Risk of adverse pregnancy and infant outcomes associated with prenatal Zika virus infection: a post-epidemic cohort in Central-West Brazil

Abstract

This study aimed to estimate the risks of adverse infant outcomes in the first year of life related to prenatal Zika virus (ZIKV) exposure. A prospective cohort of pregnant women with rash was recruited in Central-West Brazil in a post-epidemic period (January 2017 to April 2019). We evaluated participants’ medical histories and performed ZIKV diagnostic testing using molecular (reverse transcription polymerase chain reaction [RT-PCR]) and serologic (immunoglobulin [Ig]M and plaque reduction neutralization tests [PRNT90]) assays. The ZIKV-positive group included both RT-PCR-confirmed cases as well as IgM and/or PRNT90-positive probable cases. Children were evaluated at birth and in the first 12 months of life. Transfontanellar ultrasound, central nervous system computed tomography, eye fundoscopy and retinography were performed. We estimated the absolute risk and 95% confidence interval (95% CI) of adverse infant outcomes among confirmed prenatally ZIKV-exposed children. Among 81 pregnant women with rash, 43 (53.1%) were ZIKV infected. The absolute risk of microcephaly among offspring of ZIKV-infected pregnant women was 7.0% (95% CI: 1.5–19.1), including the two cases of microcephaly detected prenatally and one detected postnatally. In total, 54.5% (95% CI: 39.8–68.7) of children in the ZIKV-exposed group had at least one ophthalmic abnormality, with the most frequent abnormalities being focal pigmentary mottling and chorioretinal atrophy or scarring. Our findings reinforce the importance of long-term monitoring of prenatally ZIKV-exposed children born apparently asymptomatic for Congenital Zika Syndrome.

Microcephaly in South Brazil: Are cases of Congenital Zika Syndrome increasing in recent years?

“…Our study has some limitations: only live births and only those diagnosed with microcephaly at birth or immediately after were included. An absence of signs and symptoms at birth in exposed babies does not rule out ZIKV congenital infection with late-onset manifestations, especially visual ( Freitas et al, 2020 ; Ventura et al, 2021 ; Merle et al, 2022 ; Rosado et al, 2023 ).…”

Case report: Zika surveillance complemented with wastewater and mosquito testing

“… 8 Among infected pregnant women, the risk of microcephaly and congenital malformations is estimated to be about 10%. 9 …”