Zika virus has been sweeping through South and Central America, with more than a million suspected cases during the past few months, along with a substantial increase in reporting of infants born with microcephaly.1,2 Thus far, the two outbreaks have largely been epidemiologically associated in time and geography. However, Mlakar and colleagues3 now report in the Journal molecular genetic and electron-microscopic data from a case that helps to strengthen the biologic association. This group cared for a pregnant European woman in whom a syndrome compatible with Zika virus infection developed at 13 weeks of gestation while she was working . . .