Prenatal indicators of congenital cytomegalovirus infection

Human cytomegalovirus and neonatal infection

Human cytomegalovirus is an ancient virus that has co-evolved with humans. It establishes a life-long infection in suspectable individuals for which there is no vaccination or cure. The virus can be transmitted to a developing fetus in seropositive pregnant women, and it is the leading cause of congenital infectious disease. While the majority of infected infants remain asymptomatic at birth, congenital cytomegalovirus infection can lead to substantial long-term neurodevelopmental impairments in survivors, resulting in considerable economic and social hardships. Recent discoveries regarding cytomegalovirus pathophysiology and viral replication cycles might enable the development of innovative diagnostics and therapeutics, including an effective vaccine. This Review will detail our understanding of human cytomegalovirus infection, with an in-depth discussion regarding the viral genome and transcriptome that contributes to its pathophysiology. The neonate's clinical course will also be highlighted, including maternal and neonatal testing, treatment recommendations, and long-term outcomes.

Human trophoblast stem cells restrict human cytomegalovirus replication

Placental infection plays a central role in the pathogenesis of congenital human cytomegalovirus (HCMV) infections and is a cause of fetal growth restriction and pregnancy loss. HCMV can replicate in some trophoblast cell types, but it remains unclear how the virus evades antiviral immunity in the placenta and how infection compromises placental development and function. Human trophoblast stem cells (TSCs) can be differentiated into extravillous trophoblasts (EVTs), syncytiotrophoblasts (STBs), and organoids, and this study assessed the utility of TSCs as a model of HCMV infection in the first-trimester placenta. HCMV was found to non-productively infect TSCs, EVTs, and STBs. Immunofluorescence assays and flow cytometry experiments further revealed that infected TSCs frequently only express immediate early viral gene products. Similarly, RNA sequencing found that viral gene expression in TSCs does not follow the kinetic patterns observed during lytic infection in fibroblasts. Canonical antiviral responses were largely not observed in HCMV-infected TSCs and TSC-derived trophoblasts. Rather, infection dysregulated factors involved in cell identity, differentiation, and Wingless/Integrated signaling. Thus, while HCMV does not replicate in TSCs, infection may perturb trophoblast differentiation in ways that could interfere with placental function.

IMPORTANCE

Placental infection plays a central role in human cytomegalovirus (HCMV) pathogenesis during pregnancy, but the species specificity of HCMV and the limited availability and lifespan of primary trophoblasts have been persistent barriers to understanding how infection impacts this vital organ. Human trophoblast stem cells (TSCs) represent a new approach to modeling viral infection early in placental development. This study reveals that TSCs, like other stem cell types, restrict HCMV replication. However, infection perturbs the expression of genes involved in differentiation and cell fate determination, pointing to a mechanism by which HCMV could cause placental injury.

Maternal and congenital human cytomegalovirus infection: laboratory testing for detection and diagnosis

Human cytomegalovirus (CMV) is the leading cause of congenital infection worldwide and the most common cause of non-genetic sensorineural hearing loss. As there is no vaccine or other specific intervention to prevent congenital CMV infection, there is a need to identify maternal and congenital infections with sensitive and specific testing as early as possible. There is no widely accepted practice for screening during pregnancy or in all newborns for identification of possible cases of congenital CMV. Currently, screening during pregnancy is limited to those identified as at risk followed by fetal and/or neonatal testing when congenital infection is suspected. This review focuses primarily on the current status of laboratory testing for diagnosis of maternal and congenital CMV infections. Primary maternal infection is best diagnosed using serologic testing, including CMV IgM, IgG, and avidity testing, while fetal infection should be assessed by nucleic acid amplification testing (NAAT) of amniotic fluid. Urine and saliva NAATs are the mainstay for diagnosis of congenital CMV in the first 3 weeks of life. Testing of dried blood spots can be useful for diagnosis of congenital CMV outside of the newborn period. The gaps in knowledge such as the prognostic value of viral loads in various sample types are addressed.

Is a Higher Amniotic Fluid Viral Load Associated with a Greater Risk of Fetal Injury in Congenital Cytomegalovirus Infection-A Systematic Review and Meta-Analysis

Background: Numerous studies have aimed to predict prenatal and neonatal outcomes for pregnancies complicated by congenital cytomegalovirus (CMV). Presently, assessing CMV severity prenatally relies largely on fetal imaging. A controversy exists regarding CMV viral load (VL) and its association with fetal and neonatal sequelae. Objective: To perform a systematic review and meta-analysis investigating the association between CMV DNA VL in amniotic fluid and fetal and neonatal outcomes in pregnancies with congenital CMV. Results: All cohort, case-control and observational studies that compared outcomes of fetuses with congenital CMV and provided information on individual patient CMV VL quantified in copies per milliliter (c/mL) from inception to January 2023 were included, with no geographical or language restrictions. A total of 1251 citations were reviewed with eight studies meeting inclusion criteria and included in meta-analysis. Affected pregnancies had a higher VL in the amniotic fluid compared to those unaffected with a mean difference of 2.2e+7 (range 1.5e+7 to 2.8e+7). In subgroup analysis, the VL was significantly higher in the fetuses, with imaging findings related to CMV compared to asymptomatic fetuses with a mean difference of 4.1e+7 (95% CI 2.8e+7-5.4e+7). However, among babies with congenital CMV, the VL was not significantly different between symptomatic and asymptomatic babies. Conclusions: Amniotic fluid CMV VL is associated with fetal sequalae in congenital CMV, with a higher VL conferring a greater risk for prenatal injury.

Human Trophoblast Stem Cells Restrict Human Cytomegalovirus Replication

Placental infection plays a central role in the pathogenesis of congenital human cytomegalovirus (HCMV) infections and is a cause of fetal growth restriction and pregnancy loss. HCMV can replicate in some trophoblast cell types, but it remains unclear how the virus evades antiviral immunity in the placenta and how infection compromises placental development and function. Human trophoblast stem cells (TSCs) can be differentiated into extravillous trophoblasts (EVTs), syncytiotrophoblasts (STBs), and organoids, and this study assessed the utility of TSCs as a model of HCMV infection in the first trimester placenta. HCMV was found to non-productively infect TSCs, EVTs, and STBs. Immunofluorescence assays and flow cytometry experiments further revealed that infected TSCs frequently only express immediate early viral gene products. Similarly, RNA-sequencing found that viral gene expression in TSCs does not follow the kinetic patterns observed during lytic infection in fibroblasts. Canonical antiviral responses were largely not observed in HCMV-infected TSCs and TSC-derived trophoblasts. Rather, infection dysregulated factors involved in cell identity, differentiation, and WNT signaling. Thus, while HCMV does not replicate in TSCs, infection may perturb trophoblast differentiation in ways that could interfere with placental function.

Importance

Placental infection plays a central role in HCMV pathogenesis during pregnancy, but the species-specificity of HCMV and the limited availability and lifespan of primary trophoblasts have been persistent barriers to understanding how infection impacts this vital organ. Human TSCs represent a new approach to modeling viral infection early in placental development. This study reveals that TSCs, like other stem cell types, restrict HCMV replication. However, infection perturbs the expression of genes involved in differentiation and cell fate determination, pointing to a mechanism by which HCMV could cause placental injury.

The role of the T-cell mediated immune response to Cytomegalovirus infection in intrauterine transmission

INTRODUCTION

Prognostic markers for fetal transmission of Cytomegalovirus (CMV) infection during pregnancy are poorly understood. Maternal CMV-specific T-cell responses may help prevent fetal transmission and thus, we set out to assess whether this may be the case in pregnant women who develop a primary CMV infection.

METHODS

A multicenter prospective study was carried out at 8 hospitals in Spain, from January 2017 to April 2020. Blood samples were collected from pregnant women at the time the primary CMV infection was diagnosed to assess the T-cell response. Quantitative analysis of interferon producing specific CMV-CD8+/CD4+ cells was performed by intracellular cytokine flow cytometry.

