Congenital cytomegalovirus (CMV) epidemiology and awareness

T cell inducing vaccine against cytomegalovirus immediate early 1 (IE1) protein provides high level cross strain protection against congenital CMV

Human cytomegalovirus (HCMV) is a leading cause of congenital disease resulting in cognitive impairment and deafness in newborns. Multiple strains of HCMV enable re-infection and convalescent immunity does not protect against risk of congenital CMV (cCMV). Consequently, a cross strain protective CMV vaccine is a high priority. The guinea pig is the only small animal model for cCMV and species specific guinea pig cytomegalovirus (GPCMV) encodes homolog HCMV viral proteins making it suitable for vaccine studies. Neutralizing antibodies against viral entry glycoprotein complexes and cell free virus are insufficient for complete protection because highly cell associated virus enables evasion. CMV T-cell antigens are important in HCMV convalescent immunity and potentially in reducing the risk of cCMV. Immediate early protein IE1 is essential to HCMV and a T-cell target in humans. In this study, a recombinant defective adenovirus encoding GPCMV IE1 (AdIE1) was evaluated in a preclinical vaccine study. AdIE1 vaccinated animals evoked a T-cell response in a guinea pig IFNγ ELISPOT assay to IE1 (GP123). Vaccinated animals exhibited protection against subcutaneous challenge by GPCMV prototype strain (22122) with viral load substantially reduced compared to the unvaccinated control group and previous Ad based vaccine study against viral pp65 tegument protein. In a vaccine study against cCMV, dams were challenged mid-pregnancy with dual wild type virus strains (22122 and clinical strain TAMYC). At birth, pups were evaluated for viral load in target organs. AdIE1 vaccine had high efficacy against cCMV with GPCMV pup transmission reduced from 92% in the litters of the unvaccinated control group of dams to 23% in the vaccine group resulting in an absence of virus or statistically significant reduction in viral load in pup organs. Overall, IE1 is a more protective T-cell antigen than previously studied pp65 providing cross strain immunity against cCMV in this preclinical model.

Maternal Cytomegalovirus (CMV) Serology: The Diagnostic Limitations of CMV IgM and IgG Avidity in Detecting Congenital CMV Infection

INTRODUCTION

Congenital cytomegalovirus (cCMV) is a common congenital viral infection. Testing for cCMV usually begins with assessing maternal CMV serology, specifically IgM and IgG antibodies. A negative maternal CMV IgM suggests a low risk of recent maternal CMV infection, thereby suggesting a low risk of cCMV in the fetus. Consequently, cCMV is often ruled out when maternal CMV IgM is negative.

METHODS

In our perinatal autopsy and placental pathology database, we identified 5 cases of cCMV despite negative maternal CMV IgM results in the second trimester.

RESULTS

In all 5 cases, fetal abnormalities were first detected by ultrasound in the second trimester, prompting maternal CMV testing. Since second trimester maternal CMV IgM was negative in all cases, cCMV was considered unlikely, thus precluding further prenatal CMV testing in 4 of these cases. The diagnosis of cCMV was subsequently made through placental and/or autopsy examinations. Following this diagnosis, retrospective CMV serology and IgG avidity testing was performed on stored frozen first-trimester maternal blood samples in 3 cases. Among these, the first-trimester samples in 2 cases were IgG+, IgM+, and exhibited low IgG avidity, suggesting a primary maternal CMV infection around the time of conception. In the third case, both first and second-trimester maternal blood samples were IgG+, IgM-, and showed high IgG avidity, suggesting a non-primary maternal CMV infection (i.e., reactivation or reinfection of CMV).

CONCLUSION

A negative maternal CMV IgM in the second trimester cannot exclude cCMV infection. While CMV IgG avidity testing and analysis of stored frozen first-trimester maternal blood samples provide valuable insights, they have limitations. CMV PCR performed on amniotic fluid is a useful prenatal diagnostic tool. For cases of unexplained fetal abnormalities or death, autopsy and placental examination are recommended.

Ophthalmic Complications, Diagnosis, and Treatment of Congenital Human Cytomegalovirus Infection

Background: Human cytomegalovirus (hCMV) is the most common etiological agent of congenital infections seen in newborns. Among the most commonly observed complications in children with congenital human cytomegalovirus infection are those affecting the visual system. Ocular complications of congenital CMV (cCMV) are a topic rarely addressed in the literature, which prompted the authors to update the available knowledge with the latest data. Methodology: English-language literature published between April 2000 and November 2023 (PubMed, NIH, Google Scholar) was analyzed for ocular complications of cCMV. The data obtained were categorized according to the ocular area involved and the incidence. A compilation of criteria for the symptomatic form of cCMV was also created. Results: The cCMV complications described in the literature affect all parts of the visual system: the anterior segment, the posterior segment, the posterior visual pathways, and the visual cortex. The most commonly described ocular complication of cCMV is choroidal and retinal scarring. Conclusions: Ophthalmic complications of cCMV can cause severe visual disturbances. Ophthalmic diagnosis in newborns should include hCMV PCR testing, which has the highest sensitivity and specificity. In the symptomatic form of cCMV, treatment should be instituted according to recommendations. A consensus should be established for screening of primary hCMV infection in pregnant women, the way in which to define the symptomatic form of cCMV, and the appropriateness and standards of treatment for primary hCMV infection in pregnant women.

Association between White Matter T2 Hyper-Intense Signals in Fetal Brain Magnetic Resonance Imaging and Neurodevelopment of Fetuses with Cytomegalovirus Infection

An association between subtle changes in T2 white matter hyper-intense signals (WMHSs) detected in fetal brain magnetic resonance imaging (fbMRI) and congenital cytomegalovirus (CMV) infection has been established. The research aim of this study is to compare children with congenital CMV infection with neurodevelopment outcome and hearing deficit with and without WMHSs in a historic prospective case study cohort of 58 fbMRIs. Of these, in 37 cases, fbMRI was normal (normal group) and WMHSs were detected in 21 cases (WMHS group). The median infection week of the WMHS group was earlier than the normal fbMRI group (8 and 17 weeks of gestation, respectively). The proportion of infants treated with valganciclovir in the WMHS group was distinctly higher. Hearing impairment was not significantly different between the groups. VABS scores in all four domains were within normal range in both groups. The median score of the motor skills corrected for week of infection was better in the WMHS group. A multivariate analysis using the week of infection interaction variable of WMHS and valganciclovir treatment showed better motor score outcomes in the valganciclovir treatment group despite an earlier week of infection. WMHSs were not associated with neurodevelopmental outcome and hearing deficit. In our cohort, valganciclovir treatment may have a protective effect on fetuses with WMHSs by improving neurodevelopmental outcome.

The Auditory Pathway in Congenitally Cytomegalovirus-Infected Human Fetuses

Congenital cytomegalovirus (CMV) infection is the main cause of non-hereditary sensorineural hearing loss (SNHL). In order to shed light on SNHL pathophysiology, we examined the auditory pathway in CMV-infected fetuses; the temporal lobe, in particular the auditory cortex, and the inner ear. We investigated both inner ears and temporal lobes of 20 human CMV-infected fetuses at 21 weeks of gestation. As a negative group, five fetuses from spontaneous miscarriages without CMV infection were studied. Inner ears and temporal lobes were histologically examined, immunohistochemistry for CMV and CMV-PCR were performed. On the auditory cortex, we evaluated the local microglial reaction to the infection. CMV-positive cells were found in 14/20 brains and the damage was classified as severe, moderate, or mild, according to histological features. Fetuses with severe brain damage had a statistically higher temporal lobe viral load and a higher number of activated microglial cells in the auditory cortex compared to fetuses with mild brain damage (p: 0.01; p: 0.01). In the inner ears, the marginal cells of the stria vascularis were the most CMV positive. In our study, CMV affected the auditory pathway, suggesting a tropism for this route. In addition, in the auditory cortex, microglial activation may favor further tissue damage contributing to hearing loss.

