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

"The anxiety coming up to every scan-It destroyed me": A qualitative study of the lived experience of cytomegalovirus infection during pregnancy

BACKGROUND

Emerging evidence supporting the use of valaciclovir to reduce fetal infection after maternal primary cytomegalovirus (CMV) infection has stimulated interest in routine CMV serological screening in pregnancy. It is important to understand the healthcare consumer perspective of a CMV infection during pregnancy to minimize unintended harms of screening.

METHODS

We conducted a qualitative study using semi-structured interviews with Australian women who had a lived experience of CMV infection following serological testing during pregnancy. Participants were recruited via social media and healthcare consumer networks, and purposively selected to capture a range of perinatal outcomes. Interview transcripts were analyzed using inductive content analysis.

RESULTS

Twelve participants were interviewed: 6 had a live birth, 4 had terminations of pregnancy, 1 had a neonatal death and 1 was pregnant at the time of interview. Four major categories emerged from the analysis. Women reported a lack of CMV awareness among themselves, their social networks, and among their health care providers. The participants described their experience as "hard" and "stressful". Uncertainty and variability characterized their clinical decision-making process. The pregnancy and postpartum periods were marked by ongoing anxiety about the long-term impacts of CMV. Women supported screening for CMV, decision making and reproductive choice, but acknowledged that routine testing may not be desired by everyone and may increase stress and terminations of pregnancy. Important coping strategies included obtaining support from partners, family, and other families with lived experience of CMV, as well as having access to knowledgeable and sensitive healthcare professionals.

CONCLUSION

Serological diagnosis of maternal CMV infection during pregnancy can have severe and prolonged psychological impacts on parents, regardless of the pregnancy outcome. Improving healthcare professionals' knowledge and public awareness are essential before widespread serological screening can be responsibly introduced. Healthcare administrators that are considering implementing a prenatal screening program for secondary prevention of fetal CMV infection should pay attention to consumer perspectives to minimize unintended harms to women and their families.

Congenital infectious encephalopathies from the intrapartum period to postnatal life

Congenital infections are a common but often underrecognized cause of fetal brain abnormalities, as well as fetal-neonatal morbidity and mortality, that should be considered by all healthcare professionals providing neurological care to fetuses and newborns. Maternal infection with various pathogens (cytomegalovirus, Toxoplasmosis, Rubella virus, Parvovirus B19, lymphocytic choriomeningitis virus, syphilis, Zika virus, varicella zoster virus) during pregnancy can be transmitted to the developing fetus, which can cause multisystem dysfunction and destructive or malformative central nervous system lesions. These can be recognized on fetal and neonatal imaging, including ultrasound and MRI. Imaging and clinical features often overlap, but some distinguishing features can help identify specific pathogens and guide subsequent testing strategies. Some pathogens can be specifically treated, and others can be managed with targeted interventions or symptomatic therapy based on expected complications. Neurological and neurodevelopmental complications related to congenital infections vary widely and are likely driven by a combination of pathophysiologic factors, alone or in combination. These include direct invasion of the fetal central nervous system by pathogens, inflammation of the maternal-placental-fetal triad in response to infection, and long-term effects of immunogenic and epigenetic changes in the fetus in response to maternal-fetal infection. Congenital infections and their neurodevelopmental impacts should be seen as an issue of public health policy, given that infection and the associated complications disproportionately affect woman and children from low- and middle-income countries and those with lower socio-economic status in high-income countries. Congenital infections may be preventable and treatable, which can improve long-term neurodevelopmental outcomes in children.

Seroprevalence of Anti-Cytomegalovirus Antibodies in Pregnant Women from South-West Romania

Cytomegalovirus (CMV), in addition to other agents, is part of the TORCH complex (Toxoplasma gondii, Rubella virus, Cytomegalovirus, Herpes simplex viruses, and other agents). CMV infection is the most frequent cause of congenital malformations. This study aimed to establish the variation of prevalence of anti-CMV antibodies in pregnant women from the South-West region of Romania, according to demographic factors, such as age and area of residence, in two separate time periods (2013-2016 and 2019-2022). We collected from the hospital records the age, place of residence, and anti-CMV antibody test results using immune electrochemiluminescence and chemiluminescence. This study found that the seroprevalence of anti-CMV IgM antibodies increased slightly from 2013-2016 to 2019-2022, from 1.92% to 2.26%, and for IgG antibodies from 93.68% to 94.96%. In both groups was observed a descending trend of anti-CMV IgM seroprevalence with an increase in age, showing a decrease in seroprevalence from 3.57% to 1.09% in pregnant women from rural areas in the 31-35 years age group, while in urban areas, we observed a decrease in seroprevalence from 11.11% to 3.06% in the <20 years age group. The IgG seroprevalence showed an increase both in rural areas (from 93.97% to 95.52%) and urban areas (from 93.52% to 94.27%). In both groups, seroprevalence was higher in rural areas compared to urban regions. These results show a high rate of immunization against CMV in pregnant women in South-West Romania, which led to a low risk of acquiring the primary infection during pregnancy. However, the increase in the rate of primary CMV infections in pregnancy suggests the need for prioritizing screening programs and improving the existing protocols to enhance maternal and child healthcare.

Cytomegalovirus Infection in Pregnancy Prevention and Treatment Options: A Systematic Review and Meta-Analysis

OBJECTIVES

Cytomegalovirus (CMV) infection is a significant health concern affecting numerous expectant mothers across the globe. CMV is the leading cause of health problems and developmental delays among infected infants. Notably, this study examines CMV infection in pregnancy, its management, prevention mechanisms, and treatment options.

METHODS

Specifically, information from the Cochrane Library, PUBMED, Wiley Online, Science Direct, and Taylor Francis databases were reviewed along with additional records identified through the register, the Google Scholar search engine. Based on the search, 21 articles were identified for systematic review.

RESULTS

A total of six randomized controlled trials (RCTs) were utilized for a meta-analytic review. As heterogeneity was substantial, the random effects model was used for meta-analysis. Utilizing the random-effects model, the restricted maximum likelihood (REML) approach, the estimate of effect size (d = -0.479, 95% CI = -0.977 to 0.019, p = 0.060) suggests the results are not statistically significant, so it cannot be inferred that the prevention methods used were effective, despite an inverse relationship between treatment and number of infected cases. The findings indicated that several techniques are used to prevent, diagnose, and manage CMV infection during pregnancy, including proper hygiene, ultrasound examination (US), magnetic resonance imaging (MRI), amniocentesis, viremia, hyperimmunoglobulin (HIG), and valacyclovir (VACV).

CONCLUSIONS

The current review has significant implications for addressing CMV infection in pregnancy. Specifically, it provides valuable findings on contemporary management interventions to prevent and treat CMV infection among expectant mothers. Therefore, it allows relevant stakeholders to address these critical health concerns and understand the effectiveness of the proposed prevention and treatment options.