RESULTS

In this study, 135 pregnant women with a suspected CMV infection were evaluated, 60 of whom had a primary CMV infection and samples available. Of these, 24 mothers transmitted the infection to the fetus and 36 did not. No association was found between the presence of specific CD4 or CD8 responses against CMV at the time maternal infection was diagnosed and the risk of fetal transmission. There was no transmission among women with an undetectable CMV viral load in blood at diagnosis.

CONCLUSIONS

In this cohort of pregnant women with a primary CMV infection, no association was found between the presence of a CMV T-cell response at the time of maternal infection and the risk of intrauterine transmission. A detectable CMV viral load in the maternal blood at diagnosis of the primary maternal infection may represent a relevant biomarker associated with fetal transmission.

Congenital cytomegalovirus infection diagnostics and management

PURPOSE OF THE REVIEW

Congenital cytomegalovirus infection (cCMV) is the most frequent congenital infection and a leading nongenetic cause of sensorineural hearing loss (SNHL) and brain disease. The purpose of this review is to highlight recent developments in the diagnosis and management of children with cCMV.

RECENT FINDINGS

Progress is being made in the efforts to identify more infants with cCMV, especially those with asymptomatic infection. Largely due to efforts by various advocacy/parent groups, a number of states in the United States and many hospital systems have implemented hearing targeted CMV screening and mandated education of pregnant women about CMV.

SUMMARY

cCMV is an important cause of SNHL and neurologic morbidity worldwide. Early identification of infected children is critical to improve outcomes by providing timely interventions and guidance for long-term follow up. The fact that most infants with cCMV have no abnormal clinical findings, and the need to obtain samples for diagnosis within the first 2-3 weeks of life, makes it challenging to identify a majority of infants with cCMV without universal newborn CMV screening.

Noninvasive Prediction of Congenital Cytomegalovirus Infection After Maternal Primary Infection

OBJECTIVE

To develop and internally validate a noninvasive method for the prediction of congenital cytomegalovirus (CMV) infection after primary maternal CMV infection.

METHODS

We conducted a secondary analysis of a multicenter randomized placebo-controlled trial of CMV hyperimmune globulin to prevent congenital infection. Women were eligible if they had primary CMV infection, defined as detectable plasma CMV-specific immunoglobulin (Ig)M and CMV-specific IgG with avidity less than 50% before 24 weeks of gestation or IgG seroconversion before 28 weeks, and were carrying a singleton fetus without ultrasonographic findings suggestive of CMV infection. Antibody assays were performed in a single reference laboratory. Congenital infection was defined as CMV detection in amniotic fluid, neonatal urine or saliva, or postmortem tissue. Using backward elimination, we developed logit models for prediction of congenital infection using factors known at randomization. The performance of the model was assessed using leave-one-out cross-validation (a method of internal validation).

RESULTS

Of 399 women enrolled in the trial, 344 (86%) had informative data for this analysis. Congenital infection occurred in 68 pregnancies (20%). The best performing model included government-assisted insurance, IgM index 4.5 or higher, IgG avidity less than 32%, and whether CMV was detectable by polymerase chain reaction in maternal plasma at the time of randomization. Cross-validation showed an average area under the curve of 0.76 (95% CI 0.70-0.82), indicating moderate discriminatory ability. More parsimonious one-, two-, and three-factor models performed significantly less well than the four-factor model. Examples of prediction with the four-factor model: for a woman with government-assisted insurance, avidity less than 32%, IgM index 4.5 or higher, and detectable plasma CMV, probability of congenital infection was 0.69 (95% CI 0.53-0.82); for a woman with private insurance, avidity 32% or greater, IgM index less than 4.5, and undetectable plasma CMV, probability of infection was 0.03 (95% CI 0.02-0.07).

CONCLUSION

We developed models to predict congenital CMV infection in the presence of primary maternal CMV infection and absence of ultrasonographic findings suggestive of congenital infection. These models may be useful for patient counseling and decision making.

Quantitative and qualitative analysis of fetal temporal lobe T2 signal in cytomegalovirus infected fetuses and normal controls

Background

Temporal lobe T2 hyperintensity has been described in association with prenatal cytomegalovirus (CMV) infection on fetal MRI. However, these findings are often perplexing with high inter-observer variability. Our objective was to evaluate temporal lobe T2 signal quantitatively in prenatal CMV infection.

Methods

In this retrospective study, 119 fetuses, of which 51 fetuses with suspected CMV exposure (29-36 weeks of gestation) based on maternal seroconversion and age-matched 68 normal controls, were included. Mean and maximal temporal lobe T2 signal were evaluated quantitatively by measuring the T2 signal in the temporal lobes relative to the amniotic fluid's signal. Intra-observer, inter-observer variability and diagnostic performance were assessed. The occurrence of neonatal sensorineural hearing loss (SNHL) was recorded.

Results

Relative temporal lobe T2 signal did not change along with the examined gestational age. Of our suspected CMV cohort, 29 fetuses were positive for fetal CMV infection on polymerase chain reaction (PCR) analysis. There were no statistically significant differences in the relative mean or maximal temporal lobes T2 signal between CMV positive, CMV negative fetuses, or normal controls. No correlation was found between neonatal SNHL and temporal lobe T2 signal.

Conclusions

When temporal lobe T2 signal is analyzed quantitatively, CMV infected fetuses do not present an increased signal than age-matched controls. Thus, reported subjective temporal T2 hyperintensities should be interpreted carefully and should have a limited effect on pregnancy management, especially as an isolated finding. Our study illustrates the importance of quantitative imaging in diagnostic neuroradiology.

Congenital Human Cytomegalovirus Infection: A Narrative Review of Maternal Immune Response and Diagnosis in View of the Development of a Vaccine and Prevention of Primary and Non-Primary Infections in Pregnancy

Congenital cytomegalovirus infection (cCMV) may affect about 1% of all newborns all over the world as a result of either a primary or recurrent human cytomegalovirus (HCMV) infection. While about 90% of infants affected by cCMV are asymptomatic at birth, the remaining 10% are symptomatic often with neurodevelopmental impairment and sensorineural hearing loss. In view of identifying the best approach to vaccine prevention of cCMV, this review will examine the most important steps made in the study of the immune response to, and diagnosis of, HCMV infection. The maternal immune response and immune correlates of protection are being partially identified with a partial contribution given by our laboratory. The diagnosis of primary infection is often difficult to achieve in the first three months of pregnancy, which is the time primarily involved in virus transmission to the fetus in association with the most severe symptoms and sequelae. Prevention of cCMV is anticipated by prevention of primary infection in early pregnancy by means of different measures, such as (i) behavioral-educational measures, (ii) immunoglobulin administration, (iii) antiviral treatment with valaciclovir. However, the most promising approach to cCMV prevention appears to be the development of a non-living vaccine, including at least three viral antigens: gB, pentamer complex gHgLpUL128L, and pp65, which have been shown to be able to stimulate both the humoral and the cellular arms of the maternal immune response. Primary HCMV infection may be managed in pregnancy by counseling of the couples involved by a team of specialists that includes virologists, obstetricians, infectivologists and neonatologists.

Guideline No. 420: Cytomegalovirus Infection in Pregnancy

OBJECTIVE

To provide an update on current recommendations for cytomegalovirus (CMV) infection during pregnancy. The objectives of this guideline are: TARGET POPULATION: Patients of child-bearing age, pregnant patients, and patients planning a pregnancy.

BENEFITS, HARMS, AND COSTS

The patient partners urged us to make awareness of preventive strategies a high priority, despite concern that discussing CMV with patients could cause unnecessary anxiety. CMV educational interventions have shown benefits from increased awareness of cCMV prevalence and preventive strategies among providers, patients, and families.

