Genome-Wide fitness analysis of group B Streptococcus in human amniotic fluid reveals a transcription factor that controls multiple virulence traits.

Streptococcus agalactiae (group B Streptococcus; GBS) remains a dominant cause of serious neonatal infections. One aspect of GBS that renders it particularly virulent during the perinatal period is its ability to invade the chorioamniotic membranes and persist in amniotic fluid, which is nutritionally deplete and rich in fetal immunologic factors such as antimicrobial peptides. We used next-generation sequencing of transposon-genome junctions (Tn-seq) to identify five GBS genes that promote survival in the presence of human amniotic fluid. We confirmed our Tn-seq findings using a novel CRISPR inhibition (CRISPRi) gene expression knockdown system. This analysis showed that one gene, which encodes a GntR-class transcription factor that we named MrvR, conferred a significant fitness benefit to GBS in amniotic fluid. We generated an isogenic targeted deletion of the mrvR gene, which had a growth defect in amniotic fluid relative to the wild type parent strain. The mrvR deletion strain also showed a significant biofilm defect in vitro. Subsequent in vivo studies showed that while the mutant was able to cause persistent murine vaginal colonization, pregnant mice colonized with the mrvR deletion strain did not develop preterm labor despite consistent GBS invasion of the uterus and the fetoplacental units. In contrast, pregnant mice colonized with wild type GBS consistently deliver prematurely. In a sepsis model the mrvR deletion strain showed significantly decreased lethality. In order to better understand the mechanism by which this newly identified transcription factor controls GBS virulence, we performed RNA-seq on wild type and mrvR deletion GBS strains, which revealed that the transcription factor affects expression of a wide range of genes across the GBS chromosome. Nucleotide biosynthesis and salvage pathways were highly represented among the set of differentially expressed genes, suggesting that MrvR may be involved in regulating nucleotide availability.

Pregnancy Outcomes after ZIKV Infection in French Territories in the Americas.

BACKGROUND: The risk of congenital neurologic defects related to Zika virus (ZIKV) infection has ranged from 6 to 42% in various reports. The aim of this study was to estimate this risk among pregnant women with symptomatic ZIKV infection in French territories in the Americas. METHODS: From March 2016 through November 2016, we enrolled in this prospective cohort study pregnant women with symptomatic ZIKV infection that was confirmed by polymerase-chain-reaction (PCR) assay. The analysis included all data collected up to April 27, 2017, the date of the last delivery in the cohort. RESULTS: Among the 555 fetuses and infants in the 546 pregnancies included in the analysis, 28 (5.0%) were not carried to term or were stillborn, and 527 were born alive. Neurologic and ocular defects possibly associated with ZIKV infection were seen in 39 fetuses and infants (7.0%; 95% confidence interval, 5.0 to 9.5); of these, 10 were not carried to term because of termination of pregnancy for medical reasons, 1 was stillborn, and 28 were live-born. Microcephaly (defined as head circumference more than 2 SD below the mean for sex and gestational age) was detected in 32 fetuses and infants (5.8%), of whom 9 (1.6%) had severe microcephaly (more than 3 SD below the mean). Neurologic and ocular defects were more common when ZIKV infection occurred during the first trimester (24 of 189 fetuses and infants [12.7%]) than when it occurred during the second trimester (9 of 252 [3.6%]) or third trimester (6 of 114 [5.3%]) (P=0.001). CONCLUSIONS: Among pregnant women with symptomatic, PCR-confirmed ZIKV infection, birth defects possibly associated with ZIKV infection were present in 7% of fetuses and infants. Defects occurred more frequently in fetuses and infants whose mothers had been infected early in pregnancy. Longer-term follow-up of infants is required to assess any manifestations not detected at birth. (Funded by the French Ministry of Health and others; ClinicalTrials.gov number, NCT02916732 .).

Outcome of pregnancies with recent primary cytomegalovirus infection in first trimester treated with hyperimmunoglobulin: observational study.

