Long-term outcomes of congenital cytomegalovirus infection in Sweden and the United Kingdom

Antibody-mediated control mechanisms of viral infections

Antibodies generated after vaccination or natural pathogen exposure are essential mediators of protection against many infections. Most studies with viruses have focused on antibody neutralization, in which protection is conferred by the fragment antigen binding region (Fab) through targeting of different steps in the viral lifecycle including attachment, internalization, fusion, and egress. Beyond neutralization, the fragment crystallizable (Fc) region of antibodies can integrate innate and adaptive immune responses by engaging complement components and distinct Fc gamma receptors (FcγR) on different host immune cells. In this review, we discuss recent advances in our understanding of antibody neutralization and Fc effector functions, and the assays used to measure them. Additionally, we describe the contexts in which these mechanisms are associated with protection against viruses and highlight how Fc-FcγR interactions can improve the potency of antibody-based therapies.

What are the neurodevelopmental outcomes of children with asymptomatic congenital cytomegalovirus infection at birth? A systematic literature review

Congenital cytomegalovirus (cCMV) is among the most common congenital infections globally. Of 85%-90% cCMV-infected infants without symptoms at birth, 10%-15% develop sequelae, most commonly sensorineural hearing loss (SNHL); their childhood neurodevelopmental outcomes are less well understood. Embase and MEDLINE were searched for publications from 16th September 2016 to 9th February 2024 to identify studies reporting primary data on neurodevelopmental outcomes in children with asymptomatic cCMV (AcCMV), measured using assessment tools or as evaluated by the study investigators, clinicians, educators, or parents. The Newcastle-Ottawa scale was applied to studies to assess risk of bias. Of 28 studies from 18 mostly high-income countries, there were 5-109 children with AcCMV per study and 6/28 had a mean or median age at last follow-up of ≥5 years. Children with AcCMV had better neurodevelopmental outcomes than children with symptomatic cCMV in 16/19 studies. Of 9/28 studies comparing AcCMV with CMV-uninfected children, six reported similar outcomes whilst three reported differences limited to measures of full-scale intelligence and receptive vocabulary among children with AcCMV and SNHL, or more generally in motor impairment. Common limitations of studies for our question were a lack of cCMV-uninfected controls, heterogeneous definitions of AcCMV, lack of focus on neurodevelopment, selection bias and inadequate follow-up. There was little evidence of children with AcCMV having worse neurodevelopmental outcomes than CMV-uninfected children, but this conclusion is limited by study characteristics and quality; findings highlight the need for well-designed and standardised approaches to investigate long-term sequelae.

Congenital Cytomegalovirus-Related Hearing Loss

Congenital hearing loss is a significant global health concern that affects millions of newborns and infants worldwide, posing substantial challenges for affected individuals, their families, and healthcare systems. This condition, present at birth, can stem from genetic factors, in utero exposures, infections, or complications during pregnancy or childbirth. The spectrum of congenital hearing loss ranges from mild to profound, impacting the development of speech, language, and cognitive skills, thereby influencing educational achievements, social integration, and future employment opportunities. Early detection and intervention strategies, such as newborn hearing screenings, genetic counseling, and the use of hearing aids or cochlear implants, are crucial for mitigating these impacts. This review article aims to explore the diagnostic approaches and management strategies for congenital cytomegalovirus-related hearing loss, emphasizing the importance of interdisciplinary care and the potential for technological advances to improve outcomes for affected individuals.

Association between cytomegalovirus infection and neurological disorders: A systematic review

Cytomegalovirus (CMV) belongs to the Herpesviridae family and is also known as human herpesvirus type 5. It is a common virus that usually doesn't cause any symptoms in healthy individuals. However, once infected, the virus remains in the host's body for life and can reactivate when the host's immune system weakens. This virus has been linked to several neurological disorders, including Alzheimer's disease, Parkinson's disease, Autism spectrum disorder, Huntington's disease (HD), ataxia, Bell's palsy (BP), and brain tumours, which can cause a wide range of symptoms and challenges for those affected. CMV may influence inflammation, contribute to brain tissue damage, and elevate the risk of moderate-to-severe dementia. Multiple studies suggest a potential association between CMV and ataxia in various conditions, including Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, acute cerebellitis, etc. On the other hand, the evidence regarding CMV involvement in BP is conflicting, and also early indications of a link between CMV and HD were challenged by subsequent research disproving CMV's presence. This systematic review aims to comprehensively investigate any link between the pathogenesis of CMV and its potential role in neurological disorders and follows the preferred reporting items for systematic review and meta-analysis checklist. Despite significant research into the potential links between CMV infection and various neurological disorders, the direct cause-effect relationship is not fully understood and several gaps in knowledge persist. Therefore, continued research is necessary to gain a better understanding of the role of CMV in neurological disorders and potential treatment avenues.

Contribution of fetal blood sampling to determining the prognosis of congenital cytomegalovirus infections: a case-cohort study in Switzerland

BACKGROUND

Cytomegalovirus is responsible for the most common congenital infection, affecting 0.5% to 1.0% of live births in Europe. Congenital cytomegalovirus infection can be diagnosed during pregnancy by viral DNA amplification in the amniotic fluid, but the prognosis of fetuses without severe brain abnormalities remains difficult to establish on the basis of prenatal imaging alone.

OBJECTIVE

To identify predictors of moderate to severe symptomatic cytomegalovirus infection among fetal blood parameters and to propose an algorithm on the basis of these parameters and on prenatal imaging that would provide the best positive and negative predictive values.

STUDY DESIGN

Fetal blood sampling at 21-28 weeks gestation was performed in fetuses with congenital cytomegalovirus infection confirmed by amniocentesis after maternal infection in the first-trimester or periconceptional period. We compared the levels of hemoglobin, thrombocytes, γ-glutamyl transpeptidase, aspartate aminotransferase, alanine aminotransferase, β2-microglobulin, immunoglobulins G and M, and cytomegalovirus DNA viral loads in amniotic fluid and fetal blood between those with moderate to severe symptomatic infection and those with asymptomatic to mild infection (median follow-up of 36 months for live births).

RESULTS

Among 58 fetuses included, 25 (43%) had a moderate to severe symptomatic infection: 16 with severe cerebral abnormalities, 5 with multiple signs or symptoms at birth, 2 with bilateral sensorineural hearing loss, and 2 with neurodevelopmental delay. The values of thrombocytes, aspartate aminotransferase, β2 microglobulin, Immunoglobulin M, and cytomegalovirus viral loads differed significantly between fetuses with moderate to severe symptomatic infection and those with asymptomatic to mild infection. The optimal strategy to predict moderate to severe symptomatic infection was to first perform fetal brain imaging, followed by fetal blood sampling with the following cutoffs: thrombocytes <120,000/mL, viremia ≥5 log10/mL, and β2 microglobulin ≥12 mg/L). This recursive algorithm had a negative predictive value of 100% for moderately to severely symptomatic infection.

CONCLUSION

The combination of thrombocytes, β2-microglobulin, and cytomegalovirus viral load in fetal blood can be used for prognosis determination, particularly in cytomegalovirus-infected fetuses without severe brain abnormalities at the time of prenatal diagnosis. Future studies should evaluate whether these parameters remain useful in infected fetuses who have been treated with valacyclovir before fetal blood sampling.

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).

Short- and long-term neurological outcomes of congenital cytomegalovirus infection

Background/aim

Cytomegalovirus (CMV) is the most common congenital viral infection. Although most children with congenital CMV (approximately 85%-90%) are asymptomatic at birth, findings such as sensorineural hearing loss, microcephaly, and neurodevelopmental retardation can be observed during the follow-up. Among the brain magnetic resonance imaging (MRI) findings of CMV are white matter abnormalities, polymicrogyria, and periventricular calcification. Since a definitive diagnosis of congenital CMV cannot be made after the neonatal period, the identification of the associated phenotype is diagnostically important, but data are limited in patients who have been retrospectively diagnosed with congenital CMV infection. The aim of this study was to evaluate the short- and long-term neurological follow-up results of congenital CMV infections in a tertiary hospital.