EVIDENCE

We searched MEDLINE, EMBASE, and CENTRAL databases for CMV in pregnancy. The search terms were developed using MeSH terms and keywords (Appendix). The results were filtered for articles published between January 2010 and October 2020 and systematic reviews, meta-analyses, clinical trials, and observational studies. The main inclusion criteria were pregnant patients and infants, as the target population, and CMV infection, as the diagnosis of interest. Recommendations are graded according to the U.S. Preventive Services Task Force grade of recommendations and level of certainty.

VALIDATION METHODS

We collaborated with patient partners, including members of CMV Canada (cmvcanada.com). In formulating our recommendations, we included patients' voices to add a unique and valuable perspective, thus ensuring that our recommendations are relevant to the patient-provider partnership.

INTENDED AUDIENCE

All perinatal health care providers. RECOMMENDATIONS (GRADE AND LEVEL OF CERTAINTY IN PARENTHESES).

Renal Involvement in Congenital Cytomegalovirus Infection: A Systematic Review

BACKGROUND

Congenital cytomegalovirus (cCMV) infection is the most frequent mother-to-child transmitted infection worldwide and a prevalent cause of neonatal disease and long-term morbidity. The kidney is a target organ for CMV, which replicates in renal tubules and is excreted in large quantities in urine for years in children with cCMV infection. Nonetheless, kidney disease has rarely been reported in cCMV-infected patients.

OBJECTIVE

We aimed to describe the available data on renal involvement in patients with cCMV infection at the pathologic, functional, anatomical, and/or clinical levels.

METHODS

A systematic search was performed in the MEDLINE/PubMed, SCOPUS, and Cochrane databases. Studies describing any renal involvement in fetuses or neonates aged ≤3 weeks at diagnosis of microbiologically confirmed cCMV infection were eligible.

RESULTS

Twenty-four articles were included, with a very low level of evidence. Pathologic findings in autopsy studies universally described CMV typical inclusion bodies in tubular cells. No functional studies were identified. cCMV infection was not associated with an increased risk of kidney malformations. Congenital nephrotic syndrome was the most common clinical condition associated with cCMV, but a causal relationship cannot be established.

CONCLUSIONS

Typical pathological features of cCMV infection are very common in renal tissue, but they do not seem to entail significant consequences at the anatomical or clinical levels.

Outcome of fetuses with congenital cytomegalovirus infection and normal ultrasound at diagnosis: systematic review and meta-analysis

OBJECTIVE

To report the outcome of fetuses with congenital cytomegalovirus (CMV) infection and normal ultrasound at the time of diagnosis, and to evaluate the rate of an additional anomaly detected only on magnetic resonance imaging (MRI).

METHODS

Medline, EMBASE, CINAHL and Cochrane databases were searched for studies reporting on the outcome of fetuses with congenital CMV infection. Inclusion criteria were fetuses with confirmed CMV infection and normal ultrasound assessment at the time of the initial evaluation. The outcomes observed were an anomaly detected on a follow-up ultrasound scan, an anomaly detected on prenatal MRI but missed on ultrasound, an anomaly detected on postnatal assessment but missed prenatally, perinatal mortality, symptomatic infection at birth, neurodevelopmental outcome and hearing and visual deficits. Neurodevelopmental outcome was assessed only in cases of isolated CMV infection confirmed at birth. Subgroup analysis was performed according to the trimester in which maternal infection occurred. Random-effects meta-analysis of proportions was used to analyze the data.

RESULTS

Twenty-six studies were included, comprising 2603 fetuses with congenital CMV infection, of which 1178 (45.3%) had normal ultrasound at the time of diagnosis and were included in the analysis. The overall rate of an associated central nervous system (CNS) anomaly detected on a follow-up ultrasound scan was 4.4% (95% CI, 1.4-8.8%) (32/523; 15 studies), while the rates of those detected exclusively on prenatal MRI or on postnatal imaging were 5.8% (95% CI, 1.9-11.5%) (19/357; 11 studies) and 3.2% (95% CI, 0.3-9.0%) (50/660; 17 studies), respectively. The rate of an associated extra-CNS anomaly detected on a follow-up ultrasound scan was 2.9% (95% CI, 0.8-6.3%) (19/523; 15 studies), while the rates of those detected exclusively on MRI or on postnatal imaging were 0% (95% CI, 0.0-1.7%) (0/357; 11 studies) and 0.9% (95% CI, 0.3-1.8%) (4/660; 17 studies), respectively. Intrauterine death and perinatal death each occurred in 0.7% (95% CI, 0.3-1.4%) (2/824; 23 studies) of cases. In cases without an associated anomaly detected pre- or postnatally, symptomatic infection was found in 1.5% (95% CI, 0.7-2.7%) (6/548; 19 studies) of infants, the overall rate of a neurodevelopmental anomaly was 3.1% (95% CI, 1.6-5.1%) (16/550; 19 studies), and hearing problems affected 6.5% (95% CI, 3.8-10.0%) (36/550; 19 studies) of children. Subanalyses according to the trimester in which maternal infection occurred were affected by the very small number of included cases and lack of comparison of the observed outcomes in the original studies. Compared with fetuses infected in the second or third trimester, those infected in the first trimester had a relatively higher risk of having an additional anomaly detected on follow-up ultrasound or MRI, abnormal neurodevelopmental outcome and hearing problems.

CONCLUSIONS

In fetuses with congenital CMV infection in which no anomalies are detected on prenatal ultrasound or MRI, the risk of adverse postnatal outcome is lower than that reported previously in the published literature when not considering the role of antenatal imaging assessment. The results from this review also highlight the potential role of MRI, even in fetuses with no anomalies detected on ultrasound, as an anomaly can be detected exclusively on MRI in about 6% of cases. The findings from this study could enhance prenatal counseling of pregnancies with congenital CMV infection with normal prenatal imaging. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Pregnant women's knowledge and behaviour to prevent cytomegalovirus infection: an observational study

OBJECTIVES

Congenital cytomegalovirus (cCMV) infection can negatively affect pregnancy outcomes, but may be prevented by simple precautions. Literature suggests that gynaecologists do not always adequately inform about preventive behaviour and most pregnant women have a low-level knowledge regarding cCMV infection. The aim of this study is to evaluate knowledge and risk behaviours related to cCMV infection in an unselected group of pregnant women.

METHODS

An institutional based cross-sectional study was conducted in three Maternal and Fetal Divisions in Rome between November and February 2019 on 296 pregnant women, their knowledge on cCMV was measured using six cytomegalovirus (CMV) related questions.

RESULTS

Out of the 296 respondents, 59.1% had heard, read or seen information about cCMV infection. Regarding the way of transmission, 96/296 (32.4%) correctly recognize children as a potential source of the infection but only 25/296 (8.44%) knew all prevention practices, 28/296 (9.5%) of women reported that they have never performed cCMV test during pregnancy.

CONCLUSIONS

The results of this survey show that knowledge on cCMV infection among pregnant women is poor. This highlights the need to improve counselling on all preventive practices for cCMV infection during perinatal care consultation.

Clinical Diagnostic Testing for Human Cytomegalovirus Infections

Human cytomegalovirus (HCMV) infections are among the most common complications arising in transplant patients, elevating the risk of various complications including loss of graft and death. HCMV infections are also responsible for more congenital infections worldwide than any other agent. Congenital HCMV (cCMV) infections are the leading nongenetic cause of sensorineural hearing loss and a source of significant neurological disabilities in children. While there is overlap in the clinical and laboratory approaches to diagnosis of HCMV infections in these settings, the management, follow-up, treatment, and diagnostic strategies differ considerably. As yet, no country has implemented a universal screening program for cCMV. Here, we summarize the issues, limitations, and application of diagnostic strategies for transplant recipients and congenital infection, including examples of screening programs for congenital HCMV that have been implemented at several centers in Japan, Italy, and the United States.

