Congenital Zika syndrome (CZS) is associated with microcephaly and various neurological, musculoskeletal, and ocular abnormalities, but the long-term pathogenesis and postnatal progression of ocular defects in infants are not well characterized. Rhesus macaques are superior to rodents as models of CZS because they are natural hosts of the virus and share similar immune and ocular characteristics, including blood-retinal barrier characteristics and the unique presence of a macula. Using a previously-described model of CZS by infecting pregnant rhesus macaques with Zika virus (ZIKV) during the late first trimester, we characterized postnatal ocular development and evolution of ocular defects in 2 infant macaques over 2 years. We found that one of these animals exhibited colobomatous chorioretinal atrophic lesions with macular and vascular dragging, as well as retinal thinning caused by loss of retinal ganglion neuron and photoreceptor layers. Despite these congenital ocular malformations, axial elongation and retinal development in these infants progressed at normal rates compared to healthy animals. The ZIKV-exposed infants displayed a rapid loss of ZIKV-specific antibodies, suggesting the absence of viral replication after birth, and did not show any behavioral or neurological defects postnatally. Our findings suggest that ZIKV infection during early pregnancy can impact fetal retinal development and cause congenital ocular anomalies, but does not appear to affect postnatal ocular growth.
Glenn Yiu, Sara M. Thomasy, M. Isabel Casanova, Alexander M. Rusakevich, Rebekah I. Keesler, Jennifer Watanabe, Jodie Usachenko, Anil Singapuri, Erin E. Ball, Eliza Bliss-Moreau, Wendi Guo, Helen Webster, Tulika Singh, Sallie R. Permar, Amir Ardeshir, Lark L. Coffey, Koen K.A. Van Rompay