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=== Genome ===
=== Genome ===


Arenaviruses have a segmented [[RNA]] genome that consists of two single-stranded negative-sense RNAs <ref>{{Citation | pmid = 178925}}</ref>. As with all negative-sense RNA viruses, the genomic RNA alone is not infectious and the viral replication machinery is required to initiate infection within a host cell <ref>{{Citation | pmid = 10729120}}</ref>. Genomic sense RNA packaged into the arenavirus virion is designated negative-sense RNA, and must first be copied into a positive-sense [[mRNA]] in order to produce viral [[protein]] <ref>{{Citation | pmid = 11987804}}</ref>. The two RNA segments are denoted Small (S) and Large (L) <ref>{{Citation | pmid = 178925}}</ref> <ref>{{Citation | pmid = 4734917}}</ref>, and code for four viral proteins in a unique ambisense coding strategy <ref>{{Citation | pmid = 6492264}}</ref> <ref>{{Citation | pmid = 2916333}}</ref>. Each RNA segment codes for two viral proteins in opposite orientation such that the negative-sense RNA genome serves as the template for [[transcription]] of a single [[mRNA]] and the positive-sense copy of the RNA genome templates a second [[mRNA]] <ref>{{Citation | pmid = 11987804}}</ref>. The separate coding sequences of the two viral proteins are divided by an intergenic region RNA sequence that is predicted to fold into a stable hairpin structure <ref>{{Citation | pmid = 6324469}}</ref>.
Arenaviruses have a segmented [[RNA]] genome that consists of two single-stranded negative-sense RNAs {{cite journal |author=Añón MC, Grau O, Segovia ZM, Franzefernández MT |title=RNA composition of Junin virus |journal=J. Virol. |volume=18 |issue=3 |pages=833–8 |year=1976 |month=June |pmid=178925 |pmc=354781 |doi= |url=}}. As with all negative-sense RNA viruses, the genomic RNA alone is not infectious and the viral replication machinery is required to initiate infection within a host cell {{cite journal |author=Lee KJ, Novella IS, Teng MN, Oldstone MB, de La Torre JC |title=NP and L proteins of lymphocytic choriomeningitis virus (LCMV) are sufficient for efficient transcription and replication of LCMV genomic RNA analogs |journal=J. Virol. |volume=74 |issue=8 |pages=3470–7 |year=2000 |month=April |pmid=10729120 |pmc=111854 |doi= |url=}}. Genomic sense RNA packaged into the arenavirus virion is designated negative-sense RNA, and must first be copied into a positive-sense [[mRNA]] in order to produce viral [[protein]] {{cite journal |author=Meyer BJ, de la Torre JC, Southern PJ |title=Arenaviruses: genomic RNAs, transcription, and replication |journal=Curr. Top. Microbiol. Immunol. |volume=262 |issue= |pages=139–57 |year=2002 |pmid=11987804 |doi= |url=}}. The two RNA segments are denoted Small (S) and Large (L) {{cite journal |author=Añón MC, Grau O, Segovia ZM, Franzefernández MT |title=RNA composition of Junin virus |journal=J. Virol. |volume=18 |issue=3 |pages=833–8 |year=1976 |month=June |pmid=178925 |pmc=354781 |doi= |url=}} {{cite journal |author=Pedersen IR |title=Different classes of ribonucleic acid isolated from lymphocytic choriomeningitis virus |journal=J. Virol. |volume=11 |issue=3 |pages=416–23 |year=1973 |month=March |pmid=4734917 |pmc=355116 |doi= |url=}}, and code for four viral proteins in a unique ambisense coding strategy {{cite journal |author=Auperin DD, Romanowski V, Galinski M, Bishop DH |title=Sequencing studies of pichinde arenavirus S RNA indicate a novel coding strategy, an ambisense viral S RNA |journal=J. Virol. |volume=52 |issue=3 |pages=897–904 |year=1984 |month=December |pmid=6492264 |pmc=254611 |doi= |url=}} {{cite journal |author=Auperin DD, McCormick JB |title=Nucleotide sequence of the Lassa virus (Josiah strain) S genome RNA and amino acid sequence comparison of the N and GPC proteins to other arenaviruses |journal=Virology |volume=168 |issue=2 |pages=421–5 |year=1989 |month=February |pmid=2916333 |doi= |url=}}. Each RNA segment codes for two viral proteins in opposite orientation such that the negative-sense RNA genome serves as the template for [[transcription]] of a single [[mRNA]] and the positive-sense copy of the RNA genome templates a second [[mRNA]] {{cite journal |author=Meyer BJ, de la Torre JC, Southern PJ |title=Arenaviruses: genomic RNAs, transcription, and replication |journal=Curr. Top. Microbiol. Immunol. |volume=262 |issue= |pages=139–57 |year=2002 |pmid=11987804 |doi= |url=}}. The separate coding sequences of the two viral proteins are divided by an intergenic region RNA sequence that is predicted to fold into a stable hairpin structure {{cite journal |author=Auperin DD, Galinski M, Bishop DH |title=The sequences of the N protein gene and intergenic region of the S RNA of pichinde arenavirus |journal=Virology |volume=134 |issue=1 |pages=208–19 |year=1984 |month=April |pmid=6324469 |doi= |url=}}.