Materials and methods

The neurological results of fifteen patients under the age of 18 years, who had a definitive diagnosis of congenital CMV infection and were followed up in a tertiary care hospital between 2011 and 2020, were retrospectively evaluated.

Results

Ten of the patients in our study group were male. The mean age at presentation for neurological evaluation was 2.02 ± 1.54 months, with a median follow-up time of 36.3 months (range: 9.3-129.4 months). Neurological disorders detected during the long-term follow-up included cerebral palsy (46.7%), cognitive impairment (46.7%), epilepsy (40%), and sensorineural hearing loss (26.7%). The most common abnormality observed on MRI scans was white matter involvement (53.3%).

Conclusion

Early diagnosis and intervention are crucial in congenital CMV infection, as it commonly results in neurological involvement among the patients in our series. This preventable condition warrants further research regarding prenatal/neonatal screening.

Estimates of congenital cytomegalovirus-attributable infant mortality in high-income countries: A review

As many as 5%-10% of infants with symptomatic congenital cytomegalovirus (cCMV) disease, or 0.4%-0.8% of all liveborn infants with cCMV infection, die in early infancy in high-income countries. However, estimates are uncertain due to several potential biases that can result from data limitations and study designs. First, infants with cCMV infections who die prior to diagnosis, which usually occurs at 1-4 weeks after birth, may be excluded from both the count of deaths and the denominator of cCMV births, resulting in left truncation and immortal time biases. These 'biases' are features of the data and do not reflect bias on the part of researchers, but understanding the potential existence of threats to validity can help with interpretation of findings. Left truncation of infant deaths occurring prior to diagnosis of cCMV can result in understatement of the burden of infant deaths due to cCMV. Conversely, overestimation of infant deaths associated with symptomatic cCMV may occur in clinical case series owing to greater representation of relatively severely affected infants owing to ascertainment and referral biases. In this review, we summarise the characteristics of 26 studies that reported estimates of cCMV-associated infant deaths, including potential biases or limitations to which those estimates may have been subject. We discuss study designs whose implementation might generate improved estimates of infant deaths attributable to cCMV. More complete estimates of the overall public health impact of cCMV could inform current and future screening, prevention, and vaccine research.

Neurodevelopmental outcomes of children with congenital cytomegalovirus: a systematic scoping review

BACKGROUND

With the emergence of newborn congenital cytomegalovirus (cCMV) screening programs, more infants are being diagnosed and require long-term follow-up. The objective of the study was to summarize the literature to date on neurodevelopmental outcomes in children with cCMV with attention to study-specific definitions of disease severity (symptomatic vs. asymptomatic).

METHODS

This systematic scoping review included studies of children with cCMV (≤18 years-old) measuring neurodevelopment in ≥1 domain: global, gross motor, fine motor, speech/language, and intellectual/cognitive. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed, PsychInfo, and Embase databases were searched.

RESULTS

33 studies met inclusion criteria. Global development most frequently measured (n = 21), followed by cognitive/intellectual (n = 16) and speech/language (n = 8). Most (31/33) studies differentiated children by cCMV severity (symptomatic vs. asymptomatic), definitions of which ranged broadly. 15/21 studies described global development categorically (e.g., normal vs. abnormal). Across studies and domains, children with cCMV generally had equivalent or lower scores (vs. controls or normed measures).

CONCLUSIONS

Variation in definitions of cCMV severity and blunt categorical outcomes may limit the generalizability of findings. Future studies should utilize standardized definitions of disease severity and in-depth measurement and reporting of neurodevelopmental outcomes in children with cCMV.

IMPACT

Neurodevelopmental delays are common among children with cCMV, although gaps in the literature to have made quantification of such delays challenging. Variation in definitions of asymptomatic and symptomatic cCMV as well as the use of categorical outcomes of neurodevelopment (e.g., normal vs. abnormal) limits the generalizability and clinical utility of findings.

Human cytomegalovirus induces significant structural and functional changes in terminally differentiated human cortical neurons

IMPORTANCE

Human cytomegalovirus (HCMV) is a highly prevalent viral pathogen that can cause serious neurological deficits in infants experiencing an in utero infection. Also, as a life-long infection, HCMV has been associated with several diseases in the adult brain. HCMV is known to infect early neural progenitor cells, but whether it also infects terminally differentiated neurons is still debated. Here, we differentiated human-induced pluripotent stem cells into neurons for 84-120 days to test the ability of HCMV to infect terminally differentiated neurons and assess the downstream functional consequences. We discovered that mature human neurons are highly permissive to HCMV infection, exhibited late replication hallmarks, and produced infectious virus. Moreover, infection in terminally differentiated neurons essentially eliminated neuron function. These results demonstrate that terminally differentiated human neurons are permissive to HCMV infection, which can significantly alter both structural and functional features of this mature neuron population.

Burden of sequelae and healthcare resource utilization in the first year of life in infants born with congenital cytomegalovirus (cCMV) infection in Germany: A retrospective statutory health insurance claims database analysis

BACKGROUND

Congenital cytomegalovirus (cCMV) infection can have a broad range of manifestations. This study aimed to assess cCMV-associated sequelae and healthcare resource utilization (HCRU) in infants during the first year of life in Germany.

METHODS

A retrospective, controlled cohort study using German claims data from the Institute for Applied Health Research Berlin (InGef) database was conducted. cCMV-associated sequelae and HCRU during the first year of life were assessed by matching (1:60) infants with at least one inpatient/outpatient cCMV diagnosis (ICD-10-GM: P35.1) ≤90 days after birth (cCMV90 cohort) and infants with at least one inpatient cCMV diagnosis plus specific sequelae ≤21 days after birth (cCMV21-S) to infants without cCMV or CMV (ICD-10-GM: B25) diagnosis (control group), respectively. Outcomes were analyzed during the first 365 days of life.

RESULTS

Between 2014-2018, we identified 54 newborns for cCMV90 and 24 newborns for cCMV21-S cohort. Compared to the 3,240 and 1,440 controls, respectively, more cCMV90 infants (83.3% vs. 41.9%, p<0.01) presented with at least one sequela during the first year of life, including intrauterine growth retardation (42.6% vs. 5.3%, p<0.01), sensorineural hearing loss (SNHL) to deafness (38.9% vs. 2.2%, p<0.01), and motor development disorders (33.3% vs. 10.9%, p<0.01). Further, 13.0% of cCMV90 infants (vs. 2.3%, p<0.01) suffered from visual impairment. In cCMV21-S cohort, intrauterine growth retardation (79.2% vs. 6.0%, p<0.01), prematurity (54.2% vs. 7.3%, p<0.01), and motor development disorders (50.0% vs. 11.0%, p<0.01) were the most frequent sequelae. Infants in the cCMV90 and cCMV21-S cohort had, on average, 7.3 times and 9.5 times more hospitalizations and 2.0 times and 2.1 times more outpatient physician visits than their respective controls (p<0.01). Hospitalized infants with cCMV stayed, on average, significantly longer in hospital compared to their controls (cCMV90 cohort: 30.3 days vs. 9.0 days, p<0.01; cCMV21-S cohort: 46.5 days vs. 9.3 days, p<0.01).

CONCLUSIONS

cCMV-infection shows a considerable disease and healthcare burden during the first year of life. More than 80% of the identified newborns with cCMV suffered from at least one associated sequela during the first year of life, including long-term sequelae such as SNHL (40%) and visual impairment (13%). Additional steps for prevention of cCMV infection and associated sequelae as well as a comprehensive monitoring of disease burden are needed.

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.