Cytomegalovirus infection in pregnancy - An update

Cytomegalovirus (CMV) is a ubiquitous DNA virus with a global seroprevalence of 83 %. It is the most common pathogen causing teratogenic congenital infection. It is therefore a major public health concern. Maternal infection is associated with congenital CMV (cCMV), the leading cause of non-genetic sensorineural hearing loss. cCMV also causes impairment of cognitive development and cerebral palsy. Transmission of CMV occurs through direct contact with bodily fluids such as saliva, urine or semen from someone who is actively shedding the virus. Transmission rates are higher after primary infection with the rate of transmission increasing with gestational age. Severe fetal effects are however more common when infection occurs before 20weeks. Past infection does not confer immunity to mother or protect the fetus. cCMV may present with cerebral or extracerebral abnormalities on ultrasound, fetal growth restriction and fetal loss. Diagnosis of primary maternal CMV in pregnancy should be based on seroconversion in pregnancy (de novo appearance of virus-specific immunoglobulin G (IgG) in the serum of pregnant women who were previously seronegative) or on detection of specific immunoglobulin M (IgM) and IgG antibodies in association with low IgG avidity. Prenatal diagnosis of fetal CMV is imperfect and based on amniocentesis performed at least 8 weeks after presumed maternal infection and after 17 weeks of gestation. Hygiene information and education of pregnant women is currently the most effective strategy for prevention of CMV infection. The role of vaccines, antiviral drugs and immunoglobulins remains unproven.

Is it not time for international guidelines to combat congenital cytomegalovirus infection? A review of central nervous system manifestations

Cytomegalovirus (CMV) is the most commonly transmitted virus in utero with a prevalence of up to 1.5%. The infection has potentially debilitating and devastating consequences for the infected fetus, being a leading cause for neurological disability worldwide. Once acquired, it often goes undetected with only an assumed 10% of infected neonates displaying the classic clinical or imaging features. Viral DNA polymerase chain reaction (PCR) of saliva or urine obtained within the first 21 days of life is required to make the diagnosis. As the majority of infected neonates are initially asymptomatic, diagnosis is often delayed. An abnormal routine neonatal hearing test and characteristic antenatal cranial ultrasound imaging findings may raise the suspicion of congenital CMV (cCMV) in the asymptomatic group. Ultimately, the aim is to facilitate early diagnosis and timely treatment. In this article, we highlight diagnostic and treatment challenges of the commonest congenital infection, we present the current available central nervous system imaging severity grading systems, and highlight the need for an internationally agreed diagnostic grading system that can aid treatment decision-making.

The Association Between Previous TORCH Infections and Pregnancy and Neonatal Outcomes in IVF/ICSI-ET: A Retrospective Cohort Study

Objective: This study aimed to investigate the associations between previous TORCH infection (cytomegalovirus, toxoplasmosis, herpes simplex virus, and rubella) with pregnancy and neonatal outcomes in couples undergoing IVF/ICSI-ET. Materials and Methods: A total of 18,074 couples underwent fresh IVF/ICSI-ET (in vitro fertilization/intracytoplasmic sperm injection-embryo transfer) cycles were included in our analyses. TORCH infection status was determined by serological confirmation of cytomegalovirus, toxoplasmosis, herpes simplex virus, and rubella IgG in the absence of IgM antibodies. Clinical pregnancy, ectopic pregnancy, miscarriage, live birth, preterm birth, congenital malformation, and perinatal death were evaluated in both infection and non-infection group. Multivariate logistic regression was applied to calculate odds ratio. Results: Previous toxoplasmosis infection is associated with a significantly decreased preterm birth rate [P = 0.045, OR = 0.755 (95% CI, 0.571-0.997), Adjusted OR = 0.749 (95%CI, 0.566-0.991)]. No differences in clinical pregnancy, ectopic pregnancy, miscarriage, and perinatal death were observed between the corresponding TORCH infection group [IgM (-) IgG(+)] and the non-infection group [IgM (-) IgG (-)]. Conclusions: Previous TORCH infections were not associated with adverse pregnancy and neonatal outcomes in IVF/ICSI-ET overall, and toxoplasmosis infection might be associated with a lower preterm birth rate in patients underwent IVF/ICSI-ET. The necessity of TORCH IgG screening in IVF procedure might need re-evaluation, and further cost-effective analysis might be helpful for the clinical management strategy.

Maternal infections

Congenital infections are infections transmitted from mother to child during pregnancy (transplacentally) or delivery (peripartum). They have the potential to adversely affect fetal development and long-term neurodevelopmental outcome through inflammatory, destructive, developmental, or teratogenic lesions of the brain. Because the fetal/neonatal brain has a limited capacity to respond to injury, early inflammatory changes may be difficult to visualize and only manifest as neurocognitive disability later in life. Teratogenic effects, which may include aberrations of neuronal proliferation and migration, are more easily visible on imaging, but may be equally difficult to use to predict long-term neurocognitive outcomes. This chapter reviews the general pathophysiology of congenital infection and describes the epidemiology, the antenatal and postnatal diagnosis, and the treatment of congenital infections as well as the long-term neurodevelopmental outcomes.

No. 240-Cytomegalovirus Infection in Pregnancy

OBJECTIVES

To review the principles of prenatal diagnosis of congenital cytomegalovirus (CMV) infection and to describe the outcomes of the affected pregnancies.

OUTCOMES

Effective management of fetal infection following primary and secondary maternal CMV infection during pregnancy. Neonatal signs include intrauterine growth restriction (IUGR), microcephaly, hepatosplenomegaly, petechiae, jaundice, chorioretinitis, thrombocytopenia and anemia, and long-term sequelae consist of sensorineural hearing loss, mental retardation, delay of psychomotor development, and visual impairment. These guidelines provide a framework for diagnosis and management of suspected CMV infections.

EVIDENCE

Medline was searched for articles published in English from 1966 to 2009, using appropriate controlled vocabulary (congenital CMV infection) and key words (intrauterine growth restriction, microcephaly). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

RECOMMENDATIONS

The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

Antenatal Cytomegalovirus Infection Screening Results of 32,188 Patients in a Tertiary Referral Center: A Retrospective Cohort Study

OBJECTIVE

The present study aimed to determine cytomegalovirus (CMV) seroprevalence, low and high avidities, and the frequency of polymerase chain reaction (PCR) positivity and neonatal disease in an obstetric population.

MATERIALS AND METHODS

Sera of 32,188 women were tested for CMV IgM and/or CMV IgG between 2008 and 2017. Those with IgM were tested for antibody avidity. Of those with low avidity, PCR was offered.

RESULTS

The frequency of CMV IgG and IgM seropositivity was 62% (16,759/26,854) and 22% (74/32,188). The number with low avidity was 42. In 36/42, the infants were PCR tested for CMV and 9 were CMV positive. Only one infant had signs of congenital CMV infection at the time of birth.

CONCLUSION

This study shows the prevalence of Cytomegalovirus infections in a tertiary referral center in Turkey. Although universal screening is not recommended, it can be helpful for the prevention of congenital infection for seronegative women to be advised to at-risk patients due to high prevalence of CMV exposure.

Herpesviridae Infection: Prevention, Screening, and Management

Bacterial, viral, and parasitic pathogens add significant morbidity and even mortality to pregnancy-with adverse effects extending to both the gravida and the newborn. Three herpesviruses deserve considerable attention given the effects of perinatal infection on obstetric outcomes, specifically maternal and neonatal morbidity. In the following review, we will provide a description of cytomegalovirus, herpes simplex virus, and varicella zoster virus. For each viral pathogen, we will describe the epidemiology, natural history, screening and diagnosis modalities, treatments, and implications for antepartum care. Furthermore, we will highlight future directions of work in reducing the morbidities associated with these viral pathogens.

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.