OBJECTIVE: To examine the efficacy of hyperimmunoglobulin (HIG) treatment in women with a recent primary cytomegalovirus (CMV) infection up to 14 weeks' gestation. METHODS: This is an ongoing observational study conducted at the prenatal medicine departments of the University Hospitals of Tübingen, Bonn, Cologne and Erlangen, Germany, as well as at the Laboratory Prof. Gisela Enders and Colleagues in Stuttgart, Germany and the Institute for Medical Virology at the University of Tübingen, Tübingen, Germany. Enrolment criteria were the presence of confirmed recent primary CMV infection in the first trimester and a gestational age at first HIG administration of ≤ 14 weeks. The following inclusion criteria indicated a recent primary infection: low anti-immunoglobulin (Ig)-G levels, low anti-CMV-IgG avidity in the presence of a positive CMV-IgM test and no positive reactivity or just seroconversion anti-gB2-IgG-reactivity. HIG administration was started as soon as possible within a few days after the first visit. HIG was administered intravenously at a dose of 200 IU/kg maternal body weight and repeated every 2 weeks until about 18 weeks' gestation. The primary outcome was maternal-fetal transmission at the time of amniocentesis. Multivariate logistic regression analysis was used to determine significant covariates that could predict maternal-fetal transmission. RESULTS: We included 149 pregnancies (153 fetuses) that completed the treatment. Median maternal age and weight were 32.0 years and 65.0 kg, respectively. Median gestational age at the time of first referral to one of the four centers was 9.4 weeks. Median anti-CMV-IgG level, anti-CMV-IgM index and CMV-IgG avidity were 5.7 U/mL, 2.5 and 22.3%, respectively. HIG treatment was started at a median gestational age of 10.6 weeks and ended at a median of 17.9 weeks. Within this time frame, HIG was administered on average four times in each patient. Amniocentesis was carried out at a median gestational age of 20.4 weeks. In 143 (93.5%) of the 153 cases, the fetus was not infected. Maternal-fetal transmission occurred in 10 cases (6.5% (95% CI, 3.2-11.7%)). On uni- and multivariate logistic regression analysis, the level of anti-IgM index was the only factor associated significantly with maternal-fetal transmission at amniocentesis. However, only four (40.0%) of the 10 cases with maternal-fetal transmission had an anti-IgM index above 11.4, which corresponds to the 95th centile of pregnancies without transmission. CONCLUSIONS: HIG is a treatment option to prevent maternal-fetal transmission in pregnancy with a primary CMV infection. However, HIG treatment seems to be beneficial primarily in women with a recent primary infection in the first trimester or during the periconceptional period, and when it is administered at a biweekly dose of 200 IU/kg. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

First-trimester diagnosis of congenital cytomegalovirus infection after maternal primary infection in early pregnancy: feasibility study of viral genome amplification by PCR on chorionic villi obtained by CVS.

OBJECTIVE: To evaluate the feasibility of amplification of the viral genome by polymerase chain reaction (PCR) analysis of trophoblast samples obtained by chorionic villus sampling (CVS) in cases of maternal primary infection (MPI) with cytomegalovirus (CMV) in early pregnancy. METHODS: This was a prospective study carried out at the Department of Obstetrics and Fetal Medicine, Hopital Necker-E.M., between October 2019 and October 2020. Following CMV serology screening in early pregnancy, CVS was offered to women at 11-14 weeks' gestation after CMV-MPI ≤ 10 weeks. Array-comparative genomic hybridization and amplification of the viral genome by PCR were performed on the trophoblasts obtained by CVS. All cases also underwent amniocentesis from 17 weeks onwards and PCR was performed on the amniotic fluid. Secondary prevention with valacyclovir was initiated as soon as MPI was diagnosed, to decrease the risk of vertical transmission. We evaluated the diagnostic performance of CMV-PCR of trophoblast obtained by CVS, using as the reference standard PCR of amniotic fluid obtained by amniocentesis. RESULTS: CVS was performed in 37 pregnancies, at a median (range) gestational age of 12.7 (11.3-14.4) weeks. CMV-PCR in chorionic villi was positive in three and negative in 34 cases. CMV-PCR following amniocentesis, performed at a median (range) gestational age of 17.6 (16.7-29.9) weeks, was positive for the three cases which were positive following CVS and, of the 34 patients with a negative finding following CVS, amniocentesis was negative in 31 and positive in three. The sensitivity of CMV-PCR analysis of trophoblast obtained by CVS for the diagnosis of CMV, using as the reference standard PCR analysis of amniotic fluid obtained by amniocentesis, was 50% (95% CI, 19-81%), specificity was 100% (95% CI, 89-100%), positive predictive value was 100% (95% CI, 44-100%) and negative predictive value was 91% (95% CI, 77-97%). CONCLUSIONS: Diagnosis of placental infection following MPI in early pregnancy can be achieved by PCR amplification of the CMV genome in chorionic villi. We propose that negative CMV-PCR in the trophoblast after 12 weeks could be used to exclude CMV-related embryopathy leading to sequelae. However, this needs to be confirmed through long-term follow-up evaluation. These findings could help to establish CVS as the diagnostic test of choice following maternal serology screening in early pregnancy. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Vertical transmission of SARS-CoV2 during pregnancy: A high-risk cohort.

