Instituto Nacional de Infectologia Evandro Chagas, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
Heidelberg Institute of Global Health, Heidelberg University Hospital, Heidelberg, Germany.
J Infect Dis. 2021 Sep 17;224(6):1060-1068. doi: 10.1093/infdis/jiab054.
Zika virus (ZIKV) is associated with severe congenital abnormalities and laboratory diagnosis of antenatal infection is difficult. Here we evaluated ZIKV neutralizing antibody (nAb) kinetics in infants born to mothers with PCR-confirmed ZIKV infection during pregnancy.
Neonates (n = 98) had serum specimens tested repeatedly for ZIKV nAb over the first 2 years of life using virus neutralization test (VNT). ZIKV neonatal infection was confirmed by RT-PCR in blood or urine and/or presence of ZIKV IgM antibodies, and results were correlated with infant clinical features.
Postnatal laboratory evidence of ZIKV vertical transmission was obtained for 60.2% of children, while 32.7% exhibited clinical abnormalities. Congenital abnormalities were found in 37.3% of children with confirmed ZIKV infection and 31.0% of children without confirmed infection (P = .734). All but 1 child displayed a physiologic decline in ZIKV nAb, reflecting maternal antibody decay, despite an early ZIKV-IgM response in one-third of infants.
Infants with antenatal ZIKV exposure do not develop ZIKV nAb despite an early IgM response. Therefore, ZIKV VNT in children is not useful for diagnosis of congenital infection. In light of these findings, it remains to be determined if children infected in utero are potentially susceptible to reinfection.
寨卡病毒（ZIKV）与严重的先天性异常有关，产前感染的实验室诊断较为困难。本研究评估了在妊娠期间经 PCR 确诊感染寨卡病毒的母亲所生婴儿的寨卡病毒中和抗体（nAb）的动力学。
新生儿（n=98）在出生后的前 2 年内，使用病毒中和试验（VNT）反复检测血清样本中的寨卡病毒 nAb。通过 RT-PCR 在血液或尿液中检测到寨卡病毒和/或存在寨卡病毒 IgM 抗体，从而确认新生儿寨卡病毒感染，同时将结果与婴儿的临床特征相关联。
60.2%的儿童在出生后获得了实验室证据表明存在寨卡病毒垂直传播，而 32.7%的儿童出现了临床异常。在确诊感染寨卡病毒的儿童中，有 37.3%存在先天性异常，而在未确诊感染的儿童中，有 31.0%存在先天性异常（P=0.734）。尽管三分之一的婴儿出现了早期的寨卡病毒 IgM 反应，但除 1 名儿童外，所有儿童的寨卡病毒 nAb 均呈生理性下降，反映了母体抗体的衰减。
尽管有早期的 IgM 反应，但有产前寨卡病毒暴露的婴儿并未产生寨卡病毒 nAb。因此，VNT 不适用于诊断先天性感染。鉴于这些发现，尚需确定宫内感染的儿童是否容易再次感染。
