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Virus classification
Group: Group I (dsDNA)
Order: Herpesvirales[1]
Family: Herpesviridae
Subfamily: Betaherpesvirinae
Genus: Roseolovirus
Type species
Human herpesvirus 6A

Roseolovirus is a genus of viruses in the order Herpesvirales, in the family Herpesviridae, in the subfamily Betaherpesvirinae. Humans serve as natural hosts. There are currently three species in this genus including the type species Human herpesvirus 6A. Diseases associated with this genus include: HHV-6: sixth disease (roseola infantum, exanthem subitum); HHV-7: symptoms analog to the 'sixth disease'.[2][1]


Viruses in Roseolovirus are enveloped, with icosahedral, Spherical to pleomorphic, and Round geometries, and T=16 symmetry. The diameter is around 150-200 nm. Genomes are linear and non-segmented, around 200kb in length.[2]

Genus Structure Symmetry Capsid Genomic Arrangement Genomic Segmentation
Roseolovirus Spherical Pleomorphic T=16 Enveloped Linear Monopartite

Life Cycle[edit]

Viral replication is nuclear, and is lysogenic. Entry into the host cell is achieved by attachment of the viral glycoproteins to host receptors, which mediates endocytosis. Replication follows the dsDNA bidirectional replication model. DNA-templated transcription, with some alternative splicing mechanism is the method of transcription. The virus exits the host cell by nuclear egress, and budding. Humans serve as the natural host. Transmission routes are contact and respiratory.[2]

Genus Host Details Tissue Tropism Entry Details Release Details Replication Site Assembly Site Transmission
Roseolovirus Humans T-cells; B-cells; NK-cell; monocytes; macrophages; epithelial Glycoprotiens Budding Nucleus Nucleus Respiratory contact


Human herpesvirus 6 (HHV-6) is a set of two closely related herpes viruses known as HHV-6A and HHV-6B that infect nearly all human beings, typically before the age of two. The acquisition of HHV-6 in infancy is often symptomatic, resulting in childhood fever, diarrhea, and exanthem subitum rash (commonly known as roseola). Although rare, this initial infection can also cause febrile seizures, encephalitis or intractable seizures.

Like the other herpesviruses (Epstein Barr virus, varicella zoster virus, etc.), HHV-6 establishes life-long latency and can become reactivated later in life. This reactivation has been associated with many clinical manifestations. Reactivation can occur in locations throughout the body, including the brain, lungs, heart, kidney and gastrointestinal tract. In some cases, HHV-6 reactivation in the brain tissue can cause cognitive dysfunction, permanent disability and death.

A growing number of studies also suggest that HHV-6 may play a role in a subset of patients with chronic neurological conditions such as multiple sclerosis, mesial temporal lobe epilepsy, status epilepticus and chronic fatigue syndrome.

See also[edit]


  1. ^ a b ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. 
  2. ^ a b c "Viral Zone". ExPASy. Retrieved 15 June 2015. 

External links[edit]