Dataset Information

Evidence of Zika virus circulation in asymptomatic pregnant women in Northeast, Brazil.

ABSTRACT:

Background

Zika virus (ZIKV) is a flavivirus associated with microcephaly and other fetal anormalities. However, evidence of asymptomatic ZIKV infection in pregnant women is still scarce. This study investigated the prevalence of Zika infection in asymptomatic pregnant women attending two public maternities in Maranhão state, Northeast Brazil.

Methods

A total of 196 women were recruited at the time of delivery by convenience sampling from two maternity clinics in São Luís, Maranhão, Brazil, between April 2017 and June 2018. Venous blood, umbilical cord blood and placental fragments from maternal and fetal sides were collected from each subject. ZIKV infection was determined by reverse transcription polymerase chain reaction (RT-qPCR) for ZIKV and by serology (IgM and IgG). Nonspecific laboratory profiles (TORCH screen) were obtained from medical records.

Results

The participants were mostly from São Luís and were of 19-35 years of age. They had 10-15 years of schooling and they were of mixed race, married, and Catholic. ZIKV was identified in three umbilical cord samples and in nine placental fragments. Mothers with positive ZIKV RT-qPCR were in the age group older than 19 years. Of the 196 women tested by ZIKV rapid test, 6 and 117 women were positive for anti-ZIKV IgM and anti-ZIKV IgG antibodies, respectively. Placental Immunohistochemistry study detected ZIKV in all samples positive by RT-PCR. The newborns did not show any morphological and/or psychomotor abnormalities at birth.

Conclusions

Asymptomatic ZIKV infection is frequent, but it was not associated to morphological and/or psychomotor abnormalities in the newborns up to 6 months post-birth. Although pathological abnormalities were not observed at birth, we cannot rule out the long term impact of apparent asymptomatic congenital ZIKV infection.

SUBMITTER: Branco RCC

PROVIDER: S-EPMC8219130 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:ImportanceCongenital Zika virus infection causes a spectrum of adverse birth outcomes, including severe birth defects of the central nervous system. The association of prenatal ultrasonographic findings with adverse neonatal outcomes, beyond structural anomalies such as microcephaly, has not been described to date.ObjectiveTo determine whether prenatal ultrasonographic examination results are associated with abnormal neonatal outcomes in Zika virus-affected pregnancies.Design, setting, and participantsA prospective cohort study conducted at a single regional referral center in Rio de Janeiro, Brazil, from September 1, 2015, to May 31, 2016, among 92 pregnant women diagnosed during pregnancy with Zika virus infection by reverse-transcription polymerase chain reaction, who underwent subsequent prenatal ultrasonographic and neonatal evaluation.ExposuresPrenatal ultrasonography.Main outcomes and measuresThe primary outcome measure was composite adverse neonatal outcome (perinatal death, abnormal finding on neonatal examination, or abnormal finding on postnatal neuroimaging). Secondary outcomes include association of specific findings with neonatal outcomes.ResultsOf 92 mother-neonate dyads (mean [SD] maternal age, 29.4 [6.3] years), 55 (60%) had normal results and 37 (40%) had abnormal results on prenatal ultrasonographic examinations. The median gestational age at delivery was 38.6 weeks (interquartile range, 37.9-39.3). Of the 45 neonates with composite adverse outcome, 23 (51%) had normal results on prenatal ultrasonography. Eleven pregnant women (12%) had a Zika virus-associated finding that was associated with an abnormal result on neonatal examination (adjusted odds ratio [aOR], 11.6; 95% CI, 1.8-72.8), abnormal result on postnatal neuroimaging (aOR, 6.7; 95% CI, 1.1-38.9), and composite adverse neonatal outcome (aOR, 27.2; 95% CI, 2.5-296.6). Abnormal results on middle cerebral artery Doppler ultrasonography were associated with neonatal examination abnormalities (aOR, 12.8; 95% CI, 2.6-63.2), postnatal neuroimaging abnormalities (aOR, 8.8; 95% CI, 1.7-45.9), and composite adverse neonatal outcome (aOR, 20.5; 95% CI, 3.2-132.6). There were 2 perinatal deaths. Abnormal findings on prenatal ultrasonography had a sensitivity of 48.9% (95% CI, 33.7%-64.2%) and a specificity of 68.1% (95% CI, 52.9%-80.1%) for association with composite adverse neonatal outcomes. For a Zika virus-associated abnormal result on prenatal ultrasonography, the sensitivity was lower (22.2%; 95% CI, 11.2%-37.1%) but the specificity was higher (97.9%; 95% CI, 88.7%-99.9%).Conclusions and relevanceAbnormal results on prenatal ultrasonography were associated with adverse outcomes in congenital Zika infection. The absence of abnormal findings on prenatal ultrasonography was not associated with a normal neonatal outcome. Comprehensive evaluation is recommended for all neonates with prenatal Zika virus exposure.

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