The extreme termini of each RNA segment contains a 19 [[nucleotide]] highly conserved sequence that is critical for recruitment of the viral replication machinery and initiation of viral [[mRNA]] [[transcription]] and genomic [[replication]] <ref>{{Citation | pmid = 6278715}}</ref> <ref>{{Citation | pmid = 6287720}}</ref> <ref>{{Citation | pmid = 12502835}}</ref> <ref>{{Citation | pmid = 17005649}}</ref> <ref>{{Citation | pmid = 20978208}}</ref>. The conserved 5' and 3' RNA termini sequences are complementary and allows each RNA segment to adopt a double-stranded RNA panhandle structure <ref>{{Citation | pmid = 2435460}}</ref> that maintains the termini in close proximity and results in a circular appearance to purified arenavirus genomic templates visualized by [[electron microscopy]] <ref>{{Citation | pmid = 6682139}}</ref>. The double-stranded RNA panhandle structure is critical for efficient viral RNA synthesis <ref>{{Citation | pmid = 12502835}}</ref> <ref>{{Citation | pmid = 17005649}}</ref>, but potential intertermini double-stranded RNA interactions must be transiently relieved in order to recruit the viral [[polymerase]] <ref>{{Citation | pmid = 20978208}}</ref>.
The extreme termini of each RNA segment contains a 19 [[nucleotide]] highly conserved sequence that is critical for recruitment of the viral replication machinery and initiation of viral [[mRNA]] [[transcription]] and genomic [[replication]] {{cite journal |author=Auperin D, Dimock K, Cash P, Rawls WE, Leung WC, Bishop DH |title=Analyses of the genomes of prototype pichinde arenavirus and a virulent derivative of Pichinde Munchique: evidence for sequence conservation at the 3' termini of their viral RNA species |journal=Virology |volume=116 |issue=1 |pages=363–7 |year=1982 |month=January |pmid=6278715 |doi= |url=}} {{cite journal |author=Auperin DD, Compans RW, Bishop DH |title=Nucleotide sequence conservation at the 3' termini of the virion RNA species of New World and Old World arenaviruses |journal=Virology |volume=121 |issue=1 |pages=200–3 |year=1982 |month=August |pmid=6287720 |doi= |url=}} {{cite journal |author=Perez M, de la Torre JC |title=Characterization of the genomic promoter of the prototypic arenavirus lymphocytic choriomeningitis virus |journal=J. Virol. |volume=77 |issue=2 |pages=1184–94 |year=2003 |month=January |pmid=12502835 |pmc=140842 |doi= |url=}} {{cite journal |author=Hass M, Westerkofsky M, Müller S, Becker-Ziaja B, Busch C, Günther S |title=Mutational analysis of the lassa virus promoter |journal=J. Virol. |volume=80 |issue=24 |pages=12414–9 |year=2006 |month=December |pmid=17005649 |pmc=1676312 |doi=10.1128/JVI.01374-06 |url=}} {{cite journal |author=Kranzusch PJ, Schenk AD, Rahmeh AA, ''et al.'' |title=Assembly of a functional Machupo virus polymerase complex |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=107 |issue=46 |pages=20069–74 |year=2010 |month=November |pmid=20978208 |pmc=2993349 |doi=10.1073/pnas.1007152107 |url=}}. The conserved 5' and 3' RNA termini sequences are complementary and allows each RNA segment to adopt a double-stranded RNA panhandle structure {{cite journal |author=Bishop DH, Auperin DD |title=Arenavirus gene structure and organization |journal=Curr. Top. Microbiol. Immunol. |volume=133 |issue= |pages=5–17 |year=1987 |pmid=2435460 |doi= |url=}} that maintains the termini in close proximity and results in a circular appearance to purified arenavirus genomic templates visualized by [[electron microscopy]] {{cite journal |author=Young PR, Howard CR |title=Fine structure analysis of Pichinde virus nucleocapsids |journal=J. Gen. Virol. |volume=64 (Pt 4) |issue= |pages=833–42 |year=1983 |month=April |pmid=6682139 |doi= |url=}}. The double-stranded RNA panhandle structure is critical for efficient viral RNA synthesis {{cite journal |author=Perez M, de la Torre JC |title=Characterization of the genomic promoter of the prototypic arenavirus lymphocytic choriomeningitis virus |journal=J. Virol. |volume=77 |issue=2 |pages=1184–94 |year=2003 |month=January |pmid=12502835 |pmc=140842 |doi= |url=}} {{cite journal |author=Hass M, Westerkofsky M, Müller S, Becker-Ziaja B, Busch C, Günther S |title=Mutational analysis of the lassa virus promoter |journal=J. Virol. |volume=80 |issue=24 |pages=12414–9 |year=2006 |month=December |pmid=17005649 |pmc=1676312 |doi=10.1128/JVI.01374-06 |url=}}, but potential intertermini double-stranded RNA interactions must be transiently relieved in order to recruit the viral [[polymerase]] {{cite journal |author=Kranzusch PJ, Schenk AD, Rahmeh AA, ''et al.'' |title=Assembly of a functional Machupo virus polymerase complex |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=107 |issue=46 |pages=20069–74 |year=2010 |month=November |pmid=20978208 |pmc=2993349 |doi=10.1073/pnas.1007152107 |url=}}.


