Congenital cytomegalovirus infection: association between virus burden in infancy and hearing loss

Cytomegalovirus-induced inactivation of TSC2 disrupts the coupling of fatty acid biosynthesis to glucose availability resulting in a vulnerability to glucose starvation

IMPORTANCE

Viruses modulate host cell metabolism to support the mass production of viral progeny. For human cytomegalovirus, we find that the viral UL38 protein is critical for driving these pro-viral metabolic changes. However, our results indicate that these changes come at a cost, as UL38 induces an anabolic rigidity that leads to a metabolic vulnerability. We find that UL38 decouples the link between glucose availability and fatty acid biosynthetic activity. Normal cells respond to glucose limitation by down-regulating fatty acid biosynthesis. Expression of UL38 results in the inability to modulate fatty acid biosynthesis in response to glucose limitation, which results in cell death. We find this vulnerability in the context of viral infection, but this linkage between fatty acid biosynthesis, glucose availability, and cell death could have broader implications in other contexts or pathologies that rely on glycolytic remodeling, for example, oncogenesis.

Risk Factors for Natural Hearing Evolution in Newborns With Congenital Cytomegalovirus Infection

Importance

Congenital cytomegalovirus (cCMV) is the major cause of congenital nonhereditary sensorineural hearing loss in children. Currently, criteria to identify infants at increased risk for unfavorable hearing outcome are lacking.

Objective

To identify risk factors associated with cCMV-related hearing improvement, hearing deterioration, and late-onset hearing loss.

Design, Setting, and Participants

This multicenter cohort study included patients from 6 secondary and tertiary hospitals enrolled in the Flemish CMV registry (Belgium). Newborns with untreated cCMV infection with at least 4-year audiological follow-up were included. Patients who presented with other possible causes of sensorineural hearing loss were excluded. Data were collected for 15 years (January 1, 2007, to February 7, 2022) and analyzed from September 26, 2022, to January 16, 2023.

Main Outcomes and Measures

Primary outcome was hearing evolution (per-ear analysis; described as stable hearing, improvement, or deterioration). The association of gestational characteristics, clinical findings, timing of seroconversion, viral load, and hearing status at birth with hearing evolution was investigated using effect sizes (Cramer V, odds ratio [OR], or Hedges g).

Results

Of the 387 children, 205 of 385 with nonmissing data were male (53.2%), 113 (29.2%) had a symptomatic infection, and 274 (70.8%) had an asymptomatic infection. Every child was 4 years or older at final hearing evaluation. A total of 701 of 774 ears (90%) showed stable hearing (normal hearing or stable hearing loss since birth) over time. Late-onset hearing loss (normal hearing at birth followed by hearing loss) was present in 43 of 683 ears (6.3%). Among children with hearing loss present at birth, 24 of 34 ears (70.6%) had hearing deterioration, and 6 of 91 ears (6.6%) had hearing improvement. Prematurity was associated with a higher chance of hearing improvement (OR, 12.80; 95% CI, 2.03-80.68). Late-onset hearing loss was more prevalent in a first trimester infection (OR, 10.10; 95% CI, 2.90-34.48). None of the 104 ears of children with a third trimester seroconversion developed late-onset hearing loss.

Conclusions and Relevance

Findings of this cohort study support that ongoing audiological follow-up for untreated children with congenital hearing loss is important, as the majority of patients had hearing deterioration. The timing of seroconversion was associated with the risk of developing late-onset hearing loss. These insights can aid in parental counseling, patient stratification, and follow-up. Future research should focus on the effect of treatment, the influence of determined risk factors, and the study of eventual new risk factors in patients at high risk to develop hearing loss.

Utility of Dried Blood Spots for the Diagnosis of Congenital Cytomegaloviruses within the First 21 Days of Life in a Single Center

In this retrospective study, we aimed to evaluate the performance of dried-blood-spot (DBS) testing as a diagnostic method for the congenital cytomegalovirus (cCMV). We reviewed the medical records and DBS test results of 89 patients who had also undergone diagnostic cCMV testing within the first 21 days of life. The DBS test had a sensitivity of 83.9%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 73%. Patients with a true-positive DBS had a higher median level of CMV in blood according to PCR than those with a false-negative result. Additionally, all patients with cCMV and hearing loss had a positive DBS test, with higher median viremia levels observed in those with hearing loss compared to those without a CMV PCR blood test. These results suggest that DBS-based testing is useful in the diagnosis of cCMV, and its performance may be related to levels of CMV viremia. DBS testing accurately identified those patients with congenital/early onset hearing loss and those at risk of developing late-onset hearing loss.

Cytomegalovirus-induced inactivation of TSC2 disrupts the coupling of fatty acid biosynthesis to glucose availability resulting in a vulnerability to glucose limitation

Human cytomegalovirus (HCMV) modulates cellular metabolism to support productive infection, and the HCMV UL38 protein drives many aspects of this HCMV-induced metabolic program. However, it remains to be determined whether virally-induced metabolic alterations might induce novel therapeutic vulnerabilities in virally infected cells. Here, we explore how HCMV infection and the UL38 protein modulate cellular metabolism and how these changes alter the response to nutrient limitation. We find that expression of UL38, either in the context of HCMV infection or in isolation, sensitizes cells to glucose limitation resulting in cell death. This sensitivity is mediated through UL38's inactivation of the TSC complex subunit 2 (TSC2) protein, a central metabolic regulator that possesses tumor-suppressive properties. Further, expression of UL38 or the inactivation of TSC2 results in anabolic rigidity in that the resulting increased levels of fatty acid biosynthesis are insensitive to glucose limitation. This failure to regulate fatty acid biosynthesis in response to glucose availability sensitizes cells to glucose limitation, resulting in cell death unless fatty acid biosynthesis is inhibited. These experiments identify a regulatory circuit between glycolysis and fatty acid biosynthesis that is critical for cell survival upon glucose limitation and highlight a metabolic vulnerability associated with viral infection and the inactivation of normal metabolic regulatory controls.

Clinical Value of Serial Quantitative Analysis of Cytomegalovirus DNA in Blood and Saliva Over the First 24 Months of Life in Congenital Infection: The French Cymepedia Cohort

OBJECTIVE

To evaluate cytomegalovirus (CMV) viral load dynamics in blood and saliva during the first 2 years of life in symptomatic and asymptomatic infected infants and to identify whether these kinetics could have practical clinical implications.

STUDY DESIGN

The Cymepedia cohort prospectively included 256 congenitally infected neonates followed for 2 years. Whole blood and saliva were collected at inclusion and months 4 and 12, and saliva at months 18 and 24. Real-time CMV polymerase chain reaction (PCR) was performed, results expressed as log₁₀ IU/mL in blood and in copies per milliliter in saliva.

RESULTS

Viral load in saliva progressively decreased from 7.5 log₁₀ at birth to 3.3 log₁₀ at month 24. CMV PCR in saliva was positive in 100% and 96% of infants at 6 and 12 months, respectively. In the first month of life, neonatal saliva viral load of less than 5 log₁₀ was related to a late CMV transplacental passage. Detection in blood was positive in 92% of neonates (147/159) in the first month of life. No viral load threshold values in blood or saliva could be associated with a high risk of sequelae. Neonatal blood viral load of less than 3 log₁₀ IU/mL had a 100% negative predictive value for long-term sequelae.

CONCLUSIONS

Viral loads in blood and saliva by CMV PCR testing in congenital infection fall over the first 24 months. In this study of infants affected mainly after primary maternal infection during pregnancy, all salivary samples were positive in the first 6 months of life and sequelae were not seen in infants with neonatal blood viral load of less than 3 log₁₀ IU/mL.