Cytomegalovirus infection during pregnancy: cross-sectional survey of knowledge and prevention practices of healthcare professionals in French-speaking Switzerland

BACKGROUND

Lack of Cytomegalovirus (CMV) knowledge among healthcare professionals has been proven to be the main threat to pregnant women's awareness, preventing them from reducing the risk of infection. The aims of this study were to assess the knowledge and practices of French-speaking Swiss perinatal professionals in terms of CMV prevention, as well as the sociodemographic-professional factors that influence them.

METHODS

This observational study used a cross-sectional design to collect data-via an anonymous electronic questionnaire in French distributed to gynecologists-obstetricians, general practitioners and midwives via various channels: e-mails and social networks of partner centers, professional associations, and conferences. The 41-item questionnaire collected data on sociodemographic and professional characteristics, general CMV knowledge, national recommendation knowledge and prevention practices. Univariable and multivariable analyses were performed.

RESULTS

A total of 110 gynecologist-obstetricians, 5 general practitioners and 226 midwives participated in the study. While more than 80% of practitioners were familiar with protective hygiene measures, significant gaps were highlighted concerning the transmission routes, as well as the signs of short- and long-term congenital CMV infection. Regarding practice, 63.3% of participants provided information on CMV to their patients, mainly during the first antenatal visit. Among those who did not, lack of knowledge and forgetfulness were the two main reasons cited. Concerning systematic screening, 45.7% of participants offered it to their patients, and 37.3% only offered it to "at risk" groups. The existence of national guidelines on CMV was known by 62.0% of participants. Multivariable analysis revealed that working as a gynecologist-obstetrician was independently associated with higher score of preventive practices, while performing ultrasound or preconception consultations was independently associated with a higher score of general CMV knowledge, and working in a university hospital was independently associated with a higher score of Swiss recommendation knowledge. A level of training higher than the basic medical or midwifery diploma and participation in fetal medicine symposia both promote a higher score of CMV knowledge and prevention practices in line with current recommendations.

CONCLUSION

This study confirms the significant gaps in CMV knowledge among French-speaking Swiss caregivers along with the heterogeneity of their prevention practices. To raise awareness among pregnant women and reduce the burden of congenital CMV infections, improving professional knowledge through access to specific training and standardizing practices should be a national priority.

Congenital cytomegalovirus infection: the state of the art and future perspectives

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection, with an estimated incidence of approximately one in 200 infants in high-income settings. Approximately one in four children may experience life-long consequences, including sensorineural hearing loss and neurodisability. Knowledge regarding prevention, diagnosis, and treatment increased in the recent years, but some challenges remain. In this review, we tried to summarize the current knowledge on both the obstetrical and pediatric areas, while also highlighting controversial aspects and future perspectives. There is a need to enhance awareness among the general population and pregnant women through specific information programs. Further research is needed to better define the classification of individuals at birth and to have a deeper understanding of the long-term outcomes for so defined children. Finally, the availability of valaciclovir medication throughout pregnancy, where appropriate, has prompted the assessment of a universal serological antenatal screening. It is recommended to establish a dedicated unit for better evaluation and management of both mothers and children.

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

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

Presence of MDSC associates with impaired antigen-specific T cell reactivity following COVID-19 vaccination in cirrhotic patients

Background and aims

Cirrhosis entails high risk of serious infections and abated efficiency of vaccination, but the underlying mechanisms are only partially understood. This study aimed at characterizing innate and adaptive immune functions, including antigen-specific T cell responses to COVID-19 vaccination, in patients with compensated and decompensated cirrhosis.

Methods

Immune phenotype and function in peripheral blood from 42 cirrhotic patients and 44 age-matched healthy controls were analysed after two doses of the mRNA-based COVID-19 vaccines [BNT162b2 (Pfizer BioNTech) or mRNA-1273 (Moderna)].

Results

Cirrhotic patients showed significantly reduced blood counts of antigen-presenting dendritic cells (DC) and high counts of monocytic myeloid-derived suppressor cells (M-MDSC) as compared to healthy controls. In addition, monocytic cells recovered from cirrhotic patients showed impaired expression of the antigen-presenting molecule HLA-DR and the co-stimulatory molecule CD86 upon Toll-like receptor (TLR) stimulation. These features were more prominent in patients with decompensated cirrhosis (Child-Pugh classes B & C). Interestingly, while patients with compensated cirrhosis (Child-Pugh class A) showed an inflammatory profile with myeloid cells producing the proinflammatory cytokines IL-6 and TNF, decompensated patients produced reduced levels of these cytokines. Cirrhotic patients, in particular those with more advanced end-stage liver disease, mounted reduced antigen-specific T cell reactivity to COVID-19 vaccination. Vaccine efficiency inversely correlated with levels of M-MDSC.

Conclusion

These results implicate MDSC as mediators of immunosuppression, with ensuing deficiency of vaccine-specific T cell responses, in cirrhosis.

Stabilization of the human cytomegalovirus UL136p33 reactivation determinant overcomes the requirement for UL135 for replication in hematopoietic cells

Human cytomegalovirus (HCMV) is a beta herpesvirus that persists indefinitely in the human host through a latent infection. The polycistronic UL133-UL138 gene locus of HCMV encodes genes regulating latency and reactivation. While UL138 is pro-latency, restricting virus replication in CD34+ hematopoietic progenitor cells (HPCs), UL135 overcomes this restriction and is required for reactivation. By contrast, UL136 is expressed with later kinetics and encodes multiple proteins with differential roles in latency and reactivation. Like UL135, the largest UL136 isoform, UL136p33, is required for reactivation from latency in HPCs; viruses failing to express either protein are unresponsive to reactivation stimuli. Furthermore, UL136p33 is unstable, and its instability is important for the establishment of latency, and sufficient accumulation of UL136p33 is a checkpoint for reactivation. We hypothesized that stabilizing UL136p33 might overcome the requirement of UL135 for replication. We generated recombinant viruses lacking UL135 that expressed a stabilized variant of UL136p33. Stabilizing UL136p33 did not impact the replication of the UL135 mutant virus in fibroblasts. However, in the context of infection in HPCs, stabilization of UL136p33 strikingly compensated for the loss of UL135, resulting in increased replication in CD34+ HPCs and in humanized NOD-scid IL2Rγcnull (huNSG) mice. This finding suggests that while UL135 is essential for replication in HPCs, it functions largely at steps preceding the accumulation of UL136p33, and that stabilized expression of UL136p33 largely overcomes the requirement for UL135. Taken together, our genetic evidence indicates an epistatic relationship between UL136p33 and UL135, whereby UL135 may initiate events early in reactivation that drive the accumulation of UL136p33 to a threshold required for productive reactivation. IMPORTANCE Human cytomegalovirus (HCMV) is one of nine human herpesviruses and a significant human pathogen. While HCMV establishes a lifelong latent infection that is typically asymptomatic in healthy individuals, its reactivation from latency can have devastating consequences in the immunocompromised. Defining viral genes important in the establishment of or reactivation from latency is important to defining the molecular basis of latent and replicative states and in controlling infection and CMV disease. Here we define a genetic relationship between two viral genes in controlling virus reactivation from latency using primary human hematopoietic progenitor cells and humanized mouse models.