OBJECTIVE: Identify the potential for and risk factors of SARS-CoV-2 vertical transmission. METHODS: Symptomatic pregnant women with COVID-19 diagnosis in whom PCR for SARS-CoV-2 was performed at delivery using maternal serum and at least one of the biological samples: cord blood (CB), amniotic fluid (AF), colostrum and/or oropharyngeal swab (OPS) of the neonate. The association of parameters with maternal, AF and/or CB positivity and the influence of SARS-CoV-2 positivity in AF and/or CB on neonatal outcomes were investigated. RESULTS: Overall 73.4% (80/109) were admitted in hospital due to COVID-19, 22.9% needed intensive care and there were four maternal deaths. Positive RT-PCR for SARS-CoV-2 was observed in 14.7% of maternal blood, 13.9% of AF, 6.7% of CB, 2.1% of colostrum and 3.7% of OPS samples. The interval between COVID-19 symptoms and delivery was inversely associated with SARS-CoV-2 positivity in the maternal blood (p = 0.002) and in the AF and/or CB (p = 0.049). Maternal viremia was associated with positivity for SARS-CoV-2 in AF and/or CB (p = 0.001). SARS-CoV-2 positivity in the compartments was not associated with neonatal outcomes. CONCLUSION: Vertical transmission is possible in pregnant women with COVID-19 and a shorter interval between maternal symptoms and delivery is an influencing factor.

Gestation and COVID-19: clinical and microbiological observational study (Gesta-COVID19).

BACKGROUND: The Coronavirus Disease 2019 (COVID-19) is a novel disease which has been having a worldwide affect since December 2019. Evidence regarding the effects of SARS-CoV-2 during pregnancy is conflicting. The presence of SARS-CoV-2 has been demonstrated in biological samples during pregnancy (placenta, umbilical cord or amniotic fluid); however, maternal and fetal effects of the virus are not well known. METHODS: Descriptive, multicentre, longitudinal, observational study in eight tertiary care hospitals throughout Spain, that are referral centres for pregnant women with COVID-19. All pregnant women with positive SARS-CoV-2 real-time reverse transcriptase polymerase chain reaction during their pregnancy or 14 days preconception and newborns born to mothers infected with SARS-CoV-2 will be included. They will continue to be followed up until 4 weeks after delivery. The aim of the study is to investigate both the effect of COVID-19 on the pregnancy, and the effect of the pregnancy status with the evolution of the SARS-CoV-2 disease. Other samples (faeces, urine, serum, amniotic fluid, cord and peripheral blood, placenta and breastmilk) will be collected in order to analyse whether or not there is a risk of vertical transmission and to describe the behaviour of the virus in other fluids. Neonates will be followed until 6 months after delivery to establish the rate of neonatal transmission. We aim to include 150 pregnant women and their babies. Ethics approval will be obtained from all the participating centres. DISCUSSION: There is little information known about COVID-19 and its unknown effects on pregnancy. This study will collect a large number of samples in pregnant women which will allow us to demonstrate the behaviour of the virus in pregnancy and postpartum in a representative cohort of the Spanish population.