Risk Factors for Hearing Loss at Birth in Newborns With Congenital Cytomegalovirus Infection

Importance

With a prevalence between 0.2% and 6.1% of all live births, congenital cytomegalovirus (cCMV) infection is a major cause of congenital nonhereditary sensorineural hearing loss. Despite the large amount of research on cCMV-related hearing loss, it is still unclear which newborns are at risk of hearing loss.

Objective

To identify independent risk factors for cCMV-related congenital hearing loss and predictors of hearing loss severity at birth.

Design, Setting, and Participants

This cross-sectional study of newborns with cCMV infection used data included in the Flemish CMV registry that was collected from 6 secondary and tertiary hospitals in Flanders, Belgium, over 15 years (January 1, 2007, to February 7, 2022). Data were analyzed March 3 to October 19, 2022. Patients were included in the study after confirmed diagnosis of cCMV infection and known hearing status at birth. Patients who presented with other possible causes of sensorineural hearing loss were excluded.

Main Outcomes and Measures

Primary outcome was hearing status at birth. Clinical, neurological, and laboratory findings along with the timing of seroconversion and blood viral load were separately considered as risk factors. Binary logistic regression was performed to identify independent risk factors for congenital hearing loss in newborns with cCMV. Effect sizes were measured using Hedges g, odds ratio, or Cramer V.

Results

Of the 1033 newborns included in the study (553 of 1024 [54.0%] boys), 416 (40.3%) were diagnosed with symptomatic cCMV infection and 617 (59.7%) with asymptomatic cCMV infection. A total of 15.4% of the patients (n = 159) presented with congenital hearing loss; half of them (n = 80 [50.3%]) had isolated hearing loss. The regression model revealed 3 independent risk factors for congenital hearing loss: petechiae at birth (adjusted odds ratio [aOR], 6.7; 95% CI, 1.9-23.9), periventricular cysts on magnetic resonance imaging (MRI; aOR, 4.6; 95% CI, 1.5-14.1), and seroconversion in the first trimester (aOR, 3.1; 95% CI, 1.1-9.3). Lower viral loads were seen in patients with normal hearing compared with those with congenital hearing loss (median [IQR] viral load, 447.0 [39.3-2345.8] copies per milliliter of sample [copies/mL] vs 1349.5 [234.3-14 393.0] copies/mL; median difference, -397.0 [95% CI, -5058.0 to 174.0] copies/mL).

Conclusions and Relevance

Findings of this cross-sectional study suggest that newborns with cCMV infection and petechiae at birth, periventricular cysts on MRI, or a seroconversion in the first trimester had a higher risk of congenital hearing loss. Clinicians may use these risk factors to counsel parents in the prenatal and postnatal periods about the risk of congenital hearing loss. Moreover, linking clinical features to hearing loss may provide new insights into the pathogenesis of cCMV-related hearing loss. The importance of viral load as a risk factor for congenital hearing loss remains unclear.

Correlation of cytomegalovirus viral load between whole blood and plasma of congenital cytomegalovirus infection under valganciclovir treatment

BACKGROUND

Congenital cytomegalovirus (CMV) infection (cCMV) can cause sensorineural hearing loss and neurodevelopmental disabilities in children. Oral valganciclovir (VGCV) therapy has been reported to improve long-term audiological and neurodevelopmental outcomes in patients with cCMV. The levels of CMV DNA in whole blood have been monitored in previous studies. However, quantitative methods using whole blood have not been standardized. Recently, the plasma viral load has been standardized and widely used in CMV-associated diseases.

METHODS

CMV viral loads in whole blood and plasma were serially measured in 24 patients with a confirmatory diagnosis of cCMV during oral VGCV therapy using an in-house real-time PCR assay. Plasma samples were assayed using the Cobas 6800 system (Roche Diagnostics) in addition to an in-house assay.

RESULTS

Plasma CMV viral loads were remarkably decreased at the end of therapy compared to before therapy. A significant correlation of CMV levels between whole blood and plasma was observed (Spearman's ρ = 0.566). The levels of CMV DNA before therapy were significantly correlated with the period of decreasing the viral loads to below the detection limit, not only in whole blood (Spearman's ρ = 0.901) but also in plasma (Spearman, ρ = 0.804). Finally, CMV viral loads between the in-house assay and commercially available standardized assay in 75 plasma samples with positive PCR results for CMV were compared; a significant correlation was observed between the results of both assays.

CONCLUSIONS

There was a significant correlation between the two assays (Spearman, ρ = 0.882), suggesting that CMV plasma viral loads measured by the standardized assay are widely used to monitor the levels of CMV DNA in patients with cCMV during oral VGCV therapy.

Hearing Outcome and Virologic Characteristics of Children With Congenital Cytomegalovirus Infection in Relation to Antiviral Therapy: A Retrospective Cohort Study

BACKGROUND

Congenital cytomegalovirus infection is one of the leading causes of nongenetic sensorineural hearing loss. The aim of our retrospective cohort study was to describe the changes in hearing in relation to antiviral therapy and the trend in viremia and viruria in children with congenital cytomegalovirus infection.

METHODS

In the present study, data were collected from infants treated with valganciclovir for 6 weeks or 6 months or untreated, seen between 2000 and 2021 at the Infectious Diseases Unit, Meyer Children's University Hospital, Florence, Italy. Hearing deterioration was studied using Kaplan-Meier survival curves and risk factors for the outcome "deterioration" with Cox analysis.

RESULTS

Ninety-eight children were enrolled. Three children developed late hearing loss (2 children treated with valganciclovir for 6 weeks and 1 untreated). Kaplan-Meier survival curves of children treated for 6 weeks and 6 months overlapped until 36 months of life, after then 2 children of the 6-week group showed a worsening of hearing function (P = 0.609). Cox analysis did not show a significant impact of analyzed variables (group of therapy, viruria and viremia) on the outcome. The resolution of detectable viruria and viremia was significantly faster in the 6-month group (P = 0.011, <0.001, respectively).

CONCLUSIONS

Our study is the first that reports audiological characteristics at follow-up after 24 months of life in treated and untreated children with congenital cytomegalovirus infection. In our population, 6 months therapy may prevent the development of late hearing loss, although the different regimens did not differ in influencing the progression of congenital deafness.

Cutting Edge: CCR9 Promotes CD8+ T Cell Recruitment to the Brain during Congenital Cytomegalovirus Infection

CD8+ T lymphocytes infiltrate the brain during congenital CMV infection and promote viral clearance. However, the mechanisms by which CD8+ T cells are recruited to the brain remain unclear. Using a mouse model of congenital CMV, we found a gut-homing chemokine receptor (CCR9) was preferentially expressed in CD8+ T cells localized in the brain postinfection. In the absence of CCR9 or CCL25 (CCR9's ligand) expression, CD8+ T cells failed to migrate to key sites of infection in the brain and protect the host from severe forms of disease. Interestingly, we found that expression of CCR9 on CD8+ T cells was also responsible for spatial temporal positioning of T cells in the brain. Collectively, our data demonstrate that the CMV-infected brain uses a similar mechanism for CD8+ T cell homing as the small intestine.

