A critical unmet need
Zika is transmitted by the same Aedes mosquito species that transmits viruses associated with Dengue and Yellow Fever. As Dengue virus is endemic in much of the tropical world, background immunological reactivity to Dengue tends to confound the serological diagnosis of Zika. This highlights the need for tests that are highly specific for Zika.
Zika infection can be detected by molecular assays, but this approach is only useful during the relatively brief viremic phase—typically several weeks or less. After this period, individuals at risk for complications caused by prior infection can only be identified by serologic assays. As noted, the close genetic relationship between Zika and other flaviviruses makes serological diagnosis difficult due to cross-reactivities between viral antigens.
