First virus genome analysis gives new insights into Brazilian Zika outbreak

The first genome analysis of the Zika virus outbreak in Brazil, which has been potentially linked to the birth condition microcephaly, offers new information on how and when the virus might have entered the Americas. Scientists from the University of Oxford (UK) and the Evandro Chagas Institute (Brazil), along with collaborators from a number of other institutions, sequenced seven genomes of the Brazilian Zika virus (ZIKV), including one fatal adult case and one newborn with microcephaly. The analysis shows that Zika virus in the Americas arose from a single introduction, estimated to have occurred between May and December 2013, more than 12 months prior to the first detection of ZIKV in Brazil. This estimated date of origin coincides with an increase in air passengers to Brazil from ZIKV-endemic areas, and also with reported outbreaks in the Pacific Islands. One hypothesis discussed by the researchers involves virus introduction during the Confederations Cup soccer tournament,...