Immune-checkpoint expression in antigen-presenting cells (APCs) of cytomegaloviruses infection after transplantation: as a diagnostic biomarker

Cytomegalovirus (CMV), a member of the Herpesviridae family, mostly causes only slight feverish symptoms or can be asymptomatic in immunocompetent individuals. However, it is known to be particularly a significant cause of morbidity in immunocompromised patients, including transplant recipients, whose immune system has been weakened due to the consumption of immunosuppressor drugs. Therefore, the diagnosis of CMV infection after transplantation is crucial. New diagnostic methods for the quick detection of CMV have been developed as a result of understanding the clinical importance of invasive CMV. Antigen-presenting cells (APCs) and T cells are important components of the immune system and it may be possible to diagnose viral infections using immunological markers, such as lymphocytosis, cytotoxic T lymphocytes (CTL), and serum cytokine levels. Moreover, PD-1, CTLA 4, and TIGIT, which are expressed on certain T cells and antigen-presenting cells, are over-expressed during the infection. The assessment of CMV infection based on T cell and APC activity, and the expression of immunological checkpoints, can be helpful for the diagnosis of transplant patients at risk for CMV infection. In this review, we will investigate how immune checkpoints affect immune cells and how they impair organ transplantation after CMV infection.

The Pathogenesis of Cytomegalovirus and Other Viruses Associated with Hearing Loss: Recent Updates

Virus infection is one of the most common etiologies of hearing loss. Hearing loss associated with viral infection can be unilateral or bilateral, mild or severe, sudden or progressive, and permanent or recoverable. Many viruses cause hearing loss in adults and children; however, the pathogenesis of hearing loss caused by viral infection is not fully understood. This review describes cytomegalovirus, the most common virus causing hearing loss, and other reported hearing loss-related viruses. We hope to provide a detailed description of pathogenic characteristics and research progress on pathology, hearing phenotypes, possible associated mechanisms, treatment, and prevention measures. This review aims to provide diagnostic and treatment assistance to clinical workers.

Cytomegalovirus seronegativity rate in pregnant women and primary cytomegalovirus infection during pregnancy in rural Germany

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the most common congenital infection worldwide and one of the leading causes of congenital hearing loss in newborns. The aim of this study was to determine the seroprevalence rate for cytomegalovirus in pregnant women and the rate of CMV serological testing utilised during pregnancy in a rural region in Germany.

METHODS

Retrospective data on the prevalence of CMV IgG and IgM antibodies were obtained from 3,800 women, identified in the study group of 19,511 pregnant women from outpatient settings whose samples were collected between 1 and 2014 and 30 April 2018. In addition, the serological CMV status in regards to various billing methods was further analyzed.

RESULTS

Serological CMV tests were performed in 3,800 (19.5%) out of 19,511 pregnant women. 2,081 (54.8%) of these women were CMV seronegative. Among those, seroconversion rate of 0.37-1.42% was identified. A proportion of 2,710 (14.7%) of all 18,460 women with statutory health insurance made use of the CMV testing as an individual health service.

CONCLUSIONS

The low uptake of CMV serological testing in the study population covered indicates low risk awareness among pregnant women and their healthcare professionals. Presented seronegativity rates and routine seroconversion rate, demonstrate importance to improve intervention strategy to prevent feto-maternal CMV transmission.

Efficiency of CMV serodiagnosis during pregnancy in daily laboratory routine

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Roles of TGF-β1 in Viral Infection during Pregnancy: Research Update and Perspectives

Transforming growth factor-beta 1 (TGF-β1) is a pleiotropic growth factor playing various roles in the human body including cell growth and development. More functions of TGF-β1 have been discovered, especially its roles in viral infection. TGF-β1 is abundant at the maternal-fetal interface during pregnancy and plays an important function in immune tolerance, an essential key factor for pregnancy success. It plays some critical roles in viral infection in pregnancy, such as its effects on the infection and replication of human cytomegalovirus in syncytiotrophoblasts. Interestingly, its role in the enhancement of Zika virus (ZIKV) infection and replication in first-trimester trophoblasts has recently been reported. The above up-to-date findings have opened one of the promising approaches to studying the mechanisms of viral infection during pregnancy with links to corresponding congenital syndromes. In this article, we review our current and recent advances in understanding the roles of TGF-β1 in viral infection. Our discussion focuses on viral infection during pregnancy, especially in the first trimester. We highlight the mutual roles of viral infection and TGF-β1 in specific contexts and possible functions of the Smad pathway in viral infection, with a special note on ZIKV infection. In addition, we discuss promising approaches to performing further studies on this topic.

Recent Advancements in Understanding Primary Cytomegalovirus Infection in a Mouse Model

Animal models that mimic human infections provide insights in virus–host interplay; knowledge that in vitro approaches cannot readily predict, nor easily reproduce. Human cytomegalovirus (HCMV) infections are acquired asymptomatically, and primary infections are difficult to capture. The gap in our knowledge of the early events of HCMV colonization and spread limits rational design of HCMV antivirals and vaccines. Studies of natural infection with mouse cytomegalovirus (MCMV) have demonstrated the olfactory epithelium as the site of natural colonization. Systemic spread from the olfactory epithelium is facilitated by infected dendritic cells (DC); tracking dissemination uncovered previously unappreciated DC trafficking pathways. The olfactory epithelium also provides a unique niche that supports efficient MCMV superinfection and virus recombination. In this review, we summarize recent advances to our understanding of MCMV infection and spread and the tissue-specific mechanisms utilized by MCMV to modulate DC trafficking. As these mechanisms are likely conserved with HCMV, they may inform new approaches for preventing HCMV infections in humans.

Impact of maternal cytomegalovirus seroconversion on newborn and childhood hearing loss triological thesis 2022–2023

Objectives/hypothesis

The objective of this study is to describe long‐term hearing outcomes in infants born to mothers with a known cytomegalovirus (CMV) positivity who were not tested for congenital CMV.

Study type

Clinical research study.

Design

Retrospective cohort study.

Methods

Retrospective chart review was performed for mothers seropositive to CMV. Mother–infant dyads (130) were identified between January 1, 2013 and January 1, 2017. Outcomes data was collected through June 1, 2020. Demographics, risk factors for hearing loss, evidence of CMV infection, other causes of hearing loss, need for speech therapy services, and results of all hearing tests were collected.

Results

All 130 infants were asymptomatic and 5 were tested for congenital CMV. Five were negative for CMV and excluded from analyses. Of the remaining 125, only 1 had low‐viral avidity IgG antibodies. None had IgM antibodies. Four children (3.2%) had hearing loss at last audiogram and one child had delayed onset SNHL due to an enlarged vestibular aqueduct. Speech therapy for communication was required for 33 children (26.4%).

Conclusions

Knowledge of maternal perinatal CMV status can allow for education about possible sequelae of cCMV, as well as trigger an alert for testing babies born to mothers with low‐viral avidity IgG during the first trimester, when the risk of vertical transmission is highest. Also, babies born to CMV positive mothers may be more at risk for communication delays necessitating intervention. Studies focusing on the impact of maternal CMV related to childhood communication deficits could elucidate any direct relationships.

Ultrasound Findings of Fetal Infections: Current Knowledge

Infectious diseases during pregnancy are still a major cause of fetal mortality and morbidity worldwide. The most common teratogenic pathogens are cytomegalovirus (CMV), varicella-zoster virus (VZV), rubeovirus, parvovirus B19, herpes simplex virus (HSV), Toxoplasma gondii, Treponema pallidum and the emergent Zika virus (ZIKV). Ultrasound findings include cerebral anomalies, orbital defects, micrognathia, cardiac defects, hepatosplenomegaly, liver calcifications, abdominal anomalies, skin and limb anomalies, edema, placental and amniotic fluid anomalies and altered Doppler analyses. The classification of ultrasound markers of congenital infections by anatomical region is reported to guide differential diagnosis and prenatal care.