The S-segment RNA is approximately 3.5 kb, and encodes the viral nucleocapsid protein (NP) and glycoprotein (GPC) <ref>{{Citation | pmid = 1654373}}</ref>. The L-segment RNA is approximately 7.2 kb, and encodes the viral RNA-dependent RNA-polymerase (L) and a small RING-domain containing protein (Z) <ref>{{Citation | pmid = 2510403}}</ref> <ref>{{Citation | pmid = 2718387}}</ref> <ref>{{Citation | pmid = 2510401}}</ref>.
The S-segment RNA is approximately 3.5 kb, and encodes the viral nucleocapsid protein (NP) and glycoprotein (GPC) {{cite journal |author=Ghiringhelli PD, Rivera-Pomar RV, Lozano ME, Grau O, Romanowski V |title=Molecular organization of Junin virus S RNA: complete nucleotide sequence, relationship with other members of the Arenaviridae and unusual secondary structures |journal=J. Gen. Virol. |volume=72 ( Pt 9) |issue= |pages=2129–41 |year=1991 |month=September |pmid=1654373 |doi= |url=}}. The L-segment RNA is approximately 7.2 kb, and encodes the viral RNA-dependent RNA-polymerase (L) and a small RING-domain containing protein (Z) {{cite journal |author=Iapalucci S, López N, Rey O, Zakin MM, Cohen GN, Franze-Fernández MT |title=The 5' region of Tacaribe virus L RNA encodes a protein with a potential metal binding domain |journal=Virology |volume=173 |issue=1 |pages=357–61 |year=1989 |month=November |pmid=2510403 |doi= |url=}} {{cite journal |author=Iapalucci S, Lopez R, Rey O, ''et al.'' |title=Tacaribe virus L gene encodes a protein of 2210 amino acid residues |journal=Virology |volume=170 |issue=1 |pages=40–7 |year=1989 |month=May |pmid=2718387 |doi= |url=}} {{cite journal |author=Salvato MS, Shimomaye EM |title=The completed sequence of lymphocytic choriomeningitis virus reveals a unique RNA structure and a gene for a zinc finger protein |journal=Virology |volume=173 |issue=1 |pages=1–10 |year=1989 |month=November |pmid=2510401 |doi= |url=}}.
[[File:Example.jpg]]


=== Viral reservoir ===
=== Viral reservoir ===

Revision as of 21:10, 11 August 2011

Arenavirus
Lassa virus virions
Virus classification
Group:
Group V ((−)ssRNA)
Family:
Arenaviridae
Genus:
Arenavirus