Advances in mRNA vaccines for viral diseases

Since the onset of the pandemic caused by severe acute respiratory syndrome coronavirus 2, messenger RNA (mRNA) vaccines have demonstrated outstanding performance. mRNA vaccines offer significant advantages over conventional vaccines in production speed and cost-effectiveness, making them an attractive option against other viral diseases. This article reviewed recent advances in viral mRNA vaccines and their delivery systems to provide references and guidance for developing mRNA vaccines for new viral diseases.

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.

Cytomegalovirus (CMV) seroprevalence among women at childbearing age, maternal and congenital CMV infection: policy implications of a descriptive, retrospective, community-based study

BACKGROUND

Maternal CMV infection during pregnancy, either primary or non-primary, may be associated with fetal infection and long-term sequelae. While guidelines recommend against it, screening for CMV in pregnant women is a prevalent clinical practice in Israel. Our aim is to provide updated, local, clinically relevant, epidemiological information about CMV seroprevalence among women at childbearing age, the incidence of maternal CMV infection during pregnancy and the prevalence of congenital CMV (cCMV), as well as to provide information about the yield of CMV serology testing.

METHODS

We performed a descriptive, retrospective study of women at childbearing age who were members of Clalit Health Services in the district of Jerusalem and had at least one gestation during the study period (2013-2019). We utilized serial serology tests to determine CMV serostatus at baseline and at pre/periconception and identified temporal changes in CMV serostatus. We then conducted a sub-sample analysis integrating inpatient data on newborns of women who gave birth in a single large medical center. cCMV was defined as either positive urine CMV-PCR test in a sample collected during the first 3 weeks of life, neonatal diagnosis of cCMV in the medical records, or prescription of valganciclovir during the neonatal period.

RESULTS

The study population Included 45,634 women with 84,110 associated gestational events. Initial CMV serostatus was positive in 89% women, with variation across different ethno-socioeconomic subgroups. Based on consecutive serology tests, the detected incidence rate of CMV infection was 2/1000 women follow-up years, among initially seropositive women, and 80/1000 women follow-up years, among initially seronegative women. CMV infection in pregnancy was identified among 0.2% of women who were seropositive at pre/periconception and among 10% of women who were seronegative. In a subsample, which included 31,191 associated gestational events, we identified 54 newborns with cCMV (1.9/1000 live births). The prevalence of cCMV among newborns of women who were seropositive at pre/periconception was lower than among newborns of women who were seronegative (2.1 vs. 7.1/1000). Frequent serology tests among women who were seronegative at pre/periconception detected most primary CMV infections in pregnancy that resulted in cCMV (21/24). However, among women who were seropositive, serology tests prior to birth detected none of the non-primary infections that resulted in cCMV (0/30).

CONCLUSIONS

In this retrospective community-based study among women of childbearing age characterized by multiparity and high seroprevalence of CMV, we find that consecutive CMV serology testing enabled to detect most primary CMV infections in pregnancy that led to cCMV in newborns but failed to detect non-primary CMV infections in pregnancy. Conducting CMV serology tests among seropositive women, despite guidelines' recommendations, has no clinical value, while it is costly and introduces further uncertainties and distress. We thus recommend against routine CMV serology testing among women who were seropositive in a prior serology test. We recommend CMV serology testing prior to pregnancy only among women known to be seronegative or women whose serology status is unknown.

American Academy of Audiology Position Statement on Early Identification of Cytomegalovirus in Newborns

The American Academy of Audiology recommends early identification of congenital cytomegalovirus (cCMV) through screening to allow for appropriate early diagnosis, intervention, and monitoring for congenital, progressive, and delayed-onset hearing loss in infants with cCMV.Early identification of cCMV is a valuable component in the diagnostic evaluation of infants with sensorineural hearing loss. The Academy recognizes the important role audiologists serve as clinical care providers and educators and advocates for early identification and audiological management of infants with cCMV.

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.

The cost-effectiveness of targeted screening for congenital cytomegalovirus in newborns compared to clinical diagnosis in the US

OBJECTIVE

Congenital cytomegalovirus (cCMV) is the leading environmental cause of hearing loss (HL) among children, affecting four in one thousand newborns. cCMV testing in the US is currently based on clinical diagnosis which does not consistently identify cCMV cases and precludes early intervention to prevent and reduce the severity of HL. We estimated the cost-effectiveness of targeted newborn screening and cCMV testing among newborns compared to clinical diagnosis.

METHODS

We use a decision-analytic model to estimate the costs of preventing HL progression, of additional cases of severe HL, of identifying a case of HL one year earlier, and of identifying an additional case of cCMV, through targeted screening and cCMV testing for infants failing two newborn hearing screens with follow-up to age five. We also estimate the costs of nationwide implementation of a newborn screening and testing program. Model pathways were based on best practices for screening, testing, and treatment. Probabilities were drawn from the published literature; costs were estimated based on Medicare reimbursement rates. Probabilistic and scenario analyses were conducted to determine the robustness of results.

RESULTS

Targeted testing and cCMV screening, compared to standard of care, cost an additional $2.96 (±2.26) per infant screened and identified 0.00038 (±0.00022) cases of HL, 3.8 in 10000 children, at a cost of $8197 (±4217) per case of HL identified. Implementing targeted screening for all children in the US was estimated to cost $193,229.

CONCLUSIONS

Although cases numbers are small, our model shows that targeted newborn screening and cCMV testing reduced cases of HL progression. Adoption of newborn targeted screening as standard of care should be considered given it may prevent disability at very low cost.

Suppression of MR1 by human cytomegalovirus inhibits MAIT cell activation

Introduction

The antigen presentation molecule MHC class I related protein-1 (MR1) is best characterized by its ability to present bacterially derived metabolites of vitamin B2 biosynthesis to mucosal-associated invariant T-cells (MAIT cells).

Methods

Through in vitro human cytomegalovirus (HCMV) infection in the presence of MR1 ligand we investigate the modulation of MR1 expression. Using coimmunoprecipitation, mass spectrometry, expression by recombinant adenovirus and HCMV deletion mutants we investigate HCMV gpUS9 and its family members as potential regulators of MR1 expression. The functional consequences of MR1 modulation by HCMV infection are explored in coculture activation assays with either Jurkat cells engineered to express the MAIT cell TCR or primary MAIT cells. MR1 dependence in these activation assays is established by addition of MR1 neutralizing antibody and CRISPR/Cas-9 mediated MR1 knockout.

Results

Here we demonstrate that HCMV infection efficiently suppresses MR1 surface expression and reduces total MR1 protein levels. Expression of the viral glycoprotein gpUS9 in isolation could reduce both cell surface and total MR1 levels, with analysis of a specific US9 HCMV deletion mutant suggesting that the virus can target MR1 using multiple mechanisms. Functional assays with primary MAIT cells demonstrated the ability of HCMV infection to inhibit bacterially driven, MR1-dependent activation using both neutralizing antibodies and engineered MR1 knockout cells.

Discussion

This study identifies a strategy encoded by HCMV to disrupt the MR1:MAIT cell axis. This immune axis is less well characterized in the context of viral infection. HCMV encodes hundreds of proteins, some of which regulate the expression of antigen presentation molecules. However the ability of this virus to regulate the MR1:MAIT TCR axis has not been studied in detail.

