Alphavirus

virus genus

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Last updated

June 18, 2026

Quick Summary

The genus Alphavirus belongs to the family Togaviridae and is transmitted by mosquitoes. Some species within this genus can cause severe encephalitis in humans and can be fatal to horses, as seen with equine encephalitis. The chikungunya virus, an example of an Alphavirus, is composed of a single strand of RNA enclosed in a protein shell and a phospholipid envelope, with a diameter of 60-70 nanometres. This virus is known for causing severe joint and musculoskeletal pain, and in some cases, chronic arthritis. Nonhuman primates in Africa are considered the primary reservoir for chikungunya virus, with transmission to humans occurring through mosquito vectors like Aedes aegypti and Aedes albopictus.12

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virus
Annotated classification
There are 2 recognized genera: Alphavirus and Rubivirus. Alphavirus consists of viruses transmitted by arthropods (exclusively mosquitoes); prototypes include Sindbis virus and eastern and western equine encephalitis viruses. Rubivirus contains non-arthropod-borne viruses, including the causative agent of German measles. Family
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There are 2 recognized genera: Alphavirus and Rubivirus. Alphavirus consists of viruses transmitted by arthropods (exclusively mosquitoes); prototypes include Sindbis virus and eastern and western equine encephalitis viruses. Rubivirus contains non-arthropod-borne viruses, including the causative agent of German measles. Family
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togavirus
The togavirus genera are Alphavirus, which is carried by mosquitoes, and Rubivirus, which contains rubella, or German measles, virus. Some Alphavirus species produce severe encephalitis in humans. Horses also may be severely or fatally infected, by equine encephalitis. Rubivirus is immunologically distinct from the other togaviruses.
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The togavirus genera are Alphavirus, which is carried by mosquitoes, and Rubivirus, which contains rubella, or German measles, virus. Some Alphavirus species produce severe encephalitis in humans. Horses also may be severely or fatally infected, by equine encephalitis. Rubivirus is immunologically distinct from the other togaviruses.
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