Controversies in the natural history of congenital human cytomegalovirus infection: the paradox of infection and disease in offspring of women with immunity prior to pregnancy

Risk factors associated with late-onset hearing loss in children with congenital cytomegalovirus: a systematic review

PURPOSE

To search for existing evidence of prognostic factors related to the development of late-onset hearing loss (LOHL) in infants with congenital cytomegalovirus (cCMV).

METHODS

A PRISMA systematic review was performed, with the PubMed, Embase, and Web of Science databases searched from inception through to December 2023; after the application of inclusion and exclusion criteria a total of 9 papers were included in this review. PROSPERO registration number CRD42024492244.

RESULTS

9 studies encompassing a total of 292 children with late-onset hearing loss were included. A total of 12 risk factors were identified in the literature, with 6 found to be statistically significant. Late-onset hearing loss was more frequently reported in children with symptomatic than asymptomatic cCMV. Moreover, in asymptomatic cCMV cases, elevated DNAemia and salivary viral load were associated with late-onset hearing loss. Additionally, first-trimester seroconversion was identified as a risk factor for late- onset hearing loss. Further, gestational age < 37 weeks and low birth weight were found to correlate with late-onset hearing loss. Remarkably, only one study documented a relationship between late-onset hearing loss and ultrasonographic abnormalities.

CONCLUSIONS

Although six statistically significant risk factors have been identified, the available evidence is limited and inconsistent, preventing the establishment of reliable neonatal and maternal parameters to predict the development of LOHL in patients with CMV. There are few studies addressing this topic, and those available exhibit a low level of evidence and heterogeneous designs. More studies should be done.

Universal newborn screening for congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infection is the leading infectious cause of childhood disability, in particular sensorineural hearing loss (SNHL). Timeliness of diagnosis is crucial, since the presence of CMV in any compartment (eg, blood, urine, or saliva) after age 21 days can mean postnatal acquisition of infection, particularly in breastfed infants. Given these issues, there is considerable interest in implementation of screening programmes-either universal screening (where all newborns are tested) or targeted screening. Targeted screening is typically based on the outcome of a newborn hearing screen, and can be influenced in some strategies by findings of other signs suggestive of congenital CMV. Universal screening is likely to have the greatest overall benefit. Early identification of congenital CMV allows for interventions such as antiviral therapy (when indicated) and enables anticipatory audiological monitoring that facilitates timely detection of delayed-onset SNHL. However, there are debates about the effectiveness of screening programmes. Most infants with congenital CMV are unaffected and do not appear to be at risk for adverse neurodevelopment outcomes, except for SNHL. Screening can, therefore, raise unwarranted concern among parents and clinicians in these cases. The best clinical sample for diagnostic testing is unclear. PCR testing of saliva is sensitive but has a risk of yielding false-positive results in infants without congenital CMV. Resolving the technological issues has improved the sensitivity of dried blood spot (DBS) PCR but the technique remains suboptimum. An advantage to DBS PCR testing is that an infrastructure exists to add this test to existing newborn screening programmes. In this Review, the advantages and disadvantages of congenital CMV screening are discussed, along with high-priority areas for future research that will inform and direct this rapidly evolving field.

Fetal Cytomegalovirus Infection in the Absence of Maternal Cytomegalovirus-IgM Seropositivity

The aim of this study was to evaluate maternal serological status and fetal sonographic findings of Cytomegalovirus (CMV) infection. This is a retrospective study performed at Perinatology Department of Istanbul Başakşehir Çam and Sakura City Hospital. A computerized search was conducted to identify cases who underwent prenatal diagnosis of fetal CMV infection between September 2020 and December 2023. We identified nine cases with fetal CMV infection. The clinical data of the patients, gestational age at the time of diagnosis, serological, sonographic findings, and pregnancy outcomes were analyzed. A computer search of the database was made for the seroprevalance of CMV-IgM and CMV-IgG in our population. The CMV-IgM and IgG results of the 1235 patients who underwent CMV screening in the first trimester between September 2020 and December 2023 were evaluated. Fetal CMV infection was identified in nine patients. None of the 9 cases showed maternal CMV-IgM positivity. Seven of the 9 patients showed high IgG avidity index. Pregnant population had 98 % positivity for CMV-IgG. The evaluation of serologic tests for CMV is not straightforward in the second and third trimester. IgM and IgG avidity should be interpreted with caution in the second and third trimester. In the presence of ultrasound findings suggesting fetal CMV infection and CMV-IgG positivity, invasive diagnostic tests rather than serological test should be discussed with the patient, and non-primary infections should always be considered to minimize overlooked fetal cytomegalovirus infections and missed antiviral treatment opportunity.

Exploring health disparities in congenital CMV (cCMV): a study in a Somali-American community to assess awareness of cCMV and facilitate understanding of universal cCMV screening

Background

Congenital cytomegalovirus (cCMV) disproportionately impacts black and multiracial infants. While there have been strides made to address this health disparity, strategies to increase awareness and knowledge of cCMV have not been investigated in a Somali community.

Methods

Two survey study strategies (in-person and online), consisting of a pre-survey test, educational intervention, and a post-survey, were designed to gauge knowledge and perceptions about cCMV among Somali women aged 18 to 40 years old.

Results

96 respondents partook in the online module, and 15 in the in-person event. On recruitment, < 45% of women were aware of cCMV. Following the pre-intervention survey, educational modules were conducted, and the survey repeated. For statistical comparisons, a point was assigned for each correct survey query, and the mean of correct responses tabulated for pre- and post-surveys. In the online intervention, mean scores changed from 55 to 87% (paired t-test, p = 0.001), whereas in the in-person intervention, mean scores changed from 65 to 87% (paired t-test, p = 0.007), demonstrating enhanced cCMV awareness upon completion of both interventions. Using multiple linear regression, the expected post-test score was 2% (95% CI [- 8%, 12%]) higher for the online module compared to the in-person module, adjusting for pre-test score.

Conclusion

Both interventions were successful in enhancing knowledge about cCMV in this population, although there was no evidence either intervention was substantially better than the other. Educational efforts will be critical in enhancing the trust required to facilitate diagnostic evaluation and treatment of newborns identified with cCMV in this high-risk population.

Hygiene-based measures for the prevention of cytomegalovirus infection in pregnant women: a systematic review

BACKGROUND

Human Cytomegalovirus (HCMV) is the most frequent congenital infection worldwide causing important sequelae. However, no vaccine or antiviral treatments are currently available, thus interventions are restricted to behavioral measures. The aim of this systematic review was to assess evidence from available intervention studies using hygiene-based measures to prevent HCMV infection during pregnancy.

METHODS

Studies published from 1972 to 2023 were searched in Medline, PsycInfo, and Clinical Trials (PROSPERO, CRD42022344840) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Methodological quality was assessed by two authors, using ROBE-2 and MINORS.

RESULTS

After reviewing 6 selected articles, the outcome analysis suggested that implementation of hygiene-based interventions during pregnancy prevent, to some extent, the acquisition of congenital HCMV.

CONCLUSIONS

However, these conclusions are based on limited and low-quality evidence available from few studies using this type of intervention in clinical practice. Thus, it would be necessary to perform effective and homogeneous intervention studies using hygiene-based measures, evaluated in high-quality randomized controlled trials (RCTs).

Vaccine value profile for cytomegalovirus

Cytomegalovirus (CMV) is the most common infectious cause of congenital malformation and a leading cause of developmental disabilities such as sensorineural hearing loss (SNHL), motor and cognitive deficits. The significant disease burden from congenital CMV infection (cCMV) led the US National Institute of Medicine to rank CMV vaccine development as the highest priority. An average of 6.7/1000 live births are affected by cCMV, but the prevalence varies across and within countries. In contrast to other congenital infections such as rubella and toxoplasmosis, the prevalence of cCMV increases with CMV seroprevalence rates in the population. The true global burden of cCMV disease is likely underestimated because most infected infants (85-90 %) have asymptomatic infection and are not identified. However, about 7-11 % of those with asymptomatic infection will develop SNHL throughout early childhood. Although no licensed CMV vaccine exists, several candidate vaccines are in development, including one currently in phase 3 trials. Licensure of one or more vaccine candidates is feasible within the next five years. Various models of CMV vaccine strategies employing different target populations have shown to provide substantial benefit in reducing cCMV. Although CMV can cause end-organ disease with significant morbidity and mortality in immunocompromised individuals, the focus of this vaccine value profile (VVP) is on preventing or reducing the cCMV disease burden. This CMV VVP provides a high-level, comprehensive assessment of the currently available data to inform the potential public health, economic, and societal value of CMV vaccines. The CMV VVP was developed by a working group of subject matter experts from academia, public health groups, policy organizations, and non-profit organizations. All contributors have extensive expertise on various elements of the CMV VVP and have described the state of knowledge and identified the current gaps. The VVP was developed using only existing and publicly available information.