Detection of Zika virus in paired urine and amniotic fluid samples from symptomatic and asymptomatic women and their babies during a disease outbreak: association with neurological symptoms in newborns.

Paired maternal and newborn urine and amniotic fluid from 138 subjects collected during a Zika virus (ZIKV) outbreak was analyzed for ZIKV by gene amplification (RT-qPCR), and the findings were correlated with clinical symptoms and neurological anomalies in the babies. ZIKV was detected in 1 of 9 symptomatic women (11.1%) and in 19 of 129 asymptomatic women (14.7%). Neurological manifestations were present in 19 babies (13.7%), 10 of 20 (50%) positive and 9 of 119 (7.6%) negative (p < 0.001) for ZIKV. Twelve (8.6%) urines collected during gestation were ZIKV-positive; only 2 remained positive for ZIKV postpartum. Six (4.1%) newborn urines collected within 1 day of delivery were ZIKV-positive cases. In 3 of these cases, ZIKV was detected in mother's urine pre- and postpartum and in both mother's urine and babies' urine. Four of the amniotic fluid samples (2.9%) were ZIKV-positive. Among ZIKV-negative babies with neurological sequel, 87.5% were female; in contrast, 72.7% ZIKV-positive babies with neurological abnormalities were male (p = 0.019). We conclude that during a ZIKV outbreak, clinical symptoms and ZIKV detection in biological fluids are poor predictors of infection and adverse neurologic sequel in newborns.

Evidence for and against vertical transmission for severe acute respiratory syndrome coronavirus 2.

COVID-19 can severely affect pregnant women Furthermore, issues regarding vertical transmission of severe acute respiratory syndrome coronavirus 2 are emerging. In patients and neonates who are showing symptoms of coronavirus disease 2019, real-time polymerase chain reaction of nasal and throat swabs, sputum, and feces is performed to detect the presence of severe acute respiratory syndrome coronavirus 2. In addition, real-time polymerase chain reaction of vaginal swabs, amniotic fluid, placenta, cord blood, neonatal blood, or breast milk for the detection of severe acute respiratory syndrome coronavirus 2 did not show substantial results. Viremia was present in 1% of adult patients who were showing symptoms of coronavirus disease 2019. Here, we reviewed 12 articles published between Feb. 10, 2020, and April 4, 2020, that reported on 68 deliveries and 71 neonates with maternal infection in the third trimester of pregnancy. To determine whether infection occurred congenitally or perinatally, perinatal exposure, mode of delivery, and time interval from delivery to the diagnosis of neonatal infection were considered. Neonates with severe acute respiratory syndrome coronavirus 2 infection are usually asymptomatic. In 4 cases, a diagnostic test for severe acute respiratory syndrome coronavirus 2 infection was performed within 48 hours of life. Furthermore, detection rates of real-time polymerase chain reaction and the interpretation of immunoglobulin M and immunoglobulin G antibodies levels in cord and neonatal blood were discussed in relation with the immaturity of the fetal and neonatal immune system.

Coronavirus disease 2019 in pregnant women: a report based on 116 cases.

