Maternal preconceptional cytomegalovirus (CMV) immunity does not protect the fetus from acquiring congenital CMV infection (cCMV). Nonprimary infections due to recurrence of latent infections or reinfection with new virus strains during pregnancy can result in fetal infection. Because the prevalence of cCMV increases with increasing maternal CMV seroprevalence, the vast majority of the cases of cCMV throughout the world follow nonprimary maternal infections and is more common in individuals of lower socioeconomic background. Horizontal exposures to persons shedding virus in bodily secretions (young children, sexual activity, household crowding, low income) probably increase the risk of acquisition of an exogenous nonprimary CMV infection and fetal transmission. In addition, more frequent acquisition of new antibody reactivities in transmitter mothers suggest that maternal reinfection by new viral strains could be a major source of congenital infection in such populations. However, the exact frequency of CMV nonprimary infection in seroimmune women during pregnancy and the rate of intrauterine transmission in these women are yet to be defined. Usually, the birth prevalence of cCMV is high (≥7:1000) in highly seropositive populations. There is increasing evidence that the frequency and severity of the clinical and laboratory abnormalities in infants with congenital CMV infection born to mothers with nonprimary CMV infection are similar to infants born after a primary maternal infection. This is particularly true for sensorineural hearing loss, which contributes to one third of all early-onset hearing loss in seropositive populations. This brief overview will discuss the need for more research to better clarify the natural history of cCMV in highly seropositive populations, which, in almost all populations, remains incompletely defined.

中文翻译：

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高血清反应阳性人群中先天性巨细胞病毒感染的自然史

孕妇孕前巨细胞病毒（CMV）免疫不能保护胎儿免于获得先天性巨细胞病毒感染（cCMV）。在怀孕期间由于潜伏性感染的复发或新病毒株的重新感染而引起的非原发性感染可导致胎儿感染。由于cCMV的患病率随孕产妇CMV血清学患病率的增加而增加，因此，全世界绝大多数cCMV病例都是由非原发性孕产妇感染引起的，在社会经济背景较低的人群中更为常见。水平暴露于在身体分泌物中释放病毒的人（年幼的孩子，性活动，家庭拥挤，低收入）可能会增加获得外源性非原发性巨细胞病毒感染和胎儿传播的风险。此外，在传播者母亲中更频繁地获得新的抗体反应性表明，新病毒株对母亲的再感染可能是这类人群中先天性感染的主要来源。但是，尚未确定血清免疫妇女在怀孕期间CMV非原发感染的确切频率以及这些妇女的宫内传播率。通常，在高度血清反应阳性的人群中，cCMV的出生率很高（≥7：1000）。越来越多的证据表明，非原发性巨细胞病毒感染母亲所生先天性巨细胞病毒感染婴儿的临床和实验室异常的频率和严重程度与原发性母体感染婴儿相似。对于感觉神经性听力损失尤为如此，在血清反应阳性人群中占所有早发性听力损失的三分之一。简短的概述将讨论需要进行更多研究以更好地阐明高度血清反应阳性人群中cCMV的自然史的情况，而在几乎所有人群中，cCMV的自然史仍未完全定义。