Biweekly Versus Monthly Hyperimmune Globulin Therapy for Primary Cytomegalovirus Infection in Pregnancy

Primary cytomegalovirus (CMV) infection during pregnancy is associated with an increased risk of congenital CMV (cCMV). Hyperimmune globulin (HIG) therapy has been proposed as a potential prophylaxis to reduce maternal-fetal transmission. Data on whether the administration of HIG every 2 weeks offers benefits over HIG administration every 4 weeks are lacking. This was a retrospective analysis including pregnant women with primary CMV infection diagnosed in the first or early second trimester between 2010 and 2022 treated with HIG every 4 weeks (300 IE HIG per kg) or every 2 weeks (200 IE HIG per kg), respectively. In total, 36 women (4 weeks: n = 26; 2 weeks: n = 10) and 39 newborns (4 weeks: n = 29; 2 weeks: n = 10) were included. The median gestational age at the first HIG administration was 13.1 weeks. There was no significant difference in the cCMV rates between the women who received HIG every 4 versus every 2 weeks (n = 8/24 [33.3%] vs. 3/10 [30.0%]; p = 0.850). An abnormal fetal ultrasound was present in three fetuses and fetal magnetic resonance imaging (MRI) anomalies in four fetuses were related to cCMV infection, with no significant difference in the frequency between the two groups. A larger study will be needed to determine whether HIG administration every 2 instead of every 4 weeks improves the maternal-fetal transmission rates.

Re-Evaluating Human Cytomegalovirus Vaccine Design: Prediction of T Cell Epitopes

HCMV vaccine development has traditionally focused on viral antigens identified as key targets of neutralizing antibody (NAb) and/or T cell responses in healthy adults with chronic HCMV infection, such as glycoprotein B (gB), the glycoprotein H-anchored pentamer complex (PC), and the unique long 83 (UL83)-encoded phosphoprotein 65 (pp65). However, the protracted absence of a licensed HCMV vaccine that reduces the risk of infection in pregnancy regardless of serostatus warrants a systematic reassessment of assumptions informing vaccine design. To illustrate this imperative, we considered the hypothesis that HCMV proteins infrequently detected as targets of T cell responses may contain important vaccine antigens. Using an extant dataset from a T cell profiling study, we tested whether HCMV proteins recognized by only a small minority of participants encompass any T cell epitopes. Our analyses demonstrate a prominent skewing of T cell responses away from most viral proteins-although they contain robust predicted CD8 T cell epitopes-in favor of a more restricted set of proteins. Our findings raise the possibility that HCMV may benefit from evading the T cell recognition of certain key proteins and that, contrary to current vaccine design approaches, including them as vaccine antigens could effectively take advantage of this vulnerability.

Efficiency of CMV serodiagnosis during pregnancy in daily laboratory routine

BACKGROUND

Maternal acute primary cytomegalovirus (CMV) infection during the first trimester may cause severe long-term sequelae in newborns. For risk assessment, serological screening is routinely performed in pregnant women based on IgM, IgG and avidity tests using whole-virus antigen. A recent study evaluated the diagnostic value of recombinant protein-based ELISAs as second-line tests in pregnancy CMV screening, including anti-p52 IgM and anti-gB IgG as markers defining the early and late phase of infection, respectively. In the present study, these recombinant ELISAs were used as first-line screening tests in daily laboratory routine and compared to lysate-based assays with respect to [i] the number of conclusive results obtained with the initial sample and [ii] the underlying workload.

METHODS

553 unselected routine serum samples from pregnant women were tested for anti-CMV IgM and IgG antibodies using lysate-based ELISAs and avidity testing. Anti-CMV IgM antibodies against recombinant p52 and anti-CMV IgG antibodies against recombinant glycoprotein B (gB) were also determined by ELISA. All assays were performed and interpreted according to the manufacturer's instructions.

RESULTS

For lysate-based IgM, IgG and avidity testing, 84.6 % of samples yielded conclusive results in a total of 1156 tests, while 15.4 % needed follow-up testing of a consecutive sample. Anti-p52 CMV IgM and anti-gB CMV IgG testing produced conclusive results for 92.8 % of samples in a total of 1026 tests, while 7.2 % samples required follow-up testing.

CONCLUSIONS

The first-line use of ELISAs measuring anti-p52 CMV IgM and anti-gB CMV IgG antibodies to test for maternal CMV infection increases the number of conclusive results derived from an initial serum sample while requiring a considerably lower number of tests compared to the lysate-based approach. For day-to-day routines in a diagnostic laboratory, this high efficiency of the recombinant testing approach has significant practical relevance.

Pitfalls in the Serological Evaluation of Maternal Cytomegalovirus Infection as a Potential Cause of Fetal and Neonatal Involvements: A Narrative Literature Review

Cytomegalovirus (CMV) is the most common cause of intrauterine infection and serological assays are the primary tools for assessing CMV infections during pregnancy. CMV-specific immunoglobulin M (IgM) antibodies have been used as a diagnostic marker for primary CMV infection in pregnant women, although CMV-IgM has been detected in non-primary CMV infections. IgG avidity testing may aid the distinguishing of primary from non-primary CMV infection; however, there is no standardized assay for detecting this difference. Moreover, when maternal serology shows positive CMV-IgG with negative CMV-IgM findings, vertical transmission probability following primary CMV infection is often excluded. However, symptomatic congenital CMV infections in the context of negative findings for maternal CMV-IgM have been reported recently. The absence of CMV-IgM is recognized in both primary and non-primary CMV infections. Furthermore, maternal non-primary CMV infections during pregnancy may yield a greater proportion of symptomatic congenital CMV infections than previously thought. If universal prenatal screening is performed, ultrasonography for abnormal fetal findings should be conducted regardless of CMV-IgM antibody status. If not universally screened, CMV antibody screening should be performed whenever routine fetal ultrasound reveals abnormal findings. For suspected fetal CMV infection, amniotic fluid or postnatal infant urine CMV-DNA testing is required.

Circular RNAs Represent a Novel Class of Human Cytomegalovirus Transcripts

Human cytomegalovirus (HCMV) infects a large portion of the human population globally. Several HCMV-derived noncoding RNAs are involved in the regulation of viral gene expression and the virus life cycle. Here, we reported that circRNAs are a new class of HCMV transcripts. We bioinformatically predict 704 candidate circRNAs encoded by the TB40/E strain and 230 encoded by the HAN strain. We also systematically compare circRNA features, including the breakpoint sequence consensus, strand preference, length distribution, and exon numbers between host genome-encoded circRNAs and viral circRNAs, and showed that the unique characteristics of viral circRNAs are correlated with their genome types. Furthermore, we experimentally confirmed 324 back-splice junctions (BSJs) from three HCMV strains, Towne, TB40/E, and Toledo, and identified 4 representative HCMV circRNAs by RNase R treatment. Interestingly, we also showed that HCMV contains alternative back-splicing circRNAs. We developed a new amplified FISH method that allowed us to visualize circRNAs and quantify the number of circRNA molecules in the infected cells. The competitive endogenous RNA network analysis suggests that HCMV circRNAs play important roles in viral DNA synthesis via circRNA-miRNA-mRNA networks. Our findings highlight that circRNAs are an important component of the HCMV transcriptome that may contribute to viral replication and pathogenesis. IMPORTANCE HCMV infects 40% to 100% of the human population globally and may be a life-threatening pathogen in immunocompromised individuals. CircRNA is a family of unique RNA that is the most newly found and remains unknown in many aspects. Our current studies computationally identified HCMV-encoded circRNAs and confirmed the existence of the HCMV circRNAs in the infected cells. We systematically compared the features between host and different viral circRNAs and found that the unique characteristics of circRNAs were correlated with their genome types. We also first reported that HCMV contained alternative back-splicing circRNAs. More importantly, we developed a new amplified FISH method which allowed us for the first time not only to visualize circRNAs but also to quantify the number of circRNA molecules in the infected cells. This work describes a novel component of HCMV transcriptome bringing a new understanding of HCMV biology and disease.

Protection against Congenital CMV Infection Conferred by MVA-Vectored Subunit Vaccines Extends to a Second Pregnancy after Maternal Challenge with a Heterologous, Novel Strain Variant

Maternal reinfection of immune women with novel human cytomegalovirus (HCMV) strains acquired during pregnancy can result in symptomatic congenital CMV (cCMV) infection. Novel animal model strategies are needed to explore vaccine-mediated protections against maternal reinfection. To investigate this in the guinea pig cytomegalovirus (GPCMV) model, a strictly in vivo-passaged workpool of a novel strain, the CIDMTR strain (dose, 1 × 10⁷ pfu) was used to infect dams that had been challenged in a previous pregnancy with the 22122 strain, following either sham-immunization (vector only) or vaccination with MVA-vectored gB, gH/gL, or pentameric complex (PC) vaccines. Maternal DNAemia cleared by day 21 in the glycoprotein-vaccinated dams, but not in the sham-immunized dams. Mean pup birth weights were 72.85 ± 10.2, 80.0 ± 6.9, 81.4 ± 14.1, and 89.38 ± 8.4 g in sham-immunized, gB, gH/gL, and PC groups, respectively (p < 0.01 for control v. PC). Pup mortality in the sham-immunized group was 6/12 (50%), but reduced to 3/35 (8.6%) in combined vaccine groups (p = 0.0048). Vertical CIDMTR transmission occurred in 6/12 pups (50%) in the sham-vaccinated group, compared to 2/34 pups (6%) in the vaccine groups (p = 0.002). We conclude that guinea pigs immunized with vectored vaccines expressing 22122 strain-specific glycoproteins are protected after a reinfection with a novel, heterologous clinical isolate (CIDMTR) in a second pregnancy.