Cytomegalovirus infection in a single-centre Australian neonatal cohort

AIM

Congenital cytomegalovirus (cCMV) is the most common infectious cause of congenital malformation, non-genetic sensorineural hearing loss and neurodevelopmental sequelae in childhood. The primary aim of this retrospective cohort study was to identify the birth and neurodevelopmental outcomes of neonates diagnosed with symptomatic and asymptomatic cCMV in a large regional tertiary referral hospital.

METHODS

This was a retrospective cohort study of laboratory-based cCMV diagnoses in neonates born at a single study centre between January 2005 and January 2020. Audit of medical records was undertaken to evaluate maternal characteristics, symptom patterns, radiological and neurodevelopmental outcomes of neonates meeting the laboratory diagnostic criteria during the first 24 months.

RESULTS

There were 45 neonates with proven CMV infection and 27 mothers with proven infection with an associated pregnancy outcome. Nineteen neonates were born at term (>37 weeks). Of these, 32 (71.1%) neonates had a significant intercurrent comorbidity and 22 (48.9%) neonates were reported to have a degree of delay in one or more developmental domains. A large proportion (77.3%) of the symptomatic untreated neonates had an unknown history of maternal infection compared to the asymptomatic (10.0%) and symptomatic treated (53.8%) neonates (P = 0.001).

CONCLUSION

Up to half of the neonates with cCMV were at risk of developing a degree of developmental delay at our centre. Whether these outcomes are related primarily to CMV infection or are confounded by the co-existence of prematurity is unclear and needs further evaluation in prospective studies.

Association between Congenital Cytomegalovirus Infection and Brain Injury in Neonates: A Meta-analysis of Cohort Studies

Objective

To assess association between congenital cytomegalovirus (CMV) infection and brain injury in neonates.

Methods

The literatures from inception to November 4, 2020, were searched through PubMed, Embase, Cochrane Library, and Web of Science. Heterogeneity test was conducted for each indicator and measured by I ² statistics. If I ² ≥ 50%, the random effects model was applied; otherwise, the fixed effects model was used. Sensitivity analysis was performed for all models. Weighed mean difference (WMD) was used as the effect size for measurement data, and risk ratio (RR) was as the effect indicator.

Results

A total of 13 studies, including 4,262 congenital CMV infection neonates, were enrolled in this study. Our results showed that the rate of hearing impairment (RR: 2.105, 95% CI: (1.115, 3.971), P = 0.002), sensorineural hearing loss (SNHL) (RR: 17.051, 95% CI: (6.201, 46.886), P < 0.001), and microcephaly (RR: 2.283, 95% CI: (1.325, 3.935), P =0.003) in neonates infected congenital CMV was higher than that in control group.

Conclusion

The risks of hearing impairment, SNHL, and microcephaly in neonates during childhood may be associated with congenital CMV infection. It is necessary to establish neonatal screening programs and comprehensive diagnostic tests for patients to reduce the risk of adverse brain damage to the congenital CMV infection as early as possible and to improve the prognosis of the newborn.

A Live Olfactory Mouse Cytomegalovirus Vaccine, Attenuated for Systemic Spread, Protects against Superinfection

Vaccination against the betaherpesvirus, human cytomegalovirus (HCMV) is a public health goal. However, HCMV has proved difficult to vaccinate against. Vaccination against single HCMV determinants has not worked, suggesting that immunity to a wider antigenic profile may be required. Live attenuated vaccines provide the best prospects for protection, but the question remains as to how to balance vaccine virulence with safety. Animal models of HCMV infection provide insights into identifying targets for virus attenuation and understanding how host immunity blocks natural, mucosal infection. Here, we evaluated the vaccine potential of a mouse cytomegalovirus (MCMV) vaccine deleted of a viral G protein-coupled receptor (GPCR), designated M33, that renders it attenuated for systemic spread. A single noninvasive olfactory ΔM33 MCMV vaccine replicated locally, but as a result of the loss of the M33 GPCR, it failed to spread systemically and was attenuated for latent infection. Vaccination did not prevent host entry of a superinfecting MCMV but spread from the mucosa was blocked. This approach to vaccine design may provide a viable alternative for a safe and effective betaherpesvirus vaccine. IMPORTANCE Human cytomegalovirus (HCMV) is the most common cause of congenital infection for which a vaccine is not yet available. Subunit vaccine candidates have failed to achieve licensure. A live HCMV vaccine may prove more efficacious, but it faces safety hurdles which include its propensity to persist and to establish latency. Understanding how pathogens infect guide rational vaccine design. However, HCMV infections are asymptomatic and thus difficult to capture. Animal models of experimental infection provide insight. Here, we investigated the vaccine potential of a mouse cytomegalovirus (MCMV) attenuated for systemic spread and latency. We used olfactory vaccination and virus challenge to mimic its natural acquisition. We provide proof of concept that a single olfactory MCMV that is deficient in systemic spread can protect against wild-type MCMV superinfection and dissemination. This approach of deleting functional counterpart genes in HCMV may provide safe and effective vaccination against congenital HCMV disease.

Severe fetal anaemia caused by congenital cytomegalovirus infection

A 22-year-old pregnant woman was referred to our fetal medicine unit due to severe fetal growth restriction at 26 weeks of gestation. An extensive detailed ultrasound revealed signs of bilateral periventricular hyperechogenicity, suggesting fetal infection potentially due to cytomegalovirus (CMV). Doppler ultrasound showed a high peak systolic velocity in the middle cerebral artery. Percutaneous umbilical cord blood sampling confirmed fetal CMV infection and severe fetal anaemia. We present this case to highlight the importance of fetal anaemia, which can be fatal regardless of whether it is associated with generalised oedema or hydrops fetalis.

The human oral virome: Shedding light on the dark matter

Mediators of the initiation, development, and recurrence of periodontitis include the oral microbiome embedded in subgingival plaque and the host immune response to a dysbiosis within this dynamic and complex microbial community. Although mediators have been studied extensively, researchers in the field have been unable to fully ascribe certain clinical presentations of periodontitis to their nature. Emergence of high-throughput sequencing technologies has resulted in better characterization of the microbial oral dysbiosis that extends beyond the extensively studied putative bacterial periodontopathogens to a shift in the oral virome composition during disease conditions. Although the biological dark matter inserted by retroviruses was once believed to be nonfunctional, research has revealed that it encodes historical viral-eukaryotic interactions and influences host development. The objective of this review is to evaluate the proposed association of herpesviruses to the etiology and pathogenesis of periodontal disease and survey the highly abundant prokaryotic viruses to delineate their potential roles in biofilm dynamics, as well as their interactions with putative bacterial periodontopathogens and eukaryotic cells. The findings suggest that potential novel periodontal therapies targeting or utilizing the oral virome can alleviate certain clinical presentations of periodontitis. Perhaps it is time to embrace the viral dark matter within the periodontal environment to fully comprehend the pathogenesis and systemic implications of periodontitis.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

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

Impact of maternal nutrition in viral infections during pregnancy

Other than being a physiological process, pregnancy is a condition characterized by major adaptations of maternal endocrine and metabolic homeostasis that are necessary to accommodate the fetoplacental unit. Unfortunately, all these systemic, cellular, and molecular changes in maternal physiology also make the mother and the fetus more prone to adverse outcomes, including numerous alterations arising from viral infections. Common infections during pregnancy that have long been recognized as congenitally and perinatally transmissible to newborns include toxoplasmosis, rubella, cytomegalovirus, and herpes simplex viruses (originally coined as ToRCH infections). In addition, enterovirus, parvovirus B19, hepatitis virus, varicella-zoster virus, human immunodeficiency virus, Zika and Dengue virus, and, more recently, coronavirus infections including Middle Eastern respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) infections (especially the novel SARS-CoV-2 responsible for the ongoing COVID-19 pandemic), constitute relevant targets for current research on maternal-fetal interactions in viral infections during pregnancy. Appropriate maternal education from preconception to the early postnatal period is crucial to promote healthy pregnancies in general and to prevent and/or reduce the impact of viral infections in particular. Specifically, an adequate lifestyle based on proper nutrition plans and feeding interventions, whenever possible, might be crucial to reduce the risk of virus-related gestational diseases and accompanying complications in later life. Here we aim to provide an overview of the emerging literature addressing the impact of nutrition in the context of potentially harmful viral infections during pregnancy.