Maternal-Fetal Infections (Cytomegalovirus, Toxoplasma, Syphilis): Short-Term and Long-Term Neurodevelopmental Outcomes in Children Infected and Uninfected at Birth

(1) Background: Infections in pregnancy can lead to miscarriage, premature birth, infections in newborns, and developmental disabilities in babies. Infected infants, symptomatic at birth, can have long-term sequelae, and asymptomatic babies are also at increased risk of developing long-term sensorineural outcomes. Targeted therapy of the pregnant mother can reduce fetal and neonatal harm. (2) Aim of the study: To explore the association between symptoms and time of onset of long-term sequelae in infected children born from mothers who contracted an infection during pregnancy, by a long-term multidisciplinary follow-up. (3) Methods: For up to 2−4 years, we evaluated cognitive, motor, audiological, visual, and language outcomes in infants with symptomatic and asymptomatic congenital infections and in uninfected infants. (4) Results: 186 infants born from women who acquired Cytomegalovirus infection (n = 103), Toxoplasma infection (n = 50), and Syphilis (n = 33) during pregnancy were observed. Among them, 119 infants acquired the infection in utero. Infected infants, symptomatic at birth, obtained lower scores on the Cognitive and Motor Scale on Bayley-III compared to asymptomatic and uninfected infants (p = 0.026; p = 0.049). Many severe or moderate sequelae rose up within the first year of life. At 24 months, we observed sequelae in 24.6% (14/57) of infected children classified as asymptomatic at birth, compared to 68.6% (24/35) of symptomatic ones (χ2 = 15.56; p < 0.001); (5) Conclusions: Infected babies symptomatic at birth have a worse prognosis than asymptomatic ones. Long-term sequelae may occur in infected children asymptomatic at birth after the first year of life. Multidisciplinary follow-up until 4−6 years of age should be performed in all infected children, regardless of the presence of symptoms at birth.

Utility of Whole Genome Sequencing for Population Screening of Deafness-Related Genetic Variants and Cytomegalovirus Infection in Newborns

Background: Hearing loss affects approximately two out of every 1,000 newborns. Genetic factors and congenital cytomegalovirus (CMV) infections account for around 90% of the etiology. The purpose of this study was to develop and test a whole genome sequencing (WGS) approach to detect deafness-related genetic variants and CMV infections simultaneously in newborns.

Method: Deafness-related genes causing congenital or childhood hearing loss were curated and selected for newborn screening. Nine dried blood spots from newborns with known genetic variants (n = 6) or CMV infections (n = 3) were employed to develop and validate the WGS testing and analytic pipeline. We then pilot tested the WGS analysis on 51 de-identified clinical samples.

Results: 92 gene-disease pairs were selected for screening hearing loss in newborns. In the validation test, WGS accurately detected all types of genetic variants, including single nucleotide variations, insertions/deletions, and copy number variations in the nuclear or mitochondrial genome. Sequence reads mapping to the CMV reference genome were discovered in CMV infected samples. In the pilot test, WGS identified nine out of 51 (18%) newborns carrying pathogenic variants associated with deafness.

Conclusion: WGS can simultaneously detect genetic variants and CMV infections in dried blood spot specimens from newborns. Our study provides proof of principle that genome sequencing can be a promising alternative for newborn screening of hearing loss.

Prognostic determinants of hearing outcomes in children with congenital cytomegalovirus infection

Congenital cytomegalovirus (cCMV) infection is the most prevalent cause of non-genetic sensorineural hearing loss (SNHL) in children. However, the prognostic determinants of SNHL remain unclear. Children with cCMV infection in a tertiary hospital were enrolled. The presence of cCMV-related symptoms at birth, the newborn hearing screening (NHS) results, and the blood viral loads were ascertained. Audiologic outcomes and initial blood viral loads were compared between different groups. Of the 39 children enrolled, 16 developed SNHL. SNHL developed in 60% of children who were initially symptomatic, and in 34.5% of those who were initially asymptomatic with normal hearing or isolated hearing loss, respectively. Failuire in NHS was a reliable tool for early detection of SNHL. The initial viral loads were higher in children who were symptomatic at birth, those who failed NHS, and those who developed SNHL. We observed SNHL deterioration in a patient after CMV DNAemia clearance was achieved, and in another patient with the flare-up of viral load. The presence of cCMV-related symptoms at birth, failure in NHS, and blood viral load might be the prognostic factors for hearing outcomes. Regular audiologic examinations are necessary in all children with cCMV infection even after CMV DNAemia clearance.

Change in Viral Load during Antiviral Therapy Is Not Useful for the Prediction of Hearing Dysfunction in Symptomatic Congenital Cytomegalovirus Infection

For symptomatic congenital cytomegalovirus infections (CCMVI), the usefulness of changes in viral load during valganciclovir (VGCV) treatment for the prediction of hearing dysfunction (HD) is unclear. To determine the utility of viral load change in the whole blood or urine for the prediction of HD, we performed a retrospective study to compare viral load changes during VGCV treatment between CCMVI infants with (n = 12) or without (n = 8) HD at six months of corrected age, whose blood and urine viral loads were measured continuously for eight weeks from April 2009 to December 2019. There was no significant difference in the changes in both the blood and urine viral loads after the initiation of VGCV treatment between CCMVI infants between the groups. Moreover, this negative result was maintained in the analysis for each six weeks or six months treatment period. In conclusion, the change in viral load during antiviral therapy is not useful for the prediction of HD at six months of corrected age in symptomatic CCMVI.

Early Identification and Management of Congenital Cytomegalovirus

Congenital cytomegalovirus (cCMV) is the most common nongenetic cause of sensorineural hearing loss. Despite its prevalence, universal screening for cCMV is not currently performed. Hearing loss caused by cCMV is most often severe to profound, often bilateral, and may be fluctuating or progressive. Infants with hearing loss at birth and confirmed cCMV might benefit from antiviral therapy. Roughly half of hearing loss cases owing to cCMV are delayed in onset, and consequently, these children pass newborn hearing screening. Children with cCMV require close audiologic monitoring, require appropriate management with hearing aids, and should be monitored for cochlear implant candidacy.

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.

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.

Cytomegalovirus Infection and Inflammation in Developing Brain

Human cytomegalovirus (HCMV) is a highly prevalent herpesvirus that can cause severe disease in immunocompromised individuals and immunologically immature fetuses and newborns. Most infected newborns are able to resolve the infection without developing sequelae. However, in severe cases, congenital HCMV infection can result in life-threatening pathologies and permanent damage of organ systems that possess a low regenerative capacity. Despite the severity of the problem, HCMV infection of the central nervous system (CNS) remains inadequately characterized to date. Cytomegaloviruses (CMVs) show strict species specificity, limiting the use of HCMV in experimental animals. Infection following intraperitoneal administration of mouse cytomegalovirus (MCMV) into newborn mice efficiently recapitulates many aspects of congenital HCMV infection in CNS. Upon entering the CNS, CMV targets all resident brain cells, consequently leading to the development of widespread histopathology and inflammation. Effector functions from both resident cells and infiltrating immune cells efficiently resolve acute MCMV infection in the CNS. However, host-mediated inflammatory factors can also mediate the development of immunopathologies during CMV infection of the brain. Here, we provide an overview of the cytomegalovirus infection in the brain, local immune response to infection, and mechanisms leading to CNS sequelae.

Elimination of human cytomegalovirus DNA degradation in urine

Congenital cytomegalovirus infection (cCMVi) is an important cause of sensorineural hearing loss in newborns. Detection of human cytomegalovirus (HCMV) DNA in urine has been used to screen for cCMVi in newborns. However, the matrix effect of urine on HCMV DNA detection is unclear. To evaluate the matrix effect of urine on HCMV DNA detection and optimize the sample process strategy to eliminate or minimize the impact of urine on HCMV DNA detection, DNA in spiked samples was extracted using different DNA extraction methods, and urine samples that could inhibit HCMV DNA detection were mixed to evaluate the inhibitory substances, inhibitory mechanism, and elimination of the inhibitory effect. The optimal urine sample process strategy was evaluated using 42 adult female urine samples and 42 newborn urine samples spiked with HCMV. Some urine samples were found to inhibit HCMV DNA detection due to DNA degradation. The addition of ≥5 mM EDTA to the urine before extraction eliminated the inhibitory effect of urine and did not affect the detection results of urine exhibiting no inhibition. Of the 42 adult female and 42 newborn urine samples, four and two samples, respectively, could inhibit HCMV DNA detection. However, the inhibitory effects of these six urine samples were eliminated after the addition of EDTA. The collective results indicate that the addition of EDTA can completely eliminate the impact of inhibitors present in urine on HCMV DNA extraction and improve the detection of HCMV in urine.