BACKGROUND: The coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2, is a global public health emergency. Data on the effect of coronavirus disease 2019 in pregnancy are limited to small case series. OBJECTIVE: To evaluate the clinical characteristics and outcomes in pregnancy and the vertical transmission potential of severe acute respiratory syndrome coronavirus 2 infection. STUDY DESIGN: Clinical records were retrospectively reviewed for 116 pregnant women with coronavirus disease 2019 pneumonia from 25 hospitals in China between January 20, 2020, and March 24, 2020. Evidence of vertical transmission was assessed by testing for severe acute respiratory syndrome coronavirus 2 in amniotic fluid, cord blood, and neonatal pharyngeal swab samples. RESULTS: The median gestational age on admission was 38+0 (interquartile range, 36+0-39+1) weeks. The most common symptoms were fever (50.9%, 59/116) and cough (28.4%, 33/116); 23.3% (27/116) patients presented without symptoms. Abnormal radiologic findings were found in 96.3% (104/108) of cases. Of the 116 cases, there were 8 cases (6.9%) of severe pneumonia but no maternal deaths. One of 8 patients who presented in the first trimester and early second trimester had a missed spontaneous abortion. Of 99 patients, 21 (21.2%) who delivered had preterm birth, including 6 with preterm premature rupture of membranes. The rate of spontaneous preterm birth before 37 weeks' gestation was 6.1% (6/99). One case of severe neonatal asphyxia resulted in neonatal death. Furthermore, 86 of the 100 neonates tested for severe acute respiratory syndrome coronavirus 2 had negative results; of these, paired amniotic fluid and cord blood samples from 10 neonates used to test for severe acute respiratory syndrome coronavirus 2 had negative results. CONCLUSION: Severe acute respiratory syndrome coronavirus 2 infection during pregnancy is not associated with an increased risk of spontaneous abortion and spontaneous preterm birth. There is no evidence of vertical transmission of severe acute respiratory syndrome coronavirus 2 infection when the infection manifests during the third trimester of pregnancy.

Zika virus detection in amniotic fluid and Zika-associated birth defects.

BACKGROUND: Zika virus infection during pregnancy can cause serious birth defects, which include brain and eye abnormalities. The clinical importance of detection of Zika virus RNA in amniotic fluid is unknown. OBJECTIVE: The purpose of this study was to describe patterns of Zika virus RNA testing of amniotic fluid relative to other clinical specimens and to examine the association between Zika virus detection in amniotic fluid and Zika-associated birth defects. Our null hypothesis was that Zika virus detection in amniotic fluid was not associated with Zika-associated birth defects. STUDY DESIGN: We conducted a retrospective cohort analysis of women with amniotic fluid specimens submitted to Colombia's National Institute of Health as part of national Zika virus surveillance from January 2016 to January 2017. Specimens (maternal serum, amniotic fluid, cord blood, umbilical cord tissue, and placental tissue) were tested for the presence of Zika virus RNA with the use of a singleplex or multiplex real-time reverse transcriptase-polymerase chain reaction assay. Birth defect information was abstracted from maternal prenatal and infant birth records and reviewed by expert clinicians. Chi-square and Fisher's exact tests were used to compare the frequency of Zika-associated birth defects (defined as brain abnormalities [with or without microcephaly, but excluding neural tube defects and their associated findings] or eye abnormalities) by frequency of detection of Zika virus RNA in amniotic fluid. RESULTS: Our analysis included 128 women with amniotic fluid specimens. Seventy-five women (58%) had prenatally collected amniotic fluid; 42 women (33%) had amniotic fluid collected at delivery, and 11 women (9%) had missing collection dates. Ninety-one women had both amniotic fluid and other clinical specimens submitted for testing, which allowed for comparison across specimen types. Of those 91 women, 68 had evidence of Zika virus infection based on detection of Zika virus RNA in ≥1 specimen. Testing of amniotic fluid that was collected prenatally or at delivery identified 39 of these Zika virus infections (57%; 15 [22%] infections were identified only in amniotic fluid), and 29 infections (43%) were identified in other specimen types and not amniotic fluid. Among women who were included in the analysis, 89 had pregnancy outcome information available, which allowed for the assessment of the presence of Zika-associated birth defects. Zika-associated birth defects were significantly (P<.05) more common among pregnancies with Zika virus RNA detected in amniotic fluid specimens collected prenatally (19/32 specimens; 59%) than for those with no laboratory evidence of Zika virus infection in any specimen (6/23 specimens; 26%), but the proportion was similar in pregnancies with only Zika virus RNA detected in specimens other than amniotic fluid (10/23 specimens; 43%). Although Zika-associated birth defects were more common among women with any Zika virus RNA detected in amniotic fluid specimens (ie, collected prenatally or at delivery; 21/43 specimens; 49%) than those with no laboratory evidence of Zika virus infection (6/23 specimens; 26%), this comparison did not reach statistical significance (P=.07). CONCLUSION: Testing of amniotic fluid provided additional evidence for maternal diagnosis of Zika virus infection. Zika-associated birth defects were more common among women with Zika virus RNA that was detected in prenatal amniotic fluid specimens than women with no laboratory evidence of Zika virus infection, but similar to women with Zika virus RNA detected in other, nonamniotic fluid specimen types.