Arenavirus is a genus of virus that infects rodents and occasionally humans. At least eight Arenaviruses are known to cause human disease. The diseases derived from Arenaviruses range in severity. Aseptic meningitis, a severe human disease that causes inflammation covering the brain and spinal cord, can arise from the Lymphocytic choriomeningitis virus (LCMV) infection. Hemorrhagic fever syndromes are derived from infections such Guanarito virus (GTOV), Junin virus (JUNV), Lassa virus (LASV) causing Lassa fever, Machupo virus (MACV), Sabia virus (SABV), or Whitewater Arroyo virus (WWAV).[1] Arenaviruses are divided into two groups; the Old World or New World. The differences between these groups are distinguished geographically and genetically. Because of the epidemiological association with rodents, some arenaviruses and bunyaviruses are designated as Roboviruses.

Structure

Viewed in cross-section, they show grainy particles that are ribosomes acquired from their host cells. It is from this characteristic that they acquired the name Arena which comes from the Latin root meaning sand. These are round, pleomorphic, and enveloped with a diameter of 120 nm. The virus contains a beaded nucleocapsid with two single-stranded RNA segments. The nucleocapsid is the basic structure of a virus, consisting of a core of nucleic acid enclosed in a protein coat. The strands of RNA are considered negative sense, but encode genes in both directions and are thus ambisense. The life cycle of the arena virus is restricted to the cell cytoplasm. Virus particles, or virions, are pleomorphic because they vary in appearances but in many cases they are spherical in shape and covered with surface glycoprotein spikes.[2] The sand looking ribosomal structures are not believed to be essential in virus replication but they certainly give this replicating virus reason to its name.

Virology

Virology is the study of viruses and virus-like agents including their structure, classification, evolution, and ways to infect and exploit cells for virus reproduction, the diseases they cause, and the techniques that can be used to isolate and even cure them if possible.

Classification

Arenaviruses can be divided into two serogroups, which differ genetically and by geographical distribution:[3] When the virus is classified “Old World” this means it was found in the Eastern Hemisphere in places such as Europe, Asia, and Africa. When it is found in the Western Hemisphere, in places such as Argentina, Bolivia, Venezuela, Brazil, and the United States, it is classified “New World”. Lymphocytic choriomeningitis (LCM) virus is the only Arenavirus to exist in both areas but is classified as an Old World virus.

Genome

Arenaviruses have a segmented RNA genome that consists of two single-stranded negative-sense RNAs Añón MC, Grau O, Segovia ZM, Franzefernández MT (1976). "RNA composition of Junin virus". J. Virol. 18 (3): 833–8. PMC 354781. PMID 178925. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link). As with all negative-sense RNA viruses, the genomic RNA alone is not infectious and the viral replication machinery is required to initiate infection within a host cell Lee KJ, Novella IS, Teng MN, Oldstone MB, de La Torre JC (2000). "NP and L proteins of lymphocytic choriomeningitis virus (LCMV) are sufficient for efficient transcription and replication of LCMV genomic RNA analogs". J. Virol. 74 (8): 3470–7. PMC 111854. PMID 10729120. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link). Genomic sense RNA packaged into the arenavirus virion is designated negative-sense RNA, and must first be copied into a positive-sense mRNA in order to produce viral protein Meyer BJ, de la Torre JC, Southern PJ (2002). "Arenaviruses: genomic RNAs, transcription, and replication". Curr. Top. Microbiol. Immunol. 262: 139–57. PMID 11987804.{{cite journal}}: CS1 maint: multiple names: authors list (link). The two RNA segments are denoted Small (S) and Large (L) Añón MC, Grau O, Segovia ZM, Franzefernández MT (1976). "RNA composition of Junin virus". J. Virol. 18 (3): 833–8. PMC 354781. PMID 178925. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Pedersen IR (1973). "Different classes of ribonucleic acid isolated from lymphocytic choriomeningitis virus". J. Virol. 11 (3): 416–23. PMC 355116. PMID 4734917. {{cite journal}}: Unknown parameter |month= ignored (help), and code for four viral proteins in a unique ambisense coding strategy Auperin DD, Romanowski V, Galinski M, Bishop DH (1984). "Sequencing studies of pichinde arenavirus S RNA indicate a novel coding strategy, an ambisense viral S RNA". J. Virol. 52 (3): 897–904. PMC 254611. PMID 6492264. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Auperin DD, McCormick JB (1989). "Nucleotide sequence of the Lassa virus (Josiah strain) S genome RNA and amino acid sequence comparison of the N and GPC proteins to other arenaviruses". Virology. 168 (2): 421–5. PMID 2916333. {{cite journal}}: Unknown parameter |month= ignored (help). Each RNA segment codes for two viral proteins in opposite orientation such that the negative-sense RNA genome serves as the template for transcription of a single mRNA and the positive-sense copy of the RNA genome templates a second mRNA Meyer BJ, de la Torre JC, Southern PJ (2002). "Arenaviruses: genomic RNAs, transcription, and replication". Curr. Top. Microbiol. Immunol. 262: 139–57. PMID 11987804.{{cite journal}}: CS1 maint: multiple names: authors list (link). The separate coding sequences of the two viral proteins are divided by an intergenic region RNA sequence that is predicted to fold into a stable hairpin structure Auperin DD, Galinski M, Bishop DH (1984). "The sequences of the N protein gene and intergenic region of the S RNA of pichinde arenavirus". Virology. 134 (1): 208–19. PMID 6324469. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link).