Human Cytomegalovirus UL138 Interaction with USP1 Activates STAT1 in infection

Innate immune responses are crucial for limiting virus infection. However, viruses often hijack our best defenses for viral objectives. Human Cytomegalovirus (HCMV) is a beta herpesvirus which establishes a life-long latent infection. Defining the virus-host interactions controlling latency and reactivation is vital to the control of viral disease risk posed by virus reactivation. We defined an interaction between UL138, a pro-latency HCMV gene, and the host deubiquintase complex, UAF1-USP1. UAF1 is a scaffold protein pivotal for the activity of ubiquitin specific peptidases (USP), including USP1. UAF1-USP1 sustains an innate immune response through the phosphorylation and activation of signal transducer and activator of transcription-1 (pSTAT1), as well as regulates the DNA damage response. After the onset of viral DNA synthesis, pSTAT1 levels are elevated and this depends upon UL138 and USP1. pSTAT1 localizes to viral centers of replication, binds to the viral genome, and influences UL138 expression. Inhibition of USP1 results in a failure to establish latency, marked by increased viral genome replication and production of viral progeny. Inhibition of Jak-STAT signaling also results in increased viral genome synthesis in hematopoietic cells, consistent with a role for USP1-mediated regulation of STAT1 signaling in the establishment of latency. These findings demonstrate the importance of the UL138-UAF1-USP1 virus-host interaction in regulating HCMV latency establishment through the control of innate immune signaling. It will be important going forward to distinguish roles of UAF1-USP1 in regulating pSTAT1 relative to its role in the DNA damage response in HCMV infection.

Importance

Human cytomegalovirus (HCMV) is one of nine herpesviruses that infect humans. Following a primary infection, HCMV establishes a life-long latent infection that is marked by sporadic, and likely frequent reactivation events. While these reactivation events are asymptomatic in the immune competent host, they pose important disease risks for the immune compromised, including solid organ or stem cell transplant recipients. Its complex interactions with host biology and deep coding capacity make it an excellent model for defining mechanisms important for viral latency and reactivation. Here we define an interaction with host proteins that commandeer typically antiviral innate immune signaling for the establishment of latency.

UL135 and UL136 Epistasis Controls Reactivation of Human Cytomegalovirus

Human cytomegalovirus (HCMV) is beta herpesvirus that persists indefinitely in the human host through a protracted, latent infection. The polycistronic UL133-UL138 gene locus of HCMV encodes genes regulating latency and reactivation. While UL138 is pro-latency, restricting virus replication in CD34+ hematopoietic progenitor cells (HPCs), UL135 overcomes this restriction for reactivation. By contrast, UL136 is expressed with later kinetics and encodes multiple protein isoforms with differential roles in latency and reactivation. Like UL135, the largest UL136 isoform, UL136p33, is required for reactivation from latency in hematopoietic cells. Furthermore, UL136p33 is unstable, and its instability is important for the establishment of latency and sufficient accumulation of UL136p33 is a checkpoint for reactivation. We hypothesized that stabilizing UL136p33 might overcome the requirement of UL135 for reactivation. To test this, we generated recombinant viruses lacking UL135 that expressed a stabilized variant of UL136p33. Stabilizing UL136p33 did not impact replication of the UL135-mutant virus in fibroblasts. However, in the context of infection in hematopoietic cells, stabilization of UL136p33 strikingly compensated for the loss of UL135, resulting in increased replication in CD34+ HPCs and in humanized NOD- scid IL2Rγ _c ^null (NSG) mice. This finding suggests that while UL135 is essential for reactivation, it functions at steps preceding the accumulation of UL136p33 and that stabilized expression of UL136p33 largely overcomes the requirement for UL135 in reactivation. Taken together, our genetic evidence indicates an epistatic relationship between UL136p33 and UL135 whereby UL135 may initiate events early in reactivation that will result in the accumulation of UL136p33 to a threshold required for productive reactivation.

SIGNIFICANCE

Human cytomegalovirus (HCMV) is one of nine human herpesviruses and a significant human pathogen. While HCMV establishes a life-long latent infection that is typically asymptomatic in healthy individuals, its reactivation from latency can have devastating consequences in the immune compromised. Defining virus-host and virus-virus interactions important for HCMV latency, reactivation and replication is critical to defining the molecular basis of latent and replicative states and in controlling infection and CMV disease. Here we define a genetic relationship between two viral genes in controlling virus reactivation from latency using primary human hematopoietic progenitor cell and humanized mouse models.

Is CMV PCR of inner ear fluid during cochlear implantation a way to diagnose CMV-related hearing loss?

To evaluate the diagnostic performance of cytomegalovirus (CMV) polymerase chain reaction (PCR) on inner ear fluid collected during cochlear implantation and to assess its interest in current practice. This monocentric prospective study included consecutive children presenting with severe to profound sensorineural hearing loss (SNHL) who were candidates for unilateral and/or bilateral cochlear implantation. The etiology of the SNHL was determined before cochlear implantation when possible. During the surgery, drop-like samples of inner ear fluid and blood were collected. CMV PCR was then performed on both samples. Between January 2017 and September 2021, 113 children with severe to profound SNHL underwent cochlear implantation with inner ear fluid collection. Among these children, 77 of them presented with a known cause of SNHL (68%) and 36 of them had an unknown cause of SNHL at the time of surgery (32%). Sensitivity and specificity of the CMV PCR on inner ear fluid were 60% (95% CI: [49-71]) and 98% (95% CI: [96-100]), respectively. Positive and negative predictive values were 90% (95% CI: [83-97]) and 92% (95% CI: [86-98]), respectively. A sensitivity analysis according to age at cochlear implantation showed a decrease with age.

CONCLUSION

Sampling of inner ear fluid during cochlear implant surgery is an interesting, simple and safe way to diagnose CMV-related hearing loss, especially when the diagnosis of congenital infection can no longer be confirmed. However, the sensitivity decreases with age.

TRIAL REGISTRATION

NCT04724265 What is Known: • Congenital cytomegalovirus infection is the leading infectious cause of neurological disabilities and sensorineural hearing loss in children. In the absence of systematic screening at birth, many cCMV infections go undetected and are often undiagnosed despite the development of sensorineural sequelae.  • Nearly 40% of indications for cochlear implantation are of unknown etiology.

WHAT IS NEW

• Performing CMV PCR on inner ear fluid at the time of cochlear implantation is a safe way with high diagnostic performance (PPV = 90%, NPV = 92%) to detect a CMV-related hearing loss. • This sample may be interesting in cases of unknown cause of hearing loss in order to identify undiagnosed cCMV infections.

Distribution of CMV envelope glycoprotein B, H and N genotypes in infants with congenital cytomegalovirus symptomatic infection

Background

Cytomegalovirus (CMV) is the leading cause of congenital infections worldwide and contributes to long-term sequelae in neonates and children. CMV envelope glycoproteins play a vital role in virus entry and cell fusion. The association between CMV polymorphisms and clinical outcomes remains controversial. The present study aims to demonstrate the distribution of glycoprotein B (gB), H (gH) and N (gN) genotypes in congenitally CMV (cCMV) infected symptomatic infants and attempts to figure out the association between viral glycoprotein genotypes and clinical outcomes.

Methods

Genotyping of gB, gH and gN was performed in 42 cCMV symptomatic infants and 149 infants with postnatal CMV (pCMV) infection in Children's hospital of Fudan university. Nested PCR, gene sequencing and phylogenetic analyses were used to identify the genotypes.

