O'nyong'nyong+Virus

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[[image:chikungunya_virus_photo_-_togaviridae.png align="right"]]
The O'nyong'nyong Virus Stephanie Millwood

History
The O'nyong'nyong virus was first isolated in 1959 in Entebbe, Uganda by the Uganda Virus Research Institute. It is classified in the family Togaviridae and the genus alphavirus, and is closely related to the Chikungunya and Igbo Ora viruses. The O'nyong'nyong virus caused a widspread outbreak in Uganda between 1959 and 1962, infecting about two million people. It was estimated thaat at the height of the outbreak, the virus travelled an average of three kilometers per day.

Statistics
No deaths have been attributed to the O'nyong'nyong virus. People who contract it usually recover within one to three weeks. A small percentage of cases result in lasting joint pain.

Symptoms
The first symptom of the O'nyong'nyong virus is a low fever. As the virus progresses, the virus usually causes arthralgia or [|polyarthritis], and in 60-70% of cases, a maculopapular rash.

Transmission
The O'nyong'nyong virus is transmitted by bites from infected mosquitoes. It infects peripheral mononuclear blood cells.

Virus Structure
O'nyong'nyong is [|icosahedral] in shape, single-stranded, and contains positive sense RNA. Its complete genome contains 11835 nucleotides. It has spherical, virions which are 60 in diameter.

Infection
There is no evidence that the virus can be transmitted through human to human contact. People are infected by bites from mosquitoes carrying the virus. It is then able to replicate in the cytoplasm of cells, and symptoms begin to show after an incubation period of about eight days.

Mutation
The virus is believed to have evolved from a virus similar to the [|chikungunya fever].

Treatment
No vaccines or inti-viral treatments currently exist for the O'nyong'nyong virus, so treatment consists of treating the symptoms.