The Current Challenges in Developing Biological and Clinical Predictors of Congenital Cytomegalovirus Infection

Congenital cytomegalovirus (CMV) infection may cause severe long-term sequelae. Recent studies have demonstrated that early antiviral therapy for infants with symptomatic congenital CMV (cCMV) infection may improve neurological outcomes; thus, accurate identification of newborns at high risk of cCMV infection may contribute to improved outcomes in affected children. However, maternal serological screening for cCMV infection by diagnosing primary infection during pregnancy, which is a popular screening strategy, is inefficient, because the number of cCMV infections with nonprimary causes, including reactivation of or reinfection with CMV, is larger than that of cCMV infections with primary causes. Low levels of neutralizing antibodies against pentameric complex and potent CMV-specific T cell-mediated immune responses are associated with an increased risk of cCMV infection. Conversely, our prospective cohort studies revealed that the presence of maternal fever/flu-like symptoms, threatened miscarriage/premature delivery, or actual premature delivery are risk factors for cCMV infection among both women with normal pregnancies and those with high-risk ones, regardless of whether the infection is primary or nonprimary. This review focused on host immune responses to human CMV and current knowledge of potential biological and clinical factors that are predictive of cCMV infection.

Pathogenesis of wild-type-like rhesus cytomegalovirus strains following oral exposure of immune-competent rhesus macaques

Rhesus cytomegalovirus (RhCMV) infection of rhesus macaques (Macaca mulatta) is a valuable nonhuman primate model of human CMV (HCMV) persistence and pathogenesis. In vivo studies predominantly use tissue culture-adapted variants of RhCMV that contain multiple genetic mutations compared to wild-type (WT) RhCMV. In many studies, animals have been inoculated by non-natural routes (e.g., subcutaneous, intravenous) that do not recapitulate disease progression via the normative route of mucosal exposure. Accordingly, the natural history of RhCMV would be more accurately reproduced by infecting macaques with strains of RhCMV that reflect the WT genome using natural routes of mucosal transmission. Herein, we tested two WT-like RhCMV strains, UCD52 and UCD59, and demonstrated that systemic infection and frequent, high-titer viral shedding in bodily fluids occurred following oral inoculation. RhCMV disseminated to a broad range of tissues, including the central nervous system and reproductive organs. Commonly infected tissues included the thymus, spleen, lymph nodes, kidneys, bladder, and salivary glands. Histological examination revealed prominent nodular hyperplasia in spleens and variable levels of lymphoid lymphofollicular hyperplasia in lymph nodes. One of six inoculated animals had limited viral dissemination and shedding, with commensurately weak antibody responses to RhCMV antigens. These data suggest that long-term RhCMV infection parameters might be restricted by local innate factors and/or de novo host immune responses in a minority of primary infections. Together, we have established an oral RhCMV infection model that mimics natural HCMV infection. The virological and immunological parameters characterized in this study will greatly inform HCMV vaccine designs for human immunization. IMPORTANCE Human cytomegalovirus (HCMV) is globally ubiquitous with high seroprevalence rates in all communities. HCMV infections can occur vertically following mother-to-fetus transmission across the placenta and horizontally following shedding of virus in bodily fluids in HCMV infected hosts and subsequent exposure of susceptible individuals to virus-laden fluids. Intrauterine HCMV has long been recognized as an infectious threat to fetal growth and development. Since vertical HCMV infections occur following horizontal HCMV transmission to the pregnant mother, the nonhuman primate model of HCMV pathogenesis was used to characterize the virological and immunological parameters of infection following primary mucosal exposures to rhesus cytomegalovirus.

Characteristics of Immediate-Early 2 (IE2) and UL84 Proteins in UL84-Independent Strains of Human Cytomegalovirus (HCMV)

Human cytomegalovirus (HCMV) immediate-early 2 (IE2) protein is the major transactivator for viral gene expression and is required for lytic replication. In addition to transcriptional activation, IE2 is known to mediate transcriptional repression of promoters, including the major immediate-early (MIE) promoter and a bidirectional promoter within the lytic origin of replication (oriLyt). The activity of IE2 is modulated by another viral protein, UL84. UL84 is multifunctional and is proposed to act as the origin-binding protein (OBP) during lytic replication. UL84 specifically interacts with IE2 to relieve IE2-mediated repression at the MIE and oriLyt promoters. Originally, UL84 was thought to be indispensable for viral replication, but recent work demonstrated that some strains of HCMV (TB40E and TR) can replicate independently of UL84. This peculiarity is due to a single amino acid change of IE2 (UL122 H388D). Here, we identified that a UL84-dependent (AD169) Δ84 viral mutant had distinct IE2 localization and was unable to synthesize DNA. We also demonstrated that a TB40E Δ84 IE2 D388H mutant containing the reversed IE2 amino acid switch adopted the phenotype of AD169 Δ84. Further functional experiments, including chromatin-immunoprecipitation sequencing (ChIP-seq), suggest distinct protein interactions and transactivation function at oriLyt between strains. Together, these data further highlight the complexity of initiation of HCMV viral DNA replication. IMPORTANCE Human cytomegalovirus (HCMV) is a significant cause of morbidity and mortality in immunocompromised individuals and is also the leading viral cause of congenital birth defects. After initial infection, HCMV establishes a lifelong latent infection with periodic reactivation and lytic replication. During lytic DNA synthesis, IE2 and UL84 have been regarded as essential factors required for initiation of viral DNA replication. However, previous reports identified that some isolates of HCMV can replicate in a UL84-independent manner due to a single amino acid change in IE2 (H388D). These UL84-independent strains are an important consideration, as they may have implications for HCMV disease and research. This has prompted renewed interest into the functional roles of IE2 and UL84. The work presented here focuses on the described functions of UL84 and ascertains if those required functions are fulfilled by IE2 in UL84-independent strains.

Comparison of detection strategies for screening and confirming congenital cytomegalovirus infection in newborns in a highly seroprevalent population: a mother-child cohort study

Background

Universal screening of congenital cytomegalovirus (cCMV) infection is important for monitoring and intervention during critical stages of speech and language development. This study aimed to explore the optimal detection strategy for cCMV infection screening.

Methods

Serum samples from pregnant women and saliva and urine samples from their newborns were collected for the anti-CMV IgG and CMV DNA PCR tests, respectively. The sensitivity, specificity, and predictive values as well as the likelihood ratios of 12 potential screening strategies for cCMV infection, based on tests for saliva, urine, and their combination, were evaluated.

Findings

A total of 6729 pregnant women were enrolled, and the seroprevalence was 98.1%. Among 6350 newborns that were followed up, 49 were defined as having cCMV infection. In the screening test, the CMV DNA positivity rate remained similar from day 0 to day 5, increased slowly from day 6 to day 13, and became high in newborns beyond 13 days of birth. In the confirmatory testing, the positive rates increased significantly beyond day 21. For the 49 newborns with cCMV infection, the proportion of agreement between saliva and urine testing was poor. Upon evaluating alternative screening strategies, using saliva and urine screening with saliva and urine confirmation as the reference strategy, saliva screening with saliva and urine confirmation showed good diagnostic accuracy and feasibility, with sensitivity, specificity, positive predictive and negative predictive values of 85.7%, 100.0%, 100.0% and 99.9%, respectively.

Interpretation

In populations with high seroprevalence, saliva screening with saliva and urine confirmation might be an alternative strategy for screening cCMV infections. The suggested timeframes for screening and confirmation are within 13 (ideally 5) and 21 (ideally 13) days of birth, respectively.

Funding

National Natural Science Foundation of China, National Science and Technology Major Project of China and Merck & Co., Inc., Kenilworth, New Jersey, U.S.A.

Frequency, timing and risk factors for primary maternal cytomegalovirus infection during pregnancy in Quebec

INTRODUCTION

Maternal Cytomegalovirus (CMV) infection in the first trimester (T1) of pregnancy is a public health concern, as it increases the risk of severe neurodevelopmental outcomes associated with congenital infection compared to infections occurring later during pregnancy.

OBJECTIVES

To determine CMV seroprevalence in T1 of pregnancy, its trend, risk factors and the incidence rate of primary infection during pregnancy.

METHODS

Using the biobank of the prospective cohort "Grossesse en Santé de Québec" collected between April 2005 and March 2010 at the Québec-Laval Hospital, Québec, Canada, maternal CMV serology was determined using Abbott Architect Chemiluminescence microparticle immunoassays for immunoglobulin G(IgG), immunoglobulin M(IgM) titration and IgG avidity testing. Changepoint detection analysis was used to assess temporal trends. Risk factors associated with seropositivity were determined by multivariable logistic regression.