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

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

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

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

Congenital Cytomegalovirus Infection Following Second and Third Trimester Maternal Infection Is Associated With Mild Childhood Adverse Outcome Not Predicted by Prenatal Imaging

BACKGROUND

While it is clear that first trimester congenital cytomegalovirus (CMV) infection can lead to serious neonatal and childhood adverse outcome, the extent of the effect of second and third trimester congenital CMV infection is still unclear. Our aim was to study the short- and long-term outcomes following second and third trimester infection and to evaluate the contribution of prenatal imaging in a prospective cohort.

METHODS

We studied pregnant women with primary CMV infection in the second and third trimesters, as diagnosed by well-dated seroconversion, and proof of vertical CMV transmission. All patients underwent serial prenatal ultrasound (US) and most of them fetal magnetic resonance imaging (MRI). Follow-up information was obtained from hospital charts and by telephone interviews with parents.

RESULTS

Primary CMV infection occurred in 135 patients, 107 and 28 with second and third trimester infection, respectively. The incidence proportion of composite outcome (hearing loss or neurodevelopmental impairment) following second trimester infection was 7% (7/100, after excluding cases that were terminated) with a 3% incidence of partial unilateral sensory neural hearing loss and a 5% incidence of minor neurodevelopmental abnormalities, including slight verbal and motor delay. Following third trimester infection, there was one case of a very mild motor delay. The incidence proportion of abnormal prenatal findings on US or MRI was not significantly correlated to hearing loss or neurodevelopmental abnormalities.

CONCLUSIONS

Second trimester infection is associated with a slight risk of developing mild childhood sequelae, mostly partial unilateral hearing loss, which may develop late in childhood. Prenatal imaging failed to predict the development of childhood adverse outcome.

Low Maternal Immunoglobulin G Avidity and Single Parity as Adverse Implications of Human Cytomegalovirus Vertical Transmission in Pregnant Women with Immunoglobulin M Positivity

Human cytomegalovirus (CMV) is the leading cause of neurological sequelae in infants. Understanding the risk factors of primary CMV infection is crucial in establishing preventive strategies. Thus, we conducted a retrospective cohort study to identify risk factors of vertical transmission among pregnant women with immunoglobulin (Ig) M positivity. The study included 456 pregnant women with IgM positivity. Information on age, parity, occupation, clinical signs, IgM levels, and IgG avidity index (AI) was collected. The women were divided into infected and non-infected groups. The two groups showed significant differences in IgM level, IgG AI, number of women with low IgG AI, clinical signs, and number of pregnant women with single parity. In the multiple logistic regression analysis, pregnant women with single parity and low IgG AI were independent predictors. Among 40 women who tested negative for IgG antibody in their previous pregnancy, 20 showed low IgG AI in their current pregnancy. Among the 20 women, 4 had vertical transmission. These results provide better understanding of the risk factors of vertical transmission in pregnant women with IgM positivity.

Congenital Human Cytomegalovirus Infection Inducing Sensorineural Hearing Loss

Human cytomegalovirus (HCMV) is the primary cause of congenital infections. Despite its clinical significance, congenital HCMV infection is frequently overlooked clinically since most affected infants are asymptomatic. Sensorineural hearing loss (SNHL) is one of the most widely known disorders caused by congenital HCMV infection. The potential mechanism, however, remains unknown to date. The mechanism by which congenital HCMV infection induces sensorineural deafness has been partly characterized, leading to advancements in diagnosis, therapy, and prevention strategies. HCMV-induced hearing loss primarily involves immune responses, the release of inflammatory factors by natural killer (NK) cells, apoptosis of cochlear spiral ganglion, and potential changes due to vascular dysfunction. The diagnosis of HCMV induced SNHL includes serological examination to mothers, imaging, and amniotic fluid examination. Ganciclovir, mainly used for antiviral therapy and behavioral prevention, can, to some degree, prevent congenital HCMV infection. The role of HCMV infection in hearing loss needs further investigation since the mechanism of hearing loss caused by cytomegalovirus infection is not well understood. Although some advancement has been made in diagnosing and treating SNHL, more improvement is needed. A comprehensive understanding of cytomegalovirus’s pathogenesis is of key importance for preventing, diagnosing, and treating SNHL.

Establishment of a sandwich light-initiated chemiluminescence assay with double antigen for detecting human cytomegalovirus IgG antibody

Determination of human cytomegalovirus IgG (HCMV IgG) level is of great importance in the diagnosis of HCMV infections. In this study, a novel, double antigen sandwich homogeneous immunoassay-based light-initiated chemiluminescent assay (LICA) for measuring HCMV IgG serum levels was developed. This sandwich LICA for HCMV IgG was performed by incubating serum samples with HCMV pp150 protein coated with chemibeads, streptavidin-coated sensibeads, and biotinylated HCMV pp150 protein. The working conditions of this assay were optimized and the correlation between the results of the LICA and enzyme-linked immunosorbent assay was evaluated. As a homogeneous immunoassay, this sandwich LICA could accurately and rapidly determine the serum levels of HCMV IgG with a high-throughput. Thus, this newly developed assay could be a useful analytical tool in the clinical diagnosis of HCMV infections.

Receptors in host pathogen interactions between human cytomegalovirus and the placenta during congenital infection

Cellular receptors in human cytomegalovirus (HCMV) mother to child transmission play an important role in congenital infection. Placental trophoblast cells are a significant cell type in placental development, placental functional processes, and in HCMV transmission. Different cells within the placental floating and chorionic villi present alternate receptors for HCMV cell entry. Syncytiotrophoblasts present neonatal Fc receptors that bind and transport circulating maternal immunoglobulin G across the placental interface which can also be bound to HCMV virions, facilitating viral entry into the placenta and foetal circulation. Cytotrophoblast express HCMV receptors including integrin-α1β1, integrin-αVβ3, epidermal growth factor receptor and platelet-derived growth factor receptor alpha. The latter interacts with HCMV glycoprotein-H, glycoprotein-L and glycoprotein-O (gH/gL/gO) trimers (predominantly in placental fibroblasts) and the gH/gL/pUL128, UL130-UL131A pentameric complex in other placental cell types. The pentameric complex allows viral tropism of placental trophoblasts, endothelial cells, epithelial cells, leukocytes and monocytes. This review outlines HCMV ligands and target receptor proteins in congenital HCMV infection.

