Marburgvirus: Difference between revisions
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==Description and Significance== | ==Description and Significance== | ||
Marburg is an extremely dangerous virus as it has a human fatality rate of 25-90%, with outbreaks are impossible to predict or prevent.[1][7] Marburgvirus was the first ever filovirus recognized, discovered in 1967 when laboratory workers in Marburg, Germany developed hemorrhagic fever after handling tissue of African green monkeys from Uganda. The 1967 outbreak proved fatal in seven of the 37 cases. In 1975 the virus reemerged in Johannesburg, South Africa in a person who had been traveling in Zimbabwe. A traveling companion and a nurse of the person became infected. In 1980, another man who had been traveling near the same region became infected and transmitted the virus to his physician. Another Marburg infection was recognized in 1987 of a traveling man who became ill and soon died. In 1998, an outbreak occurred in Congo amongst individuals who had been working in a gold mine. Attempts to isolate the virus from all locations were unsuccessful. Since then, cases of Marburgvirus have been rare and sporadic, the most recent occurring in 2008 in Colorado of a man who had been traveling in Uganda.[5] The only other filovirus is the Ebola virus, discovered after Marburg in 1976.[3] The natural origins remain a complete mystery.[1] | Marburg is an extremely dangerous virus as it has a human fatality rate of 25-90%, with outbreaks that are impossible to predict or prevent.[1][7] Marburgvirus was the first ever filovirus recognized, discovered in 1967 when laboratory workers in Marburg, Germany developed hemorrhagic fever after handling tissue of African green monkeys from Uganda. The 1967 outbreak proved fatal in seven of the 37 cases. In 1975 the virus reemerged in Johannesburg, South Africa in a person who had been traveling in Zimbabwe. A traveling companion and a nurse of the person became infected. In 1980, another man who had been traveling near the same region became infected and transmitted the virus to his physician. Another Marburg infection was recognized in 1987 of a traveling man who became ill and soon died. In 1998, an outbreak occurred in Congo amongst individuals who had been working in a gold mine. Attempts to isolate the virus from all locations were unsuccessful. Since then, cases of Marburgvirus have been rare and sporadic, the most recent occurring in 2008 in Colorado of a man who had been traveling in Uganda.[5] The only other filovirus is the Ebola virus, discovered after Marburg in 1976.[3] The natural origins remain a complete mystery.[1] | ||
==Genome Structure== | ==Genome Structure== | ||
Revision as of 08:17, 22 April 2009
Classification
Viruses; ssRNA viruses; ssRNA negative-strand viruses; Mononegavirales; Filoviridae
Species
Marburgvirus Marburg
Description and Significance
Marburg is an extremely dangerous virus as it has a human fatality rate of 25-90%, with outbreaks that are impossible to predict or prevent.[1][7] Marburgvirus was the first ever filovirus recognized, discovered in 1967 when laboratory workers in Marburg, Germany developed hemorrhagic fever after handling tissue of African green monkeys from Uganda. The 1967 outbreak proved fatal in seven of the 37 cases. In 1975 the virus reemerged in Johannesburg, South Africa in a person who had been traveling in Zimbabwe. A traveling companion and a nurse of the person became infected. In 1980, another man who had been traveling near the same region became infected and transmitted the virus to his physician. Another Marburg infection was recognized in 1987 of a traveling man who became ill and soon died. In 1998, an outbreak occurred in Congo amongst individuals who had been working in a gold mine. Attempts to isolate the virus from all locations were unsuccessful. Since then, cases of Marburgvirus have been rare and sporadic, the most recent occurring in 2008 in Colorado of a man who had been traveling in Uganda.[5] The only other filovirus is the Ebola virus, discovered after Marburg in 1976.[3] The natural origins remain a complete mystery.[1]
Genome Structure
Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are genetically distinct with 7 genes and a total molecular length of approximately 19 kb (19112 bp), making them the owners of the largest known genomes of negative-strand RNA viruses. The virions appear long and filamentous, occasionally branched. In addition, the virions may appear as "6"-shaped, "U"-shaped, or circular configurations. [1][2]
Cell Structure, Metabolism and Life Cycle
Viruses are inherently dependent on a hosts machinery to replicate their genetic information. The viral genome encodes structural proteins and non-structural proteins. Virions consist of 5 structural proteins located in the envelope (surface glycoprotein), nucleocapsid (NP), polymerase complex (transcriptase-polymerase component and RNA-dependent RNA transcriptase-polymerase), matrix.[2]
Ecology and Pathogenesis
The natural history and origin of Marburg viruses remain a total mystery. It appears to be transmitted zoonotically; with human infection occuring from animals. However, all attempts to trace human cases have failed to uncover the reservoir. Recent studies point to African fruit bats as a probable reservoir.[8] Whatever the origin, human to human contact is the main route of infection and transmission in human filoviral hemorrhagic fever outbreaks. However, Marburg virus has been transmitted to primates by aerosol in laboratory experiments.[1] The disease is primarily spread through bodily fluids such as blood, excrement, saliva, and vomit. The hemorrhaging nature of Marburg infection is the main cause of prevalent transmission. The incubation period is anywhere from five to ten days and early symptoms are often mild fever and headache. Symptoms usually last for 1-3 weeks until recovery or death of the infected host.[3] The fatality rate in many African cases has been as high as 90%.[7]
References
[1] Beer et al., 1999: Beer Brigitte, Kurth Reinhard, Bukreyev Alexander Characteristics of Filoviridae: Marburg and Ebola viruses. Naturwissenschaften. 1999; 86(1): 8 - 17. [PubMed: 10024977].
[2] Marburg Virus Transmission [ http://staff.vbi.vt.edu/pathport/pathinfo/pathogens/Marburg_virus_2.html#Marburg_virus ] .
[3] Marburg Hemorrhagic Fever [ http://www.cdc.gov/ncidod/dvrd/spb/mnpages/dispages/marburg.htm ].
[4] Marburg Hemorrhagic Fever [ http://www.cdc.gov/ncidod/dvrd/spb/images/pix/pathimag/Marburg-emb.jpg ].
[5] CDC: Reported Marburg case [ http://www.medicalnewstoday.com/articles/138304.php ].
[6] ICTVdB Marburg: [ http://www.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/01.025.0.01.htm#quickIDX2 ].
[7] World Health Organization [ http://www.who.int/csr/don/2005_08_24/en/index.html ].
[8] Science Magazine [ http://www.sciencedaily.com/releases/2007/08/070822081907.htm ].
Author
Page authored by Justin Aden, student of Prof. Jay Lennon at Michigan State University.