The extreme termini of each RNA segment contains a 19 nucleotide highly conserved sequence that is critical for recruitment of the viral replication machinery and initiation of viral mRNA transcription and genomic replication Auperin D, Dimock K, Cash P, Rawls WE, Leung WC, Bishop DH (1982). "Analyses of the genomes of prototype pichinde arenavirus and a virulent derivative of Pichinde Munchique: evidence for sequence conservation at the 3' termini of their viral RNA species". Virology. 116 (1): 363–7. PMID 6278715. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Auperin DD, Compans RW, Bishop DH (1982). "Nucleotide sequence conservation at the 3' termini of the virion RNA species of New World and Old World arenaviruses". Virology. 121 (1): 200–3. PMID 6287720. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Perez M, de la Torre JC (2003). "Characterization of the genomic promoter of the prototypic arenavirus lymphocytic choriomeningitis virus". J. Virol. 77 (2): 1184–94. PMC 140842. PMID 12502835. {{cite journal}}: Unknown parameter |month= ignored (help) Hass M, Westerkofsky M, Müller S, Becker-Ziaja B, Busch C, Günther S (2006). "Mutational analysis of the lassa virus promoter". J. Virol. 80 (24): 12414–9. doi:10.1128/JVI.01374-06. PMC 1676312. PMID 17005649. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Kranzusch PJ, Schenk AD, Rahmeh AA; et al. (2010). "Assembly of a functional Machupo virus polymerase complex". Proc. Natl. Acad. Sci. U.S.A. 107 (46): 20069–74. doi:10.1073/pnas.1007152107. PMC 2993349. PMID 20978208. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link). The conserved 5' and 3' RNA termini sequences are complementary and allows each RNA segment to adopt a double-stranded RNA panhandle structure Bishop DH, Auperin DD (1987). "Arenavirus gene structure and organization". Curr. Top. Microbiol. Immunol. 133: 5–17. PMID 2435460. that maintains the termini in close proximity and results in a circular appearance to purified arenavirus genomic templates visualized by electron microscopy Young PR, Howard CR (1983). "Fine structure analysis of Pichinde virus nucleocapsids". J. Gen. Virol. 64 (Pt 4): 833–42. PMID 6682139. {{cite journal}}: Unknown parameter |month= ignored (help). The double-stranded RNA panhandle structure is critical for efficient viral RNA synthesis Perez M, de la Torre JC (2003). "Characterization of the genomic promoter of the prototypic arenavirus lymphocytic choriomeningitis virus". J. Virol. 77 (2): 1184–94. PMC 140842. PMID 12502835. {{cite journal}}: Unknown parameter |month= ignored (help) Hass M, Westerkofsky M, Müller S, Becker-Ziaja B, Busch C, Günther S (2006). "Mutational analysis of the lassa virus promoter". J. Virol. 80 (24): 12414–9. doi:10.1128/JVI.01374-06. PMC 1676312. PMID 17005649. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link), but potential intertermini double-stranded RNA interactions must be transiently relieved in order to recruit the viral polymerase Kranzusch PJ, Schenk AD, Rahmeh AA; et al. (2010). "Assembly of a functional Machupo virus polymerase complex". Proc. Natl. Acad. Sci. U.S.A. 107 (46): 20069–74. doi:10.1073/pnas.1007152107. PMC 2993349. PMID 20978208. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link).

