Arenavirus
Arenaviruses are a family of viruses that can cause severe illnesses in humans, including hemorrhagic fevers. They are typically transmitted to humans through contact with infected rodents or their excretions. The viruses are named after the sand-like appearance of their ribonucleic acid (RNA) under electron microscopy. Notable examples of arenaviruses include Lassa virus and Junin virus.
4 Key excerpts on "Arenavirus"
eBook - ePub- Erskine L. Palmer(Author)
- 2019(Publication Date)
- CRC Press(Publisher)
...Chapter 17 ARENA VIRIDAE The name Arenavirus is derived from the appearance of host cell ribosomes, which are seen as fine electron dense granules (arena = sand) within virus particles by thin section EM (Figure 94). The ribosomes are not seen by negative stain EM. There are currently at least ten known viruses of the family Arenaviridae which fall into three groups: lymphocytic choriomeningitis virus (LCM); the Tacaribe complex which includes Junin (Argentinian hemorrhagic fever), Machupo (Bolivian hemorrhagic fever), Ama-pari, Tacaribe, Pichinde, Parana, Latino, and Tamiami viruses; and the Lassa virus group which includes Lassa virus, Moepia, Mobalaand, and Ippy viruses. Arenaviruses share a common group antigen but do not cross neutralize. Lassa virus and other Arenaviruses which cause hemorrhagic fever are extremely hazardous and are currently studied in only a few laboratories with special safety precautions. The only known Arenaviruses found in the U.S. are LCM, which may cause encephalitis in man, and Tamiami virus which is not known to be pathogenic for man. All Arenaviruses have the same morphology. Particles are enveloped, spherical to pleomorphic, and measure 50 to 300 nm in diameter. Viruses have a dense lipid bilayer envelope with surface projections (Figure 95). The projections are 10 nm long and are club-shaped. The core of Arenaviruses contains several pieces of single-stranded RNA, two of which are virus-specific. Together with protein, this RNA forms circular ribonucleoprotein of at least two size modes of 650 and 1300 nm in length. The core also contains host cell ribosomal RNA and protein. The Arenaviridae and some members of the Bunyaviridae are the only viruses known to have circular, segmented ribonucleoprotein as nucleocapsids. Arenaviruses mature by budding from the plasma membrane and membrane changes are detectable at the site of virus formation. There is also an alteration of the distribution of ribosomes...
eBook - ePub- Douglas D. Richman, Richard J. Whitley, Frederick G. Hayden, Douglas D. Richman, Richard J. Whitley, Frederick G. Hayden(Authors)
- 2016(Publication Date)
- ASM Press(Publisher)
...45 Arenaviruses DANIEL G. BAUSCH Viruses of the Arenaviridae family (genus Arenavirus) are zoonotic; they are maintained in nature, with a few possible exceptions, by chronic infection in rodents of the superfamily Muroidea (1). Over 40 Arenaviruses have been identified, although less than half of these are clearly recognized as human pathogens (Table 1 and Figures 1 and 2). Arenaviruses continue to be discovered at a quickening pace in recent decades (2 – 10). TABLE 1 Arenaviruses known or suspected to cause human disease FIGURE 1 Geographic distribution of Old World Arenaviruses. The virus name and known or suspected rodent reservoir are listed. Although the virus has been isolated from the animal listed, the status of that animal as the natural reservoir is not established in all cases. Countries where Lassa fever, the major arenaviral disease in Africa, has been definitively shown are depicted in dark gray and the distribution of rodents of the genus Mastomys is shown in light gray. Only Lassa, Lujo, lymphocytic choriomeningitis, and Dandenong viruses have been definitively associated with human disease. The distribution of the virus and incidence of associated disease may vary significantly within each country. With the exception of Lassa and lymphocytic choriomeningitis viruses, most Old World Arenaviruses have been isolated on single or very few occasions and the precise distribution of the virus beyond the place of first identification is unknown. Not shown on the map: Lymphocytic choriomeningitis viruses (reservoir Mus musculus), which has a worldwide distribution, Dandenong virus (unknown reservoir), which is thought to be found in Eastern Europe, and Wenzhou virus (reservoir various rodent species and Suncus murinus) found in China. FIGURE 2 Geographic distribution of New World Arenaviruses. Above: The virus name and known or suspected rodent reservoir are listed, with viruses associated with natural infection and disease in humans in bold...