CMV-induced Hearing Loss

Congenital cytomegalovirus (cCMV) infection is the most common fetal viral infection and contributes to about 25% of childhood hearing loss by the age of 4 years. It is the leading nongenetic cause of sensorineural hearing loss (SNHL). Infants born to seroimmune mothers are not completely protected from SNHL, although the severity of their hearing loss may be milder than that seen in those whose mothers had a primary infection. Both direct cytopathic effects and localized inflammatory responses contribute to the pathogenesis of cytomegalovirus (CMV)-induced hearing loss. Hearing loss may be delayed onset, progressive or fluctuating in nature, and therefore, a significant proportion will be missed by universal newborn hearing screening (NHS) and warrants close monitoring of hearing function at least until 5-6 years of age. A multidisciplinary approach is required for the management of hearing loss. These children may need assistive hearing devices or cochlear implantation depending on the severity of their hearing loss. In addition, early intervention services such as speech or occupational therapy could help better communication, language, and social skill outcomes. Preventive measures to decrease intrauterine CMV transmission that have been evaluated include personal protective measures, passive immunoprophylaxis and valacyclovir treatment during pregnancy in mothers with primary CMV infection. Several vaccine candidates are currently in testing and one candidate vaccine in phase 3 trials. Until a CMV vaccine becomes available, behavioral and educational interventions may be the most effective strategy to prevent maternal CMV infection.

The Multifaceted Clinical Characteristics of Congenital Cytomegalovirus Infection: From Pregnancy to Long-Term Outcomes

BACKGROUND

The aim of this study was to capture multifaceted clinical characteristics of congenital cytomegalovirus (CMV) infection from diagnosis to treatment using a multidisciplinary approach including obstetrics, pediatrics, pathology, and otorhinolaryngology-head and neck surgery.

METHODS

This is a retrospective study including 30 consecutive cases of congenital CMV infection that were diagnosed at a single tertiary hospital located in Seoul, Korea from January 2009 to December 2020. Congenital CMV infection was defined as a positive result by polymerase chain reaction from urine, saliva or cerebrospinal fluid or positive CMV IgM from neonatal blood sampled within 3 weeks after birth. All cases were analyzed with respect to whole clinical characteristics from diagnosis to treatment of congenital CMV by a multidisciplinary approach including prenatal sonographic findings, maternal immune status regarding CMV infection, detailed placental pathology, neonatal clinical manifestation, auditory brainstem response test, and antiviral treatment (ganciclovir or valganciclovir). Long-term outcomes including developmental delay and hearing loss were also investigated.

RESULTS

The total number of births during the study period in our institution was 19,385, with the prevalence of congenital infection estimated to be 0.15%. Among 30 cases of congenital CMV, the median gestational age at delivery was 32.2 weeks [range, 22.6-40.0] and 66.7% of these infants were delivered preterm at less than 37 weeks. Suspected fetal growth restriction was the most common prenatal ultrasound finding (50%) followed by ventriculomegaly (17.9%) and abnormal placenta (17.9%), defined as thick placenta with calcification. No abnormal findings on ultrasound examination were observed in one-third of births. Maternal CMV serology tests were conducted in only 8 cases, and one case each of positive and equivocal IgM were found. The most common placental pathologic findings were chronic villitis (66.7%) and calcification (63.0%), whereas viral inclusions were identified in only 22.2%. The most common neonatal manifestations were jaundice (58.6%) followed by elevation of aspartate aminotransferase (55.2%) and thrombocytopenia (51.7%). After excluding cases for which long-term outcomes were unavailable due to death (n = 4) or subsequent follow up loss (n = 3), developmental delay was confirmed in 43.5% of infants (10/23), and hearing loss was confirmed in 42.9% (9/21) during the follow-up period. In our cohort, 56.7% (17/30) of neonates were treated for congenital CMV with ganciclovir or valganciclovir.

CONCLUSION

Our data show that prenatal findings including maternal serologic tests and ultrasound have limited ability to detect congenital CMV in Korea. Given that CMV is associated with high rates of developmental delay and hearing loss in infants, there is an urgent need to develop specific strategies for the definite diagnosis of congenital CMV infection during the perinatal period by a multidisciplinary approach to decrease the risks of neurologic impairment and hearing loss through early antiviral treatment.

ADCC-activating antibodies correlate with decreased risk of congenital human cytomegalovirus transmission

Human cytomegalovirus (HCMV) is the most common vertically transmitted infection worldwide, yet there are no vaccines or therapeutics to prevent congenital HCMV (cCMV) infection. Emerging evidence indicates that antibody Fc effector functions may be a previously underappreciated component of maternal immunity against HCMV. We recently reported that antibody-dependent cellular phagocytosis (ADCP) and IgG activation of FcγRI/FcγRII were associated with protection against cCMV transmission, leading us to hypothesize that additional Fc-mediated antibody functions may be important. In this same cohort of HCMV-transmitting (n = 41) and nontransmitting (n = 40) mother-infant dyads, we report that higher maternal sera antibody-dependent cellular cytotoxicity (ADCC) activation is also associated with lower risk of cCMV transmission. We investigated the relationship between ADCC and IgG responses against 9 viral antigens and found that ADCC activation correlated most strongly with sera IgG binding to the HCMV immunoevasin protein UL16. Moreover, we determined that higher UL16-specific IgG binding and FcγRIII/CD16 engagement were associated with the greatest risk reduction in cCMV transmission. Our findings indicate that ADCC-activating antibodies against targets such as UL16 may represent an important protective maternal immune response against cCMV infection that can guide future HCMV correlates studies and vaccine or antibody-based therapeutic development.

Neurodevelopmental outcome in children with congenital cytomegalovirus infection: A prospective multicenter cohort study

BACKGROUND

Congenital cytomegalovirus infection (cCMV) is the most common congenital infection worldwide and is a major cause of neurodevelopmental impairment in children. At this point there are insufficient data on neurodevelopmental outcome of children with cCMV, both symptomatic and asymptomatic.

AIM

This study aimed to describe the neurodevelopmental outcome in a large prospective cohort of children with cCMV.

METHODS

All children with cCMV, included in the Flemish cCMV register, were eligible for this study. Data on neurodevelopmental outcome was available in 753 children. Data on neuromotor, cognitive, behavioral, audiological and ophthalmological outcome were analyzed.

RESULTS

Neurodevelopmental outcome was normal in 530/753 (70,4 %) at any age of last follow-up. Mild, moderate and severe neurodevelopmental impairment was found in 128/753 (16,9 %), 56/753 (7,4 %) and 39/753 (5,2 %), respectively. Adverse outcome is found both in the symptomatic and asymptomatic children (53,5 % versus 17,8 %). Autism spectrum disorder (ASD) was diagnosed more often than in the general population in Flanders (2,5 % versus 0,7 %). Speech and language impairment was found in 2 %, even in absence of hearing loss.

CONCLUSION

Both symptomatic and asymptomatic cCMV children are at risk of sequelae, with higher risk in case of first trimester infection. During follow-up of this population, special attention should be given to the audiological follow-up, the presence of hypotonia at young age, the possible higher risk of ASD and the risk of speech and language impairment even in absence of hearing loss. Our results emphasize the need for multidisciplinary neurodevelopmental follow-up of all cCMV infected children.

Metabolic regulation of NK cell antiviral functions during cytomegalovirus infection

Natural killer (NK) cells quickly mount cytotoxic responses, produce cytokines, and proliferate in response to infected or transformed cells. Moreover, they can develop memory, with enhanced effector responses following activation, in some cases with antigen specificity. To optimally execute these functions, NK cells undergo metabolic reprogramming. Here, we discuss the interplay between metabolism and NK cell function in the context of viral infections. We review findings supporting metabolic regulation of NK cell effector functions, with a focus on NK cell antiviral infection in the context of cytomegalovirus in the mouse (MCMV) and human (HCMV).