Results

Our study demonstrated that: 1. The CMV gB1, gH1 and gN1 were the predominant genotypes among symptomatic cCMV infected infants, while gB1, gH1 and gN3a were more prevalent in pCMV group. gH1 genotype has a significant association with symptomatic cCMV infection (p = 0.006). 2. No significant correlation was found between CMV genotypes and hearing impairment. However, gH1 was more prevalent among cCMV infected infants with moderate/severe hearing loss although without statistical difference (p = 0.130). 3. gB3 was more prevalent among infants with skin petechiae (p = 0.049) and found to be associated with an increased risk of skin petechiae (OR = 6.563). The gN4a subtype was significantly associated with chorioretinitis due to cCMV infection (p = 0.007). 4. Urine viral loads were not significantly associated with different genotypes or hearing impairment among symptomatic cCMV infected infants.

Conclusions

Our findings demonstrated the overall distribution of gB, gH and gN genotypes in infants with symptomatic cCMV infection in Shanghai for the first time. The findings in our study may suggest a possible association between gH1 genotype and early infancy hearing loss. gB3 genotype was associated with a 6.5-fold increased risk of petechiae while gN4a strongly correlated with chorioretinitis due to cCMV infection. No significant correlation was found between urine viral loads and CMV genotypes or hearing impairment in cCMV infected infants.

Cross-sectional study to assess awareness of cytomegalovirus infection among pregnant women in Germany

BACKGROUND

Study aimed to assess awareness of congenital cytomegalovirus (CMV) infection and its determinants in pregnancy.

METHODS

Cross-sectional survey was conducted in five hospital-based maternity units in Germany. Pregnant women attending the maternity departments completed interviewer/self-administered survey questionnaire. High-risk group was defined according to contact with children under five years of age (at home or at work). Quantitative analyses using multivariable logistic regression were performed.

RESULTS

One thousand two hundred thirty-three pregnant women were included. 48.5% (n = 598) of women reported any knowledge about risk of CMV infection during pregnancy. CMV infection was less known than other infections or diseases (education about toxoplasmosis 95.5% (n = 1,177), listeriosis 60.5% (n = 746). 38% (n = 468) of participants received education about CMV. CMV awareness was associated with the level of education and employment in childcare or medical care. Only 32% (n = 394) of the women made use of serological screening for CMV during pregnancy (individual health service). 40.8% (n = 503) of pregnant women were classified as high-risk group. They had significantly higher knowledge and education about CMV, and msignificantlycant more often use of the serological screening.

CONCLUSIONS

Less than half of pregnant women surveyed were aware of potential risk associated with CMV infection during pregnancy. In our study,one-third third of pregnant women made use of the serological screening for CMV. Regarding the lack of current consensus on the role of serological CMV screening for pregnant women, hygiene preventive measures are the only evidence-based recommendation for pregnant women and knowledge increase could potentially have major public health impact.

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

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

Hearing outcomes in children with Congenital Cytomegalovirus: A multi-center, single-enterprise experience

BACKGROUND

Cytomegalovirus (CMV) is the most common cause of non-genetic sensorineural hearing loss (SNHL) in the United States; yet screening for congenital CMV (cCMV) remains controversial. CMV related SNHL can be present at birth, or develop in a delayed manner, and it is a consistent feature in children with either symptomatic or asymptomatic disease. A retrospective chart review was performed to determine the characteristics of patients diagnosed with cCMV and SNHL.

METHODS

The electronic database warehouse of the Nemours Children's Health System (NCHS) was queried from 01/01/2004 to 10/05/2019. ICD 9 (771.1) and ICD 10 (B25.9, P35.1) diagnostic codes were used to identify patients throughout the system with a diagnosis of cCMV infection. Patient demographics including gender, race/ethnicity, age of diagnosis, results of newborn hearing screening (NBHS), detection and progression of hearing loss, presence of antiviral therapy, and frequency of monitoring were collected, and descriptive statistics performed.

RESULTS

Of the 170 patients confirmed to have cCMV, 153 (90%) were symptomatic and 17 (10%) were asymptomatic. CNS involvement (63.5%), radiographic evidence of disease present (69.4%), and SNHL (50.6%) were the most common manifestations of the disease. Of these 170 patients, 83 (48.8%) were determined to have SNHL eligible for evaluation. For these patients with SNHL, the average time of hearing monitoring was 50.6 months. At the time of initial reported detection 63 of 83 (76%) had bilateral hearing loss and 20 (24%) had unilateral loss. Over the study period 3 (15%) progressed from unilateral to bilateral involvement, and 32 (47%) had a deterioration in hearing, with severe to profound SNHL in at least one ear identified at the last visit in 53 (64%) patients. Newborn hearing testing results were available for 69 (83%) of those with hearing loss and 26 patients passed initial testing. However, of the 26 patients who passed, 22 (85%) eventually developed SNHL by their last visit. Within our cohort, females with cCMV were significantly more likely to have SNHL than males with cCMV (62.3% versus 37.6%; p < 0.01).

CONCLUSION

In the absence of targeted or universal cCMV screening, the majority of children identified with this condition present symptomatically. Approximately one half of children with symptomatic cCMV failed NBHS at birth while at least 25% develop SNHL later in life. Children with cCMV are at high risk of delayed onset loss and such children, particularly females, should be monitored closely.

Maternal cytomegalovirus infection and delayed language development in children at 3 years of age-a nested case-control study in a large population-based pregnancy cohort

INTRODUCTION

Maternal cytomegalovirus (CMV) infection in pregnancy may result in vertical transmission of CMV to the child. Long-term effects of congenital CMV infection include visual, cognitive as well as neurological impairment. The aim of this study was to estimate the odds ratios for CMV seropositivity and seroconversion in mothers, with and without delayed language development in 3 year old children, nested within a large cohort.

MATERIAL AND METHODS

The Norwegian Mother, Father and Child Cohort Study (MoBa) is a prospective population-based pregnancy cohort that includes 95 200 mothers and 114 500 children. Blood samples were obtained from mothers during pregnancy weeks 17 or 18 in pregnancy and after birth. We included 300 women from MoBa with children suffering from delayed language development at three years of age, based on validated questionnaires. Within the cohort, 1350 randomly selected women were included as controls to perform a nested case-control study. The cases and controls were tested for CMV IgG antibodies by an enzyme-linked immunosorbent assay.

RESULTS

Among mothers of cases, 63.2% were CMV-IgG positive in the sample at birth, as compared to 55.9% among controls; OR 1.36, (95% CI; 1.05 to 1.76). Also, among case mothers, 8/118 (6.8%) initially seronegative cases, seroconverted. Among initially seronegative controls, seroconversion occurred in 23/618 (3.7%) mothers. The OR for seroconversion in cases as compared to control mothers was 1.88 (CI; 0.82 to 4.31), thus not statistically significant different.

CONCLUSION

This study shows a higher risk of delayed language development at three years of age in children born by mothers seropositive for CMV, compared to children born from seronegative mothers.

Knowledge of cytomegalovirus infection among women in Saudi Arabia: A cross-sectional study

Background

Cytomegalovirus (CMV) is the most common intrauterine congenital infection in humans. Worldwide seropositive rates of CMV are considerably high among women of childbearing age. There is currently no optimal drug treatment nor a vaccine for congenital CMV infection and therefore the best available program to date of prevention is practicing standard hygienic measures. The success of this program relies on women’s knowledge of CMV modes of transmissions, and risk and preventative behaviors.

Objective

The current study aims to assess the awareness and knowledge of CMV infection among women in Saudi Arabia.

Method

In this cross-sectional study, an online self-administered questionnaire was distributed to women 18 years of age or older residing in all regions of Saudi Arabia. The questionnaire included questions to assess awareness of CMV, knowledge of symptoms, transmission, and preventative measures of CMV infection.