Apoptosis Disorder, a Key Pathogenesis of HCMV-Related Diseases

Human cytomegalovirus (HCMV) belongs to the β-herpesvirus family, which is transmitted in almost every part of the world and is carried by more than 90% of the general population. Increasing evidence indicates that HCMV infection triggers numerous diseases by disrupting the normal physiological activity of host cells, particularly apoptosis. Apoptosis disorder plays a key role in the initiation and development of multiple diseases. However, the relationship and molecular mechanism of HCMV-related diseases and apoptosis have not yet been systematically summarized. This review aims to summarize the role of apoptosis in HCMV-related diseases and provide an insight into the molecular mechanism of apoptosis induced by HCMV infection. We summarize the literature on HCMV-related diseases and suggest novel strategies for HCMV treatment by regulating apoptosis.

Association between Viral Infections and Risk of Autistic Disorder: An Overview

Autism spectrum disorder (ASD) is a neurodevelopmental condition of the central nervous system (CNS) that presents with severe communication problems, impairment of social interactions, and stereotypic behaviours. Emerging studies indicate possible associations between viral infections and neurodegenerative and neurobehavioural conditions including autism. Viral infection during critical periods of early in utero neurodevelopment may lead to increased risk of autism in the offspring. This review is aimed at highlighting the association between viral infections, including viruses similar to COVID-19, and the aetiology of autism. A literature search was conducted using Pubmed, Ovid/Medline, and Google Scholar database. Relevant search terms included "rubella and autism", "cytomegalovirus and autism", "influenza virus and autism", "Zika virus and autism", "COVID-19 and autism". Based on the search terms, a total of 141 articles were obtained and studies on infants or children with congenital or perinatal viral infection and autistic behaviour were evaluated. The possible mechanisms by which viral infections could lead to autism include direct teratogenic effects and indirect effects of inflammation or maternal immune activation on the developing brain. Brain imaging studies have shown that the ensuing immune response from these viral infections could lead to disruption of the development of brain regions and structures. Hence, long-term follow up is necessary for infants whose mothers report an inflammatory event due to viral infection at any time during pregnancy to monitor for signs of autism. Research into the role of viral infection in the development of ASD may be one avenue of improving ASD outcomes in the future. Early screening and diagnosis to detect, and maybe even prevent ASD are essential to reduce the burden of this condition.

Congenital Cytomegalovirus Infection

Congenital cytomegalovirus (cCMV) infection is a leading cause of hearing loss and neurological disabilities in children, with the disease burden and disabilities due to cCMV greater than many other well recognized childhood conditions. A minority of infants with cCMV will have symptoms at birth. Infants with symptomatic cCMV are at higher risk for sequelae than those born without symptoms. The majority of infants with cCMV are asymptomatic at birth, but 10%-15% will develop hearing loss. Although clinical symptoms can help predict which infants will have sensorineural hearing loss, among asymptomatic cCMV there are currently no predictors of adverse outcome. The identification of a biomarker to identify those at highest risk of sequelae is highly desirable to target interventions to those who could potentially benefit. Because there is increasing rationale for establishing both targeted and universal screening programs for cCMV in the United States and worldwide, this is an urgent priority.

Late-onset Hearing Loss From Congenital Cytomegalovirus Infection After Newborn Period in a Highly Immune Population in China

After following 141 children with likely asymptomatic congenital cytomegalovirus infection in a highly immune population in China, four children (2.8%) were found to have late-onset hearing loss. No maternal or childhood factors, except higher saliva cytomegalovirus viral load at birth (P = 0.03), were associated with increased risk of developing a hearing loss.

Maternal high-dose valacyclovir and its correlation with newborn blood viral load and outcome in congenital cytomegalovirus infection

BACKGROUND/OBJECTIVE

Currently, there is no validated treatment for fetal cytomegalovirus (CMV). Two studies suggest that high-dose maternal valacyclovir decreases fetal viral load and improves outcomes in moderately-symptomatic fetuses. We offered valacyclovir in cases of fetal infection lacking ultrasound abnormalities or with non-severe infection. Maternal tolerability, fetal outcome and newborn blood viral load were evaluated in pregnancies of mothers receiving valacyclovir.

STUDY DESIGN

We performed a case series including 8 pregnancies with fetal CMV classified as unaffected/mildly-moderately affected. Mothers received valacyclovir (8 g/24h) from fetal infection diagnosis to delivery. Standard newborn evaluation was performed, and viremia was determined in the first 48 h of life and compared according to length of maternal treatment and presence/absence of prenatal anomalies.

RESULTS

Valacyclovir was administered at a median gestational age of 26.5 weeks (23.8-33.1) in 3 cases without fetal abnormalities, and 5 with mild/moderate abnormalities. Three were 3 first trimester primary infections, one non-primary infection, and in 4 the type of infection was unknown. Valacyclovir was well-tolerated. Fetal features did not progress. Three newborns were asymptomatic, and one was severely affected (bilateral chorioretinitis). The median newborn viral load (IQR) was 502 IU/mL (231-191781) with lower levels when maternal treatment was administered ≥10 weeks, and in cases without fetal abnormalities [median 234 IU/mL (228-711) vs. 4061 (292-510500) p = .18; and 234 IU/mL (228-379500) vs. 711 IU/mL (292-4061) p = .65, respectively], these differences being non-significant.

CONCLUSIONS

Fetal CMV lesions remained stable with high-dose maternal valacyclovir. Newborn viral load was unchanged despite treatment duration and fetal/neonatal abnormalities.

SUMMARY

Fetal cytomegalovirus lesions remained stable with high-dose maternal valacyclovir. Newborn viral load was unchanged despite treatment duration and fetal/newborn abnormalities.

Association of human cytomegalovirus (HCMV) neutralizing antibodies with antibodies to the HCMV glycoprotein complexes

Background

Human cytomegalovirus (HCMV) causes asymptomatic infections, but also causes congenital infections when women were infected with HCMV during pregnancy, and life-threatening diseases in immunocompromised patients. To better understand the mechanism of the neutralization activity against HCMV, the association of HCMV NT antibody titers was assessed with the antibody titers against each glycoprotein complex (gc) of HCMV.

Methods

Sera collected from 78 healthy adult volunteers were used. HCMV Merlin strain and HCMV clinical isolate strain 1612 were used in the NT assay with the plaque reduction assay, in which both the MRC-5 fibroblasts cells and the RPE-1 epithelial cells were used. Glycoprotein complex of gB, gH/gL complexes (gH/gL/gO and gH/gL/UL128–131A [PC]) and gM/gN were selected as target glycoproteins. 293FT cells expressed with gB, gM/gN, gH/gL/gO, or PC, were prepared and used for the measurement of the antibody titers against each gc in an indirect immunofluorescence assay (IIFA). The correlation between the IIFA titers to each gc and the HCMV-NT titers was evaluated.

Results

There were no significant correlations between gB-specific IIFA titers and the HCMV-NT titers in epithelial cells or between gM/gN complex-specific IIFA titers and the HCMV-NT titers. On the other hand, there was a statistically significant positive correlation between the IIFA titers to gH/gL complexes and HCMV-NT titers.

Conclusions

The data suggest that the gH/gL complexes might be the major target to induce NT activity against HCMV.