RESULTS

CMV seroprevalence in T1 of pregnancy was 23.4% (965/4111, 95% CI, 22.1-24.7%). The incidence rate for CMV primary infection during pregnancy was 1.8 (95% CI, 1.2-2.6) per 100 person-years. No changepoint was identified in the maternal CMV-seroprevalence trend. Multivariable analyses showed that T1 maternal CMV seropositivity was associated with having one child OR 1.3 (95% CI, 1.10-1.73) or two or more children OR 1.5 (95%CI, 1.1-2.1), ethnicity other than Caucasian OR 2.1 (95% CI, 1.1-3.8) and country of birth other than Canada and the USA OR 2.8 (95% CI, 1.5-4.9).

CONCLUSIONS

In this cohort, maternal seroprevalence in T1 of pregnancy and seroconversion rate were low. This information and identified risk factors could help guide the development and implementation of preventive actions and evidence-based health policies to prevent CMV infection during pregnancy.

Pregnancy and viral infections: Mechanisms of fetal damage, diagnosis and prevention of neonatal adverse outcomes from cytomegalovirus to SARS-CoV-2 and Zika virus

Some maternal infections, contracted before or during pregnancy, can be transmitted to the fetus, during gestation (congenital infection), during labor and childbirth (perinatal infection) and through breastfeeding (postnatal infection). The agents responsible for these infections can be viruses, bacteria, protozoa, fungi. Among the viruses most frequently responsible for congenital infections are Cytomegalovirus (CMV), Herpes simplex 1–2, Herpes virus 6, Varicella zoster. Moreover Hepatitis B and C virus, HIV, Parvovirus B19 and non-polio Enteroviruses when contracted during pregnancy may involve the fetus or newborn at birth. Recently, new viruses have emerged, SARS-Cov-2 and Zika virus, of which we do not yet fully know the characteristics and pathogenic power when contracted during pregnancy.

Viral infections in pregnancy can damage the fetus (spontaneous abortion, fetal death, intrauterine growth retardation) or the newborn (congenital anomalies, organ diseases with sequelae of different severity). Some risk factors specifically influence the incidence of transmission to the fetus: the timing of the infection in pregnancy, the order of the infection, primary or reinfection or chronic, the duration of membrane rupture, type of delivery, socio-economic conditions and breastfeeding. Frequently infected neonates, symptomatic at birth, have worse outcomes than asymptomatic. Many asymptomatic babies develop long term neurosensory outcomes.

The way in which the virus interacts with the maternal immune system, the maternal-fetal interface and the placenta explain these results and also the differences that are observed from time to time in the fetal‑neonatal outcomes of maternal infections. The maternal immune system undergoes functional adaptation during pregnancy, once thought as physiological immunosuppression. This adaptation, crucial for generating a balance between maternal immunity and fetus, is necessary to promote and support the pregnancy itself and the growth of the fetus. When this adaptation is upset by the viral infection, the balance is broken, and the infection can spread and lead to the adverse outcomes previously described. In this review we will describe the main viral harmful infections in pregnancy and the potential mechanisms of the damages on the fetus and newborn.

Review of Mathematical Models of Vaccination for Preventing Congenital Cytomegalovirus Infection

BACKGROUND

Several cytomegalovirus (CMV) vaccine candidates are under development. To reduce the burden of congenital CMV infection, potential strategies under consideration include vaccination of adult women, adolescent girls, and/or young children (both sexes).

METHODS

We reviewed 5 studies that used infectious disease modeling to assess the potential impact of vaccination for preventing congenital CMV infection. All models assumed CMV vaccination would prevent primary infection and 2 models also assumed prevention of reinfections and reactivations.

RESULTS

Despite differences in structure, assumptions, and population data, infant vaccination (both sexes) was the optimal strategy in all models, but in 1 model vaccinating seronegative women at 19-21 years of age was also optimal (for duration of vaccine protection ≥8 years). In 3 models, infant vaccination increased average age at primary infection as a result of decreased secondary transmission (herd immunity) combined with waning vaccine-induced immunity. This effect could increase the risk of congenital CMV infections in populations where primary CMV infection occurs early in childhood but could be minimized by administering a second dose of vaccine during adolescence.

CONCLUSIONS

Understanding vaccine efficacy and duration of immunity, and how these might vary depending on CMV serostatus and age at vaccination, will be key to defining CMV vaccination strategies.

Natural History of Congenital Cytomegalovirus Infection in Highly Seropositive Populations

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

Perspectives of women on screening and prevention of CMV in pregnancy

OBJECTIVE

To assess the choice and attitude of pregnant women regarding CMV serological screening and CMV prevention behaviors in pregnancy.

STUDY DESIGN

In this cross-sectional study, pregnant women were recruited in a single center during routine prenatal screening tests at 11-16 weeks. Participants filled out a questionnaire assessing knowledge about congenital CMV (cCMV) infection, risk perception and willingness to have CMV serological screening as well as their attitude toward CMV prevention behaviors.

RESULTS

Among 234 pregnant women, 74.4 % (95 % confidence interval: 68.8-80.0 %) wanted CMV serological screening in pregnancy. The factors significantly associated with the desire for screening were perceived risk and perceived severity of cCMV. An informed choice regarding CMV screening (value-consistent, based on good knowledge and deliberated) was performed by 54 % of women who chose the screening and 30 % of women who declined the screening (p = 0.039). The median scores regarding attitudes toward CMV prevention behaviors were 3.7/5 for avoiding sharing behaviors and 4.0/5 for not kissing a child on the lips.

CONCLUSION

The majority of pregnant women want to have CMV serological screening once informed about congenital CMV infection. New tools need to be developed to allow for informed choice regarding CMV serological screening in pregnancy.

Overview of Human Cytomegalovirus Pathogenesis

Human cytomegalovirus (HCMV) is a betaherpesvirus with a global seroprevalence of 60-90%. HCMV is the leading cause of congenital infections and poses a great health risk to immunocompromised individuals. Although HCMV infection is typically asymptomatic in the immunocompetent population, infection can result in mononucleosis and has also been associated with the development of certain cancers, as well as chronic inflammatory diseases such as various cardiovascular diseases. In immunocompromised patients, including AIDS patients, transplant recipients, and developing fetuses, HCMV infection is associated with increased rates of morbidity and mortality. Currently there is no vaccine for HCMV and there is a need for new pharmacological treatments. Ongoing research seeks to further define the complex aspects of HCMV pathogenesis, which could potentially lead to the generation of new therapeutics to mitigate the disease states associated with HCMV infection. The following chapter reviews the advancements in our understanding of HCMV pathogenesis in the immunocompetent and immunocompromised hosts.

Impact of breast milk-acquired cytomegalovirus infection in premature infants: Pathogenesis, prevention, and clinical consequences?

Maternal-fetal transmission of cytomegalovirus (CMV) represents the most common infectious cause of long-term neurodevelopmental disability in children. Congenital CMV (cCMV) infection is associated with microcephaly, seizure disorders, cognitive disability, developmental delay, and sensorineural hearing loss (SNHL). Of these disabilities, SNHL is the most common, affecting approximately 10% of infants with cCMV. Although the sequelae of cCMV are well recognized, it is much less clear what long-term morbidities may occur in neonates that acquire post-natal CMV infection. Post-natal CMV (pCMV) infection is most commonly transmitted by breast-feeding, and in full-term infants is of little consequence. However, in preterm, very-low birthweight (VLBW) infants (<1500 g), pCMV can result in a severe sepsis-like syndrome, with wide-ranging end-organ disease manifestations. Although such short-term complications are well recognized among clinicians caring for premature infants, the long-term risks with respect to adverse neurodevelopmental outcomes remain controversial. In this review, we provide an overview of the clinical manifestations of breast milk-acquired pCMV infection. In particular, we summarize studies that have examined-sometimes with conflicting conclusions-the risks of long-term adverse neurodevelopmental outcome in VLBW infants that acquire pCMV from breast milk. We highlight proposed preventive strategies and antiviral interventions, and offer recommendations for high-priority areas for future basic science and clinical research.

Maternal cytomegalovirus immune status and hearing loss outcomes in congenital cytomegalovirus-infected offspring

Objectives

The purpose of this study is to determine the relationship between maternal primary and recurrent CMV infection during pregnancy, symptoms at birth in the newborn, and long term hearing loss through18 years of age.

Patients and methods

237 mother-infant pairs in the Houston, Texas area identified through maternal CMV IgG and IgM antibody serologic screening and newborn screening using urine CMV culture to identify congenital CMV infection were enrolled in the Houston Congenital CMV Longitudinal Study. Mothers were categorized as having primary or recurrent or unknown maternal CMV infections, and newborns were categorized at birth as having symptomatic or asymptomatic congenital CMV infection, or as uninfected controls. All three newborn groups were followed longitudinally with serial hearing evaluations up to 18 years of age. The relationship between type of maternal CMV infection, newborn classification, and the occurrence of hearing loss over time was determined through Kaplan-Meier survival analysis, life table analysis, and a simulated ascertainment of maternal infection type for the unknown categories.