Maternal and fetal cytomegalovirus infection: diagnosis, management, and prevention

Congenital cytomegalovirus infection is a major cause of central nervous system and sensory impairments that affect cognition, motor function, hearing, language development, vestibular function, and vision. Although the importance of congenital cytomegalovirus infection is readily evident, the vast majority of maternal and fetal infections are not identified, even in developed countries. Multiple studies of prenatal cytomegalovirus infections have produced a body of knowledge that can inform the clinical approach to suspected or proven maternal and fetal infection. Reliable diagnosis of cytomegalovirus infection during pregnancy and accurate diagnosis of fetal infection are a reality. Approaches to preventing the transmission of cytomegalovirus from mother to fetus and to the treatment of fetal infection are being studied. There is evidence that public health approaches based on hygiene can dramatically reduce the rate of primary maternal cytomegalovirus infections during pregnancy. This review will consider the epidemiology of congenital cytomegalovirus infection, the diagnosis and management of primary infection during pregnancy, and approaches to preventing maternal infection.

Congenital cytomegalovirus infection: management update

PURPOSE OF REVIEW

Until recently, management options in congenital cytomegalovirus (cCMV) infection have been either conservative or termination of pregnancy. However, medical therapies aimed at reducing the risk of infection and/or its severity have recently been investigated.

RECENT FINDINGS

In a phase 2 open label, nonrandomized trial, valaciclovir (ValACV) was given to women carrying a CMV-infected fetus. ValACV was associated with a greater proportion of asymptomatic neonates when compared with a historical cohort (82 vs. 43%). However, the study design and the small number of treated women limit its applicability. Even though initial observational data suggested that hyperimmune globulin (HIG) therapy in pregnancy was associated with a significantly lower risk of cCMV, its efficacy has not been borne out in a subsequent phase 2 randomized, placebo controlled, double-blind study [cCMV 30% in the HIG group, 44% in the placebo group (P = 0.13)]. Furthermore, 11% of fetuses in the HIG group had transient or permanent abnormalities, compared with 16% in the placebo group.

SUMMARY

ValACV might have a promising role in the antenatal treatment of cCMV infection, but definitive recommendations require further research. The use of HIG should currently be limited to the research setting.Video abstract http://links.lww.com/COID/A18.

Cytomegalovirus

Cytomegalovirus (CMV), the largest of the herpesviruses, causes a wide range of clinical syndromes, from asymptomatic infection to severe disease in immunocompromised hosts. Laboratory methods for diagnosis include molecular testing, antigenemia, culture, serology, and histopathology. Treatment of CMV infection and disease is indicated in selected immunocompromised hosts, and preventive approaches are indicated in high-risk groups. This chapter reviews the epidemiology, clinical aspects, and the laboratory diagnosis and management of CMV in immunocompromised hosts.

Prenatal diagnosis of congenital cytomegalovirus infection in 115 cases: a 5 years' single center experience

OBJECTIVE

The objective of this study is to investigate the diagnostic value of invasive prenatal diagnosis (PD) of congenital cytomegalovirus (CMV) infection from amniotic fluid (AF) and fetal blood (FB).

METHODS

A retrospective study was conducted on 115 pregnancies with CMV primary infection. A total of 111 AF and 106 FB samples were investigated for various virological and non-virological markers. Detailed ultrasound examinations were performed at time of PD.

RESULTS

Overall sensitivity of CMV PCR in FB (75.6%; 95%CI 60-87) and AF (72.7%; 95%CI 57-85) was comparable. In women with amniocentesis >8 weeks between seroconversion and PD, we did not observe significant differences between amniocentesis performed ≥17 + 0 (sensitivity 90.9%; 95%CI 71-99) and ≥20 + 0 gestational weeks (sensitivity 90.0%; 95%CI 68-99). Virological markers in FB were higher in symptomatic compared with asymptomatic fetuses (p < 0.05). No significant differences were observed for non-virological markers. However, platelet counts <120 × 10e9/L and beta-2 microglobulin values >14 mg/L were more frequently found in fetuses with severe ultrasound abnormalities compared with fetuses with no or mild abnormalities (p < 0.001).

CONCLUSION

Optimal timing of amniocentesis in women with primary infection in early gestation should be reevaluated in a prospective study. Analysis of FB markers may be beneficial in the individual management of pregnant women with confirmed congenital CMV infection. © 2017 John Wiley & Sons, Ltd.

Cytomegalovirus infection in pregnancy

Cytomegalovirus (CMV) is a DNA herpesvirus that is common worldwide. The two known main sources of primary CMV infection during pregnancy are through sexual activity and contact with young children. Primary infection occurs in approximately 1 to 4% of pregnancies, and is mostly asymptomatic in immunocompetent adults. However, primary infection may manifest as a mild mononucleosis or flu-like syndrome with persistent fever and fatigue. CMV can be transmitted from mother-to-child in utero, intrapartum, or during breastfeeding. Intrauterine transmission can lead to congenital CMV infection, a leading cause of permanent hearing and vision loss and neurological disability among children. Congenital CMV transmission rates are as high as 50% in women who acquire primary CMV infection during pregnancy, and less than 2% in women with nonprimary infection. There is no licensed CMV vaccine. Good hygiene practices and avoiding intimate contact with young children (e.g., kissing on the mouth and sharing utensils) have been suggested as an approach to prevent maternal primary CMV infection during pregnancy, but remains an unproven method of reducing the risk of congenital CMV infection. Approximately 1 in 10 infants who acquire CMV in utero will have clinical signs at birth, and an additional 10 to 15% will go on to develop late-onset sequelae. Antiviral treatment prenatally and postnatally has not proven effective at preventing congenital or postnatal CMV infection, and is not recommended for routine clinical care. However, antiviral treatment when initiated in the first month of life for symptomatic congenital CMV infection is recommended for improved neurodevelopmental and audiologic outcomes. Birth Defects Research 109:336-346, 2017. © 2017 Wiley Periodicals, Inc.

Congenital cytomegalovirus infection in pregnancy and the neonate: consensus recommendations for prevention, diagnosis, and therapy

Congenital cytomegalovirus is the most frequent, yet under-recognised, infectious cause of newborn malformation in developed countries. Despite its clinical and public health importance, questions remain regarding the best diagnostic methods for identifying maternal and neonatal infection, and regarding optimal prevention and therapeutic strategies for infected mothers and neonates. The absence of guidelines impairs global efforts to decrease the effect of congenital cytomegalovirus. Data in the literature suggest that congenital cytomegalovirus infection remains a research priority, but data are yet to be translated into clinical practice. An informal International Congenital Cytomegalovirus Recommendations Group was convened in 2015 to address these questions and to provide recommendations for prevention, diagnosis, and treatment. On the basis of consensus discussions and a review of the literature, we do not support universal screening of mothers and the routine use of cytomegalovirus immunoglobulin for prophylaxis or treatment of infected mothers. However, treatment guidelines for infected neonates were recommended. Consideration must be given to universal neonatal screening for cytomegalovirus to facilitate early detection and intervention for sensorineural hearing loss and developmental delay, where appropriate. The group agreed that education and prevention strategies for mothers were beneficial, and that recommendations will need continual updating as further data become available.

Fetal cytomegalovirus infection

Cytomegalovirus (CMV) congenital infection affects 0.7% of live births worldwide and is the leading cause of congenital neurological handicap of infectious origin. However, systematic screening for this infection has not been implemented in pregnancy or at birth in any country. This apparent paradox had been justified by persisting gaps in the knowledge of this congenital infection: uncertain epidemiological data, difficulty in the diagnosis of maternal infection, absence of validated prenatal prognostic markers, unavailability of an efficient vaccine and scarcity of data available on the treatment. However, in the last decade, new data have emerged towards better management of this congenital infection, including solid epidemiological data, good evidence for the accuracy of diagnosis of maternal CMV infection and good evidence for the feasibility of predicting the outcome of fetal infection by a combination of fetal imaging and fetal laboratory parameters. There is also some evidence that valaciclovir treatment of mothers carrying an infected fetus is feasible, safe and might be effective. This review provides an update on the evidence for diagnosis, prognosis and treatment of congenital infection in the antenatal period. These suggest a benefit to a proactive approach for prenatal congenital infections.