Vertical transmission of SARS-CoV-2 infection and preterm birth.

Viral infections are common complications of pregnancy, with a wide range of obstetric and neonatal sequelae. Currently, there are limited data on whether SARS-CoV-2 is vertically transmitted in pregnant women tested positive for the virus. Here we describe a case of a known SARS-CoV-2-positive woman giving preterm birth to two fetuses with SARS-CoV-2 positive testing in placental tissue and amniotic fluid. The placental histological examinations showed chronic intervillositis and extensive intervillous fibrin depositions with ischemic necrosis of the surrounding villi.

No intrauterine vertical transmission in pregnancy with COVID-19: A case report.

The coronavirus disease 2019 (COVID-19) has been a worldwide pandemic diseases, nearly 400,000 people died at now. The data of status of pregnant women and neonates after infection of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is limited. We report a case of pregnant woman in her third trimester with critical COVID-19, and amniotic fluid, umbilical cord blood, placenta, and neonatal gastric fluid were retained during cesarean section. The SARS-COV-2 nucleic acid test results of these specimens were negative. There is no evidence of intrauterine vertical transmission during delivery in the third trimester, but the data are limited and need to be further explored.

Fetal and maternal outcome after hyperimmunoglobulin administration for prevention of maternal-fetal transmission of cytomegalovirus during pregnancy: retrospective cohort analysis.

PURPOSE: To determine the frequency of fetal infection as well as adverse pregnancy outcomes following antenatal hyperimmunoglobulin (HIG) treatment for primary cytomegalovirus (CMV) infection in pregnancy. METHODS: In our observational cohort study, data from 46 women with a primary CMV infection during pregnancy were evaluated. Primary CMV infection was defined by seroconversion or the presence of CMV-IgM and low CMV-IgG avidity. All women received at least two or more infusions of HIG treatment (200 IU/kg). Congenital CMV infection (cCMV) was diagnosed by detection of CMV in amniotic fluid and/or neonatal urine. We compared the rate of maternal-fetal transmission from our cohort to data without treatment in the literature. The frequency of adverse pregnancy outcomes was compared to those of live-born infants delivered in our clinic. RESULTS: We detected 11 intrauterine infections in our cohort, which correlates to a transmission rate of 23.9%. Compared to the transmission rate found in cases without treatment (39.9%), this is a significant reduction (P = 0.026). There were no adverse pregnancy outcomes in our cohort. The mean gestational age at delivery was 39 weeks gestation in treatment and control group. CONCLUSION: The administration of HIG for prevention of maternal-fetal CMV transmission during pregnancy seems safe and effective.

Highly efficient maternal-fetal Zika virus transmission in pregnant rhesus macaques.

Infection with Zika virus (ZIKV) is associated with human congenital fetal anomalies. To model fetal outcomes in nonhuman primates, we administered Asian-lineage ZIKV subcutaneously to four pregnant rhesus macaques. While non-pregnant animals in a previous study contemporary with the current report clear viremia within 10-12 days, maternal viremia was prolonged in 3 of 4 pregnancies. Fetal head growth velocity in the last month of gestation determined by ultrasound assessment of head circumference was decreased in comparison with biparietal diameter and femur length within each fetus, both within normal range. ZIKV RNA was detected in tissues from all four fetuses at term cesarean section. In all pregnancies, neutrophilic infiltration was present at the maternal-fetal interface (decidua, placenta, fetal membranes), in various fetal tissues, and in fetal retina, choroid, and optic nerve (first trimester infection only). Consistent vertical transmission in this primate model may provide a platform to assess risk factors and test therapeutic interventions for interruption of fetal infection. The results may also suggest that maternal-fetal ZIKV transmission in human pregnancy may be more frequent than currently appreciated.

Maternal and neonatal screening methods for congenital cytomegalovirus infection.