Results

Of 77 newborns with symptomatic congenital CMV infection, 12 (16%) of mothers had a primary CMV infection during pregnancy; 4 (5%) had a non-primary infection, and the type of infection in 48 (79%) could not be determined and were classified as unknown type of maternal infection. Fifty Seven (74%) of the 77 symptomatic children had hearing loss by 18 years of age, including 9 of the 12 (75%) who were born to mothers with primary infection and 48 (79%) of the 61 with unknown type of maternal infection. Of the 109 newborns with asymptomatic congenital CMV infection, 51 (47%) were born to mothers with a primary CMV infection during pregnancy, 18 (17%) to mothers with a recurrent infection; and 40 (37%) had unknown type of infection. Of these 109 asymptomatic cases, 22 (20%) developed hearing loss, including 14 out of 51 (28%) of those born to mothers with primary infection, two out of the 18 (11%) born to mothers with recurrent infection, and 6 out of the 40 (15%) to mothers of unknown infection type. Of the 51 uninfected newborn controls, 10 (20%) of mothers had a primary CMV infection during pregnancy, 5 (10%) had a non-primary infection, 10 (20%) were never infected, and 26 (51%) were assigned unknown type of infection. Three controls (6%) developed hearing loss, with 1 being born to a mother with primary infection and 1 to a mother never infected with CMV.

Conclusions

Both primary and non-primary maternal CMV infections during pregnancy resulted in symptomatic and asymptomatic congenital CMV infection. Symptomatic congenital CMV infection was more likely to occur after primary maternal CMV infection. Sensorineural hearing loss occurred in children born to mothers with both primary and non-primary CMV infections, and in both asymptomatic and symptomatic congenital CMV infection, but was more common after maternal primary infection. Most, but not all, hearing loss in children with cCMV associated hearing loss was first detected within the first year of life.

Hygiene promotion might be better than serological screening to deal with Cytomegalovirus infection during pregnancy: a methodological appraisal and decision analysis

BACKGROUND

Cytomegalovirus infection is the most frequent viral congenital infection, with possible consequences such as deafness, or psychomotor retardation. In 2016, the French High Council of Public Health was mandated to update recommendations regarding prevention of cytomegalovirus infection in pregnant women. We summarize a critical appraisal of knowledge and deterministic decision analysis comparing the current no-screening situation to serological screening during pregnancy, and to hygiene promotion.

METHODS

Screening was defined as systematic serological testing, during the first trimester, with repeated tests as needed, to all pregnant women. Outcomes were: 1) severe sequela: intellectual deficiency with IQ ≤ 50 or hearing impairment < 70 dB or sight impairment (≤ 3/10 at best eye); 2) moderate sequela: any level of intellectual, hearing or sight deficiency; and 3) death or termination of pregnancy. We simulated the one-year course of cytomegalovirus infection in a cohort of 800,000 pregnant women. We developed a deterministic decision model, using best and min-max estimates, extracted from systematic reviews or original studies.

RESULTS

Relevant data were scarce or imprecise. We estimated that 4352 maternal primary infections would result in 1741 foetal infections, and an unknown number of maternal reinfections would result in 1699 foetal infections. There would be 788 cytomegalovirus-related consequences, including 316 foetal deaths or terminations of pregnancy, and 424 moderate and 48 severe sequelae. Screening would result in a 1.66-fold increase of poor outcomes, mostly related to a 2.93-fold increase in deaths and terminations of pregnancy, not compensated by the decrease in severe symptomatic newborns. The promotion of hygiene would result in a 0.75-fold decrease of poor outcomes, related to both a decrease in severe sequelae among symptomatic newborns (RR = 0.75; min-max: 1.00-0.68), and in deaths and terminations of pregnancy (RR = 0.75; min-max: 0.97-0.68).

CONCLUSIONS

Prevention of cytomegalovirus infection during pregnancy should promote hygiene; serological screening should not be recommended.

The CD4+ T Cell Response to Human Cytomegalovirus in Healthy and Immunocompromised People

While CD8+ T cells specific for human cytomegalovirus (HCMV) have been extensively studied in both healthy HCMV seropositive carriers and patients undergoing immunosuppression, studies on the CD4+ T cell response to HCMV had lagged behind. However, over the last few years there has been a significant advance in our understanding of the importance and contribution that CMV-specific CD4+ T cells make, not only to anti-viral immunity but also in the potential maintenance of latently infected cells. During primary infection with HCMV in adults, CD4+ T cells are important for the resolution of symptomatic disease, while persistent shedding of HCMV into urine and saliva is associated with a lack of HCMV specific CD4+ T cell response in young children. In immunosuppressed solid organ transplant recipients, a delayed appearance of HCMV-specific CD4+ T cells is associated with prolonged viremia and more severe clinical disease, while in haematopoietic stem cell transplant recipients, it has been suggested that HCMV-specific CD4+ T cells are required for HCMV-specific CD8+ T cells to exert their anti-viral effects. In addition, adoptive T-cell immunotherapy in transplant patients has shown that the presence of HCMV-specific CD4+ T cells is required for the maintenance of HCMV-specific CD8+ T cells. HCMV is a paradigm for immune evasion. The presence of viral genes that down-regulate MHC class II molecules and the expression of viral IL-10 both limit antigen presentation to CD4+ T cells, underlining the important role that this T cell subset has in antiviral immunity. This review will discuss the antigen specificity, effector function, phenotype and direct anti-viral properties of HCMV specific CD4+ T cells, as well as reviewing our understanding of the importance of this T cell subset in primary infection and long-term carriage in healthy individuals. In addition, their role and importance in congenital HCMV infection and during immunosuppression in both solid organ and haemopoietic stem cell transplantation is considered.

Human Cytomegalovirus Congenital (cCMV) Infection Following Primary and Nonprimary Maternal Infection: Perspectives of Prevention through Vaccine Development

Congenital cytomegalovirus (cCMV) might occur as a result of the human cytomegalovirus (HCMV) primary (PI) or nonprimary infection (NPI) in pregnant women. Immune correlates of protection against cCMV have been partly identified only for PI. Following either PI or NPI, HCMV strains undergo latency. From a diagnostic standpoint, while the serological criteria for the diagnosis of PI are well-established, those for the diagnosis of NPI are still incomplete. Thus far, a recombinant gB subunit vaccine has provided the best results in terms of partial protection. This partial efficacy was hypothetically attributed to the post-fusion instead of the pre-fusion conformation of the gB present in the vaccine. Future efforts should be addressed to verify whether a new recombinant gB pre-fusion vaccine would provide better results in terms of prevention of both PI and NPI. It is still a matter of debate whether human hyperimmune globulin are able to protect from HCMV vertical transmission. In conclusion, the development of an HCMV vaccine that would prevent a significant portion of PI would be a major step forward in the development of a vaccine for both PI and NPI.

Cytomegalovirus Seroprevalence and Birth Prevalence of Congenital CMV Infection in Bosnia and Herzegovina: A Single-Center Experience

BACKGROUND

Congenital cytomegalovirus infection (cCMV) is a leading cause of sensorineural hearing loss (SNHL) and neurodevelopmental disabilities in developed countries. Although high cCMV rates have been reported in populations with high seroprevalence, the cCMV prevalence in low/middle-income countries in Europe has not been defined.

OBJECTIVE

To determine cytomegalovirus (CMV) seroprevalence and the cCMV prevalence in Bosnia and Herzegovina.

METHODS

Between March 2010 and February 2019, 5222 sera samples from patients seen at the University Clinical Hospital Mostar were tested for CMV IgG. The cord blood samples collected from 2091 infants between July 2011 and January 2013 were analyzed for CMV IgG and CMV DNA. The cCMV prevalence was determined by testing saliva swabs from 1293 infants between November 2015 and October 2016.

RESULTS

The overall CMV IgG prevalence was 81.4% (95% confidence interval: 0.8-0.82). Significantly higher prevalence was observed among females (84.9%) than in males (77.0%), and the rate increased from 50.8% in the 1 to 5 years group to 97.7% in the group > 65 years old. Most cord blood samples (2091/1925, 92.1%) were CMV IgG positive, and 2 (0.1%) were CMV DNA positive. Of the 1293 saliva swabs, 8 (0.62%; 95% confidence interval: 0.3-1.2) were CMV positive. All 8 infected infants had asymptomatic cCMV, and none had SNHL at 18 months of age.

CONCLUSIONS

In a highly CMV seropositive population, the prevalence of cCMV was lower compared with that reported from other low/middle-income countries populations. None of the infected infants had symptomatic infection or SNHL at 18 months.

The MRI spectrum of congenital cytomegalovirus infection

Human cytomegalovirus (CMV) is an ubiquitous pathogen, with a high worldwide seroprevalence. When acquired in the prenatal period, congenital CMV (cCMV) is a major cause of neurodevelopmental sequelae and hearing loss. cCMV remains an underdiagnosed condition, with no systematic screening implemented in pregnancy or in the postnatal period. Therefore, imaging takes a prominent role in prenatal diagnosis of cCMV. With the prospect of new viable therapies, accurate and timely diagnosis becomes paramount, as well as identification of fetuses at risk for neurodevelopmental sequelae. Fetal magnetic resonance imaging (MRI) provides a complementary method to ultrasound (US) in fetal brain and body imaging. Anterior temporal lobe lesions are the most specific finding, and MRI is superior to US in their detection. Other findings such as ventriculomegaly, cortical malformations and calcifications, as well as hepatosplenomegaly, liver signal changes and abnormal effusions are unspecific. However, when seen in combination these should raise the suspicion of fetal infection, highlighting the need for a full fetal assessment. Still, some fetuses deemed normal on prenatal imaging are symptomatic at birth or develop delayed cCMV-associated symptoms, leaving room for improvement of diagnostic tools. Advanced MR sequences may help in this field and in determining prognosis, but further studies are needed.

