O vírus Zika na gestação: um estudo prospectivo em coorte de gestantes e seus conceptos

Abstract

Zika virus (ZIKV) is Flaviviridae family member virus, transmitted mainly by Aedes mosquitoes. In early 2015, the first cases of autochthonous transmission of Zika in Brazil were confirmed and the infection, during pregnancy, has been associated with a spectrum of congenital malformations, the most striking being microcephaly. Many aspects of ZIKV infection are not clear yet, so it is crucial to conduct studies that target aspects of mother-to-child transmission and the long-term monitoring of children prenatally exposed to ZIKV. Thus, the present study aimed to understand virological and immunological aspects of ZIKV infection during pregnancy and its impact on the first years of life of congenitally ZIKV exposed infants, through a cohort of 58 suspected cases of Zika infection during pregnancy, occurred in Espírito Santo, Brazil, between 2015 and 2017. Our results show that after a ZIKV infection during second trimester of pregnancy, virus can still be detected in postpartum breast milk, however with no evidence of transmission to breastfed newborns. In addition, we demonstrate here that ZIKV infection during pregnancy does not impair the efficiency of maternal-fetal transference of antibodies – the specific for ZIKV and flavivirus, and those vaccine-elicited – which plays an important role for the neonate protection. Furthermore, we observed that children congenitally exposed to ZIKV, without microcephaly at birth, present higher prevalence of cerebral anomalies on head imaging at birth, which supports the performance of these exams, even when the child does not present microcephaly. However, non-microcephalic congenitally exposed ZIKV infants present normal cognitive development within the first 2.5 years of life. Finally, we contributed to the development of a viral antigen that has much potential to be used in simple diagnostic platforms and can overcome the cross reactions limitations of current serological tests.