The S-segment RNA is approximately 3.5 kb, and encodes the viral nucleocapsid protein (NP) and glycoprotein (GPC) Ghiringhelli PD, Rivera-Pomar RV, Lozano ME, Grau O, Romanowski V (1991). "Molecular organization of Junin virus S RNA: complete nucleotide sequence, relationship with other members of the Arenaviridae and unusual secondary structures". J. Gen. Virol. 72 ( Pt 9): 2129–41. PMID 1654373. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link). The L-segment RNA is approximately 7.2 kb, and encodes the viral RNA-dependent RNA-polymerase (L) and a small RING-domain containing protein (Z) Iapalucci S, López N, Rey O, Zakin MM, Cohen GN, Franze-Fernández MT (1989). "The 5' region of Tacaribe virus L RNA encodes a protein with a potential metal binding domain". Virology. 173 (1): 357–61. PMID 2510403. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Iapalucci S, Lopez R, Rey O; et al. (1989). "Tacaribe virus L gene encodes a protein of 2210 amino acid residues". Virology. 170 (1): 40–7. PMID 2718387. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link) Salvato MS, Shimomaye EM (1989). "The completed sequence of lymphocytic choriomeningitis virus reveals a unique RNA structure and a gene for a zinc finger protein". Virology. 173 (1): 1–10. PMID 2510401. {{cite journal}}: Unknown parameter |month= ignored (help).

Viral reservoir

Some arenaviruses are zoonotic pathogens and are generally associated with rodent—transmitted disease in humans. Each virus usually is associated with a particular rodent host species in which it is maintained. Arenaviruses persist in nature by infecting rodents first and then transmitted in to humans. Humans can be infected through mucosal exposure to aerosols, or by direct contact of abraded skin with the infectious material, derived from infected rodents.[2] Aersols are fine mists or sprays of rodent dried excreta, especially urine that is dropped in the environment. Most of the Arenaviruses caught by humans are within their own homes when these rodents seek shelter. The virus can be caught in factories, from food that has been contaminated, or within agricultural work areas. The risk of getting the Arenavirus infection for humans is related to age, race, or sex within the degree of contact with the dried rodent excreta.

Epidemiology

Vectors

Arenavirus diseases and vectors
Virus Disease Vector Distribution
Lymphocytic choriomeningitis virus Lymphocytic choriomeningitis House mouse (Mus musculus) Worldwide
Lassa virus Lassa fever Natal Multimammate Mouse (Mastomys natalensis) West Africa
Junin virus Argentine hemorrhagic fever Drylands Vesper Mouse (Calomys musculinus) Argentina
Machupo virus Bolivian hemorrhagic fever Large Vesper Mouse (Calomys callosus) Bolivia
Guanarito virus Venezuelan hemorrhagic fever Short-tailed Cane Mouse (Zygodontomys brevicauda) Venezuela
Sabiá virus Brazilian hemorrhagic fever Unknown Brazil
Tacaribe virus Bat (Artibeus) Trinidad
Flexal virus Influenza-like illness Rice rat (Oryzomys) Brazil
Whitewater Arroyo virus Hemorrhagic fever Woodrat (Neotoma) Southwestern USA

Clinical diseases

1. LCM viruses causes influenza -like febrile illness,but occasionally it may cause meningitis,characteristically accompanied by large numbers of lymphocytes in the CSF (as the name LCM suggests).

2. Lassa fever virus causes Lassa fever. Lassa fever is endemic in west Africa.The virus was first isolated from Americans stationed in the village of Lassa, Nigeria.The virus can be transmitted person-to -person.

a. Subclinical diseases: Serological studies suggest that inapparent infections particularly among members of hunting tribes are common.

b. Clinical infections:Lassa fever is characterised by high fever,severe myalgia,coagulopathy,haemorrhagic skin rash,and occasional visceral haemorrhage as well as necrosis of liver and spleen.

3. other Arenaviruses like Junin virus, Machupo virus cause haemorrhagic fevers.

All of these diseases pose a great threat to public health in the regions where it is taking place. For example, when the Old World Lassa virus turns into Lassa fever, this usually results in a significant amount of mortality. Similarly the New World Junin virus causes Argentine hemorrhagic fever. This fever is a several illness with hemorrhagic and neurological manifestations and a case fatality of fifteen to thirty percent.[2] The way this virus spreads is through increased traveling to and from endemic regions. This traveling has led to the importation of Lassa fever into non- endemic metropolitan areas all over the world.

