1016/S0140-6736(10)60667-8Cite or Link Using DOI
Published Online: 16 November 2010

Summary

Ebola viruses are the causative agents of a severe form of viral haemorrhagic fever in man, designated Ebola haemorrhagic fever, and are endemic in regions of central Africa. The exception is the species Reston Ebola virus, which has not been associated with human disease and is found in the Philippines.

Ebola virus constitutes an important local public health threat in Africa, with a worldwide effect through imported infections and through the fear of misuse for biological terrorism.

Ebola virus is thought to also have a detrimental effect on the great ape population in Africa. Case-fatality rates of the African species in man are as high as 90%, with no prophylaxis or treatment available.Ebola virus infections are characterised by

  • immune suppression and
  • a systemic inflammatory response that causes
  • impairment of the vascular, coagulation, and immune systems,
  • leading to multiorgan failure and shock,
  • and thus, in some ways, resembling septic shock.
Lancet

  • LÄHDE 2. 

Siddhartha Mahanty a, Dr Mike Bray b
Pathogenesis of filoviral haemorrhagic fevers
The Lancet Infectious Diseases, Volume 4, Issue 8, Pages 487 - 498, August 2004
doi:10.1016/S1473-3099(04)01103-XCite or Link Using DOI

Summary

The filoviruses, marburgvirus and ebolavirus, cause epidemics of haemorrhagic fever with high casefatality rates.

The severe illness results from a complex of pathogenetic mechanisms that enable the virus
  • to suppress innate and adaptive immune responses,
  • infect and kill a broad variety of cell types,
  • and elicit strong inflammatory responses
  • and disseminated intravascular coagulation (DIC),
  • producing a syndrome resembling septic shock.
Most experimental data have been obtained on Zaire ebolavirus, which causes uniformly lethal disease in experimentally infected non-human primates but produces a broader range of outcomes in naturally infected human beings.
10—30% of patients can survive the illness by mobilising adaptive immune responses, and there is limited evidence that mild or symptomless infections also occur.

The other filoviruses that have caused human disease, Sudan ebolavirus, Ivory Coast ebolavirus, and marburgvirus, produce a similar illness but with somewhat lower case-fatality rates.

Variations in outcome during an epidemic might be due partly to genetically determined differences in innate immune responses to the viruses.
  • Recent studies in non-human primates have shown that blocking of certain host responses, such as the coagulation cascade, can result in reduced viral replication and improved host survival.

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