Results

Out of the 1004 women who completed the questionnaire, self-reported knowledge of CMV was considerably low with only 82 women (8.17%) having heard of CMV infection. Most women reported learning about CMV from the internet and university. In binary logistic analyses, women pursuing studies in healthcare and those working in health professions, as well as those with undergraduate and graduate college degrees were significantly associated with higher knowledge of CMV. Urban area of residence was significantly associated with lower levels of knowledge of CMV. Among women who reported they had heard of CMV, their knowledge of CMV modes of transmission, symptoms, and preventative measures was considerably low. Regarding the transmission route, 23% reported no knowledge of modes of transmission, 59.75% reported mother-to-child transmission, 48.78% reported sexual intercourse, and 45% reported contact with body fluids of an infected person. Regarding knowledge of symptoms of congenital CMV, mental retardation and death were the most commonly reported clinical presentations.

Conclusion

The current study showed that the overall knowledge of CMV is very low among women in Saudi Arabia. Working in the healthcare field and higher education levels were significantly associated with better knowledge of CMV. It is crucial that women are provided with information regarding CMV-associated complications and preventative measures against mother-to-fetus transmission of CMV.

Placental angiogenesis, IUGR & CMV awareness in Iraqi women

The placenta is considered the first interface between mother and fetus, and a normal placenta is essential for pregnancy without complications. IUGR is considered the most common condition recognized in complicated pregnancy and accounts for 26% or more of stillbirth. The current study aims to explore the presence of IUGR and placental angiogenesis by investigating the expression of VEGF and eNOS in both placenta of IUGR of CMV-infected mother and placenta of normal mother in relation to awareness of CMV in Iraqi women.

The expressions of VEGF and e NOS was studied using the avidin-biotin-peroxidase technique, while awareness was studied using 10-minute surveys in Al-Karkh directorate (Baghdad) to investigate their knowledge of CMV infection in relation to the level of education and economic status.

The expression of angiogenic factors (VEGF, eNOS) was significant in syncitiotrophoblasts, smooth muscle cells and corionic villous stromal cells, and was significant in unaware, low-educated women with low income. Increased expression of angiogenic factors of IUGR babies may be a result of unawareness of CMV infection, which leads to dysregulation of angiogenic factors, and, subsequently, to inadequate placental vascularization.

Predictors of cochleovestibular dysfunction in children with congenital cytomegalovirus infection

The purpose of this study is to assess the predictive factors of both hearing and vestibular impairment in congenitally cytomegalovirus-infected children (cCMV) through a multivariate analysis of clinical and imaging characteristics collected during pregnancy and at birth. This retrospective study was conducted between March 2014 and March 2020, including confirmed congenitally CMV-infected children with a complete vestibular and hearing assessment. Data concerning pregnancy, date of infection, clinical characteristics, and symptomatology at birth were collected. In total, 130 children were included, with a median age of 21 months. Eighty-three children (64%) presented with an inner ear impairment (both cochlear and vestibular impairment). Sex, modality of maternal infection (seroconversion or reactivation), pregnancy term, weight and head circumference at birth, neonatal clinical signs of infection, and treatment were not significantly correlated with inner ear impairment. However, multivariate analysis confirmed that there are two independent predictive factors of inner ear impairment: antenatal imaging lesions (OR_a = 8.02 [1.74; 60.27], p-value = 0.01) and infection during the first trimester (OR_a = 4.47 [1.21; 19.22], p-value = 0.03). Conversely, infections occurring during the second trimester were rarely associated with inner ear impairment: 4/13 (31%) in our series, with vestibular impairment alone (4/4) and no hearing loss. None of the children infected during the third trimester developed inner ear dysfunction.

CONCLUSION

Besides the symptomatic status of the CMV infection at birth, we found that antenatal imaging brain damage and early infection (mainly during the first trimester) constitute the two best independent predictive factors of inner ear involvement in congenitally CMV-infected children.

WHAT IS KNOWN

• Congenital cytomegalovirus infection is the leading infectious cause of neurological disabilities and sensorineural hearing loss in children and responsible of vestibular disorders, which are probably underestimated. • No articles have yet defined the predictive factors of the entire inner ear impairment (vestibule and cochlea).

WHAT IS NEW

• The timing of the infection during pregnancy (first and second trimester, ORa=4.47) and antenatal imaging lesions (ORa=8.02) are independently predictive (in a multivariate analysis) of inner ear involvement. • The symptomatic status at birth is a poor predictor of inner ear impairment.

Circular RNAs Represent a Novel Class of Human Cytomegalovirus Transcripts

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

Congenital cytomegalovirus awareness and knowledge among health professionals and pregnant women: an action towards prevention

INTRODUCTION

Cytomegalovirus (CMV), is a major cause of childhood disabilities and consensus recommendations emphasize the importance of hygienic measures to reduce perinatal infection.

OBJECTIVE

To evaluate the level of awareness about CMV among health professionals and pregnant women.

METHODS

We submitted a 20-item online survey regarding CMV perinatal infection to all obstetricians and midwives in Catalonia (Spain) and a 7-item lay-version of the questionnaire to 700 pregnant women. Levels of knowledge were compared among groups.

RESULTS

Of the 1449 health professionals approached, 338 surveys were answered. 72% of professionals considered CMV a relevant problem. 47% of obstetricians and 28% of midwives (p=<0.001) routinely informed pregnant women, and less than half knew the risk of fetal transmission. We observed significant differences in knowledge between obstetricians and midwives concerning the risks of recurrent infections, risk of transmission, and risk of severe infection (60.7% vs 45.6%, p=0.006 and 50.6% vs 22.5% p=<0.001); and regarding maternal and neonatal symptoms, and newborn sequelae (23% vs. 8.8% p=<0.001). Of the 700 women approached, we obtained a response rate of 72%. Only 23% had previously heard about CMV; 22% identified transmission routes, and 15% preventive measures. Compared to women without risk factors for CMV infection women at greater risk had heard more about CMV [mothers of children <3 years: 36% vs. 20% p< 0.001; occupational exposure: 43% vs. 20% p=<0.001] and had received more information (mothers of children <3 years: 18% vs. 9.5% p=<0.001; occupational exposure: 23% vs. 9.3% p=0.001).

CONCLUSIONS

Health care professionals have limited knowledge about CMV and may fail to enforce preventive measures. While pregnant women have limited awareness about CMV infection, they recognize the need for information. Health campaigns should be promoted to enhance awareness about this perinatal infection.

Universal First-Trimester Cytomegalovirus Screening and Valaciclovir Prophylaxis in Pregnant Persons: A Cost-Effectiveness Analysis

BACKGROUND

Recent studies suggest a possible benefit of valaciclovir prophylaxis to prevent vertical transmission after a positive serologic screen for primary maternal cytomegalovirus infection during pregnancy, although its cost-effectiveness remains uncertain.

OBJECTIVE

We sought to determine the circumstances under which universal first-trimester maternal serologic screening for maternal cytomegalovirus infection, with valaciclovir prophylaxis to prevent congenital cytomegalovirus, is cost-effective.

STUDY DESIGN

We performed a decision analysis from the perspective of the pregnant person to assess whether universal maternal screening in the first trimester, with subsequent valaciclovir prophylaxis (8g/day from time of positive serologic screen for primary maternal cytomegalovirus infection through 21 weeks' gestation) for those who are acutely infected, is cost-effective compared to usual care (i.e., no routine serologic screening, but amniocentesis if mid-trimester sonographic findings suggest cytomegalovirus). For baseline estimates, we assumed a 35% risk of congenital cytomegalovirus after primary maternal infection and a 71% risk reduction with valaciclovir. We varied valaciclovir's efficacy to identify whether and at what threshold universal screening would be estimated to be cost-effective, compared to usual care. Monte Carlo analyses were performed. A willingness-to-pay threshold of $100,000/quality-adjusted life year was used to define cost-effectiveness.