Human cytomegalovirus (CMV) is a common cause of congenital infection that may lead to severe long-term sequelae. Because there are no established vaccines, fetal interventions or neonatal treatments, neither maternal nor neonatal screening is recommended. However, recent studies have indicated that early antiviral treatment may improve neurological outcomes in symptomatic infants with congenital infection. Therefore, prenatal detection may be important in newborns at high risk of such infection. Polymerase chain reaction for CMV DNA in the amniotic fluid is considered the gold standard for diagnosis of intrauterine infection, but its use is limited because amniocentesis is an invasive procedure. In a prospective cohort study, we have reported that the presence of CMV DNA in secretions of the maternal uterine cervix were predictive of congenital infection in groups at high risk. However, we also recently demonstrated that maternal serological screening for primary CMV infection using specific immunoglobulin G, the immunoglobulin G avidity index or specific immunoglobulin M can overlook many cases. Previous research has indicated that the combination of early detection by universal neonatal screening of urinary CMV DNA combined with early antiviral therapy can improve outcomes in infants with symptomatic congenital infection. In this article, we review the current state of maternal and neonatal screening for congenital CMV infection.

APOBEC3A Is Upregulated by Human Cytomegalovirus (HCMV) in the Maternal-Fetal Interface, Acting as an Innate Anti-HCMV Effector.

Human cytomegalovirus (HCMV) is the leading cause of congenital infection and is associated with a wide range of neurodevelopmental disabilities and intrauterine growth restriction. Yet our current understanding of the mechanisms modulating transplacental HCMV transmission is poor. The placenta, given its critical function in protecting the fetus, has evolved effective yet largely uncharacterized innate immune barriers against invading pathogens. Here we show that the intrinsic cellular restriction factor apolipoprotein B editing catalytic subunit-like 3A (APOBEC3A [A3A]) is profoundly upregulated following ex vivo HCMV infection in human decidual tissues-constituting the maternal aspect of the placenta. We directly demonstrated that A3A severely restricted HCMV replication upon controlled overexpression in epithelial cells, acting by a cytidine deamination mechanism to introduce hypermutations into the viral genome. Importantly, we further found that A3 editing of HCMV DNA occurs both ex vivo in HCMV-infected decidual organ cultures and in vivo in amniotic fluid samples obtained during natural congenital infection. Our results reveal a previously unexplored role for A3A as an innate anti-HCMV effector, activated by HCMV infection in the maternal-fetal interface. These findings pave the way to new insights into the potential impact of APOBEC proteins on HCMV pathogenesis.IMPORTANCE In view of the grave outcomes associated with congenital HCMV infection, there is an urgent need to better understand the innate mechanisms acting to limit transplacental viral transmission. Toward this goal, our findings reveal the role of the intrinsic cellular restriction factor A3A (which has never before been studied in the context of HCMV infection and vertical viral transmission) as a potent anti-HCMV innate barrier, activated by HCMV infection in the authentic tissues of the maternal-fetal interface. The detection of naturally occurring hypermutations in clinical amniotic fluid samples of congenitally infected fetuses further supports the idea of the occurrence of A3 editing of the viral genome in the setting of congenital HCMV infection. Given the widely differential tissue distribution characteristics and biological functions of the members of the A3 protein family, our findings should pave the way to future studies examining the potential impact of A3A as well as of other A3s on HCMV pathogenesis.

Identification of Symptomatic Fetuses Infected with Cytomegalovirus Using Amniotic Fluid Peptide Biomarkers.