Viral Infections and the Neonatal Brain

This review includes the congenital infections best known by the acronym TORCH (Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes virus), as well as Zika virus infection and perinatally acquired infections (enterovirus, parechovirus, rotavirus, parvovirus). Congenital infections are due to pathogens that can cross the placenta and are more likely to injure the brain when the infection occurs early in pregnancy. There are many similarities, with regards to brain lesions, for congenital Zika syndrome and congenital cytomegalovirus infection. Perinatally acquired viral infections tend to injure the white matter, with cystic evolution being more likely in the (late) preterm infant compared to the full-term infant. Congenital and perinatally acquired viral infections can be associated with adverse neurological outcomes. Prevention is important, especially as therapeutic options are limited. In this review both congenital as well as perinatally acquired viral infections will be discussed with a focus on neuro-imaging findings.

A Replication-Defective Human Cytomegalovirus Vaccine Elicits Humoral Immune Responses Analogous to Those with Natural Infection

Human cytomegalovirus (HCMV) can cause congenital infections, which are a leading cause of childhood disabilities. Since the rate of maternal-fetal transmission is much lower in naturally infected (HCMV-seropositive) women, we hypothesize that a vaccine candidate capable of eliciting immune responses analogous to those of HCMV-seropositive subjects may confer protection against congenital HCMV. We have previously described a replication-defective virus vaccine based on strain AD169 (D. Wang, D. C. Freed, X. He, F. Li, et al., Sci Transl Med 8:362ra145, 2016, https://doi.org/10.1126/scitranslmed.aaf9387). The vaccine, named V160, has been shown to be safe and immunogenic in HCMV-seronegative human subjects, eliciting both humoral and cellular immune responses (S. P. Adler, S. E. Starr, S. A. Plotkin, S. H. Hempfling, et al., J Infect Dis 220:411-419, 2019, https://doi.org/10.1093/infdis/171.1.26). Here, we further showed that sera from V160-immunized HCMV-seronegative subjects have attributes similar in quality to those from seropositive subjects, including high-avidity antibodies to viral antigens, coverage against a panel of genetically distinct clinical isolates, and protection against viral infection in diverse types of human cells in culture. More importantly, vaccination appeared efficient in priming the human immune system, inducing memory B cells in six V160 recipients at frequencies comparable to those of three HCMV-seropositive subjects. Our results demonstrate the ability of V160 to induce robust and durable humoral memory responses to HCMV, justifying further clinical evaluation of the vaccine against congenital HCMV.IMPORTANCE In utero HCMV infection can lead to miscarriage or childhood disabilities, and an effective vaccine is urgently needed. Since children born to women who are seropositive prior to pregnancy are less likely to be affected by congenital HCMV infection, it has been hypothesized that a vaccine capable of inducing an immune response resembling the responses in HCMV-seropositive women may be effective. We previously described a replication-defective virus vaccine that has been demonstrated safe and immunogenic in HCMV-seronegative subjects. Here, we conducted additional analyses to show that the vaccine can induce antibodies with functional attributes similar to those from HCMV-seropositive subjects. Importantly, vaccination can induce long-lived memory B cells at frequencies comparable to those seen in HCMV-seropositive subjects. We conclude that this vaccine is a promising candidate that warrants further clinical evaluation for prevention of congenital HCMV.

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.

The Membrane-Spanning Peptide and Acidic Cluster Dileucine Sorting Motif of UL138 Are Required To Downregulate MRP1 Drug Transporter Function in Human Cytomegalovirus-Infected Cells

The human cytomegalovirus (HCMV) UL138 protein downregulates the cell surface expression of the multidrug resistance-associated protein 1 (MRP1) transporter. We examined the genetic requirements within UL138 for MRP1 downregulation. We determined that the acidic cluster dileucine motif is essential for UL138-mediated downregulation of MRP1 steady-state levels and inhibition of MRP1 efflux activity. We also discovered that the naturally occurring UL138 protein isoforms, the full-length long isoform of UL138 and a short isoform missing the N-terminal membrane-spanning domain, have different abilities to inhibit MRP1 function. Cells expressing the long isoform of UL138 show decreased MRP1 steady-state levels and fail to efflux an MRP1 substrate. Cells expressing the short isoform of UL138 also show decreased MRP1 levels, but the magnitude of the decrease is not the same, and they continue to efficiently efflux an MRP1 substrate. Thus, the membrane-spanning domain, while dispensable for a UL138-mediated decrease in MRP1 protein levels, is necessary for a functional inhibition of MRP1 activity. Our work defines the genetic requirements for UL138-mediated MRP1 downregulation and anticipates the possible evolution of viral escape mutants during the use of therapies targeting this function of UL138.IMPORTANCE HCMV UL138 curtails the activity of the MRP1 drug transporter by reducing its steady-state levels, leaving cells susceptible to killing by cytotoxic agents normally exported by MRP1. It has been suggested in the literature that capitalizing on this UL138-induced vulnerability could be a potential antiviral strategy against virally infected cells, particularly those harboring a latent infection during which UL138 is one of the few viral proteins expressed. Therefore, identifying the regions of UL138 required for MRP1 downregulation and predicting genetic variants that may be selected upon UL138-targeted chemotherapy are important ventures. Here we present the first structure-function examination of UL138 activity and determine that its transmembrane domain and acidic cluster dileucine Golgi sorting motif are required for functional MRP1 downregulation.

Preparation and identification of polyclonal antibody against human cytomegalovirus encoding protein UL23

Human cytomegalovirus (HCMV), a member of the human herpesvirus family, is a common opportunistic virus causing severe ailments and deaths in people with immature or compromised immune systems. UL23 is a virion protein found in the tegument and is expressed in the cytoplasm in HCMV infected cells. However, UL23 is dispensable for viral replication in cultured cells and little is currently known about its function. In order to further study of UL23, polyclonal antibody of UL23 was prepared. UL23 gene fragment was cloned from HCMV Towne by PCR and ligated into pET28a (+). The recombinant plasmid pET28a (+)-UL23 was transformed into E.coli BL21(DE3) to induce expression of the target protein. Then we efficiently purified the recombinant protein affinity chromatography under unique denaturation conditions. Recombinant UL23 protein was used as immunogen to inoculate New Zealand white rabbits and the sera was collected after the fourth immunization. UL23 Polyclonal antibody was purified from antisera using CNBr-activated Sepharose 4 beads. Our UL23 Polyclonal antibody showed specific reaction with UL23 in ELISA, Western-blot and immunofluorescence. More importantly, UL23 Polyclonal antibody could specifically recognize UL23 protein in HCMV infected cells, which laid a foundation for further study of HCMV UL23.

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.

Congenital and perinatal infections

Congenital and perinatal infections represent major causes of permanent disability among children worldwide. Linked together by the acronym TORCH, denoting Toxoplasma gondii, rubella virus, cytomegalovirus, and herpes virus, congenital infections can result from only a modest number of human pathogens that cross the placenta and infect the fetus. Although congenital rubella syndrome has been eliminated in the Americas by immunization, several pathogens discussed in this chapter cannot currently be prevented by vaccines or effectively treated with the available antimicrobial drugs. Due to the immaturity of the immune system, newborn infants are at risk for postnatally acquired infections with certain viruses and several bacteria. This chapter summarizes the epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment, and prevention of selected pathogens that can damage the developing nervous system. As emphasized by the persisting challenges of preventing congenital cytomegalovirus infection and the emergence of severe brain damage associated with congenital Zika syndrome, these pathogens remain important causes of cerebral palsy, epilepsy, and intellectual disability.

Preventing vertical virus infections: the role of serologic screening of pregnant women

Several virus infections affect the pregnancy itself as well as the foetal development (rubella, PVB19, VZV, HSV, HCMV, HBV, HIV). Prevention can be established by vaccination or an assessment of the immunity status as well as by chemotherapy. The following review provides an update to current aspects focusing on the role of serologic screening.

A fifty-year odyssey: prospects for a cytomegalovirus vaccine in transplant and congenital infection

INTRODUCTION

It has been almost fifty years since the Towne strain was used by Plotkin and collaborators as the first vaccine candidate for cytomegalovirus (CMV). While that approach showed partial efficacy, there have been a multitude of challenges to improve on the promise of a CMV vaccine. Efforts have been dichotomized into a therapeutic vaccine for patients with CMV-infected allografts, either stem cells or solid organ, and a prophylactic vaccine for congenital infection.

AREAS COVERED

This review will evaluate research prospects for a therapeutic vaccine for transplant recipients that recognizes CMV utilizing primarily T cell responses. Similarly, we will provide an extensive discussion on attempts to develop a vaccine to prevent the manifestations of congenital infection, based on eliciting a humoral anti-CMV protective response. The review will also describe newer developments that have upended the efforts toward such a vaccine through the discovery of a second pathway of CMV infection that utilizes an alternative receptor for entry using a series of antigens that have been determined to be important for prevention of infection.

