Zika Virus-Associated Microcephaly and Eye Lesions in the Newborn

On February 1, 2016, Zika virus (ZIKV) was designated as a Public Health Emergency of International Concern by the director of the World Health Organization. Zika virus has spread to numerous countries throughout the Americas, affecting up to an estimated 1.3 million people since the first reports from Brazil in early 2015. Although ZIKV infections are self-limiting, fetal microcephaly and ophthalmic anomalies have been associated with ZIKV infection as a possible result of perinatal transmission. The causal link between maternal ZIKV infection and newborn microcephaly and eye lesions has not been proven beyond doubt and is currently debated. We discuss the possibility of causality by ZIKV using Koch's postulates and the more appropriate Bradford Hill criteria. In this review, we summarize and consolidate the current literature on newborn microcephaly and eye lesions associated with ZIKV infection and discuss current perspectives and controversies.