eBook - ePub- Richard L. Hodinka, Stephen A. Young, Benjamin A. Pinksy, Richard L. Hodinka, Stephen A. Young, Benjamin A. Pinksy(Authors)
- 2016(Publication Date)
- ASM Press(Publisher)
...36 Animal-Borne Viruses GREGORY J. BERRY, MICHAEL J. LOEFFELHOLZ, AND GUSTAVO PALACIOS Zoonotic infections are infections of animals that can be transmitted to humans. There are more than 400 viruses with a zoonotic origin that can cause mild or severe clinical pathology in humans. This chapter will attempt to cover a handful of these viruses that have been especially relevant as human pathogens: Arenaviruses, Ebola virus, Nipah virus, and Hantavirus. Arenaviruses consist of a number of species and collectively have a worldwide distribution. They cause mild to severe illness in humans. Filoviruses have a sylvatic epidemiology in Africa and can spill over into humans, where they usually cause severe illness with a high mortality rate. Filoviruses are efficiently spread person-to-person, as highlighted in the 2014 to 2015 urban epidemic in West Africa. Nipah virus has caused a relatively limited number of human cases in Southeast Asia. Nipah virus infection with central nervous system involvement is associated with high mortality. Hantaviruses have a worldwide distribution and cause renal and pulmonary syndromes in humans. VIRAL CLASSIFICATION AND BIOLOGY Arenaviruses Arenaviruses are spherical or pleomorphic virions with a mean diameter of 110 to 130 nanometers. Their genome consists of two single-strand RNA molecules, with ambisense properties, named the L (large) and S (small) segments. The L segment encodes the Z matrix protein (which appears to be an important regulator of innate signaling pathways) and the RNA polymerase (which encodes the viral replicative capacity). The S segment encodes the glycoprotein precursor (GPC), which is encoded in the viral-sense strand and is crucial for cellular tropism since it contains the receptor binding site...
eBook - ePub- Brian W.J. Mahy(Author)
- 2009(Publication Date)
- Academic Press(Publisher)
...There is also a free-standing genus, Anellovirus, which contains the TT virus one of the most ubiquitous species known. In plants there are three important families of ssDNA viruses, the Inoviridae, Microviridae, and the Geminiviridae. single-stranded RNA viruses The families containing viruses which affect vertebrates are: Arenaviridae ambisense, 2 segments Arteriviridae + strand, unsegmented Astroviridae + strand, unsegmented Bornaviridae − strand, unsegmented Bunyaviridae − or ambisense, 3 segments Caliciviridae + strand, unsegmented Coronaviridae + strand, unsegmented Filoviridae − strand, unsegmented Flaviviridae + strand, unsegmented Nodaviridae + strand, 2 segments Orthomyxoviridae − strand, 6, 7, or 8 segments Paramyxoviridae − strand, unsegmented Picornaviridae + strand, unsegmented Retroviridae + strand,unsegmented, diploid Rhabdoviridae − strand, unsegmented Togaviridae + strand, unsegmented Sin Nombre virus (SNV) A species in the genus Hantavirus. The principal etiologic agent of hantavirus pulmonary syndrome, first recognized in the Four Corners region of the USA in June–August, 1993. Antigenically related to, but distinct from, other hantaviruses. Isolated from the deer mouse, Peromyscus maniculatus (grassland form), which is the natural reservoir species in North America. The infection is spread to humans (who are dead-end hosts and do not transmit the virus), through contact with urine or other excreta of chronically infected mice. Infection results in an acute pulmonary distress syndrome with a fatality rate of 50%. No specific treatment is available. Control is by avoiding close contact with infected deer mice or their excreta. A Mid-western variant, Blue River virus, has also been recognized in Indiana and Oklahoma, where the host is the white-footed mouse, Peromyscus leucopus. Another variant strain, Monongahela virus, was identified in P maniculatus from the north-eastern USA...