RESULTS

Under base-case estimates, first-trimester universal screening and valaciclovir prophylaxis for seropositive pregnant persons with acute cytomegalovirus infection is not cost-effective, with a cost of $137,854 per maternal QALY, but results in 14 fewer cytomegalovirus-affected children per 100,000 pregnancies compared to usual care. In one-way sensitivity analysis, universal screening and treatment is estimated to be the cost-effective strategy if the incidence of primary maternal cytomegalovirus infection exceeds 2.6%, baseline risk of vertical transmission of cytomegalovirus without prophylaxis is greater than 36.8%, and the risk reduction of vertical transmission of cytomegalovirus with valaciclovir prophylaxis exceeds 75.9%. In Monte Carlo analyses, first-trimester universal serologic screening with valaciclovir prophylaxis is estimated to be the cost-effective strategy in 46.8% of runs.

CONCLUSION

Universal first-trimester serologic screening with valaciclovir prophylaxis is not the cost-effective strategy for antenatal management of cytomegalovirus under the base-case estimates. Although universal screening is cost-effective in certain circumstances when the efficacy of valaciclovir exceeds the base case, that result is not robust to variation of estimates across their reasonable ranges. These data can inform future studies to evaluate screening and treatment to prevent congenital CMV.

Audiovestibular Consequences of Congenital Cytomegalovirus Infection: Greater Vulnerability of the Vestibular Part of the Inner Ear

OBJECTIVES

To investigate the impact of congenital cytomegalovirus infection on cochlear and vestibular function.

DESIGN

This retrospective study conducted between March 2014 and March 2020 included children with confirmed congenital cytomegalovirus infection who underwent a complete audio-vestibular evaluation. It included a bithermal caloric test, a video head impulse test and a cervical vestibular evoked myogenic potential associated with a complete hearing assessment.

RESULTS

The cohort of 130 children included in the study had a median age of 21 months (interquartile range: 12 to 37 months). Eighty-three children (64%) showed an inner ear impairment (both cochlear and vestibular). The vestibular part of the inner ear was significantly more frequently impaired than the cochlear part (ρ = 0.003). Sixty-two children (48%) showed confirmed hearing impairment. The severity of hearing loss was variable, with a high proportion of profound hearing loss (30/62, 48%), which was often bilateral (47/62, 76%). The vestibular assessment showed a canal function disorder in 67 children (88%) and an otolith function disorder in 63 children (83%; ρ = 0.36). The video head impulse test was significantly less altered (64%) compared with the bithermal caloric test (80%; ρ = 0.02) and the cervical vestibular evoked myogenic potential (83%; ρ = 0.009). Only seven out of 83 children (8%) showed hearing loss without vestibular dysfunction, of which only one had a normal hearing screening test at birth. For the children who passed the hearing screening test at birth and presented an inner ear impairment [n = 36, median age: 16 (11 to 34) months], vestibular disorders were later found in 35 children (97%) and 17 of them (47%) developed hearing loss secondarily. This underlines the importance of assessing both vestibular and auditory parts of the inner ear. When comparing the agreement of cochlear and vestibular impairment, the severity and the laterality of the impairment were low [Cohen's kappa 0.31 (0.22 to 0.40) and 0.43 (0.32 to 0.55), respectively].

CONCLUSION

In our study, we demonstrated that although both cochlear and vestibular parts of the inner ear can be impaired by congenital cytomegalovirus infection, the vestibular part seems more often impaired compared with the cochlear part. This underlines the importance of vestibular evaluation in the follow-up of cytomegalovirus-infected children associated with hearing assessment.

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.

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.

Early Life Inflammation and the Developing Hematopoietic and Immune Systems: The Cochlea as a Sensitive Indicator of Disruption

Emerging evidence indicates that perinatal infection and inflammation can influence the developing immune system and may ultimately affect long-term health and disease outcomes in offspring by perturbing tissue and immune homeostasis. We posit that perinatal inflammation influences immune outcomes in offspring by perturbing (1) the development and function of fetal-derived immune cells that regulate tissue development and homeostasis, and (2) the establishment and function of developing hematopoietic stem cells (HSCs) that continually generate immune cells across the lifespan. To disentangle the complexities of these interlinked systems, we propose the cochlea as an ideal model tissue to investigate how perinatal infection affects immune, tissue, and stem cell development. The cochlea contains complex tissue architecture and a rich immune milieu that is established during early life. A wide range of congenital infections cause cochlea dysfunction and sensorineural hearing loss (SNHL), likely attributable to early life inflammation. Furthermore, we show that both immune cells and bone marrow hematopoietic progenitors can be simultaneously analyzed within neonatal cochlear samples. Future work investigating the pathogenesis of SNHL in the context of congenital infection will therefore provide critical information on how perinatal inflammation drives disease susceptibility in offspring.

Suppression of human trophoblast syncytialization by human cytomegalovirus infection

INTRODUCTION

Placental dysfunction triggers fetal growth restriction in congenital human cytomegalovirus (HCMV) infection. Studies suggest that HCMV infection interferes with the differentiation of human trophoblasts. However, the underlying mechanisms have not been clarified. This study investigated the impact of HCMV infection on gene transcriptomes in cytotrophoblasts (CTBs) associated with placental dysfunction.

METHODS

CTBs were isolated from human term placentas, and spontaneous syncytialization was observed in vitro. The transcriptome profiles were compared between CTB groups with and without HCMV infection by cap analysis gene expression sequencing. The effect of HCMV infection on trophoblast differentiation was evaluated by examining cell fusion status using immunocytochemical staining for desmoplakin and assessing the production of cell differentiation markers, including hCG, PlGF, and soluble Flt-1, using ELISA.

RESULTS

The expression of the genes categorized in the signaling pathways related to the cell cycle was significantly enhanced in CTBs with HCMV infection compared with uninfected CTBs. HCMV infection hindered the alteration of the gene expression profile associated with syncytialization. This suppressive effect under HCMV infection was concurrent with the reduction in hCG and PlGF secretion. Immunostaining for desmoplakin revealed that HCMV infection reduced the cell fusion of cultured CTBs. These findings imply that HCMV infection has a negative impact on syncytialization, which is indispensable for the maintenance of villous function.

DISCUSSION

HCMV infection interferes with gene expression profiles and functional differentiation of trophoblasts. Suppression of syncytialization may be a survival strategy for HCMV to expand infection and could be associated with placental dysfunction.