Congenital Cytomegalovirus Infection: Prognostic Value of Maternal DNAemia at Amniocentesis

BACKGROUND

Human Cytomegalovirus (HCMV) is the most common cause of childhood hearing loss and can lead to neurodevelopmental delay. To date, few studies have examined the correlation between maternal viremia and congenital HCMV infection. The aim of our study was to ascertain if HCMV DNA in the peripheral blood of pregnant women with primary HCMV infection at the time of amniocentesis may have a prognostic value in terms of congenital infection and neonatal symptomatic disease.

METHODS

We performed a prospective observational study of pregnant women referred to our maternal-fetal medicine division with suspected HCMV infection. Primary infection was diagnosed based on seroconversion for HCMV and/or HCMV immunoglobulin M-positive and low or moderate HCMV immunoglobulin G avidity. At the time of amniocentesis, maternal blood samples were collected and analyzed by means of real-time polymerase chain reaction to determine the presence of viral DNAemia. Fetuses and newborns were evaluated for the presence of congenital infection and symptomatic disease.

RESULTS

A total of 239 pregnant women were enrolled; 32 blood samples (13.4%) were positive, and 207 (86.6%) were negative for HCMV DNA. The overall rate of transmission was 23.4%. Fifteen infected patients (26.8%) were symptomatic. Vertical transmission occurred in 14 women (43.8%) with positive and 42 (20.3%) with negative results for HCMV DNAemia (P = .006; odds ratio, 3.06; 95% confidence interval, 1.41-6.64). Symptomatic infection occurred in 6 (42.9%) infected fetuses or newborns from women with and in 9 (21.4%) from women without viral DNAemia (P = .16).

CONCLUSION

Maternal viremia at amniocentesis is associated with a 3-fold greater chance of congenital infection, but it is not correlated with symptomatic disease.

Feasibility of predicting the outcome of fetal infection with cytomegalovirus at the time of prenatal diagnosis

BACKGROUND

Congenital cytomegalovirus infection occurs in 0.7% of live births with 15-20% of infected children developing long-term disability including hearing loss and cognitive deficit. Fetal cytomegalovirus infection is established by viral DNA amplification by polymerase chain reaction in amniotic fluid obtained by amniocentesis following maternal seroconversion or after the diagnosis of ultrasound features suggestive of fetal infection. Severe brain ultrasound anomalies are associated with a poor prognosis. The prognosis of an infected fetus showing either no ultrasound features or nonsevere ultrasound anomalies is difficult to establish up until late in the second or third trimester of pregnancy.

OBJECTIVE

We sought to evaluate the prognostic value of fetal ultrasound, amniotic fluid, and fetal blood analysis at the time of prenatal diagnosis of fetal infection.

STUDY DESIGN

We reviewed all cases of fetal cytomegalovirus infection with a sample of amniotic fluid positive for viral DNA and/or fetal blood analyzed in our laboratory from 2008 through 2013. Prenatal ultrasound features along with cytomegalovirus DNA loads in amniotic fluid and in fetal blood and fetal platelet counts were reviewed in relation to gestational age at maternal infection, neonatal examination, and postnatal follow-up or postmortem examination.

RESULTS

In all, 82 fetuses were infected following maternal infection mainly in the first trimester. At the time of prenatal diagnosis at a median of 23 weeks, 19, 22, and 41 fetuses showed severe brain ultrasound abnormalities, nonsevere ultrasound features, and normal ultrasound examination, respectively. Nonsevere ultrasound features, higher DNA load in amniotic fluid, fetal platelet count ≤114,000/mm(3), and DNA load ≥4.93 log10 IU/mL in fetal blood were associated with a symptomatic status at birth in univariate analysis (P < .001, P = .001, and P = .018, respectively). Bivariate analysis combining ultrasound results and either adjusted viral load in amniotic fluid or fetal blood profile showed that these were independent prognostic factors of a symptomatic status at birth. Both fetal blood parameters were better predictors than amniotic fluid viral load. At the time of prenatal diagnosis, the ultrasound negative predictive value for symptoms at birth or at termination of pregnancy was 93%. The combined negative predictive values of ultrasound and viral load in amniotic fluid and that of ultrasound and fetal blood parameters were 95% and 100%, respectively. In fetuses presenting with nonsevere ultrasound features, the positive predictive values of ultrasound alone and in combination with amniotic fluid viral load or with fetal blood parameters were 60%, 78%, and 79%, respectively.

CONCLUSION

Risk assessment of infected fetuses for being symptomatic at birth is possible as early as the time of diagnosis by using a combination of targeted ultrasound examination along with viral load in amniotic fluid and in fetal blood together with platelet count. The advantage of using amniotic fluid is that it is available at prenatal diagnosis. One may wonder if increasing the negative predictive value of the overall assessment of an infected fetus from 95-100% is worth the additional risk of cordocentesis for fetal blood sampling. This can only be an individual decision made by well-informed women and it seems therefore appropriate to use the figures presented here and their confidence intervals for counseling.

Diagnosis and antenatal management of congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) is the most common viral infection, affecting nearly 40,000 infants each year in the United States. Of seronegative women, 1-4% will acquire a primary infection during pregnancy, and the majority of these women will be asymptomatic. Prior maternal exposure to CMV does not preclude neonatal infection. The purpose of this document is to review diagnosis of primary maternal CMV infection, diagnosis of fetal CMV infection, and whether antenatal therapy is warranted. We recommend the following: (1) that women with a diagnosis of primary CMV infection in pregnancy be advised that the risk of congenital infection is 30-50%, on average, and that the severity of infection varies widely (Best Practice); (2) for women suspected of having primary CMV infection in pregnancy, we recommend that diagnosis should be either by IgG seroconversion or with positive CMV IgM, positive IgG, and low IgG avidity (grade 1B); (3) amniocentesis is the best option as a prenatal diagnostic tool to detect fetal congenital CMV infection, performed >21 weeks of gestation and >6 weeks from maternal infection (grade 1C); (4) we do not recommend routine screening of all pregnant women for evidence of primary CMV infection at this time (grade 1B); and (5) we do not recommend antenatal treatment with ganciclovir or valacyclovir; and we recommend that any antenatal therapy, either with antivirals or CMV hyperimmune globulin, should only be offered as part of a research protocol (Best Practice).

Region-specific reductions in brain apparent diffusion coefficient in cytomegalovirus-infected fetuses

OBJECTIVE

To evaluate the effects of cytomegalovirus (CMV) infection on apparent diffusion coefficient (ADC) values of the fetal brain in utero.

METHODS

In this retrospective analysis we compared 58 fetal head magnetic resonance imaging (fhMRI) scans of PCR-verified CMV-infected fetuses, obtained in 2008-2012, with those of a normal control group of 36 gestational age (GA)-matched uninfected fetuses scanned between 2006 and 2012. Estimated GA at infection ranged from 1 to 32 weeks, and fhMRI was performed at 24 to 38 weeks. The frontal, parietal, temporal and occipital lobes (mainly white matter), basal ganglia, thalamus, pons and cerebellum were analyzed by assessing ADC values. Two pregnancies were terminated and postmortem confirmation was available in these cases.

RESULTS

ADC values of CMV-infected fetuses correlated significantly and negatively with GA in all brain regions except the basal ganglia. The cerebellum had the greatest reduction (r = -0.52, P < 0.0001). Maternal age correlated positively with ADC in the frontal lobe (P < 0.05). GA at infection and overt pathological changes did not affect ADC significantly. Compared with non-infected fetuses, ADC values of affected fetuses were significantly reduced in the frontal (P < 0.0001), parietal (P < 0.0001), occipital (P = 0.0005) and temporal (P = 0.001) lobes and thalamus (P = 0.006).

CONCLUSION

CMV infection of the fetal brain results in a highly significant, region-dependent reduction of ADC values in the frontal, parietal, occipital and temporal lobes and thalamus, probably reflecting hypercellularity and inclusion bodies in damaged areas. Further studies are needed to determine if reduction in ADC values may serve as a prognostic factor in CMV-infected fetuses. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

Rare detection of cytomegalovirus in severe fetal malformations in China

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of fetal abnormalities in developed world. Whether this could be applied in developing world remains unknown.