Blood genome expression profiles in infants with congenital cytomegalovirus infection

Congenital CMV infection (cCMVi) affects 0.5–1% of all live births worldwide, making it the leading cause of sensorineural hearing loss (SNHL) in childhood. The majority of infants with cCMVi have normal hearing at birth, but are at risk of developing late-onset SNHL. Currently, we lack reliable biomarkers to predict the development of SNHL in these infants. Here, we evaluate blood transcriptional profiles in 80 infants with cCMVi (49 symptomatic, 31 asymptomatic), enrolled in the first 3 weeks of life, and followed for 3 years to assess emergence of late-onset SNHL. The biosignatures of symptomatic and asymptomatic cCMVi are indistinguishable, suggesting that immune responses of infants with asymptomatic and symptomatic cCMVi are not different. Random forest analyses of initial samples in infants with cCMVi, irrespective of their clinical classification, identify a 16-gene classifier signature associated with the development of SNHL with 92% accuracy, suggesting its potential value as a biomarker.

Congenital CMV infection can result in sensorineural hearing loss, but predicting this outcome is not yet possible. Here, the authors show that while blood gene expression profiles are not substantially different between symptomatic and asymptomatic infants with congenital CMV infection, a 16-gene signature is identified and able to predict late-onset hearing loss in these children.

Outcome and management of newborns with congenital cytomegalovirus infection

Congenital cytomegalovirus (CMV) infection is the most common non-genetic cause of hearing loss and neurological disorder in children. Its overall prevalence is approximately 0.5% in Europe. In France, systematic screening during pregnancy is not recommended; screening is performed only if there are maternal or fetal symptoms suggestive of this infection. Approximately 90% of infected newborns are asymptomatic at birth, and among them the risk of neurosensory sequelae is 5-15%. By contrast, the prevalence of neurosensory impairment in symptomatic newborns at birth varies from 17% to 60%. Congenital CMV infection must be confirmed at birth before the 21st day of life by polymerase chain reaction (PCR) on saliva or urine samples. A complete clinical examination, blood tests (blood count, liver function test, CMV PCR), hearing tests, brain ultrasound and eye fundus examination should be performed. Neurological and auditory follow-up must be extended well beyond the neonatal period because the occurrence of neurosensory sequelae may be delayed. Oral valganciclovir is the recommended treatment in moderate or severe congenital CMV infections for a period of 6 weeks to 6 months; such treatment requires regular monitoring because of its possible side effects.

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.

Association of Adverse Hearing, Growth, and Discharge Age Outcomes With Postnatal Cytomegalovirus Infection in Infants With Very Low Birth Weight

IMPORTANCE

Studies suggest that postnatal cytomegalovirus (CMV) infection can lead to long-term morbidity in infants with very low birth weight (VLBW; <1500 g), including bronchopulmonary dysplasia (BPD), necrotizing enterocolitis (NEC), and neurodevelopmental impairment. However, to date, the association of postnatal CMV with hearing, growth, and length of stay among VLBW infants is unknown.

OBJECTIVES

To determine the risk for failed hearing screen, increased postnatal age at discharge, or decreased growth at discharge in VLBW infants with postnatal CMV infection compared with CMV-uninfected infants and to compare the risk for other major outcomes of prematurity, including BPD and NEC, in infants with and without postnatal CMV infection.

PARTICIPANTS

This multicenter retrospective cohort study included VLBW infants from 302 neonatal intensive care units managed by the Pediatrix Medical Group from January 1, 2002, through December 31, 2016. Infants hospitalized on postnatal day 21 with a diagnosis of postnatal CMV and hearing screen results after a postmenstrual age of 34 weeks were included in the study population. Data were analyzed from December 11, 2017, to June 14, 2019.

MAIN OUTCOMES AND MEASURES

Infants with and without postnatal CMV infection were matched using propensity scores. Poisson and linear regression were used to examine the association between postnatal CMV and the risk of failed hearing screen, postnatal age at discharge, growth, BPD, and NEC.

RESULTS

A total of 304 infants with postnatal CMV were identified, and 273 of these infants (89.8%; 155 boys [56.8%]) were matched with 273 infants without postnatal CMV (148 boys [54.2%]). Hearing screen failure occurred in 45 of 273 infants (16.5%) with postnatal CMV compared with 25 of 273 infants (9.2%) without postnatal CMV (risk ratio [RR], 1.80; 95% CI, 1.14 to 2.85; P = .01). Postnatal CMV was also associated with an increased postnatal age at discharge of 11.89 days (95% CI, 6.72 to 17.06 days; P < .001) and lower weight-for-age z score (-0.23; 95% CI, -0.39 to -0.07; P = .005). Analysis confirmed an increased risk of BPD (RR, 1.30; 95% CI, 1.17 to 1.44; P < .001), previously reported on infants from this cohort from 1997 to 2012, but not an increased risk of NEC after postnatal day 21 (RR, 2.00; 95% CI, 0.18 to 22.06; P = .57).

CONCLUSIONS AND RELEVANCE

These data suggest that postnatal CMV infection is associated with lasting sequelae in the hearing and growth status of VLBW infants and with prolonged hospitalization. Prospective studies are needed to determine the full effects of postnatal CMV infection and whether antiviral treatment reduces the associated morbidity.

Executive Functions, Pragmatic Skills, and Mental Health in Children With Congenital Cytomegalovirus (CMV) Infection With Cochlear Implants: A Pilot Study

Congenital cytomegalovirus (cCMV) infection is the most common cause of progressive hearing impairment. In our previous study around 90% of children with a cCMV infection and CI had severely damaged balance functions (Karltorp et al., 2014). Around 20% had vision impairment, 15% were diagnosed with Autism-Spectrum-Disorder, and 20% with ADHD. One clinical observation was that children with cCMV infection had problems with executive functioning (EF), while controls with a genetic cause of deafness (Connexin 26 mutations; Cx26) did not have similar difficulties. A follow-up study was therefore initiated with the main objective to examine EF and pragmatic skills in relation to mental health in children with a cCMV infection and to draw a comparison with matched controls with Cx26 mutations (age, sex, hearing, non-verbal cognitive ability, vocabulary, and socioeconomic status level). Ten children with a cCMV infection and CI (4.8–12:9 years) and seven children with CI (4:8–12:8 years) participated in the study, which had a multidisciplinary approach. Executive functioning was assessed both with formal tests targeting working memory and attention, parent and teacher questionnaires, and a systematic observation by a blinded psychologist during one test situation. Pragmatics and mental health were investigated with parent and teacher reports. In addition, the early language outcome was considered in non-parametric correlation analyses examining the possible relationships between later EF skills, pragmatics, and mental health. Children with cCMV had a statistically significant worse pragmatic outcome and phonological working memory than controls despite their groups having similar non-verbal cognitive ability and vocabulary. However, there were no statistical differences between the groups regarding their EF skills in everyday settings and mental health. There were associations between early language outcomes and later EF skills and pragmatics in the whole sample.

Conclusion: Children with a cCMV infection are at risk of developing learning difficulties in school due to difficulties with phonological working memory and pragmatic skills in social interactions.

Blood Viral Load in Symptomatic Congenital Cytomegalovirus Infection

BACKGROUND

Viral loads (VLs) frequently are followed during treatment of symptomatic congenital cytomegalovirus disease, but their predictive value is unclear.

METHODS

Post hoc analysis of 2 antiviral studies was performed. Seventy-three subjects were treated for 6 weeks and 47 subjects were treated for 6 months. Whole blood VL was determined by real-time polymerase chain reaction before and during therapy.