Primary, Secondary, and Tertiary Prevention of Congenital Cytomegalovirus Infection

Cytomegalovirus infection is the most common congenital infection, affecting about 1% of births worldwide. Several primary, secondary, and tertiary prevention strategies are already available during the prenatal period to help mitigate the immediate and long-term consequences of this infection. In this review, we aim to present and assess the efficacy of these strategies, including educating pregnant women and women of childbearing age on their knowledge of hygiene measures, development of vaccines, screening for cytomegalovirus infection during pregnancy (systematic versus targeted), prenatal diagnosis and prognostic assessments, and preventive and curative treatments in utero.

A systematic literature review on the humanistic burden of cytomegalovirus

OBJECTIVE

Cytomegalovirus (CMV) infection is typically asymptomatic in healthy individuals; however, certain populations are vulnerable to infection and may develop serious sequelae. CMV infection may also have a broad impact on humanistic outcomes, including patient health status and quality of life (QoL). We conducted a systematic literature review (SLR) to describe the global humanistic burden of CMV and congenital CMV (cCMV) infections across all age groups.

METHODS

Medline, Embase, and LILACS were searched to identify studies on humanistic outcomes following CMV infection, including health status/QoL and any outcomes in domains such as auditory, cognitive ability, developmental status, intelligence, language, memory, mental health, motor performance, social communication, speech, and vocabulary. The SLR included articles published from 2000-2020 and focused geographically on Australia, Europe, Israel, Japan, Latin America, and North America.

RESULTS

Sixty-three studies met the inclusion criteria. In general, individuals with symptomatic cCMV infection experience a greater burden of disease and more substantial impact on QoL versus those with asymptomatic cCMV infection. Children with hearing loss due to cCMV infection, both symptomatic and asymptomatic, showed improved auditory outcomes following cochlear implantation. Newborns, infants, and children with cCMV infections had worse cognitive outcomes in psychological development, sequential and simultaneous processing, phonological working memory, and attention control versus age-matched controls without cCMV infection. CMV infection was also associated with cognitive decline in elderly populations.

CONCLUSIONS

CMV infection can have substantial, lifelong, heterogenous impacts on humanistic outcomes, including health status and QoL, which should be considered when developing and implementing treatment and prevention strategies.

Human Cytomegalovirus Induces Significant Structural and Functional Changes in Terminally Differentiated Human Cortical Neurons

Human cytomegalovirus (HCMV) is a highly prevalent viral pathogen that typically presents asymptomatically in healthy individuals despite lifelong latency. However, in 10-15% of congenital cases, this beta-herpesvirus demonstrates direct effects on the central nervous system, including microcephaly, cognitive/learning delays, and hearing deficits. HCMV has been widely shown to infect neural progenitor cells, but the permissiveness of fully differentiated neurons to HCMV is controversial and chronically understudied, despite potential associations between HCMV infection with neurodegenerative conditions. Using a model system representative of the human forebrain, we demonstrate that induced pluripotent stem cell (iPSC)-derived, excitatory glutamatergic and inhibitory GABAergic neurons are fully permissive to HCMV, demonstrating complete viral replication, competent virion production, and spread within the culture. Interestingly, while cell proliferation was not induced in these post-mitotic neurons, HCMV did increase expression of proliferative markers Ki67 and PCNA suggesting alterations in cell cycle machinery. These finding are consistent with previous HCMV-mediated changes in various cell types and implicate the virus' ability to alter proliferative pathways to promote virion production. HCMV also induces significant structural changes in forebrain neurons, such as the formation of syncytia and retraction of neurites. Finally, we demonstrate that HCMV disrupts calcium signaling and decreases neurotransmission, with action potential generation effectively silenced after 15 days post infection. Taken together, our data highlight the potential for forebrain neurons to be permissive to HCMV infection in the CNS, which could have significant implications on overall brain health and function.

The cost-effectiveness of maternal and neonatal screening for congenital cytomegalovirus infection in Japan

Congenital cytomegalovirus infection is the most common congenital infection. Using a decision tree model, cost-effectiveness of maternal screening with subsequent prenatal valacyclovir treatment and newborn screening with neonatal valganciclovir treatment was evaluated. The incremental cost-effectiveness ratio (ICER) was calculated for (1) universal maternal antibody screening with prenatal valacyclovir treatment compared to targeted newborn screening, and (2) universal newborn screening with postnatal valganciclovir treatment compared to targeted newborn screening. We performed a one-way sensitivity analysis. Compared to targeted newborn screening, the ICERs for universal newborn screening and maternal screening were 2 966 296 Japanese Yen (JPY) (21 188 USD) and 1 026 984 JPY (7336 USD), respectively. In all scenarios in the one-way sensitivity analysis, the ICERs of the maternal screening and the universal newborn screening strategies were less than three gross domestic product per capita compared with the targeted newborn screening strategy. Both maternal and universal newborn screening strategies may be cost-effective than a targeted newborn screening program. The potential utility of the maternal screening with valacyclovir treatment strategy, while potentially cost effective in regions with lower baseline seroprevalence rates, requires further study as the modeling was based on limited evidence.

Congenital cytomegalovirus infection diagnostics and management

PURPOSE OF THE REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

A systematic literature review of the global seroprevalence of cytomegalovirus: possible implications for treatment, screening, and vaccine development

Background

Cytomegalovirus (CMV) is a common pathogen that affects individuals of all ages and establishes lifelong latency. Although CMV is typically asymptomatic in healthy individuals, infection during pregnancy or in immunocompromised individuals can cause severe disease. Currently, treatments are limited, with no prophylactic vaccine available. Knowledge of the current epidemiologic burden of CMV is necessary to understand the need for treatment and prevention. A systematic literature review (SLR) was conducted to describe the most recent epidemiologic burden of CMV globally.

Methods

Medline, Embase, and LILACS were searched to identify data on CMV prevalence, seroprevalence, shedding, and transmission rates. The SLR covered the time period of 2010–2020 and focused geographically on Australia, Europe, Israel, Japan, Latin America (LATAM), and North America. Studies were excluded if they were systematic or narrative reviews, abstracts, case series, letters, or correspondence. Studies with sample sizes < 100 were excluded to focus on studies with higher quality of data.

Results

Twenty-nine studies were included. Among adult men, CMV immunoglobulin G (IgG) seroprevalence ranged from 39.3% (France) to 48.0% (United States). Among women of reproductive age in Europe, Japan, LATAM, and North America, CMV IgG seroprevalence was 45.6-95.7%, 60.2%, 58.3-94.5%, and 24.6-81.0%, respectively. Seroprevalence increased with age and was lower in developed than developing countries, but data were limited. No studies of CMV immunoglobulin M (IgM) seroprevalence among men were identified. Among women of reproductive age, CMV IgM seroprevalence was heterogenous across Europe (1.0-4.6%), North America (2.3-4.5%), Japan (0.8%), and LATAM (0-0.7%). CMV seroprevalence correlated with race, ethnicity, socioeconomic status, and education level. CMV shedding ranged between 0% and 70.2% depending on age group. No findings on CMV transmission rates were identified.

Conclusions

Certain populations and regions are at a substantially higher risk of CMV infection. The extensive epidemiologic burden of CMV calls for increased efforts in the research and development of vaccines and treatments.

Trial registration

N/A.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13971-7.

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.

Prevalence and Characteristics of Cytomegalovirus Ocular Disease in Children: A Multi-Center Study

Purpose

The objective of this study was to identify the prevalence of CMV ocular disease in children and to identify associated risk factors for ocular involvement.

Design

Retrospective multicenter, cross-sectional study.

Methods

Setting: Hospitalized patients screened for CMV viremia by PCR between 2005 and 2018 at four pediatric referral centers. Participants: Seven-hundred and ninety-three children showed CMV viremia (>135 copies/mL by polymerase chain reaction; PCR). Main Outcomes and Measures: (1) Occurrence of ophthalmologic examination. (2) Presence of CMV ocular disease, defined as retinitis, vasculitis, hemorrhage, optic nerve atrophy, or anterior uveitis in the setting of CMV viremia without other identifiable causes.