EXPERT COMMENTARY

There is a concerted effort to unify separate therapeutic and prophylactic vaccine strategies into a single delivery agent that would be effective for both transplant-related and congenital infection.

Cytomegalovirus Shedding in Seropositive Pregnant Women From a High-Seroprevalence Population: The Brazilian Cytomegalovirus Hearing and Maternal Secondary Infection Study

Background

Most congenital cytomegalovirus (CMV) infections in highly seropositive populations occur in infants born to women with preexisting CMV seroimmunity. Although essential for developing prevention strategies, CMV shedding patterns in pregnant women with nonprimary infections have not been characterized. We investigated correlates of CMV shedding in a cohort of seropositive pregnant women.

Methods

In a prospective study, saliva, urine, vaginal swabs, and blood were collected from 120 CMV-seropositive women in the first, second, and third trimesters and 1 month postpartum. Specimens were tested for CMV DNA by polymerase chain reaction. We analyzed the contribution of the specific maternal characteristics to viral shedding.

Results

CMV shedding was detected at least once in 42 (35%) women. Mothers living with or providing daily care to young children (3-6 years) were twice as likely to shed CMV at least once compared to women with less exposure to young children (58% vs 26%; adjusted relative risk [aRR], 2.21; 95% confidence interval [CI], 1.37-3.56). Living in crowded households (≥2 people per room) was associated with viral shedding (64% vs 31%; aRR, 1.99; 95% CI, 1.26-3.13). Sexual activity as indicated by the number of sexual partners per year or condom use was not found to be a correlate of viral shedding.

Conclusions

CMV shedding is relatively frequent in seropositive pregnant women. The association between virus shedding and caring for young children as well as crowded living conditions may provide opportunities for increased exposures that could lead to CMV reinfections in seropositive women.

Maternal Immunity and the Natural History of Congenital Human Cytomegalovirus Infection

Congenital human cytomegalovirus (HCMV) is the most common viral infection of the developing fetus, and a significant cause of neurodevelopmental abnormalities in infants and children. Congenital HCMV infections account for an estimated 25% of all cases of hearing loss in the US. It has long been argued that maternal adaptive immune responses to HCMV can modify both the likelihood of intrauterine transmission of HCMV, and the severity of fetal infection and risk of long term sequelae in infected infants. Over the last two decades, multiple studies have challenged this paradigm, including findings that have demonstrated that the vast majority of infants with congenital HCMV infections in most populations are born to women with established immunity prior to conception. Furthermore, the incidence of clinically apparent congenital HCMV infection in infants born to immune and non-immune pregnant women appears to be similar. These findings from natural history studies have important implications for the design, development, and testing of prophylactic vaccines and biologics for this perinatal infection. This brief overview will provide a discussion of existing data from human natural history studies and animal models of congenital HCMV infections that have described the role of maternal immunity in the natural history of this perinatal infection.

Human Cytomegalovirus-Specific Memory CD4+ T-Cell Response and Its Correlation With Virus Transmission to the Fetus in Pregnant Women With Primary Infection

Background

Primary human cytomegalovirus (HCMV) infection during pregnancy is the major cause of congenital viral sequelae. The HCMV-specific T-cell response may have a role in the prevention of virus transmission to the fetus.

Methods

HCMV-specific memory T cells were investigated in the second month after primary infection onset in 44 pregnant women (15 transmitting the infection to the fetus) and 8 pregnant women with remote infection. Peripheral blood mononuclear cells were stimulated for 12 days with peptide pools of HCMV proteins IE-1, IE-2, and pp65, and subsequently restimulated for 24 hours with the same peptide pools in a cultured enzyme-linked immunospot (ELISPOT) assay.

Results

In pregnant women with primary infection, the cultured ELISPOT assay detected a higher T-cell response to pp65 than to IE-1 or IE-2, whereas in remote infection pp65-, IE-1-, and IE-2-specific T cells were detected at comparable levels. During primary infection, the cultured ELISPOT response was mainly mediated by CD4+ T cells, and was lower than in remote infection. Strikingly, the cultured ELISPOT response to pp65 (but not to IE-1 or IE-2) was significantly higher in nontransmitting mothers. To detect other factors potentially associated with nontransmission, different serological parameters were analyzed. Only immunoglobulin G avidity index was higher in nontransmitting mothers, who showed also a lower DNAemia level. These 2 parameters remained associated with congenital infection in multivariate analysis.

Conclusions

Determination of HCMV-specific T cells by cultured ELISPOT, in pregnant women with primary HCMV infection, in association with avidity index and DNAemia may help to assess the risk of HCMV fetal transmission.

Transfusion-associated hazards: A revisit of their presentation

As a therapy or a support to other therapies, despite being largely beneficial to patients in general, transfusion it is not devoid of some risks. In a moderate number of cases, patients may manifest adverse reactions, otherwise referred to as transfusion-associated hazards (TAHs). The latest French 2016 haemovigilance report indicates that 93% of TAHs are minor (grade 1), 5.5% are moderate (grade 2) and 1.6% are severe (grade 3), with only five deaths (grade 4) being attributed to transfusion with relative certainty (imputability of level [or grade] 1 to 3). Health-care providers need to be well aware of the benefits and potential risks (to best evaluate and discuss the benefit-risk ratio), how to prevent TAHs, the overall costs and the availability of alternative therapeutic options. In high-income countries, most blood establishments (BEs) and hospital blood banks (HBBs) have developed tools for reporting and analysing at least severe transfusion reactions. With nearly two decades of haemovigilance, transfusion reaction databases should be quite informative, though there are four main caveats that prevent it from being fully efficient: (ai) reporting is mainly declarative and is thus barely exhaustive even in countries where it is mandatory by law; (aii) it is often difficult to differentiate between the different complications related to transfusion, diseases, comorbidities and other types of therapies in patients suffering from debilitating conditions; (aiii) there is a lack of consistency in the definitions used to describe and report some transfusion reactions, their severity and their likelihood of being related to transfusion; and (aiv) it is difficult to assess the imputability of a particular BC given to a patient who has previously received many BCs over a relatively short period of time. When compiling all available information published so far, it appears that TAHs can be analysed using different approaches: (bi) their pathophysiological nature; (bii) their severity; (biii) the onset scheme; (biv) a quality assessment (preventable or non-preventable); (bv) their impact on ongoing therapy. Moreover, TAHs can be reported either in a non-integrative or in an integrative way; in the latter case, presentation may also differ when issued by a blood establishment or a treating ward. At some point, a recapitulative document would be useful to gain a better understanding of TAHs in order to decrease their occurrence and severity and allow decision makers to determine action plans: this is what this review attempts to make. This review attempts to merge the different aspects, with a focus on the hospital side, i.e., how the most frequent TAHs can be avoided or mitigated.

What family doctors know about congenital CMV: a regional survey in Iran

BACKGROUND

Since there is no effective treatment or vaccine against the congenital cytomegalovirus (cCMV) infection, knowledge and awareness of medical doctor's (MDs) especially family doctors are essential for preventive strategies and it also seems to be usually ignored by healthcare providers. Aim of this study was to investigate awareness of MDs about cCMV infection in Iran.

METHODS

A single page questionnaire was randomly distributed among 450 MDs including general practitioners, pediatricians, gynecologists, internal and other medical specialists concerning of their knowledge in clinical presentation, diagnosis, prevention, prognosis, epidemiology, transmission, and management of cCMV infection. All statistical analyses were performed using SPSS version 16.

RESULTS

More than half of questionnaire recipients refused to take part in any of the questionnaire items. The most of the respondents were agreed for newborn CMV screening tests and mandatory CMV test for women trying to get pregnant, which, are not routinely tested. The knowledge of general practitioners about cCMV was less than usual. The field of expertise had a profound effect in this survey, but age and gender did not.

CONCLUSIONS

Our results indicated that the knowledge of cCMV infection, especially among family doctors contains several gaps. Urgent action is required to improve family doctor's knowledge of CMV infection. Surveys to evaluate CMV awareness among MDs, healthcare professionals and women of childbearing age are proposed.

Progress toward Development of a Vaccine against Congenital Cytomegalovirus Infection

A vaccine against congenital human cytomegalovirus (CMV) infection is a major public health priority. Congenital CMV causes substantial long-term morbidity, particularly sensorineural hearing loss (SNHL), in newborns, and the public health impact of this infection on maternal and child health is underrecognized. Although progress toward development of a vaccine has been limited by an incomplete understanding of the correlates of protective immunity for the fetus, knowledge about some of the key components of the maternal immune response necessary for preventing transplacental transmission is accumulating. Moreover, although there have been concerns raised about observations indicating that maternal seropositivity does not fully prevent recurrent maternal CMV infections during pregnancy, it is becoming increasing clear that preconception immunity does confer some measure of protection against both CMV transmission and CMV disease (if transmission occurs) in the newborn infant. Although the immunity to CMV conferred by both infection and vaccination is imperfect, there are encouraging data emerging from clinical trials demonstrating the immunogenicity and potential efficacy of candidate CMV vaccines. In the face of the knowledge that between 20,000 and 30,000 infants are born with congenital CMV in the United States every year, there is an urgent and compelling need to accelerate the pace of vaccine trials. In this minireview, we summarize the status of CMV vaccines in clinical trials and provide a perspective on what would be required for a CMV immunization program to become incorporated into clinical practice.