RESULTS

Higher baseline VL was associated with central nervous system involvement (3.82 log, range 1-5.65 vs 3.32 log, range 1-5.36; P = .001), thrombocytopenia (3.68 log, range 1-5.65 vs 3.43 log, range 1-5.36; P = .03), and transaminitis at presentation (3.73 log, range 1-5.60 vs 3.39 log, range 1-5.65; P = .009), but with overlap in the amount of virus detected between groups. In subjects treated for 6 months, lower VL at presentation correlated with better hearing outcomes at 12 months, but VL breakpoints predictive of hearing loss were not identified. Sustained viral suppression during 6 months of therapy correlated with better hearing outcomes at 6, 12, and 24 months (P = .01, P = .0007, P = .04), but a majority without viral suppression still had improved hearing.

CONCLUSIONS

In infants with symptomatic congenital cytomegalovirus disease, higher whole blood VL before initiation of antiviral therapy has no clinically meaningful predictive value for long-term outcomes.

The Natural History of Hearing Disorders in Asymptomatic Congenital Cytomegalovirus Infection

Background and Aim: Cytomegalovirus (CMV) is the main cause of congenital infection in developed countries leading to deafness but the burden of sensorineural hearing loss (SNHL) in asymptomatic children remains incompletely characterized. Aim of this study was to evaluate the long-term audiological outcome in this group of patients. Methods: Consecutive neonates with congenital CMV infection were followed from 2002 to 2018. Patients were considered asymptomatic if free from any clinical and instrumental impairment at referral and underwent serial clinical exams, audiological evaluations and CMV-PCR determinations. Results: A cohort of 258 children was analyzed and the disease onset was asymptomatic in 125 (48%) infants. Among these, we studied 102 patients with a follow-up longer than 1 year and a median observation period of 2.8 years (range: 1-10.3 years). No patient developed a stable delayed SNHL but only 14 (14%) presented a variable hearing impairment, seven of which bilateral. The unstable SNHL was mild in 12 infants and moderate in two. Patients with fluctuating SNHL had significantly higher urine viral load (p 0.002) and more often positive viremia (p 0.015) than babies with stable normal hearing. Conclusions: CMV infected, asymptomatic neonates have a low risk of transient SNHL later in infancy. Positive viremia and high urine viral load at onset are significant risk factors for delayed fluctuating SNHL. These data are relevant for an appropriate follow up plan of these patients.

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.

Blood viral load in the diagnostic workup of congenital cytomegalovirus infection

BACKGROUND

There is limited data on the role of cytomegalovirus (CMV) blood quantitative polymerase chain reaction (qPCR) in the diagnostic workup of congenital CMV (cCMV) infection.

OBJECTIVES

The objective of this study was to determine if CMV blood qPCR at the time diagnosis could differentiate between symptomatic and asymptomatic infants according to the recent consensus classification.

STUDY DESIGN

Retrospective study of children diagnosed with cCMV infection at CHU Sainte-Justine, Montreal, Canada, between 2008 and 2016. Cases for whom qPCR was done at baseline (<4 weeks of age) alongside a complete diagnostic workup were included. The association between CMV blood viral load (VL) and clinical severity group was determined. The probability of having moderate to severe symptoms was assessed using univariate logistic regression analysis.

RESULTS

Forty-seven patients were included in the analysis. Median VL was significantly higher among infants with moderate to severely symptomatic disease vs. those asymptomatic or asymptomatic with isolated sensorineural hearing loss (SNHL) (13 736 vs. 1876 copies/ml, p = 0.004), infants with moderate to severe disease or asymptomatic with isolated SNHL vs. asymptomatic (17 736 vs. 1496 copies/ml, p < 0.001), and in infants with baseline neurological involvement vs. those without (17 317 vs. 2641 copies/ml, p = 0.03). Using logistic regression, an infant would have a >75 % probability of being moderate to severely symptomatic above 18 770 copies/ml, with a threshold of 100 000 copies/ml approaching a 100 % probability.

CONCLUSIONS

Our baseline assessment of CMV blood VL suggests that that the level of CMV viremia correlates with symptom severity.

The Natural History and Rehabilitative Outcomes of Hearing Loss in Congenital Cytomegalovirus: A Systematic Review

OBJECTIVE

The purpose of this study was to examine the literature regarding the natural history and rehabilitative outcomes of sensorineural hearing loss from congenital cytomegalovirus infections.

DATA SOURCES AND STUDY ELIGIBILITY CRITERIA

A systematic search was performed in PubMed, PsychINFO, CINAHL, and Web of Science to identify peer-reviewed research. Eligible studies were those containing original peer-reviewed research in English addressing either the natural history or rehabilitative outcomes of sensorineural hearing loss (SNHL) in congenital cytomegalovirus (cCMV).

STUDY APPRAISAL AND SYNTHESIS METHODS

Two investigators independently reviewed all articles and extracted data. Bias was assessed using the Cochrane Collaboration's tool and the Newcastle-Ottawa Assessment Scale.

RESULTS

Thirty-six articles were reviewed. Universal screening identifies 0.2 to 1% of newborns with cCMV infection. SNHL ranged from 8 to 32% of infants and was more prevalent in symptomatic versus asymptomatic cases. Nine to 68% of hearing loss occurs in a late or delayed fashion. In 7 to 71% of cases hearing loss is progressive. Cochlear implantation (CI) is a viable option for patients with cCMV associated hearing loss and leads to improvements in hearing and language. There is limited literature comparing rehabilitation outcomes in cCMV and non-cCMV CI recipients.

CONCLUSION

Late onset and progressive hearing loss is seen in children who develop hearing loss from cCMV. Frequent audiologic follow-up is necessary considering the natural history of cCMV hearing loss. Universal screening should be pursued due to the number of asymptomatic children, at birth, who develop late onset/delayed hearing loss. CI is an effective means of improving speech and language in this population.

Neutralizing Monoclonal Antibodies Reduce Human Cytomegalovirus Infection and Spread in Developing Placentas

Congenital human cytomegalovirus (HCMV) infection is a leading cause of birth defects worldwide, yet the most effective strategies for preventing virus transmission during pregnancy are unknown. We measured the efficacy of human monoclonal antibodies (mAbs) to HCMV attachment/entry factors glycoprotein B (gB) and the pentameric complex, gH/gL-pUL128–131, in preventing infection and spread of a clinical strain in primary placental cells and explants of developing anchoring villi. A total of 109 explants from five first-trimester placentas were cultured, and infection was analyzed in over 400 cell columns containing ~120,000 cytotrophoblasts (CTBs). mAbs to gB and gH/gL, 3-25 and 3-16, respectively, neutralized infection in stromal fibroblasts and trophoblast progenitor cells. mAbs to pUL128-131 of the pentameric complex, 1-103 and 2-18, neutralized infection of amniotic epithelial cells better than mAbs 3-25 and 3-16 and hyperimmune globulin. Select mAbs neutralized infection of cell column CTBs, with mAb 2-18 most effective, followed by mAb 3-25. Treatment of anchoring villi with mAbs postinfection reduced spread in CTBs and impaired formation of virion assembly compartments, with mAb 2-18 achieving better suppression at lower concentrations. These results predict that antibodies generated by HCMV vaccines or used for passive immunization have the potential to reduce transplacental transmission and congenital disease.

Is Polymerase Chain Reaction in Neonatal Dried Blood Spots Reliable for the Diagnosis of Congenital Cytomegalovirus Infection?

BACKGROUND

Detection of cytomegalovirus (CMV) DNA by real-time polymerase chain reaction (rt-PCR) in dried blood spots (DBSs) collected for newborn screening has been assessed for retrospective diagnosis of congenital CMV (cCMV) infection, with variable results (sensitivities ranging from 34% to 100%). We aimed to assess the accuracy of this technique in Spain in a large patient series.

