Mussi-Pinhata Marisa Marcia, Yamamoto Aparecida Yulie
Department of Pediatrics, Ribeirão Preto Medical School, University of São Paulo, Brazil.
J Infect Dis. 2020 Mar 5;221(Suppl 1):S15-S22. doi: 10.1093/infdis/jiz443.
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.
孕妇孕前巨细胞病毒（CMV）免疫力并不能保护胎儿免受先天性CMV感染（cCMV）。孕期潜伏感染复发或感染新病毒株导致的非原发性感染可致使胎儿感染。由于cCMV的患病率随孕妇CMV血清阳性率的升高而增加，全球绝大多数cCMV病例都源于孕妇的非原发性感染，且在社会经济背景较低的人群中更为常见。通过接触身体分泌物中排出病毒的人（幼儿、性行为、家庭拥挤、低收入）而发生的水平传播可能会增加获得外源性非原发性CMV感染及胎儿传播的风险。此外，传播母亲中更频繁地获得新抗体反应性表明，新病毒株导致的孕妇再感染可能是这类人群先天性感染的主要来源。然而，血清免疫女性孕期CMV非原发性感染的确切频率以及这些女性的宫内传播率仍有待确定。通常，在血清阳性率高的人群中，cCMV的出生患病率较高（≥7:1000）。越来越多的证据表明，非原发性CMV感染母亲所生先天性CMV感染婴儿的临床和实验室异常的频率及严重程度与原发性孕妇感染后所生婴儿相似。对于感音神经性听力损失而言尤其如此，在血清阳性人群中，感音神经性听力损失占所有早发性听力损失的三分之一。本简要概述将讨论开展更多研究的必要性，以更好地阐明血清阳性率高的人群中cCMV的自然史，在几乎所有人群中，cCMV的自然史仍未完全明确。