Results

A total of 296/793 (37%) underwent ophthalmologic examination following CMV viremia. A total of23/296 patients (8%) had ocular symptoms prompting evaluation while the rest had eye exams for baseline screening unrelated to CMV viremia. Of these, 13 cases (4% of those with an eye exam) with ocular disease were identified (three congenital CMV, five severe combined immunodeficiency disorder (SCID) status post-stem cell transplantation, three hematologic malignancy status post-stem cell transplantation for two of them, one Evans syndrome status post-stem cell transplantation, and one medulloblastoma status post-bone marrow transplantation). No patients with solid organ transplantation developed CMV ocular disease in our cohort.

Conclusion

CMV ocular disease was a rare occurrence in this cohort without an identifiable pattern across sub-groups. Excluding the three congenital CMV cases, nine out of ten patients with CMV ocular disease were status post-stem cell transplantation. We provide integrated screening guidelines based on the best available evidence for this rare condition.

eLearning significantly improves maternity professionals' knowledge of the congenital cytomegalovirus prevention guidelines

Aims

Cytomegalovirus (CMV) is a preventable cause of neurodevelopmental disability. Australian guidelines recommend that pregnant women are informed about CMV to reduce their risk of infection; however, less than 10% of maternity health professionals routinely provide prevention advice. The aim was to develop and evaluate the effectiveness of an eLearning course for midwives to improve knowledge and confidence about CMV.

Materials and Methods

Participants undertaking the course between March and November 2020 were invited to complete an evaluation questionnaire: before the course (T1), immediately after (T2) and three months post completion (T3). A linear mixed model was used to evaluate change in participant scores; P < 0.05 was considered statistically significant.

Results

Midwives (316/363, 87%), midwifery students (29/363, 8%) and nurses (18/363, 5%) participated. At T1 80% indicated they had not received education about CMV. Total adjusted mean scores for questionnaires completed between T1 (n = 363) and T2 (n = 238) increased significantly (from 17.2 to 22.8, P < 0.001). Limited available T3 scores (n = 27) (−1.7, P < 0.001), while lower than T2, remained higher than at T1 (+3.6, P < 0.001). Participants’ awareness of CMV information resources improved from 10 to 97% from T1 to T2. Confidence in providing CMV advice increased from 6 to 95% between T1 and T2 (P < 0.001) and was maintained at T3. Almost all (99%) participants indicated they would recommend the course to colleagues.

Conclusion

Participants who completed the eLearning course had significantly improved knowledge and confidence in providing advice about CMV. Programs targeting other maternity health professionals should be considered, to further support the implementation of the congenital CMV prevention guidelines.

The long-term burden of congenital cytomegalovirus: Hospitalisation and mortality in a population-based matched cohort study

AIM

Congenital cytomegalovirus (cCMV) infection can result in considerable morbidity and mortality. However, the impact of cCMV on health system utilisation beyond infancy is poorly defined. Here we sought to describe the burden of cCMV health service use and mortality using linked population-based datasets.

METHODS

The design was a matched cohort study using record-linked administrative datasets. Participants included all children aged 0-15 years identified through the New South Wales (NSW), Australia, Admitted Patient Data Collection who were hospitalised with an admission code for cCMV infection between 2001 and 2011. Participants were then matched by age, sex and birth postcode quintile using Socio-Economic Indexes for Area, to children randomly selected from the NSW Perinatal Data Collection, excluding those with central nervous system infections or cerebral palsy. We calculated rate ratios (RR) for hospital admissions adjusted for preterm birth, the median length of stay, cost weights of admission and odds ratio (OR) for deaths.

RESULTS

There were 130 children with cCMV matched to 2672 children. Neonates (aged <1 month) with cCMV had twice the rate of admissions (RR 2.4 95%CI 2.0, 2.8) and children aged ≥ 5yr to < 15yrs with cCMV almost eight times the rate of admissions (RR 7.8 95%CI 5.1, 11.5). Children with cCMV had significantly higher cost weights of admissions and an increased risk of mortality (OR 18.4 95%CI 7.8, 43.6).

CONCLUSION

Throughout childhood, children with cCMV had higher rates of hospital admissions, higher admission cost weights and an increased risk of mortality compared with matched peers without cCMV.

Commentary: Development of Therapeutics for Congenital Cytomegalovirus Infection

In the mid 1980’s, I flew from Birmingham, Alabama to San Francisco, rented a car, and drove to Palo Alto so that I could meet with John Martin at Syntex. John, along with Julian Verheyden, synthesized ganciclovir, which had significant in vitro activity against cytomegalovirus (CMV) in vitro. This drug provided my colleagues and me an opportunity to evaluate it as a therapeutic agent for congenital CMV infection, knowing full well that it was mutagenic, teratogenic, and carcinogenic. John in his wisdom convinced the management of Syntex to provide ganciclovir for this disease, allowing me to study this drug in symptomatic congenitally infected children through the NIAID Collaborative Antiviral Study Group (CASG). Certainly, no other person or company would advocate for the use of such a medication in children, regardless of disease severity, because of its toxicity profile. Since these early days, ganciclovir, and subsequently its prodrug valganciclovir, have become the standard of care for the treatment of congenital cytomegalovirus infection. The following commentary defines the need and progress in the development of therapy

Non-primary CMV infection not always innocent. A case-report and literature review

OBJECTIVES

Cytomegalovirus (CMV) is the most common infectious cause of congenital malformations. CMV infections are frequently symptomatic in case of a primary infection during pregnancy. Generally, maternal immunity protects the newborn against a symptomatic course of the CMV infection.

METHODS

We present clinical information and medical images of a neonate with non-primary congenital CMV infection.

RESULTS

We report the case of a severe congenital infection in a newborn clinically presenting with diffuse petechia, facial dysmorphisms, respiratory distress, hepatomegaly and hypotonia. The girl was born to a mother with CMV immunity. Blood results demonstrated thrombocytopenia and elevated transaminases. Brain MRI revealed ventricular dilatation and germinolytic cysts, compatible with CMV infection. Auditory brain stem response testing was abnormal. CMV culture of saliva was positive. This led to the diagnosis of a severe congenital CMV infection due to a non-primary maternal infection. Antiviral treatment with valganciclovir was initiated immediately and continued for 6 months.

CONCLUSION

Our case illustrates that, even when the mother was demonstrated CMV immune, congenital CMV infection is still an important differential diagnostic consideration in neonates presenting with congenital cerebral abnormalities, thrombocytopenia and/or hearing loss.

ABBREVIATIONS

ABR: auditory brainstem responses; CMV: Cytomegalovirus; CPAP: Continuous Positive Airway Pressure; CRP: C-Reactive Protein; dBnHL: Decibel Above Normal Adult Hearing Level; IV: intravenously; MRI: Magnetic Resonance Imaging; SGA: Small for Gestational Age; SNHL: Sensorineural Hearing Loss.

Pharmacokinetics, Safety, and Tolerability of NPC-21, an Anti-Cytomegalovirus Monoclonal Antibody, in Healthy Japanese and White Adult Men: A Randomized, Placebo-Controlled, First-in-Human Phase 1 Study

NPC-21 (EV2038) is a fully human monoclonal antibody that targets the antigenic domain 1 of glycoprotein B on the human cytomegalovirus (hCMV) envelope. NPC-21 has been shown to have broadly neutralizing activity and to inhibit cell-to-cell transmission of hCMV in preclinical studies. It is currently in development for the prophylactic or preemptive treatment of hCMV in patients receiving a solid-organ transplant or hematopoietic stem cell transplant. A first-in-human phase 1 study was conducted to assess the pharmacokinetics, safety, and tolerability of NPC-21 in healthy adult men. Forty participants (Japanese, n = 32; White, n = 8) were randomly assigned to receive a single intravenous dose of NPC-21 1, 3, 10, or 20 mg/kg or placebo. Six Japanese participants were included in each dose group and six White participants received a 10-mg/kg dose. The placebo group included 8 Japanese participants and 2 White participants. All 40 participants completed the study. Serum concentration, maximum serum concentration, area under the plasma concentration-time curve from time 0 to the last measurable concentration, and area under the plasma concentration-time curve from time 0 to infinity increased dose dependently; dose proportionality was linear. NPC-21 demonstrated a biphasic elimination pattern, with an estimated half-life between 612 and 790 hours. NPC-21 was safe and well tolerated up to 20 mg/kg. All adverse events were mild, and none led to treatment discontinuation or were considered related to the study drug. There were no differences in pharmacokinetics or safety between Japanese and White participants. These results support further investigation of NPC-21.

