Virus classification
Group: Group IV ((+)ssRNA)
Family: Flaviviridae

Flaviviridae is a family of viruses. Humans and other mammals serve as natural hosts. They are primarily spread through arthropod vectors (mainly ticks and mosquitoes). The family gets its name from the Yellow Fever virus, the type virus of Flaviviridae; flavus means yellow in Latin, and Yellow fever in turn was named because of its propensity to cause jaundice in victims.[1] There are currently over 100 species in this family, divided among four genera. Diseases associated with this family include: hepaciviruses, hepatitis, pestiviruses, hemorrhagic syndromes, fatal mucosal disease, flavivirus, hemorrhagic fever, encephalitis, and the birth defect microcephaly.[2][3]


Group: ssRNA(+)



Flaviviridae have monopartite, linear, single-stranded RNA genomes of positive polarity, 9.6 to 12.3 kilobase in length. The 5'-termini of flaviviruses carry a methylated nucleotide cap, while other members of this family are uncapped and encode an internal ribosome entry site.

Virion structure

Virus particles are enveloped, with icosahedral and spherical geometries, about 40–60 nm in diameter.[2]

Genus Structure Symmetry Capsid Genomic Arrangement Genomic Segmentation
HepacivirusIcosahedral-likePseudo T=3EnvelopedLinearMonopartite
FlavivirusIcosahedral-likePseudo T=3EnvelopedLinearMonopartite
PegivirusIcosahedral-likePseudo T=3EnvelopedLinearMonopartite
PestivirusIcosahedral-likePseudo T=3EnvelopedLinearMonopartite

Life Cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the viral envelope protein E to host receptors, which mediates clathrin-mediated endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Translation takes place by viral initiation. The virus exits the host cell by budding. Humans and mammals serve as the natural host. The virus is transmitted via a vector (ticks and mosquitoes).[2]

Genus Host Details Tissue Tropism Entry Details Release Details Replication Site Assembly Site Transmission
HepacivirusHumansEpithelium: skin; epithelium: kidney; epithelium: intestine; epithelium: testesClathrin-mediated endocytosisSecretionCytoplasmCytoplasmSex; blood
FlavivirusHumans; mammals; mosquitoes; ticksEpithelium: skin; epithelium: kidney; epithelium: intestine; epithelium: testesClathrin-mediated endocytosisSecretionCytoplasmCytoplasmZoonosis; arthropod bite
PegivirusMammalsNoneClathrin-mediated endocytosisSecretionCytoplasmCytoplasmUnknown
PestivirusMammalsNoneClathrin-mediated endocytosisSecretionCytoplasmCytoplasmVertical: parental

Clinical importance

Major diseases caused by the Flaviviridae family include:


  1. "Flaviviridae". Microbe Wiki. Retrieved July 22, 2008.
  2. 1 2 3 "Viral Zone". ExPASy. Retrieved 15 June 2015.
  3. 1 2 ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
  4. Paula T, Pablo R, Eugenia V, Pablo B, Sabino P, José M, et al. (2009). "New drug targets for hepatitis C and other Flaviviridae viruses". Infect Disord Drug Targets. 9 (2): 133–47. doi:10.2174/187152609787847749. PMID 19275702.

External links

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