Cytomegalovirus (CMV) is the most common cause of congenital infection, and is a major cause of sensorineural hearing loss and neurological disabilities. Evaluating the risk for a CMV infected fetus to develop severe clinical symptoms after birth is crucial to provide appropriate guidance to pregnant women who might have to consider termination of pregnancy or experimental prenatal medical therapies. However, establishing the prognosis before birth remains a challenge. This evaluation is currently based upon fetal imaging and fetal biological parameters, but the positive and negative predictive values of these parameters are not optimal, leaving room for the development of new prognostic factors. Here, we compared the amniotic fluid peptidome between asymptomatic fetuses who were born as asymptomatic neonates and symptomatic fetuses who were either terminated in view of severe cerebral lesions or born as severely symptomatic neonates. This comparison allowed us to identify a 34-peptide classifier in a discovery cohort of 13 symptomatic and 13 asymptomatic neonates. This classifier further yielded 89% sensitivity, 75% specificity and an area under the curve of 0.90 to segregate 9 severely symptomatic from 12 asymptomatic neonates in a validation cohort, showing an overall better performance than that of classical fetal laboratory parameters. Pathway analysis of the 34 peptides underlined the role of viral entry in fetuses with severe brain disease as well as the potential importance of both beta-2-microglobulin and adiponectin to protect the injured fetal brain infected with CMV. The results also suggested the mechanistic implication of the T calcium channel alpha-1G (CACNA1G) protein in the development of seizures in severely CMV infected children. These results open a new field for potential therapeutic options. In conclusion, this study demonstrates that amniotic fluid peptidome analysis can effectively predict the severity of congenital CMV infection. This peptidomic classifier may therefore be used in clinical settings during pregnancy to improve prenatal counseling.

Antenatal treatment options for primary cytomegalovirus infections.

PURPOSE OF REVIEW: Cytomegalovirus (CMV) infection is by far the most common fetal viral infection. It carries a risk of long-term sequelae for the neonate; though the severity depends on the gestational age at the time of infection. Improvement in primary prevention of a CMV infection during pregnancy can be achieved by providing information regarding hygiene to the mother. Once a maternal infection occurs, treatment options include prevention of maternal-fetal transmission and, once transmission occurs, attempts to reduce the severity of its effect on the fetus. RECENT FINDINGS: Several recent studies have shown that providing detailed information regarding the effects of CMV on the fetus and providing common sense hygiene advice reduced new primary infections by more than 75%. In cases with a documented maternal primary CMV infection, treatment with intravenous immunoglobulins have been tried to reduce maternal fetal transmission with a variable degree of success. In the randomized controlled study of Revello et al., immunoglobulins did not reduce the transmission rate. In a recent study, immunoglobulins were given only to women with very recent first trimester infections. In this study, the transmission rate was 2.5%, which is significantly less than expected. Leruez-Ville et al. treated mothers with known transmission of CMV to the fetus with 8 g of valaciclovir daily. They observed a significant reduction in the number of neonatal symptoms in the treated cases. SUMMARY: Protocols are available to prevent primary CMV infections during pregnancy and, in cases where an infection does occur, steps can be taken to reduce its effect on the fetus thereby reducing the chance of long-term sequelae.

Comparison of quantitative real-time PCR and short-term (18-hour) microculture in diagnosis of fetal cytomegalovirus infection: Impact of hyperimmunoglobulin treatment.

OBJECTIVE: The prognostic value of human cytomegalovirus detection (HCMV) DNA levels from amniotic fluid (AF) for the outcome of the infected newborn is still a matter of debate, especially if the onset of maternal primary infection at amniocentesis is unknown. The objective of this study was to investigate the analytical performance in short-term (18-hour) microculture from preconcentrated samples and quantitative real-time PCR (rtPCR) for diagnosis of fetal HCMV infection. METHODS: A retrospective diagnostic study was conducted on 51 AF samples taken from women that transmitted HCMV prenatally. Amniocentesis was performed around 22-week gestation. The samples were tested for HCMV viral load via quantitative rtPCR and additionally with quantitative short-term (18-hour) microculture following preconcentration via a 50 000 g centrifugation step prior to inoculation to fibroblast monolayers. RESULTS: Both methods show correlating results (ρ = 0.903). In 25 samples, the women received intravenous hyperimmunoglobulin prior to amniocentesis resulting in a lower correlation of both quantitative methods (ρ = 0.445), in reduced median copy numbers of HCMV DNA (P = .037) and reduced viral infectivity in short-term microculture (P = .025). CONCLUSION: Both methods lead to correlating results using AF samples from HIG-naïve women. Human cytomegalovirus viral load and infectivity in cell culture are reduced in samples following maternal hyperimmunoglobulin treatment.