Universal Newborn Screening for Congenital Cytomegalovirus Infection - From Infant to Maternal Infection: A Prospective Multicenter Study

INTRODUCTION

Most infants at risk for cytomegalovirus (CMV)-associated sensorineural hearing loss (SNHL) are unrecognized because of the absence of a universal neonatal CMV screening. The search of CMV-DNA by molecular methods in salivary swabs was demonstrated to be a reliable approach. This study describes the results obtained by carrying out a universal screening for congenital CMV (cCMV) infection including all live-born newborns in three Italian sites, as well as the therapeutic interventions and clinical outcome of the CMV-infected neonates. Moreover, CMV maternal infection's characteristics were evaluated.

METHODS

To confirm or exclude cCMV infection, a CMV-DNA-positive result on a first salivary swab was followed by repeated saliva and urine samples collected within 21 days of age. Breast milk samples were also collected. The search of CMV-DNA was performed with a single automated quantitative commercial real-time PCR assay, regardless of the type of samples used.

RESULTS

A total of 3,151 newborns were enrolled; 21 (0.66%) of them were congenitally infected (median saliva viral load at screening, 6.65 [range, 5.03-7.17] log₁₀ IU/ml). Very low/low viral load in screening saliva samples (median value, 1.87 [range, 1.14-2.59] log₁₀ IU/ml) was associated with false-positive results (n = 54; 1.7%). CMV-DNA was detected in almost half of the breast milk samples of mother-infant pairs with a false-positive result, suggesting that contamination from breast milk may not be the only explanation in the study population. cCMV infection confirmation with the search of CMV-DNA in a urine sample proved to be the gold standard strategy, since false-positive results were observed in 4/54 (7.5%) of the repeated saliva samples. Symptomatic cCMV infection was observed in 3/21 (14.3%) infants; notably, one (4.7%) developed moderate unilateral SNHL at 5 months after birth. Finally, two symptomatic cCMV infections were associated with primary maternal infection acquired in the first trimester of gestation; one newborn with severe cCMV symptoms was born to a mother with no CMV checkups in pregnancy.

CONCLUSION

Without universal neonatal CMV screening, some infected infants who develop late neurological sequelae may not be recognized and, consequently, they are not able to benefit early from instrumental and therapeutic interventions to limit and/or treat CMV disease.

Delays in diagnosis and treatment initiation for congenital cytomegalovirus infection - Why we need universal screening

INTRODUCTION

Congenital cytomegalovirus (cCMV) is the leading cause of neurodevelopmental and hearing impairment from in-utero infection. Late diagnosis results in limited treatment options and may compromise long-term outcome.

METHODS

A retrospective audit of infants with cCMV referred to a Tertiary Pediatric Infectious Diseases center from 2012-2021. Data collected included timing of diagnostics, treatment initiation and reasons for delays.

RESULTS

90 infants with confirmed cCMV were included, 46/90 (51%) were symptomatic at birth. Most common reasons for diagnostics in asymptomatic infants were failed newborn hearing screening (17/44, 39%) and antenatal risk-factors (14/44, 32%). Median age at cCMV diagnosis was 3 (range 0-68) and 7 (0-515) days, with median referral age 10 (1-120) and 22 (2-760) days for symptomatic and asymptomatic infants respectively. There was a significant risk of delay in diagnosis (>21 days) for asymptomatic infants [RR 2.93 (1.15-7.45); p = 0.02]. Of asymptomatic infants who received treatment, 13/24 (54%) commenced it within 28 days of life, a significant delay in treatment compared to 30/36 (83%) symptomatic infants [RR 2.75 (1.18-6.43); p = 0.02]. The commonest reason for delayed treatment initiation was delayed first diagnostic test for both symptomatic 4/6 (67%) and asymptomatic infants 9/11 (82%).

CONCLUSIONS

Delays in diagnosis and treatment for cCMV are unacceptably frequent and significantly higher in asymptomatic infants. Our study highlights the need for increased awareness among healthcare professionals, reconsideration of age-targets for Newborn Hearing Screening, and research that addresses the barriers to implementation of universal screening, which would ultimately facilitate prompt diagnosis and management of all infants with cCMV.

Association Between First-Trimester Maternal Cytomegalovirus Infection and Stillbirth: A Prospective Cohort Study

BACKGROUND

Given that the time lag between cytomegalovirus (CMV) screening and diagnosed testing, a better knowledge of the association between pregnant women with CMV screening test positive and stillbirth in an epidemiological perspective was required to assist people being counseled reframe their pregnancy and birth plans based on the magnitude of the risk.

METHODS

This study recruited 44048 eligible pregnant women from March 13, 2013 to December 31, 2019. Serological tests including CMV-specific IgM and IgG, and IgG avidity index were used to screen for maternal CMV infection and were measured by automated chemiluminescence immunoassay. The association was assessed using the inverse probability of group-weighted multivariate-adjusted log-binomial models.

RESULTS

A total of 540 infants ended with a stillbirth (12.3 per 1000 pregnancies), and 2472 pregnancies with maternal CMV infection were screened out (56.1 per 1000 pregnancies) among all eligible pregnancies. In the comparison analysis, 326 infants ended with a stillbirth (86.6 per 1000 pregnancies) in the maternal CMV infection group compared with 214 infants (7.8 per 1000 pregnancies) in the group where mothers were not infected with CMV (RR 12.17; 95% CI 9.43-15.71). After excluding the pregnancies of stillbirth with birth defects, a strong association between the two groups was still observed (RR 9.38; 95% CI 6.92-12.70).

CONCLUSION

Our findings quantified the risk of a woman having a baby with stillbirth if she had a positive serologic CMV screening test in her first trimester, and supported the value of using CMV serologic tests as part of regular testing in pregnant women.

TRIAL REGISTRATION

Registered in Chinese Clinical Trial Registry Center; registration number, ChiCTR1800016635; registration date, 06/14/2018 (Retrospectively registered); URL of trial registry record, https://www.chictr.org.cn/showproj.aspx?proj=28300.

Severe fetal symptomatic infection from human cytomegalovirus following non-primary maternal infection: report of two cases

Introduction Human cytomegalovirus (HCMV) is the most common congenital infection, expecially severe after a maternal primary infection; sequelae in neonates born to mothers experiencing a non-primary infection have been already reported. Hereby, two cases of severe fetal HCMV disease in seroimmune gravidas referred to our Unit are described. Cases presentation Case 1 A fetus at 21 weeks' gestation with signs of anemia and brain abnormalities at ultrasound (US), described at magnetic resonance (MR) imaging as ependymal irregularity and bilateral asymmetric parenchimal thinning; amniotic fluid sample was positive for HCMV although the woman had a previous immunity; after termination of pregnancy, autopsy demonstrated a thicken layer of disorganized neurons on the right cortical plate, while on the left there was a morphological pattern coherent with polymicrogyria. Case 2 A fetus at 20 weeks' gestation with anemia, moderate atrio-ventricular insufficiency, hepatosplenomegaly but no major cerebral lesions. Fetal blood was positive for HCMV, although unexpected for pre-pregnancy maternal immunity, and intrauterine transfusion was needed. A cesarean section at 34 weeks gestation was performed due to worsening condition of the fetus, who had a birthweight of 2210 grams, needed platelet transfusions but MR examination and clinical evaluation were normal. Conclusion The impact of non-primary maternal infection on pregnancy outcome is unknown and fetal brain damage in HCMV seroimmune transmitter-mothers can occur as a consequence of maternal re-infection or reactivation for a hypotetic different role of HCMV-primed CD4+ or CD8+ T-cells in fetal brain, with progressive brain lesions coexistent in the first case and with severe unexpected anemia in the second case. A previous maternal HCMV immunity should not exempt to test anemic fetuses for such infection, nor to consider a potential transplacental transmission.

