cdc updates interim guidance on caring for Women With possible Exposure to Zika Virus The current Zika virus outbreak was identified in Brazil in May 2015, and knowledge about the virus, its transmission, and its potential adverse effects on pregnancy outcomes is evolving. Epidemiologic, clinical, laboratory, and pathologic evidence supports a link between infection during pregnancy and outcomes such as pregnancy loss, fetal microcephaly, intracranial calcifications, and fetal brain and eye abnormalities. The level of risk of these outcomes is not known. Studies suggest that it may be as high as 29%, but microcephaly caused by viral destruction of brain tissue is likely part of a spectrum of neurologic damage caused by Zika virus, and this percentage may substantially underestimate the proportion of infants affected.