Overview of Human Cytomegalovirus Pathogenesis

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

Maternal infection and stillbirth: a review

Introduction: Maternal infections likely are an important cause of stillbirths, especially in sub-Saharan Africa and south Asia, where the burden is highest. Due to the lack of routine testing for infection, which can be complex and often expensive, the prevalence of infection during pregnancy and the association of many infections with stillbirth are not well-documented, especially in low-resource countries.Methods: Following an extensive literature review of infection and stillbirth initially published in 2010, we conducted a review of literature in the last 10 years to identify infections associated with stillbirth, focused on those in low-resource settings.Results: During the last 10 years, over 40 bacterial, viral and other pathogens have been associated with stillbirth. Newly emerging viral infections such as Denge as well as several well-established, but not yet eliminated infections such as rubella have been associated with stillbirth. Two of the maternal infections most strongly associated with stillbirth, each with about a 2-fold risk, are malaria and syphilis but others have been associated with risk in a range of studies. With a lack of routine antenatal screening, many pathogens are identified as associated with stillbirth only through case reports. Infection remains an important, yet understudied, cause of stillbirth.Conclusion: Research studies to determine definitive associations between various infections and stillbirth are important to better understand the role of infections and strategies to reduce infection-related stillbirth.Summary This review explores the association between infections and stillbirths focusing on low-income country studies published in the last 10 years. Much information about these relationships comes from case reports. Research resulting in a better understanding of the causes and strategies to reduce infection-related stillbirth is necessary.

Outcome of cochlear implantation in children with congenital Cytomegalovirus infection: A retrospective case control study

INTRODUCTION

To date, cCMV represents the most frequent non-genetic congenital cause of permanent sensorineural hearing loss (SNHL) in childhood and the leading infectious cause of developmental and neurologic disabilities. The aim of this paper is to describe the outcome of cochlear implantation in children affected by severe-to-profound sensorineural hearing loss, due to a symptomatic or asymptomatic cCMV infection, particularly comparing their performance results to that of matched mutated Connexin 26 (Cx26) implanted patients.

METHODS

Retrospective case control study. The clinical data of symptomatic cCMV and asymptomatic cCMV patients were collected and compared to those of Cx26 patients matched for age and pre-CI (cochlear implant) linguistic category; all subjects were affected by bilateral severe-to-profound SNHL and were treated by CI and speech therapy rehabilitation. The Speech Perception Category, the language stage and the linguistic level scores, at 6 months, 1 year, and 3-4 years after CI of the three groups (symptomatic cCMV, asymptomatic cCMV and Cx26 mutation) were collected and compared.

RESULTS

Statistical analysis did not show any significant difference in pre-CI perception category and linguistic level among the three groups; the symptomatic cCMV group showed a statistically worse performance of the language stage over time (p = 0.017).

CONCLUSIONS

Our data support that children affected by cCMV have improved language abilities over time, although the symptomatic cCMV group achieved a lower language stage 3-4 years after CI compared to the asymptomatic cCMV and Cx26 mutation groups. Nonetheless, to date, CI supported by speech therapy can be considered an effective intervention for children affected by cCMV-related severe-to-profound hearing loss.

A multiple regression model for predicting a high cytomegalovirus immunoglobulin G avidity level in pregnant women with IgM positivity

OBJECTIVE

To establish a model to predict high cytomegalovirus (CMV) immunoglobulin (Ig)G avidity index (AI) using clinical information, to contribute to the mental health of CMV-IgM positive pregnant women.

METHODS

We studied 371 women with IgM positivity at ≤14 w of gestation. Information on the age, parity, occupation, clinical signs, IgM and G values, and IgG AI was collected. The IgG AI cut-off value for diagnosing congenital infection was calculated based on a receiver operating characteristic curve analysis. Between-group differences were assessed using the Mann-Whitney U-test or χ² analysis. The factors predicting a high IgG AI were determined using multiple logistic regression.

RESULTS

The women were divided into high or low IgG AI groups based on an IgG AI cut-off value of 31.75. There were significant differences in the IgG and IgM levels, age, clinical signs, and the number of women with one parity between the two groups. In a multiple logistic regression analysis, IgM and the number of women with one parity were independent predictors. This result helped us establish a mathematical model that correctly classified the IgG AI level for 84.6% of women.

CONCLUSION

We established a highly effective model for predicting a high IgG AI immediately after demonstrating IgM positivity.

Human Neural Stem Cell Systems to Explore Pathogen-Related Neurodevelopmental and Neurodegenerative Disorders

Building and functioning of the human brain requires the precise orchestration and execution of myriad molecular and cellular processes, across a multitude of cell types and over an extended period of time. Dysregulation of these processes affects structure and function of the brain and can lead to neurodevelopmental, neurological, or psychiatric disorders. Multiple environmental stimuli affect neural stem cells (NSCs) at several levels, thus impairing the normal human neurodevelopmental program. In this review article, we will delineate the main mechanisms of infection adopted by several neurotropic pathogens, and the selective NSC vulnerability. In particular, TORCH agents, i.e., Toxoplasma gondii, others (including Zika virus and Coxsackie virus), Rubella virus, Cytomegalovirus, and Herpes simplex virus, will be considered for their devastating effects on NSC self-renewal with the consequent neural progenitor depletion, the cellular substrate of microcephaly. Moreover, new evidence suggests that some of these agents may also affect the NSC progeny, producing long-term effects in the neuronal lineage. This is evident in the paradigmatic example of the neurodegeneration occurring in Alzheimer's disease.

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

Purpose

To determine the frequency of fetal infection as well as adverse pregnancy outcomes following antenatal hyperimmunoglobulin (HIG) treatment for primary cytomegalovirus (CMV) infection in pregnancy.

Methods

In our observational cohort study, data from 46 women with a primary CMV infection during pregnancy were evaluated. Primary CMV infection was defined by seroconversion or the presence of CMV-IgM and low CMV-IgG avidity. All women received at least two or more infusions of HIG treatment (200 IU/kg). Congenital CMV infection (cCMV) was diagnosed by detection of CMV in amniotic fluid and/or neonatal urine. We compared the rate of maternal–fetal transmission from our cohort to data without treatment in the literature. The frequency of adverse pregnancy outcomes was compared to those of live-born infants delivered in our clinic.

Results

We detected 11 intrauterine infections in our cohort, which correlates to a transmission rate of 23.9%. Compared to the transmission rate found in cases without treatment (39.9%), this is a significant reduction (P = 0.026). There were no adverse pregnancy outcomes in our cohort. The mean gestational age at delivery was 39 weeks gestation in treatment and control group.

Conclusion

The administration of HIG for prevention of maternal–fetal CMV transmission during pregnancy seems safe and effective.

Congenital cytomegalovirus infection and audiological follow-up: electrophysiological auditory threshold before 3 months of age as a predictor of hearing outcome at 3 years of age

OBJECTIVE

We aimed to evaluate whether electrophysiological auditory thresholds (EATs) before 3 month of age, as assessed by the auditory brainstem responses (ABR) test and the auditory steady state responses (ASSR) test, can predict hearing outcome at 3 years of age among children born with congenital cytomegalovirus (cCMV) infection.

STUDY DESIGN

Audiological assessment was performed before 3 months of age, and every 6 months thereafter until 3 years of age, in a population of 63 children (126 ears). EATs before 3 months of age and at 3 years of age were compared.

RESULT

No ear with an EAT of ≤30 dBHL (i.e. normal hearing) before 3 months of age showed worsening EATs at 3 years of age.

CONCLUSION

An EAT of ≤30 dBHL obtained by ABR and ASSR tests before 3 months of age is predictive of a normal hearing at 3 years of age in children born with cCMV.