Awareness and knowledge of congenital cytomegalovirus infection among pregnant women and the general public: a web-based survey in Japan

Background

The best approach to reduce congenital cytomegalovirus infection (cCMVi) is to practice behaviors that reduce cytomegalovirus (CMV) transmission during pregnancy. Expanding awareness and knowledge of CMV is expected to result in increased practice of preventative behaviors. To this end, it is necessary to understand current awareness and knowledge of CMV.

Methods

This web-based cross-sectional survey assessed the awareness and knowledge of cCMVi among pregnant women and the general public in Japan. Participants aged 20–45 years (pregnant and non-pregnant women, and men) were identified from a consumer panel. Study outcomes (all participants) included awareness of cCMVi and other congenital conditions. Among those aware of cCMVi, outcomes included knowledge of CMV transmission routes, long-term outcomes of cCMVi, and behaviors to prevent CMV transmission during pregnancy. Outcomes limited to pregnant women included the practice of preventative behaviors and opinion on how easy it is to implement these behaviors. The data of the pregnant group (pregnant at the time of the survey) were compared with those of the general group (non-pregnant women and men).

Results

There were 535 participants in the pregnant group and 571 in the general group. Awareness of cCMVi was generally low (pregnant, 16.1%; general, 10.2%). Pregnant participants were significantly more aware of most congenital conditions than those in the general group, including cCMVi (P = 0.004). Knowledge about CMV/cCMVi was limited; there were no significant differences between the two groups for 24 of the 26 knowledge questions. A small proportion (one third or less) of pregnant women practiced behaviors to prevent the transmission of CMV, though most (73.3–95.3%) pregnant women who were aware of cCMVi considered such behaviors easy to implement.

Conclusions

Awareness and knowledge of CMV/cCMVi is low among pregnant women in Japan; the level of knowledge is similar to that among the general public. This needs to be improved. Most pregnant women considered behaviors to prevent CMV transmission easy to perform, which indicates that effectively educating pregnant women regarding the long-term outcomes of cCMVi, CMV transmission routes, and preventative behaviors will contribute to a reduced incidence of cCMVi.

Trial registration

UMIN Clinical Trials Registry, UMIN000041260.

Survey of physician knowledge of congenital cytomegalovirus infection and clinical practices in Japan: A web-based survey

Congenital cytomegalovirus infection (cCMVi) can cause serious and long-term effects in newborns. Without available vaccines or antiviral prophylaxis, prevention strategies for cCMVi and cytomegalovirus disease during pregnancy are limited to hygiene and behavioral interventions to prevent transmission. The objective of this study was to assess cCMVi-related awareness, knowledge, and physicians' actual and preferred clinical practices in Japan. This web-based cross-sectional survey was conducted using online panels. Survey invitations were sent by email to physicians (pediatricians, obstetricians, otolaryngologists, and internists). Participants were asked about their awareness of congenital conditions, including cCMVi. Participants who were aware of cCMVi were then asked additional questions related to the study objectives. Participants included 292 pediatricians, 245 obstetricians, 245 otolaryngologists, and 279 internists. Awareness of cCMVi was generally high (69.2%-97.6%). Pediatricians and obstetricians were most knowledgeable about cCMVi; however, responses to specific questions such as those pertaining to risk factors, patient counseling, and clinical management of cCMVi varied. For example, correct identification of potential cytomegalovirus transmission routes among pediatricians ranged from 36.8% to 65.6%. Survey results showed a discrepancy between responses when physicians were asked about their actual and preferred clinical practices to manage cCMVi. For example, although around 90% of obstetricians and pediatricians considered it preferred practice to educate pregnant women about cCMVi, only 60.1% of obstetricians reported being able to actually do so in current practice.This survey revealed that knowledge about cCMVi among Japanese physicians could be improved and identified variability in clinical practice.

Serial Monitoring and Hyperimmunoglobulin versus Standard of Care to Prevent Congenital Cytomegalovirus Infection: A Phase III Randomized Trial

INTRODUCTION

Nonrandomized studies support the potential of cytomegalovirus hyperimmunoglobulin (CMV-HyperIg) in preventing maternofetal CMV transmission, but prospective interventional studies show equivocal results. We pre-sent a prospective phase-III international randomized open-label trial on the potential effect of CMV-HyperIg following serial monitoring of CMV serostatus.

METHODS

CMV-seronegative pregnant women (gestational age [GA] <14 weeks) were 1:1 randomized to monthly CMV-serostatus monitoring and CMV-HyperIg upon seroconversion (treatment), or routine prenatal care with CMV-serostatus testing at end of pregnancy (control). Ethical considerations required that control subjects with confirmed seroconversion be offered Cytotect®. The primary endpoint was the proportion of fetuses/newborns with congenital CMV infection. Secondary endpoints included neonatal CMV disease and safety during the 24-month follow-up.

RESULTS

The treatment arm counted 4,800 randomized subjects: 52 seroconverted (median GA 24 [11-35] weeks), of which 45 completed follow-up. The control arm counted 4,735 randomized subjects: 42 seroconverted, of which 34 completed follow-up (evaluable data for 28 newborns) and 8 subjects chose off-label Cytotect®. Congenital CMV rates were 13/28 newborns (46.4% [CI 27.51; 66.13]) vs. 16/45 newborns (35.6% [CI 21.87; 51.22]) in control and treated arms, respectively (p = 0.46). Newborn CMV disease was mostly mild and spontaneously resolving. There were no major safety concerns. The target sample was not reached within an acceptable time frame.

CONCLUSIONS

Serial monitoring of CMV serostatus with CMV-HyperIg treatment was associated with a mild nonsignificant reduction in the vertical CMV transmission rate. Studies on the optimal preventive strategy are hampered by epidemiological and ethical challenges and should focus on GA-dependent transmission rates and accurate dating of infection.

New evidence on prognostic features, prevention and treatment of congenital Cytomegalovirus infection

PURPOSE OF REVIEW

Congenital Cytomegalovirus (CMV) infection remains a major cause of lifelong disability, with no systematic screening implemented in pregnancy or the postnatal period. In this review article, we outline the preventive strategies, antenatal prognostic features and experimental therapies as well as evidence of efficacy from recent trials.

RECENT FINDINGS

A recent randomized, double blinded, placebo-controlled study investigated the efficacy of Valaciclovir in women contracting primary CMV in the periconception period or first trimester. They concluded that Valaciclovir at a dose of 8 g/day is effective in reducing the rate of foetal CMV infection following early maternal primary infection. Administration of CMV hyperimmune globulin (HIG) was investigated in a recent randomized double-masked controlled trial. This study concluded that CMV HIG was ineffective at reducing the risk of congenital CMV among women with primary CMV in early pregnancy.

SUMMARY

Congenital CMV infection remains a significant cause of disability. There is currently no vaccine available, with the best preventive strategy being patient education on transmission as well as hygiene measures to reduce risk of exposure. Experimental therapies have been investigated in recent years and there is evidence supporting the use of Valaciclovir. Data for the efficacy of CMV HIG remains inconsistent and administration is currently limited to clinical trial settings.

Early-childhood cytomegalovirus infection and children's neurocognitive development

BACKGROUND

Despite a clear association seen in congenitally infected children, the effect of postnatal cytomegalovirus (CMV) infection during early childhood on cognitive development has not yet been determined.

