Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, University of Washington, Seattle, WA.
Fourth Dimension Biomedical and Research Consulting, Victoria, British Columbia, Canada.
Am J Obstet Gynecol. 2019 Jan;220(1):45-56. doi: 10.1016/j.ajog.2018.08.035. Epub 2018 Aug 29.
Zika virus is a mosquito-transmitted flavivirus and was first linked to congenital microcephaly caused by a large outbreak in northeastern Brazil. Although the Zika virus epidemic is now in decline, pregnancies in large parts of the Americas remain at risk because of ongoing transmission and the potential for new outbreaks. This review presents why Zika virus is still a complex and worrisome public health problem with an expanding spectrum of birth defects and how Zika virus and related viruses evade the immune response to injure the fetus. Recent reports indicate that the spectrum of fetal brain and other anomalies associated with Zika virus exposure is broader and more complex than microcephaly alone and includes subtle fetal brain and ocular injuries; thus, the ability to prenatally diagnose fetal injury associated with Zika virus infection remains limited. New studies indicate that Zika virus imparts disproportionate effects on fetal growth with an unusual femur-sparing profile, potentially providing a new approach to identify viral injury to the fetus. Studies to determine the limitations of prenatal and postnatal testing for detection of Zika virus-associated birth defects and long-term neurocognitive deficits are needed to better guide women with a possible infectious exposure. It is also imperative that we investigate why the Zika virus is so adept at infecting the placenta and the fetal brain to better predict other viruses with similar capabilities that may give rise to new epidemics. The efficiency with which the Zika virus evades the early immune response to enable infection of the mother, placenta, and fetus is likely critical for understanding why the infection may either be fulminant or limited. Furthermore, studies suggest that several emerging and related viruses may also cause birth defects, including West Nile virus, which is endemic in many parts of the United States. With mosquito-borne diseases increasing worldwide, there remains an urgent need to better understand the pathogenesis of the Zika virus and related viruses to protect pregnancies and child health.
Zika 病毒是一种通过蚊子传播的黄病毒，最初与巴西东北部的一次大规模暴发有关，被认为是导致先天性小头畸形的原因。尽管 Zika 病毒疫情现已呈下降趋势，但由于持续传播以及新暴发的可能性，美洲大部分地区的妊娠仍面临风险。本综述介绍了为什么 Zika 病毒仍然是一个复杂且令人担忧的公共卫生问题，其导致的出生缺陷范围不断扩大，以及 Zika 病毒和相关病毒如何逃避免疫反应进而损害胎儿。最近的报告表明，与 Zika 病毒暴露相关的胎儿脑和其他异常的范围比单纯小头畸形更广泛、更复杂，包括胎儿脑和眼部的细微损伤；因此，产前诊断与 Zika 病毒感染相关的胎儿损伤的能力仍然有限。新的研究表明，Zika 病毒对胎儿生长的影响不成比例，且股骨免受影响，这可能为识别胎儿病毒损伤提供了一种新方法。需要开展新的研究来确定产前和产后检测识别 Zika 病毒相关出生缺陷和长期神经认知缺陷的局限性，以便更好地指导可能存在感染风险的女性。此外，我们还迫切需要研究为什么 Zika 病毒如此擅长感染胎盘和胎儿大脑，以便更好地预测其他可能引发新疫情的具有类似能力的病毒。Zika 病毒逃避早期免疫反应以感染母亲、胎盘和胎儿的效率可能对理解为什么这种感染可能迅速致命或局限至关重要。此外，研究表明，包括西尼罗河病毒在内的几种新兴和相关病毒也可能导致出生缺陷，西尼罗河病毒在美国许多地区流行。随着全世界蚊媒疾病的增加，迫切需要更好地了解 Zika 病毒和相关病毒的发病机制，以保护妊娠和儿童健康。