Maternal type of CMV infection and sequelae in infants with congenital CMV: Systematic review and meta-analysis

Cytomegalovirus (CMV) is the most common congenital infection. Intrauterine transmission may occur following primary (PI) or non-primary (NPI) maternal infection and result in both neonatal symptomaticdisease and long-term complications.The aim of the present systematic review and meta-analysis was the qualitative and quantitative comparison of neonatal symptomatic disease and long-term sequelae of congenitally CMV infected children born following maternal PI or NPI. Articles from MEDLINE and SCOPUS databases were systematically reviewed. Articles describing neonatal symptoms and/or long-term sequelae in infants and children with cCMV born to mothers following PI and NPI were eligible.From eligible articles, data on the prevalence of neonatal symptoms, sensorineural hearing loss (SNHL) or neurologic sequelae in children born following PI and NPI were extracted and statistically analyzed. Maternal infection status did not influence neonatal symptomatic disease (pooled Odds Ratio (OR) 0.83, 95 % CI [0.55; 1.27], p=0.397). Additionally, the two groups of cCMV infected children had similar risk of developing SNHL, bilateral SNHL or other neurologic outcomes. Importantly, these findings remained as such, when newborns identified through universal screening were separately analyzed. Finally, when data on symptomatic and/or asymptomatic newborns were evaluated alone, maternal type was not associated with outcomes examined. Considering available data, the universal screening of all newborns for CMV infection may be discussed as a perspective. The systematic review and meta-analysis were registered in PROSPERO (Prospero registration number: CRD42019125179).

Cytomegalovirus seroprevalence in pregnant women in the western region of Romania: A large-scale study

Cytomegalovirus (CMV) infection is the most common congenital infection worldwide, and remains a significant cause of the neurological deficiency and sensory deafness in developed countries. Maternal primary infection, reactivation or reinfection during pregnancy may lead to fetal infection and congenital CMV syndrome. The purpose of this study was to analyze the CMV seroprevalence according to demographic features of pregnant women in western Romania as well as the evolution of CMV immunity in two time intervals. IgG anti-CMV antibodies were tested in sera of 8,951 pregnant women during two successive intervals: 2008-2010 (n=1466) and 2015-2018 (n=7485). The CMV seroprevalence in women of reproductive age decreased from 94.6 to 91.80% in the last decade. The seroprevalence was higher in women from rural areas compared with those from urban areas. These results show that the western region of Romania has a low-risk profile for primary CMV infection during pregnancy due to a large number of seropositive women. However, this risk has increased in the last ten years, from 5.4 to 8.2%, which may show the need to implement a national screening program.

Acute Perinatal Infection and the Evidenced-Based Risk of Intrauterine Diagnostic Testing: A Structured Review

BACKGROUND

The prevalence of perinatal infection from maternal exposure is increasing. The prevalence of acute maternal infections identifies cytomegalovirus, parvovirus B19, toxoplasmosis, and varicella as the most common organisms and in the order of frequency. Maternal informed consent and understanding is required before intrauterine testing for fetal infectious and possible genetic risk assessment.

METHODS

This structured review of the reproductive published literature focuses on the risks of amniocentesis and cordocentesis diagnostic procedure-related fetal loss rates and fetal vertical transmission (VT) rates from published infected pregnant cohorts.

RESULTS

The total postprocedure fetal loss rate for diagnostic amniocentesis procedures, in limited infectious cohorts, is 1.5% and does not appear to be increased compared to "noninfected" amniocentesis cohorts using an estimated background spontaneous fetal loss rate (no procedure) of 0.65%. The "pooled" unintended fetal loss rate is from small infected population cohorts, but can be used for counseling purposes. Postcordocentesis fetal loss risk, in an infected cohort, is not possible to estimate due to limited data. The "biological spontaneous fetal loss rate" risk with a perinatal infection (positive or negative fetal anomalies) and no diagnostic procedure before 20 weeks of gestation is reviewed. The risk of VT in acute infection cohorts as a result of the intra-amniotic diagnostic procedure is not found to be increased.

CONCLUSION

The unintended "fetal loss" rate after amniocentesis for perinatal infected cohorts is similar to that of noninfected cohorts, but the estimate is based on limited infected cohorts. There was no procedure-based risk of fetal VT in the infected cohorts, but identification of postprocedure maternal bleeding into the amniotic cavity increases the potential risk. Maternal knowledge translation and an informed consent process with risk-benefit maternal/fetal risk counseling are required prior to any diagnostic amniocentesis procedure.

Impact of Syrian refugees on congenital TORCH infections screening in Turkey

AIM

To demonstrate the effect of the Syrian refugee population on the prevalence of congenital TORCH (Toxoplasmosis, Other [syphilis, varicella-zoster, parvovirus B19], Rubella, Cytomegalovirus [CMV] and Herpes) infections and to evaluate the cost-effectiveness of population-based TORCH screening during pregnancy in Turkey.

METHODS

Pregnant women (n = 9754) were enrolled. Ultrasonographic findings, immunoglobulin (Ig)M and IgG seropositivity, avidity, amniocentesis and DNA-polymerase chain reaction (PCR) results were compared. Costs were calculated based on invoice amounts from the Health Applications Communique pricing system.

RESULTS

The prevalence of TORCH seropositivity in Turkey was not significantly different between all regions (P > 0.05). Overall, 1333 (13.67%) pregnant Syrian refugees were included in the study. Acute CMV, rubella and Toxoplasma gondii infections (according to low IgG avidity in IgM positive patients) were detected in 17.82%, 21.53% and 14.07% of women, respectively. Twenty-four women underwent an amniocentesis procedure and nine of them had positive DNA-PCR and reverse transcription-PCR results. All women with positive results opted to terminate the pregnancy. There was no statistical difference among groups according to the rate of low IgG avidity in IgM-positive patients and termination rates for T. gondii, rubella and CMV (P > 0.05). Total cost for screening the entire study population was presented in US dollars (USD). A total of 71 529 and prenatal diagnosis with positive invasive test results were obtained in nine women: toxoplasmosis in four, CMV in three and rubella in two women.

CONCLUSION

Population-based screening for prenatal TORCH infections is not cost-effective in Turkey. Syrian refugees have a limited effect on the increasing prevalence of congenital TORCH infections.

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

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

Cytomegalovirus and Epstein-Barr Virus Associations with Neurological Diseases and the Need for Vaccine Development

Herpesviruses have been isolated from a wide range of hosts including humans—for which, nine species have been designated. The human herpesviruses are highly host adapted and possess the capacity for latency, allowing them to survive in the host for life, effectively hidden from the immune system. This ability of human herpesviruses to modulate the host immune response poses particular challenges for vaccine development but at the same time proves attractive for the application of human herpesvirus vaccines to certain spheres of medicine. In this review, congenital cytomegalovirus (CMV) infection and hearing loss will be described followed by a comment on the status of current vaccine development. Secondly, the association of Epstein–Barr virus (EBV) infection with multiple sclerosis (MS) and how EBV vaccination may be of benefit will then be discussed. Prevention of congenital CMV by vaccination is an attractive proposition and several vaccines have been evaluated for potential use. Particularly challenging for the development of CMV vaccines are the needs to prevent primary infection, reinfection, and reactivation at the same time as overcoming the capacity of the virus to generate highly sophisticated immunomodulatory mechanisms. Cost and the practicalities of administering potential vaccines are also significant issues, particularly for low- and middle-income countries, where the burden of disease is greatest. An effective EBV vaccine that could prevent the 200,000 new EBV-associated malignancies which occur globally each year is not currently available. There is increasing interest in developing EBV vaccines to prevent MS and, in view of the association of infectious mononucleosis with MS, reducing childhood infectious mononucleosis is a potential intervention. Currently, there is no licensed EBV vaccine and, in order to progress the development of EBV vaccines for preventing MS, a greater understanding of the association of EBV with MS is required.