METHODS

Ambispective, multicenter study including patients with confirmed cCMV from the Spanish Registry of cCMV patients. cCMV was established on the presence of CMV DNA in any body fluid, by positive culture findings or by molecular techniques during the first 2 weeks of life. Children in whom cCMV had been excluded were used as negative controls. Neonatal DBS samples were collected from both groups. The presence of CMV DNA was assessed by rt-PCR (RealStar CMV, Altona, Germany) in a central laboratory.

RESULTS

One-hundred three patients and 81 controls from 10 hospitals were included. The performance of CMV DNA determination in DBS for the diagnosis of cCMV was as follows (95% confidence interval): sensitivity 0.56 (0.47-0.65), specificity 0.98 (0.91-0.99), positive likelihood ratio 22.81 (5.74-90.58) and negative likelihood ratio 0.45 (0.36-0.56). Sensitivity increased with the birth viral load (bVL) log category. In cCMV patients, lower bVL was the single variable associated with a negative DBS rt-PCR result (P = 0.017).

CONCLUSIONS

The sensitivity of CMV rt-PCR in DBS in our series was low and correlated with the bVL. Thus, a negative DBS result would not rule out cCMV infection, especially in patients with a low viremia level at birth.

Human Vascular Pericytes and Cytomegalovirus Pathobiology

Pericytes are multipotent cells of the vascular system with cytoplasmic extensions proximal to endothelial cells that occur along the abluminal surface of the endothelium. The interactions between endothelial cells and pericytes are essential for proper microvascular formation, development, stabilization, and maintenance. Pericytes are essential for the regulation of paracellular flow between cells, transendothelial fluid transport, angiogenesis, and vascular immunosurveillance. They also influence the chemical composition of the surrounding microenvironment to protect endothelial cells from potential harm. Dysregulation or loss of pericyte function can result in microvascular instability and pathological consequences. Human pericytes have been shown to be targets for human cytomegalovirus (HCMV) infection and lytic replication that likely contribute to vascular inflammation. This review focuses on human vascular pericytes and their permissiveness for HCMV infection. It also discusses their implication in pathogenesis in the blood⁻brain barrier (BBB), the inner blood⁻retinal barrier (IBRB), the placenta⁻blood barrier, and the renal glomerulus as well as their potential role in subclinical vascular disease.

Evaluation of rapid and sensitive DNA extraction methods for detection of cytomegalovirus in dried blood spots

BACKGROUND

Dried blood spots (DBS), collected universally from newborns in the U.S., could be used as a matrix for the detection of cytomegalovirus (CMV) infection in infants. However, sensitivity to detect CMV in DBS as compared to saliva and urine is variable across studies largely due to the DNA extraction method. Thermal shock, a widely used DNA extraction method, is highly sensitive for the detection of CMV in DBS, however, the processing time required is not practical for high-throughput testing.

OBJECTIVE

To determine if rapid and cost-effective DNA extraction methods amenable to newborn screening (NBS) could achieve the same sensitivity as the thermal shock method.

STUDY DESIGN

DBS were prepared from CMV positive blood samples from 20 organ transplant recipients. Three DNA extraction methods were compared for relative yield and sensitivity of detection of CMV DNA: thermal shock, KOH Tris buffer, and DNA Extract All. CMV DNA was detected by real-time quantitative polymerase chain reaction (qPCR).

RESULTS

The KOH Tris and DNA Extract All methods gave higher yields and sensitivity of CMV detection in DBS than thermal shock, which were significantly greater when viral loads were ≤ 10,000 copies/ml blood. Both methods gave faster turnaround times than thermal shock and would be better suited for NBS.

CONCLUSIONS

The choice of DNA extraction method greatly influences the ability to detect low levels of CMV DNA in DBS. Moreover, development of highly sensitive yet rapid methods for CMV detection could help facilitate future newborn screening of CMV in DBS.

Aortic Arch Thrombosis Associated with Fetal Cytomegalovirus Viremia

Cytomegalovirus(CMV) associated thrombosis has been reported sporadically in the medical literature; however, its antenatal scenario has not been documented. We herein present the antenatal, Doppler's ultrasound and magnetic resonance angiographic features of thrombosis in the aortic arch showing extension toward the medial lumen of the brachiocephalic trunk with critical occlusion of the left common carotid artery and left subclavian artery in a term fetus to raise obstetricians'/ neonatologists'/pediatric cardiologists' awareness for the association between CMV viremia and intrauterine thrombosis that caused cerebral injury, neurodevelopmental impairment, and permanent sequela.

Congenital cytomegalovirus infection inducing non-congenital sensorineural hearing loss during childhood; a systematic review

BACKGROUND

Congenital cytomegalovirus (CMV) infection is one of the most important risk factors for delayed onset and progressive hearing loss in children. However, the relevant literature is limited, heterogeneous and currently insufficient to provide guidance toward the effective monitoring of hearing acuity in these children.

OBJECTIVES

The aim of this study was to provide a systematic review focused on types of hearing loss that may escape diagnosis through universal neonatal hearing screening and/or present significant changes during childhood, such as progressive, fluctuating and late-onset hearing loss.

DATA SOURCES

A review of the present literature was conducted via the PubMed database of the US National Library of Medicine (www.pubmed.org) and Scopus database (www.scopus.com) with the search terms "late-onset hearing loss cytomegalovirus", "progressive hearing loss cytomegalovirus" and "fluctuating hearing loss cytomegalovirus".

STUDY ELIGIBILITY CRITERIA

Prospective or retrospective clinical studies were included if they presented a detailed audiological assessment, for a follow-up period of >2years.

METHODS

The prevalence and time of diagnosis of progressive, fluctuating and late-onset hearing loss were considered as primary outcomes. Results were recorded separately for symptomatic and asymptomatic children, when possible.

RESULTS

This analysis refers to a population of 181 children with CMV-induced hearing loss, who were diagnosed among 1089 with congenital CMV infection. The prevalence of CMV-induced hearing loss was significantly higher among symptomatic children (p < 0.0001), who were also significantly more likely to develop bilateral hearing loss (p = 0.001). There was not sufficient information on the prevalence, laterality, degree and time of diagnosis of progressive, fluctuating and late-onset hearing loss that could constitute the basis toward the report of specific follow-up guidelines.

CONCLUSIONS

Further studies are needed in order to understand and quantify the potential effects of congenital CMV infection in the inner ear and hearing acuity. The results presented in the relative studies should be very carefully evaluated and compared to each other, since they correspond to substantially different cohorts, study designs, and result elaboration. Infants with congenital CMV infection should be closely monitored, regarding their hearing acuity at least during their preschool years, although substantial changes in hearing thresholds have been reported as late as the 16th year of age. Parental counseling is of outmost importance in order to minimize the numbers of children lost to follow-up.

CMV on surfaces in homes with young children: results of PCR and viral culture testing

Background

Caring for young children is a known risk factor for cytomegalovirus (CMV) infection mainly through exposure to their saliva and urine. In a previous study, 36 CMV-seropositive children 2 mo. to 4 years old were categorized as CMV shedders (n = 23) or non-shedders (n = 13) based on detection of CMV DNA in their saliva and urine. The current study evaluated the presence of CMV on surfaces in homes of the children.

Methods

Study staff made 4 visits to homes of the 36 enrolled children over 100 days. Saliva was collected by swabbing the mouth and urine was collected on filter paper inserted into diapers. In addition, five surface specimens were collected: three in contact with children’s saliva (spoon, child’s cheek, washcloth) and two in contact with children’s urine (diaper changing table, mother’s hand). Samples were tested by PCR and viral culture to quantify the presence of CMV DNA and viable virus.

