Classification
Family—The Bunyaviridae family is made up of over
350 mainly arthropod borne
(ARBO) viruses. Some viruses in the family that
you may have heard of are: Sin Nombre virus, Hantaan
virus, Rift Valley fever
virus,
La Crosse virus, California Encephalitis virus, and Congo/Crimean
hemorrhagic
fever virus. All of the viruses in the Bunyaviridae family share the
following
properties:
- Single stranded RNA
- Negative stranded
(except for Phlebovirus and Topsovirus genera which
use an ambisense translation strategy for
the S segment and M segment respectively.)
- Icosahedral virion (T=12)
- Enveloped
- Segmented (3 segments: large, medium, and
small)
- Helical nucleocapsids
- Virion is 80-120 nm in
diameter
- Spherical or pleiomorphic shape
- EM
appearance varies depending on the virus. Generally glycoprotein spikes
protrude from the surface.
Hantaviruses have a grid-like pattern
Genera—The family
consists of 5 genera: Bunyavirus, Phlebovirus,
Nairovirus, Hantavirus, and Topsovirus based on common
morphological, biochemical,
and genetic properties. However, even within the same genus, viruses often
have
very different biological characteristics. Below are some of the properties
of each genus:
Bunyavirus:
- almost
all transmitted by mosquitoes
- wide variety of vertebrate hosts
- over 150 viruses and
16 serogroups
- present everywhere except Australia
- ex. LaCrosse virus, Bunyamwera,
Akabane, Oropouche
Phlebovirus:
- most members associated with
phlebotomine sandflies (hence the name). But
there are prominent exceptions such as Rift Valley Fever
virus
- present everywhere except Australia
- examples: Sandfly Fever virus, Rift Valley
Fever virus
Nairovirus:
- almost exclusively tick borne
- most important serogroups are: Crimean-Congo
hemmorrhagic fever group and
Nairobi Sheep Disease Group
- examples: Crimean-Congo
hemmorrhagic fever, Nairobi Sheep Disease
Hantavirus:
- rodent borne viruses (ROBO)
- Associated with
Hemmorrhagic Fever with Renal Syndrome (HFRS) and Hantavirus
Pulmonary Syndrome (HPS)
- examples: Sin Nombre virus, Seoul virus, Belgrade virus, Puumala virus,
Hantaan virus
Topsovirus:
- plant
viruses
- transmitted by thrips
- example: Tomato Spotted Wilt virus
For more information on this topic, see another student webpage at:
http://www.stanford.edu/group/virus/bunya/classificationtaxonomy.html
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