Viral Infections and the Neonatal Brain

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

A Custom-Designed Recombinant Multiepitope Protein for Human Cytomegalovirus Diagnosis

BACKGROUND

The Human Cytomegalovirus (HCMV) has infected more than 90% of the world population and its prevalence can be related to the individuals geographical and socialeconomic status. Serological tests based on ELISA are pivotal for HCMV diagnosis. Due to the lack of standardization in the production/purification of antigens from viral preparations, ELISA tests are based on several recombinant proteins or peptides. As an alternative, multiepitope proteins may be employed.

OBJECTIVE

In this work, we developed a recombinant multiepitope protein (rMEHCMV) for HCMV diagnosis based on conserved and immunodominant epitopes derived from tegument (pp150, pp65 and pp28), glycoprotein gB (pp38) and DNA polymerase subunit (pp52) of HCMV.

METHODS

The rMEHCMV gene was synthesized de novo and overexpressed in Escherichia coli cells. The recombinant protein was purified to homogeneity using a Ni-NTA column. Biophysical analysis of recombinant protein was performed by circular dichroism. A preliminary biological activity test was performed using 12 positive human sera samples by using an in-house IgG ELISA. The following patents database were consulted: Espacenet, Google Patents and the National Institute of Intellectual Property (INPI, Brazil).

RESULTS

The recombinant multiepitope protein was successfully expressed in E. coli. The structural data obtained by circular dichroism spectroscopy showed that rMEHCMV is structurally disordered. An in-house IgG ELISA test with rMEHCMV was successfully used to recognized IgG from human serum samples.

CONCLUSION

Together, our results show that rMEHCMV should be considered as a potential antigenic target for HCMV diagnosis.

Infections in pregnancy

Infections in pregnancy represent a challenging and often underappreciated area of concern for many specialists and general practitioners and can cause serious sequelae. Antenatal status should be highlighted on pathology request forms, as this serves to alert the laboratory of the need to store serum for an extended period. Prior antenatal specimens can be forwarded to other laboratories to enable testing in parallel with the more recent sample. Women with a confirmed, potentially vertically transmissible infection should be referred to a specialist with expertise in the management of perinatal infections. Cytomegalovirus infection is the most common congenital infection. Women who care for young children are at greater risk of exposure to the virus. Preventive steps including hand hygiene and avoiding contact with children's urine, mucous and saliva are recommended for all pregnant women. The incidence of parvovirus B19 infection in pregnancy is unknown. This infection is highly contagious and may result in fetal loss; particularly in the first half of pregnancy, pregnant women should avoid contact with adults or children who may have an infection.

Diagnostic Value of Cytomegalovirus IgM Antibodies at Birth in PCR-Confirmed Congenital Cytomegalovirus Infection

Although cytomegalovirus (CMV) DNA detection in urine is the standard method for diagnosing congenital cytomegalovirus infection (CCMVI), polymerase chain reaction (PCR) is not comprehensively available. Currently, the efficacy of CMV-specific IgM (CMV-IgM) and CMV-specific IgG (CMV-IgG) detection remains unclear. To determine the sensitivity and specificity of CMV-specific antibodies at birth, we investigated CMV-IgM and CMV-IgG titers in CCMVI cases and non-CCMVI controls, with confirmed diagnoses by urine quantitative real-time PCR within 3 weeks after birth. We included 174 infants with suspected CCMVI in whom serological testing was performed within the first 2 weeks after birth during 2012–2018. We classified the participants into a CCMVI group (n = 32) and non-CCMVI group (n = 142) based on their urine PCR results. The CMV-IgM-positive rate was 27/32 (84.4%) in the CCMVI group, compared with 1/142 (0.7%) in the non-CCMVI group (p < 0.0001). The positive CMV-IgG rates were 32/32 (100%) in the CCMVI group and 141/142 (99.3%) in the non-CCMVI group. The positive predictive value for CMV-IgM was high at 96.4% (27/28). This value may be sufficient for clinical use, especially in settings with limited resources where PCR is unavailable. However, CCMVI screening by CMV-IgM alone appears insufficient because of the considerable number of false-negative cases.

Challenges and Clinical Implications of the Diagnosis of Cytomegalovirus Lung Infection in Children

PURPOSE OF REVIEW

Pulmonary cytomegalovirus (CMV) infection is a potential lethal disease in children, but it remains a diagnostic challenge. The differentiation between latent CMV infections with viral shedding and active infections is difficult and may lead to false positives in bronchoalvolar lavage (BAL) PCR detection. This review summarizes current diagnostic approaches for CMV lung infection in children including progress in the identification of underlying immune defects linked to this condition.

RECENT FINDINGS

There is increasing literature supporting that the combined assessment of host risk factors and lung disease pattern is essential for the diagnosis of pulmonary CMV infection in children. The most important host risk factor is an immunecompromised state that has expanded from primary or acquired immunodeficiency (e.g., HIV) to include a myriad of immune-dysregulation syndromes (e.g., CTLA4, PIK3 defects). Newborns, paricularly those born premature, are also a high-risk group. At the pulmonary level, active CMV infection is typically characterized by alveolar compromise leading to hypoxemia, ground-glass opacities, and intra-alveolar infiltrates with CMV inclusions in lung biopsy. The identification of active CMV lung infection should trigger additional evaluation of immune defects (primary or secondary) impairing T and NK cell function or innate antiviral responses as well as other immune dysregulation disorders. Lung CMV infections in children are more prevalent in immunocompromised hosts and premature newborns. Lung CMV infections should prompt further investigation into conditions altering immune mechanisms usually in place to contain CMV infections. Common clinical and radiological patterns such as hypoxemia and ground-glass pulmonary opacities may allow early identification and treatment of CMV lung infection and underlying causes in the pediatric population.

Immunometabolic phenotype of BV-2 microglia cells upon murine cytomegalovirus infection

Microglia are resident brain macrophages with key roles in development and brain homeostasis. Cytomegalovirus (CMV) readily infects microglia cells, even as a possible primary target of infection in development. Effects of CMV infection on a cellular level in microglia are still unclear; therefore, the aim of this research was to assess the immunometabolic changes of BV-2 microglia cells following the murine cytomegalovirus (MCMV) infection. In light of that aim, we established an in vitro model of ramified BV-2 microglia (BV-2^∅FCS, inducible nitric oxide synthase (iNOS^low), arginase-1 (Arg-1^high), mannose receptor CD206^high, and hypoxia-inducible factor 1α (HIF-1α^low)) to better replicate the in vivo conditions by removing FCS from the cultivation media, while the cells cultivated in 10% FCS DMEM displayed an ameboid morphology (BV-2^{FCS high}, iNOS^high, Arg-1^low, CD206^low, and HIF-1α^high). Experiments were performed using both ramified and ameboid microglia, and both of them were permissive to productive viral infection. Our results indicate that MCMV significantly alters the immunometabolic phenotypic properties of BV-2 microglia cells through the manipulation of iNOS and Arg-1 expression patterns, along with an induction of a glycolytic shift in the infected cell cultures.