Results

A total of 654 surface samples from 36 homes were tested; 136 were CMV DNA positive, 122 of which (90%) were in homes of the children shedding CMV (p < 0.001). Saliva–associated samples were more often CMV positive with higher viral loads than urine-associated samples. The higher the CMV viral load of the child in the home, the more home surfaces that were PCR positive (p = 0.01) and viral culture positive (p = 0.05).

Conclusions

The main source for CMV on surfaces in homes was saliva from the child in the home. Higher CMV viral loads shed by children correlated with more viable virus on surfaces which could potentially contribute to viral transmission.

Concurrent Hearing, Genetic, and Cytomegalovirus Screening in Newborns, Taiwan

OBJECTIVE

To evaluate the feasibility and potential benefits of incorporating genetic and cytomegalovirus (CMV) screenings into the current newborn hearing screening (NHS) programs.

STUDY DESIGN

Newborns were recruited prospectively from a tertiary hospital and a maternity clinic between May 2016 and December 2016 and were subjected to hearing screening, CMV screening, and genetic screening for 4 common mutations in deafness genes (p.V37I and c.235delC of GJB2 gene, c.919-2A>G of SLC26A4 gene, and the mitochondrial m.1555A>G). Infants with homozygous nuclear mutations or homoplasmic/heteroplasmic mitochondrial mutation (referred to as "conclusively positive genotypes") and those who tested positive for CMV received diagnostic audiologic evaluations.

RESULTS

Of the total 1716 newborns enrolled, we identified 20 (1.2%) newborns with conclusively positive genotypes on genetic screening, comprising 15 newborns (0.9%) with GJB2 p.V37I/p.V37I and 5 newborns (0.3%) with m.1555A>G. Three (0.2%) newborns tested positive on CMV screening. Twelve of the 20 newborns (60%) with conclusively positive genotypes and all 3 newborns who tested positive for CMV (100%) passed NHS at birth. Diagnostic audiologic evaluations conducted at 3 months confirmed hearing impairment in 6 of the 20 infants (30%) with conclusively positive genotypes.

CONCLUSIONS

This study confirms the feasibility of performing hearing, genetic, and CMV screenings concurrently in newborns and provides evidence that the incorporation of these screening tests could potentially identify an additional subgroup of infants with impaired hearing that might not be detected by the NHS programs.

Expression Levels of Glycoprotein O (gO) Vary between Strains of Human Cytomegalovirus, Influencing the Assembly of gH/gL Complexes and Virion Infectivity

The tropism of human cytomegalovirus (HCMV) is influenced by the envelope glycoprotein complexes gH/gL/gO and gH/gL/UL128-131. During virion assembly, gO and the UL128-131 proteins compete for binding to gH/gL in the endoplasmic reticulum (ER). This assembly process clearly differs among strains, since Merlin (ME) virions contain abundant gH/gL/UL128-131 and little gH/gL/gO, whereas TR contains much higher levels of total gH/gL, mostly in the form of gH/gL/gO, but much lower levels of gH/gL/UL128-131 than ME. Remaining questions include (i) what are the mechanisms behind these assembly differences, and (ii) do differences reflect in vitro culture adaptations or natural genetic variations? Since the UL74(gO) open reading frame (ORF) differs in 25% of amino acids between TR and ME, we analyzed recombinant viruses in which the UL74(gO) ORF was swapped. TR virions were >40-fold more infectious than ME. Transcriptional repression of UL128-131 enhanced the infectivity of ME to the level of TR, despite still far lower levels of gH/gL/gO. Swapping the UL74(gO) ORF had no effect on either TR or ME. A quantitative immunoprecipitation approach revealed that gH/gL expression levels were within 4-fold between TR and ME, but the gO expression level was 20-fold lower for ME, which suggested differences in mRNA transcription, translation, or rapid ER-associated degradation of gO. trans-Complementation of gO expression during ME replication gave a 6-fold enhancement of infectivity beyond the 40-fold effect of UL128-131 repression alone. Overall, strain variations in the assembly of gH/gL complexes result from differences in the expression of gO and UL128-131, and selective advantages for reduced UL128-131 expression during fibroblast propagation are much stronger than those for higher gO expression.IMPORTANCE Specific genetic differences between independently isolated HCMV strains may result from purifying selection on de novo mutations arising during propagation in culture or random sampling among the diversity of genotypes present in clinical specimens. Results presented indicate that while reduced UL128-131 expression may confer a powerful selective advantage during cell-free propagation of HCMV in fibroblast cultures, selective pressures for increased gO expression are much weaker. Thus, variation in gO expression among independent strains may represent natural genotype variability present in vivo This may have important implications for virus-host interactions, such as immune recognition, and underscores the value of studying molecular mechanisms of replication using multiple HCMV strains.

Pilot Study of Model-Based Dosage Individualization of Ganciclovir in Neonates and Young Infants with Congenital Cytomegalovirus Infection

Newborns with congenital cytomegalovirus (CMV) infection are at high risk for developing permanent sequelae. Intravenous ganciclovir therapy is frequently used for the treatment of congenital CMV infection. A target area under the concentration-time curve from 0 to 24 h (AUC_0-24) of 40 to 50 μg · h/ml is recommended. The standard dose has resulted in a large variability in ganciclovir exposure in newborns, indicating the unmet need of dosage individualization for this vulnerable population, but the implementation of this strategy remains challenging in clinical practice. We aim to evaluate the clinical utility of model-based dosage individualization of ganciclovir in newborns using an opportunistic sampling approach. The predictive performance of a published ganciclovir population pharmacokinetic model was evaluated using an independent patient cohort. The individual dose was adjusted based on the target AUC_0-24 to ensure its efficacy. A total of 26 newborns with congenital CMV infection were included in the present study. Only 11 (42.3%) patients achieved the target AUC_0-24 after being given the standard dose. For all the subtherapeutic patients (achieving <80% of the target AUC) (n = 5), a model-based dosage adjustment was performed using the Bayesian estimation method combined with the opportunistic sampling strategy. The adjusted doses were increased by 28.6% to 60.0% in these five patients, and all adapted AUC_0-24 values achieved the target (range, 48.6 to 66.1 μg · h/ml). The clinical utility of model-based dosing individualization of ganciclovir was demonstrated in newborns with congenital CMV infection. The population pharmacokinetic model combined with the opportunistic sampling strategy provides a clinically feasible method to adapt the ganciclovir dose in neonatal clinical practice. (This study has been registered at ClinicalTrials.gov under registration no. NCT03113344.).

Evaluation of cellulose pads as a method to detect cytomegalovirus DNA in neonatal urine

Background Several approaches exist to screen neonates for congenital cytomegalovirus infection. We here describe a new method using cellulose pads for urine collection and its evaluation in an experimental and a clinical setting. Methods We systematically tested the effect of storage duration of the pads after exposure to cytomegalovirus-positive urine, meconium contamination and specimen handling on the cytomegalovirus load and the detection rate. Further, the method was tested in clinical practice in a cohort of 500 neonates. Results Following exposure of urine pads with cytomegalovirus-positive urine, the viral load decreased after 15 min, 12 h, 24 h, and 7 days to 63.2%, 42.1%, 31.6%, and 9.3% of the baseline value. Cytomegalovirus detection rate after seven days was 100%. Contamination with meconium resulted in a comparable reduction of the viral load. The detection rate for dried urine pads after seven days was 93.3%. In clinical practice, urine collection from pads was successful in 73.6% by the first attempt and in 26.4% by the second attempt. Conclusions Urine collection using cellulose pads seems feasible regardless of a reduction of the cytomegalovirus load due to exposure to the pad itself or to meconium. Drying of the exposed urine pad should be avoided.