OBJECTIVES

To investigate CMV infection in severe fetal malformations in China.

STUDY DESIGN

During 2007-2014, 436 fetuses (237 males) with severe malformations and terminated pregnancy at median gestational age of 26(+1) weeks were enrolled. CMV DNA was detected in fetal kidneys and other tissues by real-time PCR, and CMV IgG and IgM were measured by ELISA.

RESULTS

CMV DNA was positive in kidneys and other tissues of seven (1.60%) fetuses. Hematoxylin-eosin staining showed intranuclear and intracytoplasmic inclusion bodies in kidneys of three fetuses, which was also positive for CMV antigens in immunohistochemistry. CMV DNA was found in 5 (6.1%) of 82 fetuses with central nervous system anomalies, 1 (11.1%) of 9 fetuses with abdominal anomalies, 1 (0.59%) of 168 fetuses with multiple congenital malformations, and none of fetuses with other anomalies (177). Of 293 pregnant women with plasma available, 279 (95.2%) were CMV IgG positive only and 6 (2.1%) were CMV IgG and IgM positive. Of 5 mothers with infected fetuses 1 (20%) was CMV IgG and IgM positive, while 5 (1.7%) of 288 mothers with uninfected fetuses were positive respectively (P=0.099).

CONCLUSIONS

Congenital CMV infection in fetuses with severe congenital malformations is rare, indicating no close association between CMV infection and severe fetal malformations in China. Maternal screening for CMV may have minimal value in identifying fetal malformations in developing world.

Antenatal risk factors for symptomatic congenital CMV disease following primary maternal CMV infection

OBJECTIVES

This study aimed to evaluate antenatal risk factors associated with symptomatic congenital cytomegalovirus (CMV) disease, following in utero vertical infection.

METHODS

This study included a retrospective cohort of 155 neonates with congenital CMV infection, following primary maternal CMV infection during pregnancy, and were divided to symptomatic (n=95) and asymptomatic (n=60) newborns.

RESULTS

Young maternal age (29.1±5.12 vs. 31.6±5.36 years, P=0.005), high risk occupation for viral exposure (20.0% vs. 11.7%, P=0.04), CMV IgG seroconversion at diagnosis (83.1% vs. 63.3%, P=0.005) and abnormal fetal MRI (11.6% vs. 0%, P=0.003) were found to be prognostic risk factors associated with symptomatic CMV disease of the newborn. Maternal febrile illness at diagnosis, IgG avidity, US findings and the timing of maternal infection were not associated with the occurrence of neonatal symptoms.

CONCLUSIONS

Knowledge of the reported risk factors may assist in counseling parents with intra uterine CMV infection.

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.

CMV is the most common cause of congenital infection, and can result in significant neonatal morbidity and neurological disabilities. The birth prevalence of congenital CMV is estimated at 0.7% worldwide, and 10 to 20% of these neonates develop severe symptoms. In such cases the outcome is generally poor. Therefore, identification of additional prognostic markers is crucial for prenatal counseling in cases with an infected fetus. This may influence the decision of continuing with the pregnancy or requesting its termination, but also the decision of starting experimental antiviral therapy. The pathophysiology of CMV brain injury is not completely understood, and the identification of new biomarkers of CMV infection might also pave the way towards the development of new therapeutic alternatives. Here, we apply a recently developed and modern non-targeted peptidomics approach to amniotic fluid obtained from symptomatic and asymptomatic CMV-infected fetuses/neonates, followed by network analysis of the peptides of interest in the context of fetal infection and in relation with outcome. Our study identified 34 amniotic fluid peptides that form new prognostic biomarkers that could be used in clinical settings to improve prenatal counseling. In addition, this study provides novel mechanistic insight into the pathobiology of CMV congenital disease.

Congenital cytomegalovirus infection in pregnancy: a review of prevalence, clinical features, diagnosis and prevention

Human cytomegalovirus (CMV) is under-recognised, despite being the leading infectious cause of congenital malformation, affecting ~0.3% of Australian live births. Approximately 11% of infants born with congenital CMV infection are symptomatic, resulting in clinical manifestations, including jaundice, hepatosplenomegaly, petechiae, microcephaly, intrauterine growth restriction and death. Congenital CMV infection may cause severe long-term sequelae, including progressive sensorineural hearing loss and developmental delay in 40-58% of symptomatic neonates, and ~14% of initially asymptomatic infected neonates. Up to 50% of maternal CMV infections have nonspecific clinical manifestations, and most remain undetected unless specific serological testing is undertaken. The combination of serology tests for CMV-specific IgM, IgG and IgG avidity provide improved distinction between primary and secondary maternal infections. In pregnancies with confirmed primary maternal CMV infection, amniocentesis with CMV-PCR performed on amniotic fluid, undertaken after 21-22 weeks gestation, may determine whether maternofetal virus transmission has occurred. Ultrasound and, to a lesser extent, magnetic resonance imaging are valuable tools to assess fetal structural and growth abnormalities, although the absence of fetal abnormalities does not exclude fetal damage. Diagnosis of congenital CMV infection at birth or in the first 3 weeks of an infant's life is crucial, as this should prompt interventions for prevention of delayed-onset hearing loss and neurodevelopmental delay in affected infants. Prevention strategies should also target mothers because increased awareness and hygiene measures may reduce maternal infection. Recognition of the importance of CMV in pregnancy and in neonates is increasingly needed, particularly as therapeutic and preventive interventions expand for this serious problem.

Strong Cell-Mediated Immune Response to Human Cytomegalovirus Is Associated With Increased Risk of Fetal Infection in Primarily Infected Pregnant Women

BACKGROUND

Human cytomegalovirus (CMV) represents one of the leading causes of congenital infections worldwide. Early diagnosis of fetal infection and consequent rapid therapeutic intervention with immunoglobulin treatment may prevent fetal transmission and virus-related sequelae. In this study, the cell-mediated immunity and immunoglobulin avidity were evaluated as potential predictors of congenital transmission of the infection.

METHODS

CMV immunoglobulin G (IgG) avidity and CMV enzyme-linked immunospot (ELISpot) assays were employed in 80 pregnant women including 57 primary and 23 nonprimary CMV infections. Congenital infection was assessed using CMV DNA quantitative polymerase chain reaction on amniotic fluid or offspring urine. Logistic regression and receiver operating characteristic statistical methods were employed to determine the association with congenital infection.

RESULTS

Low CMV IgG avidity (25%) alone correlated with a probability of congenital transmission of 18.2% (95% confidence interval, 7.7%-28.8%). In contrast to the expectations, an increase in CMV ELISpot levels was statistically associated with congenital transmission (P = .006). The combined use of CMV ELISpot and low CMV IgG avidity resulted in a higher level of association than either method alone with the incidence of fetal transmission (area under the curve, 0.8685).

CONCLUSIONS

CMV-specific cell-mediated immunity represents a relevant marker in assessing the likelihood of congenital CMV transmission, particularly in combination with CMV IgG avidity.

A novel flow cytometry-based tool for determining the efficiency of human cytomegalovirus infection in THP-1 derived macrophages

Human cytomegalovirus (hCMV) is a ubiquitous pathogen that causes congenital infection and severe infections in immunocompromised patients. Chronic hCMV infection may also play an important role in immunosenescence and adverse health outcomes in older adults. THP-1, a human monocytic cell line and its derived macrophages serve as a useful cell culture model for mechanistic studies of hCMV infection and its underlying biology. A major methodological challenge is the lack of a quick and reliable tool to accurately determine the efficiency of hCMV infection in THP-1 derived macrophages. In this study, we developed a flow cytometry based method using commercially available monoclonal antibody (MAb) against hCMV immediate early (IE) antigen that can accurately determine infection efficiency. We used 0.5% formaldehyde for fixation, 90% methanol for permeabilization, and incubation with FITC conjugated MAb at 37°C. The method was tested by hCMV infection with laboratory Towne strain in the presence or absence of hydrocortisone. It was also compared with the routine flow cytometry protocol using Cytofix/Cytoperm solution and with immunofluorescence. The results indicate that this new method is reliable and time saving for accurate determination of infection efficiency. It may facilitate further investigations into the underlying biological mechanisms of hCMV infection.