Recent outbreaks

A new species of arenavirus named the Lujo virus has been linked to five patients who exhibited symptoms of viral hemorrhagic fever in South Africa.[4] The disease originated near Lusaka, Zambia and spread to Johannesburg, South Africa, after the first patient was transported to a hospital there. The results of genetic sequencing tests conducted by epidemiologists at Columbia University in New York CIty, USA, and at the Special Pathogens Branch of the Centers for Disease Control in Atlanta, USA, provided evidence that the causative agent of the disease is a virus from the Arenaviridae family, which ultimately resulted in the deaths of four out of the five infected in Zambia and South Africa during the outbreak which began in September 2008.

Arenavirus has also recently pinpointed as the cause of death of three donor organ recipients in Australia who contracted the virus after receiving kidney and a liver donations from a single infected organ donor in late 2006. All three died in the first week of 2007.[5]

WHO and its Global Outbreak Alert and Response Network (GOARN) partners continue to support the Ministries of Health of the two countries in various facets of the outbreak investigation, including laboratory diagnosis, investigations, active case finding and follow-up of contacts.[6]

Treatments

This virus can be very devastating yet there are very few treatment methods available. The current lack of a licensed vaccine and limited therapeutic options for the Arenavirus make it arguably among the most neglected virus to be dealt with. The only licensed drug for the treatment of human Arenavirus infection is the nucleoside analogue ribavirin.[7] Ribavirin reduces morbidity and mortality in humans who have certain Arenaviruses, such as LASV and JUNV infections, if it is taken in the early stages of the disease. Ribavirin displays mixed success in treating severe Arenaviral disease and is associated with significant toxicities.[8] Effective anti-viral drugs need to be produced at a low cost, taken orally, and able to withstand tropical climates due to the regions where these infections are occurring. For this reason high throughput screening (HTS) of small molecular libraries could be the answer to finding a better remedy. HTS collects libraries of small synthetic molecules that can be used to identify protein promoting “agonist” molecules or protein inhibiting “antagonist” interactions.[9] With HTS sustainable anti-viral drugs can be discovered against possible new human pathogenic viruses.

References

Notes

  1. ^ Botten, J; Whitton, JL; Barrowman, P; Sidney, J; Whitmire, JK; Alexander, J; Kotturi, MF; Sette, A; Buchmeier, MJ (2010). "A Multivalent Vaccination Strategy for the Prevention of Old World Arenavirus Infection in Humans". Journal of Virology. 84 (19): 9947–56. doi:10.1128/JVI.00672-10. PMC 2937778. PMID 20668086. Retrieved 2011-28-4. {{cite journal}}: Check date values in: |accessdate= (help)
  2. ^ a b c Emonet, Sebastien E.; Urata, Shuzo; De La Torre, Juan C. (2011). "Arenavirus reverse genetics: New approaches for the investigation of arenavirus biology and development of antiviral strategies". Virology. 411 (2): 416–425. doi:10.1016/j.virol.2011.01.013. PMC 3057228. PMID 21324503.
  3. ^ "Chapare Virus, a Newly Discovered Arenavirus Isolated from a Fatal Hemorrhagic Fever Case in Bolivia". Public Library of Science Pathogens. Retrieved 2008-04-17.
  4. ^ Scientists identify new lethal virus in Africa
  5. ^ "Virus identified - nurse ill". News24.com. Retrieved 2008-10-13.
  6. ^ "Virus kills organ recipients". www.theage.com.au. Retrieved 2009-10-16.
  7. ^ , PMID 21183197 {{citation}}: Missing or empty |title= (help)
  8. ^ Mendenhall, M.; Russell, A.; Juelich, T.; Messina, E. L.; Smee, D. F.; Freiberg, A. N.; Holbrook, M. R.; Furuta, Y.; De La Torre, J.-C. (2010). "T-705 (Favipiravir) Inhibition of Arenavirus Replication in Cell Culture". Antimicrobial Agents and Chemotherapy. 55 (2): 782–787. doi:10.1128/AAC.01219-10. PMC 3028760. PMID 21115797.
  9. ^ , PMID 21183197 {{citation}}: Missing or empty |title= (help)

Bibliography

External links

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