METHODS

CMV-infection status was obtained based on serological measurements when children were 7 years old. Using population-based longitudinal data, we employed multivariate Poisson regression with a robust variance estimator to characterize the relationship between childhood CMV infection and adverse neurocognitive outcomes in children. Suboptimal neurocognitive outcomes were compared between CMV-positive and CMV-negative children using various cognitive assessments from 8 to 15 years of age. Children were evaluated on the cognitive domains of language, reading, memory and general intelligence, with a suboptimal score being >2 standard deviations lower than the mean score. Approximate Bayes factor (ABF) analysis was used to determine the level of evidence for the observed associations.

RESULTS

With adjustment for potential confounders, we observed that early-childhood CMV infection was associated with suboptimal total intelligence quotient (IQ) at 8 years of age [incidence-rate ratio (IRR) = 2.50, 95% confidence interval (CI) 1.35-4.62, ABF = 0.08], but not with suboptimal total IQ at 15 years of age (IRR = 0.97, 95% CI 0.43-2.19, ABF = 1.68). Suboptimal attentional control at 8 years (IRR = 1.74, 95% CI 1.13-2.68, ABF = 0.18) and reading comprehension at 9 years (IRR = 1.93, 95% CI 1.12-3.33, ABF = 0.24) were also associated with CMV infection. ABF analysis provided strong evidence for the association between CMV infection and total IQ at 8 years, and only anecdotal evidence for attentional control at 8 years and reading comprehension at 9 years. All other cognitive measures assessed were not associated with CMV infection.

CONCLUSION

In this large-scale prospective cohort, we observed some evidence for adverse neurocognitive effects of postnatal CMV infection on general intelligence during early childhood, although not with lasting effect. If confirmed, these results could support the implementation of preventative measures to combat postnatal CMV infection.

Guideline No. 420: Cytomegalovirus Infection in Pregnancy

OBJECTIVE

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

BENEFITS, HARMS, AND COSTS

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

EVIDENCE

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

VALIDATION METHODS

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

INTENDED AUDIENCE

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

Renal Involvement in Congenital Cytomegalovirus Infection: A Systematic Review

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cytomegalovirus infection and IQ in patients with severe mental illness and healthy individuals

Cytomegalovirus (CMV) infection in immunocompetent adults is usually asymptomatic, but results in lifelong latency. Infection occurring congenitally or in immunodeficiency can lead to cognitive impairment. We aimed to investigate the associations between CMV exposure and intelligence quotient (IQ) in patients with schizophrenia spectrum disorders (SZS), bipolar spectrum disorders (BDS) and healthy controls (HC). CMV immunoglobulin G antibody concentrations were measured by immunoassay and expressed as dichotomous measures (seropositive/CMV+ vs. seronegative/CMV-). Based on a significant CMV-by-diagnosis-by-sex interaction on IQ, we investigated main and interaction effects of CMV and sex on IQ in each diagnostic category. Significant CMV-by-sex interactions were found in patient groups. In SZS, CMV+ female patients (n = 50) had significantly lower IQ than CMV- female patients (n = 33), whereas CMV+ (n = 48) and CMV- (n = 45) male patients did not differ in IQ. In BDS, CMV+ (n = 49) and CMV- (n = 37) female patients did not differ in IQ, whereas CMV+ male patients (n = 33) had significantly higher IQ than CMV- male patients (n = 32). Among HC, CMV+ (n = 138) and CMV- (n = 118) male participants as well as CMV+ (n = 125) and CMV- (n = 93) female participants did not differ in IQ. Our findings suggest that CMV exposure may affect IQ in patients with severe mental illness but not HC.

Economic assessments of the burden of congenital cytomegalovirus infection and the cost-effectiveness of prevention strategies

OBJECTIVE

This is a critical review of published economic analyses on congenital cytomegalovirus infection and strategies for its detection and prevention.

FINDINGS

The review identified four cost-of-illness studies and nine cost-effectiveness analyses: three of vaccination of young women, two of prenatal screening, and four of newborn screening. All reported either large economic costs or favorable cost-effectiveness of interventions. However, sensitivity analyses did not address some of the most critical assumptions.

CONCLUSIONS

Reviewed economic analyses overattributed certain adverse long-term outcomes to congenital cytomegalovirus infection, while other long-term costs were not included. Overall, limited conceptual frameworks, unrepresentative data sources, and unsupported or inadequately documented assumptions regarding outcomes and costs hinder the ability of policymakers to draw conclusions. A major challenge is the limited information on long-term outcomes and costs for representative cohorts of individuals with congenital cytomegalovirus, which further research could helpfully address.

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.

Neurological Manifestations of Congenital Cytomegalovirus Infection at a Tertiary Care Centre from Southern India

Background  Cytomegalovirus (CMV) is a ubiquitous herpes virus. It is the most common congenital viral infection. Data on congenital CMV in India are lacking and hence the present study was undertaken.

Objectives  The aim of the study is to evaluate the clinical and radiological profile of neurological manifestations of congenital CMV infections in tertiary care hospital.

Methods  This is a retrospective chart review of the clinical and laboratory profile of congenital CMV infections presenting from January 2018 to February 2020 to a tertiary care hospital in Southern India. Details of clinical profile, serological and neuroimaging data were obtained and analyzed.

Results  A total of 42 cases with female preponderance (57%) were reported during the study period. The mean age of presentation was 2.9 years. Clinical features were developmental delay (81%), microcephaly (93%), seizures (33%), intrauterine growth restriction (19%), neonatal encephalopathy (10%), anemia (9%), jaundice (10%), hepato-splenomegaly (7%), and eye abnormalities (14%). Antenatal maternal fever was reported by 12%. Sensorineural hearing loss was present in 57%. Neuroimaging showed periventricular calcification (79%), cerebral atrophy (69%), ventricular dilatation (55%), malformations (26%), dysmyelination (12%), and temporal lobe cysts (5%). CMV-immunoglobulin-M positivity was seen in 14 cases (33%), urinary polymerase chain reaction for CMV was positive in 21 cases (50%), and clinical diagnosis was done in seven cases (16%).

Conclusion  Common findings in congenital CMV are microcephaly, developmental delay, seizures, anemia, and sensorineural hearing loss. Common neuroimaging findings are periventricular calcification, cerebral atrophy, malformation, white matter signal changes, and cysts. CMV can mimic like cerebral palsy, malformations of the brain, demyelinating disorders, and calcified leukoencephalopathies like Aicardi-Goutières syndrome.

Vestibular, Gaze, and Balance Disorders in Asymptomatic Congenital Cytomegalovirus Infection

BACKGROUND AND OBJECTIVES

Congenital cytomegalovirus (cCMV) is the leading nongenetic cause of sensorineural hearing loss and developmental disabilities. Because there are limited data from studies of vestibular involvement in select groups of children with cCMV, the true frequency of vestibular disorders in cCMV is likely underestimated. Our objective for this study is to determine the prevalence of vestibular, gaze, and balance disorders in a cohort of children with asymptomatic cCMV.

METHODS

Comprehensive vestibular, gaze, and balance assessments were performed in 40 children with asymptomatic cCMV. The function of semicircular canals of the inner ear and vestibulo-visual tract were assessed by measuring vestibulo-ocular reflex in a computer-driven motorized rotary chair; inner ear saccular function was assessed by using cervical vestibular evoked myogenic potential; gaze stability during head movement was assessed by using clinical dynamic visual acuity, and balance was assessed by using the sensory organization test and the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition. Test results for each variable were compared with those of a control group without cCMV and/or compared to age-matched normative published data.

RESULTS

Vestibular disorders were evident in 45% of the cohort on the basis of rotary chair and cervical vestibular evoked myogenic potential testing, suggesting abnormalities in semicircular canals, the utricle and saccule of the inner ear, and vestibulo-visual tracts. Additionally, 46% of the cohort had difficulties maintaining gaze during head movement, and one-third to one-half of the cohort had difficulties maintaining balance.

CONCLUSIONS

Vestibular, gaze, and balance disorders are highly prevalent in children with asymptomatic cCMV. Systematic screening for vestibular disorders will be used to determine the full clinical impact for the development of effective interventions.

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.