A multifactorial analysis of the pregnancy outcomes in cytomegalovirus-infected women

AIMS

To investigate the impacts of cytomegalovirus (CMV) viral load, TORCH (toxoplasmosis, others, rubella, CMV and herpes) coinfections, CMV glycoprotein B (gB) genotypes and maternal genetic polymorphisms on pregnancy outcomes among CMV-infected women.

METHODS

A total of 731 CMV-infected pregnant women (634 and 97 with normal and adverse pregnancy outcomes, respectively) were recruited. CMV load quantification and screening of TORCH coinfections were performed by using real-time polymerase chain reaction (PCR) and immunodetection techniques, respectively. Genotyping of CMV gB and maternal NFKB1 -94 ins/del, NFKBIA -826C/T and -881A/G polymorphisms was performed by using PCR-restriction fragment length polymorphism.

RESULTS

We found that the mean CMV viral load in women with adverse pregnancy outcomes was significantly higher than that in women with normal outcomes at all pregnancy stages (p < 0.01). We also found that TORCH coinfections resulted in a 1.65-fold (95% CI = 1.00-2.73) increase in the risk of adverse pregnancy outcomes (p = 0.05). Additionally, we noticed no significant difference in the distribution of CMV gB genotypes between women with normal and adverse pregnancy outcomes (p = 0.42). We also observed that the ins/ins variant genotype of the NFKB1 polymorphism could reduce the risk of adverse pregnancy outcomes (OR = 0.38, 95% CI = 0.15-0.98; p = 0.04).

CONCLUSION

CMV viral load, TORCH coinfections and maternal NFKB1 polymorphism could influence pregnancy outcomes among CMV-infected women.

Seroprevalence and Seroconversion Rates of Cytomegalovirus pp65 Antigen and Cord Blood Screening of Pregnant Women in Malatya, Turkey

OBJECTIVE

The rates of seropositivity, seroconversion and fetal infection with human cytomegalovirus were analyzed in pregnant women and newborn cord blood in this study. The relationships between maternal age, parity, cytomegalovirus serology and polymerase chain reaction results were evaluated.

MATERIALS AND METHODS

A total of 217 pregnant women attended our pregnancy clinic between April 2004 and October 2005. During each trimester, 5 cc of maternal blood was obtained and 5 cc of cord blood was collected after birth. An enzyme-linked immunosorbent assay (ELISA) was used to assess these samples for the presence of human cytomegalovirus protein pp65 antigen (in leukocytes) and cytomegalovirus DNA (in plasma).

RESULTS

The mean age of the pregnant women in our study was 28.1±5.3 years. No seroconversion was observed. Among the pregnant women, 212 (97.7%) were IgG positive, and 29 (13.4%) were IgM positive. Five of the pregnant women were positive for IgM alone (2.3%), whereas 24 (11.3%) were positive for both IgM and IgG. The 29 IgM-positive patients were reevaluated using the polymerase chain reaction, and no seropositivity was found. None of the cord blood samples were IgM positive, whereas 211 (97.3%) were IgG positive. There was no significant correlation between parity and seropositivity (p=0.487). The relationship between human cytomegalovirus seropositivity and maternal age was evaluated by dividing the pregnant women into two groups, with a cut-off age of 35 years. There was a significant difference in seropositivity between these two groups (p=0.045).

CONCLUSION

Clearly, there is no need to screen pregnant women for Human cytomegalovirus (HCMV) in the Malatya region. Confirming serology results using the polymerase chain reaction and antigenemia testing to detect false positive results offers the advantage of avoiding unnecessary invasive interventions.

Role of cytomegalovirus (CMV) IgG avidity testing in diagnosing primary CMV infection during pregnancy

The risk of intrauterine transmission of cytomegalovirus (CMV) during pregnancy is much greater for women who contract primary CMV infection after conception than for women with evidence of infection (circulating CMV antibodies) before conception. Thus, laboratory tests that aid in the identification of recent primary CMV infection are important tools for managing the care of pregnant women suspected of having been exposed to CMV. CMV IgM detection is a sensitive marker of primary CMV infection, but its specificity is poor because CMV IgM is also produced during viral reactivation and persists following primary infection in some individuals. Studies conducted over the last 20 years convincingly demonstrate that measurement of CMV IgG avidity is both a sensitive and a specific method for identifying pregnant women with recent primary CMV infection and thus at increased risk for vertical CMV transmission. IgG avidity is defined as the strength with which IgG binds to antigenic epitopes expressed by a given protein; it matures gradually during the 6 months following primary infection. Low CMV IgG avidity is an accurate indicator of primary infection within the preceding 3 to 4 months, whereas high avidity excludes primary infection within the preceding 3 months. In this minireview, we summarize published data demonstrating the clinical utility of CMV IgG avidity results for estimating time since primary infection in pregnant women, describe commercially available CMV IgG avidity assays, and discuss some of the issues and controversies surrounding CMV IgG avidity testing during pregnancy.

Congenital cytomegalovirus infection: Clinical presentation, epidemiology, diagnosis and prevention

Cytomegalovirus is the most common congenital infection causing serious disease in infants. It is the leading infectious cause of sensorineural hearing loss and neurodevelopmental disability in developed countries. Despite the clinical importance of congenital cytomegalovirus, surveys show there is limited awareness and knowledge in the medical and general community about congenital cytomegalovirus infection. This article reviews the clinical features, global epidemiology, transmission and risk factors for cytomegalovirus infections. It also highlights several major advances made in recent years in the diagnosis and prevention of cytomegalovirus infection during pregnancy. Although research is ongoing, no therapy is currently proven to prevent or treat maternal, fetal or neonatal cytomegalovirus infection. Education of women regarding hygiene measures can help prevent cytomegalovirus infection and are currently the best strategy to prevent congenital cytomegalovirus disease.

Epidemiological survey of human cytomegalovirus antibody levels in children from Southeastern China

Background

This study investigated infection status and distribution of human cytomegalovirus (HCMV) serum markers in hospitalized children from the Wenzhou region.

Methods

This survey was performed on 10,147 hospitalized children from birth to 14 years of age in Southeastern China (Wenzhou region) from March 2010 to March 2013. IgM and IgG antibodies to HCMV were quantitatively detected by chemiluminescence immunoassay (CLIA). HCMV IgM or IgG detection rates, concentration, and distribution in various age groups were retrospectively analyzed.

Results

In this study of hospitalized children, the overall rates of HCMV IgM⁺ and IgG⁺ were 10.8% (1,099/10,147) and 83.0% (8,425/10,147), respectively. The lowest HCMV IgM⁺ rate (1.0%, P < 0.001) was observed in the group of patients <28 days of age whereas the highest HCMV IgM⁺ rate (19.9%, P < 0.001) occurred in the 28 days ~ 5 months old group. However, the concentrations of HCMV specific IgM in all age groups were not significantly different (P > 0.05). The HCMV IgG⁺ rate was highest in the <28 days group (98.1%, P < 0.001). The 28 days ~ 5 months old group had the lowest HCMV specific IgG concentrations (median, 133.9 AU/mL, P < 0.001). Among 1,099 HCMV IgM⁺ children, 405 (36.9%) were diagnosed with respiratory infections which pneumonia accounted for 18.2% (200/1,099) of the total population. However, children with respiratory infections had the lowest HCMV IgG concentrations (median, 161.1 AU/mL, P < 0.05).

Conclusions

HCMV specific antibody responses are very common in hospitalized children with respiratory infection in Wenzhou region. Protection against HCMV airway infection needs greater emphasis and further studies will be helpful to reveal the role of HCMV in children respiratory disease.