Explore the recorded discovery and history of Zika virus, with source links and stated limits.
WHO describes Zika as a mosquito-borne virus spread primarily by Aedes mosquitoes that bite mostly during the day, with most infected people developing no symptoms. Its documented importance is infection during pregnancy, which can cause microcephaly and other congenital malformations, and an association with Guillain-Barré syndrome in adults and children.
WHO records that Zika virus was first identified in Uganda in 1947 in a Rhesus macaque monkey, followed by evidence of infection and disease in humans in other African countries in the 1950s. Identification in one country is not evidence that the virus originated there or that it spread from there.
WHO records that when Zika virus emerged in the Americas, with a large epidemic in Brazil in 2015, an association between Zika infection and microcephaly was first described; similar findings were then seen on retrospective review in French Polynesia.
WHO declared a Public Health Emergency of International Concern from February to November 2016 regarding microcephaly, other neurological disorders and Zika virus, and the causal link with congenital malformations was confirmed soon thereafter.
WHO records that the first local mosquito-transmitted Zika cases in Europe were reported in 2019. In total, 92 countries and territories have reported evidence of mosquito-transmitted Zika infection, while surveillance remains limited globally.
The 1947 record describes identification of the virus in a monkey in Uganda, with human infection documented in the 1950s. It does not identify the first infected person, and the 2015 Brazilian epidemic is an outbreak record rather than an origin.
Source check: 2026-09-19. Educational content; independent scientific review remains pending.