From Science Advances
February 27, 2019
Zika virus (ZIKV) belongs to the family of Flaviviridae, which includes other arboviruses, such as dengue virus (DENV), Japanese encephalitis virus (JEV), and West Nile virus (1). ZIKV unexpectedly surfaced recently as a major public health concern because of the ongoing and spreading epidemic in South and Central America and the realization that it could cause birth defects and neurological complications (2, 3). In a recent study, the rate of neurologic and ocular defects in fetuses born to ZIKV-infected mothers was calculated to be ~7% (4). Rarely, adults experience ZIKV-induced Guillain-Barré syndrome (5), but the congenital Zika syndrome in infants that includes a spectrum of neurological defects, including microcephaly, is the most devastating and pressing aspect of ZIKV infection (6). It has been suggested that the risk of microcephaly is higher in the fetus when mothers are exposed to ZIKV during the first trimester of pregnancy (3, 4). Some studies have reported the direct effects of ZIKV infection on neuronal tissue damage (7, 8). However, not all ZIKV infections during pregnancy appear to result in brain abnormality during embryonic development, and the mechanisms that lead to microcephaly in some fetuses but not others are not yet understood.