Neutralization of Human Cytomegalovirus Entry into Fibroblasts and Epithelial Cells

Human cytomegalovirus (HCMV) is a leading cause of permanent birth defects, highlighting the need to develop an HCMV vaccine candidate. However, HCMV vaccine development is complicated by the varying capacity of neutralizing antibodies (NAb) to interfere in vitro with the HCMV entry routes mediating infection of fibroblast (FB) and epithelial cells (EC). While HCMV infection of FB and EC requires glycoprotein complexes composed of gB and gH/gL/gO, EC infection depends additionally on the envelope pentamer complex (PC) composed of gH, gL, UL128, UL130 and UL131A. Unlike NAb to gB or gH epitopes that can interfere with both FB and EC infection, NAb targeting predominantly conformational epitopes of the UL128/130/131A subunits are unable to prevent FB entry, though they are highly potent in blocking EC infection. Despite the selective requirement of the PC for EC entry, the PC is exceptionally immunogenic as vaccine antigen to stimulate both EC- and FB-specific NAb responses due to its capacity to elicit NAb that target epitopes of the UL128/130/131A subunits and gH. These findings suggest that the PC could be sufficient in a subunit vaccine formulation to induce robust FB- and EC-specific NAb responses. In this short review, we discuss NAb responses induced through natural infection and vaccination that interfere in vitro with HCMV infection of FB and EC.

Murine Cytomegalovirus Spreads by Dendritic Cell Recirculation

Herpesviruses have coevolved with their hosts over hundreds of millions of years and exploit fundamental features of their biology. Cytomegaloviruses (CMVs) colonize blood-borne myeloid cells, and it has been hypothesized that systemic dissemination arises from infected stem cells in bone marrow. However, poor CMV transfer by stem cell transplantation argues against this being the main reservoir. To identify alternative pathways for CMV spread, we tracked murine CMV (MCMV) colonization after mucosal entry. We show that following intranasal MCMV infection, lung CD11c⁺ dendritic cells (DC) migrated sequentially to lymph nodes (LN), blood, and then salivary glands. Replication-deficient virus followed the same route, and thus, DC infected peripherally traversed LN to enter the blood. Given that DC are thought to die locally following their arrival and integration into LN, recirculation into blood represents a new pathway. We examined host and viral factors that facilitated this LN traverse. We show that MCMV-infected DC exited LN by a distinct route to lymphocytes, entering high endothelial venules and bypassing the efferent lymph. LN exit required CD44 and the viral M33 chemokine receptor, without which infected DC accumulated in LN and systemic spread was greatly reduced. Taken together, our studies provide the first demonstration of virus-driven DC recirculation. As viruses follow host-defined pathways, high endothelial venules may normally allow DC to pass from LN back into blood.

Human cytomegalovirus (HCMV) causes devastating disease in the unborn fetus and in the immunocompromised. There is no licensed vaccine, and preventive measures are impeded by our poor understanding of early events in host colonization. HCMV and murine CMV (MCMV) both infect blood-borne myeloid cells. HCMV-infected blood cells are thought to derive from infected bone marrow stem cells. However, infected stem cells have not been visualized in vivo nor shown to produce virus ex vivo, and hematopoietic transplants poorly transfer infection. We show that MCMV-infected dendritic cells in the lungs reach the blood via lymph nodes, surprisingly migrating into high endothelial venules. Dissemination did not require viral replication. It depended on the constitutively active viral chemokine receptor M33 and on the host hyaluronan receptor CD44. Thus, viral chemokine receptors are a possible target to limit systemic CMV infections.

Intrauterine therapy of cytomegalovirus infection with valganciclovir: review of the literature

Congenital cytomegalovirus (CMV) infection is the leading cause for sensorineural hearing loss and mental retardation in children without genetic diseases worldwide. There is little evidence guiding therapeutic strategies during pregnancy when intrauterine fetal CMV infection is confirmed. We provide a systematic review of the use of ganciclovir (GCV) or VGCV during pregnancy discussing safety of its use for mother and fetus and describe two cases of intrauterine therapy of fetal CMV infection with valganciclovir (VGCV). A PubMed database search was done up to November 16, 2016 without any restrictions of publication date or journal, using the following keywords: "valganciclovir" or "ganciclovir" and "pregnan*". Furthermore, citations were searched and expert references were obtained. Reported cases were considered if therapy was in humans and initiation of treatment of the CMV infection was during pregnancy. In total, seven case reports were retrieved which described GCV or VGCV use during pregnancy for fetal or maternal CMV infection. In the four cases of treatment for maternal CMV infection, no negative effects on the fetus were reported. Three cases of GCV administration to pregnant woman with the intention of fetal treatment after proven fetal infection were found. We additionally present two cases of VGCV treatment in pregnancy from our center of tertiary care. VGCV seems to be a safe treatment for congenital CMV infection for the mother and the fetus. Therapeutic concentrations can be achieved in the fetus by oral intake of the mother and CMV replication can be suppressed. Larger studies are needed to evaluate this therapeutic intervention and the long-term effects.

Genomic Programming of Human Neonatal Dendritic Cells in Congenital Systemic and In Vitro Cytomegalovirus Infection Reveal Plastic and Robust Immune Pathway Biology Responses

Neonates and especially premature infants are highly susceptible to infection but still can have a remarkable resilience that is poorly understood. The view that neonates have an incomplete or deficient immune system is changing. Human neonatal studies are challenging, and elucidating host protective responses and underlying cognate pathway biology, in the context of viral infection in early life, remains to be fully explored. In both resource rich and poor settings, human cytomegalovirus (HCMV) is the most common cause of congenital infection. By using unbiased systems analyses of transcriptomic resources for HCMV neonatal infection, we find the systemic response of a preterm congenital HCMV infection, involves a focused IFN regulatory response associated with dendritic cells. Further analysis of transcriptional-programming of neonatal dendritic cells in response to HCMV infection in culture revealed an early dominant IFN-chemokine regulatory subnetworks, and at later times the plasticity of pathways implicated in cell-cycle control and lipid metabolism. Further, we identify previously unknown suppressed networks associated with infection, including a select group of GPCRs. Functional siRNA viral growth screen targeting 516-GPCRs and subsequent validation identified novel GPCR-dependent antiviral (ADORA1) and proviral (GPR146, RGS16, PTAFR, SCTR, GPR84, GPR85, NMUR2, FZ10, RDS, CCL17, and SORT1) roles. By contrast a gene family cluster of protocadherins is significantly differentially induced in neonatal cells, suggestive of possible immunomodulatory roles. Unexpectedly, programming responses of adult and neonatal dendritic cells, upon HCMV infection, demonstrated comparable quantitative and qualitative responses showing that functionally, neonatal dendritic cell are not overly compromised. However, a delay in responses of neonatal cells for IFN subnetworks in comparison with adult-derived cells are notable, suggestive of subtle plasticity differences. These findings support a set-point control mechanism rather than immaturity for explaining not only neonatal susceptibility but also resilience to infection. In summary, our findings show that neonatal HCMV infection leads to a highly plastic and functional robust programming of dendritic cells in vivo and in vitro. In comparison with adults, a minimal number of subtle quantitative and temporal differences may contribute to variability in host susceptibility and resilience, in a context dependent manner.

Outcomes of congenital cytomegalovirus disease following maternal primary and non-primary infection

BACKGROUND

Natural history and long term prognosis of congenital cytomegalovirus (CMV) disease according to maternal primary versus non-primary infection are not clearly documented.

OBJECTIVE

To investigate clinical, laboratory and neuroimaging features at onset and long term outcome of congenitally CMV-infected patients born to mothers with non-primary infection compared with a group of patients born to mothers with primary infection.

STUDY DESIGN

Consecutive neonates born from 2002 to 2015 were considered eligible for the study. Patients underwent clinical, laboratory and instrumental investigation, and audiologic and neurodevelopmental evaluation at diagnosis and during the follow up.

RESULTS

A cohort of 158 congenitally infected children was analyzed. Ninety-three were born to mothers with primary CMV infection (Group 1) and 65 to mothers with a non-primary infection (Group 2). Eighty-eight infants had a symptomatic congenital CMV disease: 49 (46.2%) in Group 1 and 39 (60%) in Group 2. Maternal and demographic characteristics of patients of Group 1 and Group 2 were comparable, with the exception of prematurity and a 1-min Apgar score less than 7, which were more frequent in Group 2 compared to Group 1. Prevalence of neuroimaging findings did not significantly differ between the two groups. An impaired neurodevelopmental outcome was observed in 23.7% of patients of Group 1 and in 24.6% cases of Group 2. Similarly, the frequency of hearing loss did not differ between the two groups (25.8% versus 26.2%, respectively).

CONCLUSIONS

Neurodevelopmental and hearing sequelae are not affected by the type of maternal CMV infection. Preventing strategies should be developed for both primary and non-primary infections.