Risk factors associated with the vertical transmission of cytomegalovirus in seropositive pregnant women

Congenital cytomegalovirus infection (cCMV) is the leading cause of childhood disabilities. More recent data indicates that cCMV following maternal nonprimary infection occurs frequently and can cause similar rates of sequelae as those following maternal primary infection. However, the risks associated with cCMV especially in CMV-seropositive women remain unclear. This review summarizes potential risk factors of cCMV in seropositive women with perspectives on the causal link including sociodemographic factors, virological characteristics, the host immune system, genomics, metabonomics and proteomics. These observations and some new molecular markers, although not yet validated as a reliable tool predictive of cCMV, could be the basis for designing future prospective studies.

Rare etiology of arthrogryposis multiplex congenita at term: congenital cytomegalovirus infection

Background

Arthrogryposis multiplex congenita is the presence of multiple congenital contractures of two or more body parts. Congenital cytomegalovirus (CMV) infection is a rare etiology of arthrogryposis.

Case presentation

We report a case of intrauterine fetal akinesia and arthrogryposis multiplex congenita delivered at term with subsequent neonatal demise. Placental pathology and autopsy revealed congenital CMV infection.

Conclusions

Evaluation for potential CMV infection is an important part of the arthrogryposis evaluation which is often missed due to lack of maternal infectious symptoms during pregnancy.

Maturation of the immune system in the fetus and the implications for congenital CMV

Congenital cytomegalovirus (CMV) infection is the most prevalent and consequential congenital infection, among others, that affects approximately 0.6% of all live births worldwide. Timing of maternal infection and maternal immune status largely determine the likelihood of a symptomatic infection. However, recent studies suggest that the fetal immune system, long perceived as naïve and immature, may also play a role in deciding the outcome of congenital CMV infection. Here, we review the development of four immune cells most pertinent to CMV control in the human fetus. αβT cells, B cells, natural killer (NK) cells, and γδT cells are all present, mature and partially functional in utero, and are capable of mounting some form of response to congenital CMV infection. Whether this response is negligible, effective, or harmful remains an open question. Expanding our knowledge of normal and abnormal immune development could provide clinicians with more accurate tools for the detection, monitoring, and treatment of congenital CMV infection in fetuses.

Recognition, treatment, and sequelae of congenital cytomegalovirus in Australia: An observational study

BACKGROUND AND OBJECTIVES

Australian national surveillance data was used to assess recognition, sequelae, and antiviral therapy for congenital cytomegalovirus (CMV) cases.

STUDY DESIGN

Data from congenital CMV cases reported through the Australian Paediatric Surveillance Unit born January 1999 to December 2016 were described and Chi-square tests used to characterise trends and associations in case reporting, maternal CMV serology testing, and antiviral therapy. Descriptive analyses for hearing loss and developmental delay were reported for cases born ≥2004, following introduction of universal neonatal hearing screening.

RESULTS

There were 302 congenital CMV cases (214 symptomatic, 88 asymptomatic). Congenital CMV was suspected in 70.6% by 30 days of age, with no differences across birth cohorts. Maternal CMV serology testing was associated with maternal illness during pregnancy but not birth cohort. There was increasing antiviral use for symptomatic cases, being used in 14% born 1999-2004, 19.6% born 2005-2010, and 44.4% born 2011-2016 (p < 0.001). For those born ≥2004, hearing loss was reported in 42.1% of symptomatic and 26.6% of asymptomatic cases; while developmental delay was reported in 16.9% of symptomatic and 1.3% of asymptomatic cases.

CONCLUSION

There appears to be under-reporting and under-recognition of congenital CMV despite increasing use of antiviral therapy. Universal newborn CMV screening should be considered to facilitate follow-up of affected children and targeted linkage into hearing and developmental services, and to provide population-level infant CMV epidemiology to support research and evaluation of antiviral and adjunctive therapies.

Apparent Diffusion Coefficient Levels and Neurodevelopmental Outcome in Fetuses with Brain MR Imaging White Matter Hyperintense Signal

BACKGROUND AND PURPOSE

One of the perplexing findings of fetal brain MR imaging is white matter T2 hyperintense signal. The aims of our study were initially to determine the main etiologies associated with white matter T2 hyperintense signal, then to examine whether the different etiologies have different ADC values, and, last, to assess the association of white matter T2 hyperintense signal with developmental outcome.

MATERIALS AND METHODS

This was a prospective cohort study of 44 MR imaging scans of fetal brains obtained for suspected brain pathologies at a tertiary medical center during 2011-2015. Clinical data were collected from electronic medical charts. ADC values were measured and averaged in the frontal, parietal, occipital, and temporal lobes. Neurodevelopmental assessments were performed with the Vineland Adaptive Behavior Scales II.

RESULTS

Half of the cases of MRI hyperintense T2 signal of the fetal brain were associated with congenital cytomegalovirus infection. The other half were mainly idiopathic. Thus, the study group was divided to subgroups positive and negative for cytomegalovirus. Both groups had hyperintense signal in the temporal lobe. The group positive for cytomegalovirus had involvement of the parietal lobe. Only this group had increased ADC values in the temporal and parietal lobes. There was no association between the neurodevelopment outcome and the etiologies or ADC values.

CONCLUSIONS

T2 hyperintense signal in fetal brain MRI associated with positive cytomegalovirus infection has increased ADC values in the temporal and parietal lobes, suggestive of brain edema in these areas. However, the association between this finding and neurodevelopment outcome requires further evaluation.

DISTURBANCE OF THE PROGESTERONE AND ITS METABOLITES SYNTHESIS IN THE DEVELOPMENT OF NEUROLOGICAL DISORDERS IN CHILDREN AFTER CYTOMEGALOVIRUS INFECTION DURING PREGNANCY

Cytomegalovirus (CMV) infection is one of the causes of congenital neurological disorders and the virus itself is the most common viral  agent causing an imbalance in the production of placenta  progesterone and its neuroactive metabolites – allopregnenolone and 5α-dihydroprogesterone. The aim was to evaluate the concentration  of progesterone and its metabolites – 5α-dihydroprogesterone and  allopregnenolone – in placenta during exacerbation of CMV infection  in the first trimester of pregnancy, and the impact of these  disturbances on the development of neurological disorders in children. We examined 30 pregnant women with exacerbation of  CMV infection in the first trimester of pregnancy and 30 pregnant  women with latent disease; and later their newborns. The enzyme  immunoassay was used to determine  concentration of progesterone  in placenta; the histochemical method – to determine 5α-dihydroprogesterone and allopregnenolone. Newborns underwent  neurosonography studies. Exacerbation of CMV infection in the first  trimester of pregnancy decreased progesterone in placenta by 1.3  times, 5α-dihydroprogesterone – by 1.73 times and allopregnenolone – by 2 times. Ultrasound examination of the brain  showed ventriculomegaly, periventricular ischemia, and pseudocysts  in newborns up to one year from mothers with exacerbation of CMV  during pregnancy. Later, minimal brain dysfunctions were manifested by motor disorders, increased general, vegetative excitability, and a  tendency to digestive and sleep disorders. The data obtained  indicate that the exacerbation of CMV infection in the first trimester  of pregnancy is interrelated with a decrease in the concentration of progesterone and its metabolites (5α-dihydroprogesterone, allopregnenolone) in the placenta and development of neurological dysfunction in newborns.