[1][3] The Spondweni virus was first isolated in Nigeria in 1952, and ever since, SPONV transmission and activity have been reported throughout Africa.

[1][3] Similar to other flaviviruses, SPONV has a positive-sense, single stranded RNA genome, which is about 11 kilobases in length.

[1] The RNA genome contains 5' and 3' untranslated regions that surround a single open reading frame that encodes for a polyprotein that is specifically cleaved.

[1] This strain was originally misclassified as Zika virus, and this misidentification eventually lead to the 1955 South African SA 94 isolation from the Mansonia uniformis mosquito.

For flaviviruses, Env proteins on the virion exterior interact and attach to host factors on the plasma membrane surface.

[9] Similar to Zika, the Spondweni virus's primary vector of transmission is mosquitos from the genus Aedes.

No detectable infection or dissemination of the Chuku strain has been found in two different Aedes species (Ae.

[1][10] Intensive field studies have been carried out in areas with high SPONV transmission to eliminate potential host species.

[1] Due to its serological cross-reactivity and similar clinical presentations with ZIKV, SPONV may be maintained and transmitted in a sylvatic cycle to nonhuman primates and certain species of mosquitoes.

[3] Successful transmission and infection by either SPONV strain can result in the infectious disease known as Spondweni fever.

[3] Six cases of Spondweni virus infections have been well documented, and the signs and symptoms parallel closely to Zika fever.

[1][12][13] Diagnosis of Spondweni viral infection can be confirmed by testing blood samples for the presence of the positive-sense, single-stranded RNA virion through the use of serologic assay, virus isolation, or PCR/qPCR.

The evolution and dispersal patterns of flaviviruses are determined by arthropod vectors, the vertebrate hosts, the ecology nearby, and the influence of human commercial activity.

Blood-meal data from the Aedes genus demonstrate that mammals are the main hosts of most species.