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

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

Serological Markers of Viral Infections (Rubella Virus, Human Cytomegalovirus and Arboviruses) among Symptomatic Pregnant Women in Rural and Urban Areas of Mwanza, Tanzania

Viral infections have been associated with poor pregnancy outcomes. We investigated the magnitude of rubella virus (RV), dengue virus (DENV), Zika virus (ZIKV) and human cytomegalovirus (HCMV) among symptomatic pregnant women in rural and urban areas of Mwanza. A cross-sectional study was conducted between July 2017 and April 2018 in Mwanza. A rapid immunochromatographic test was done to detect ZIKV IgM and IgG as well as DENV IgM and IgG antibodies. A multiplex_RT-PCR was also done to detect the viral RNA genome. Enzyme immunoassays were done to detect RV and HCMV. Out of 171 participants, 1 (0.6%) was found to be seropositive for ZIKV_IgM antibodies, while 5 (2.9%) were ZIKV_IgG seropositive. DENV seropositivity was 9 (5.3%) and 3 (1.8%) for IgM and IgG, respectively, with all being PCR negative. Two participants (1.2%) were RV_IgM seropositive. 100% were HCMV_IgG seropositive and none was HCMV_IgM seropositive. Among 70 women with high HCMV_IgG titters, 10 (14.3%) had a low avidity index, indicating recent infections. Residing in rural areas (p = 0.044) and advanced age (p = 0.024) independently predicted ZIKV/DENV seropositivity. A substantial proportion of pregnant women had markers for viral infections. There is a need for introducing routine screening and monitoring pregnancy outcomes of positive cases to establish the relationship of these viruses and adverse pregnancy outcomes in endemic areas.

Sjögren's Syndrome and Viral Infections

Sjögren's syndrome (SS) is a systemic autoimmune disease, characterized by lymphocytic infiltration of the secretory glands. This leads to dryness of the main mucosal surfaces such as the mouth, eyes, nose, larynx, pharynx, and vagina. Although there is little morbidity data at the initial diagnosis, SS may be a serious disease, with extra mortality caused by hematological cancer. The cause of SS is unknown, but factors postulated to play a role include genetic and environmental factors, hormonal abnormality, and viral infection. Under the influence of these factors, the immune system becomes abnormal and the tissue is damaged. In this study, we summarize recent developments in our understanding of the relationship between SS and viral infections, including Epstein-Barr virus (EBV), hepatitis C virus (HCV), human T cell lymphotropic virus type 1 (HTLV-1), cytomegalovirus (CMV), and human immunodeficiency virus (HIV).

PPAR Gamma and Viral Infections of the Brain

Peroxisome Proliferator-Activated Receptor gamma (PPARγ) is a master regulator of metabolism, adipogenesis, inflammation and cell cycle, and it has been extensively studied in the brain in relation to inflammation or neurodegeneration. Little is known however about its role in viral infections of the brain parenchyma, although they represent the most frequent cause of encephalitis and are a major threat for the developing brain. Specific to viral infections is the ability to subvert signaling pathways of the host cell to ensure virus replication and spreading, as deleterious as the consequences may be for the host. In this respect, the pleiotropic role of PPARγ makes it a critical target of infection. This review aims to provide an update on the role of PPARγ in viral infections of the brain. Recent studies have highlighted the involvement of PPARγ in brain or neural cells infected by immunodeficiency virus 1, Zika virus, or human cytomegalovirus. They have provided a better understanding on PPARγ functions in the infected brain, and revealed that it can be a double-edged sword with respect to inflammation, viral replication, or neuronogenesis. They unraveled new roles of PPARγ in health and disease and could possibly help designing new therapeutic strategies.

Changing knowledge, attitudes and behaviours towards cytomegalovirus in pregnancy through film-based antenatal education: a feasibility randomised controlled trial of a digital educational intervention

BACKGROUND

Congenital cytomegalovirus (CMV) is the most common congenital infection globally, however information about CMV is not routinely included in antenatal education in the United Kingdom. This feasibility study aimed to gather the essential data needed to design and power a large randomised controlled trial (RCT) to investigate the efficacy of a digital intervention in reducing the risk of CMV acquisition in pregnancy. In order to do this, we carried out a single-centre RCT, which explored the knowledge, attitudes and risk reduction behaviours in women in the intervention and treatment as usual groups, pre- and post-intervention.

METHODS

CMV seronegative women living with a child less than four years old, receiving antenatal care at a single UK tertiary centre, were randomised to the digital intervention or 'treatment as usual' groups. Participants completed questionnaires before the digital intervention and after and at 34 gestational weeks, and responses within groups and between groups were compared using tailored randomisation tests. CMV serology was tested in the first trimester and at the end of pregnancy.

RESULTS

Of the 878 women screened, 865 samples were analysed with 43% (n = 372) being CMV seronegative and therefore eligible to take part in the RCT; of these, 103 (27.7%) women were enrolled and 87 (84%) of these completed the study. Most participants (n = 66; 64%) were unfamiliar with CMV at enrolment, however at 34 gestational weeks, women in the intervention group (n = 51) were more knowledgeable about CMV compared to the treatment as usual group (n = 52) and reported engaging in activities that may increase the risk of CMV transmission less frequently. The digital intervention was highly acceptable to pregnant women. Overall, four participants seroconverted over the course of the study: two from each study group.

CONCLUSIONS

A large multi-centre RCT investigating the efficacy of a CMV digital intervention is feasible in the United Kingdom; this study has generated essential data upon which to power such a study. This single-centre feasibility RCT demonstrates that a digital educational intervention is associated with increase in knowledge about CMV and can result in behaviour change which may reduce the risk of CMV acquisition in pregnancy.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03511274 , Registered 27.04.18, http://www.Clinicaltrials.gov.

Distribution of Human Cytomegalovirus Glycoprotein H Genotypes in Different Samples from Chinese Children

Objective This study aimed to investigate characteristics of human cytomegalovirus (HCMV) glycoprotein H (gH) genotypes in urine, throat swab, and serum from children and breast milk from children's mothers.

Methods Fresh urine samples, throat swabs, or serum samples from children and breast milk samples from children's mothers were collected for HCMV DNA detection. The positive samples of HCMV DNA were further detected by fluorescent quantitative polymerase chain reaction (PCR) with gH typing.

Results Of 1,703 HCMV DNA-positive samples, the highest proportion (83.3%, 85/102) of children aged between 21 days and 3 months was detected positive in breast milk samples (p = 0.002), and the highest proportion (70.5%, 110/156) of children aged above 3 months was detected positive in throat swab samples (p = 0.002). HCMV in throat swab specimens is mainly high copy (p < 0.0001), and low-copy HCMV is prevalent in breast specimens (p < 0.0001). Among them, 1,059 samples were identified as gH1 genotype, 530 samples were gH2, and 114 samples were coinfection (gH1/2). There had the highest gH2 rates (32.3%) and lowest gH1 (61.0%) rates in urine samples (p = 0.041), whereas the highest gH1 rates (71.6%) and lowest gH2 rates (19.6%) were found in breast milk samples (p = 0.032). Concerning age groups, patients aged between 21 days and 3 months had the highest gH1 proportion (p = 0.017), while patients aged above 3 months had the highest gH1 and gH2 HCMV coinfection proportion (p = 0.002). Among 43 pairs of maternal and child samples corresponding to positive samples, gH genotype of 35 pairs of samples was consistent with a rate of 81.4%.

Conclusion gH1 is the predominant genotype of HCMV in each kind of sample in China. However, the distribution of the HCMV gH genotype is different among different samples.

Viral infection of the ovaries compromises pregnancy and reveals innate immune mechanisms protecting fertility

Viral infections during pregnancy are a considerable cause of adverse outcomes and birth defects, and the underlying mechanisms are poorly understood. Among those, cytomegalovirus (CMV) infection stands out as the most common intrauterine infection in humans, putatively causing early pregnancy loss. We employed murine CMV as a model to study the consequences of viral infection on pregnancy outcome and fertility maintenance. Even though pregnant mice successfully controlled CMV infection, we observed highly selective, strong infection of corpus luteum (CL) cells in their ovaries. High infection densities indicated complete failure of immune control in CL cells, resulting in progesterone insufficiency and pregnancy loss. An abundance of gap junctions, absence of vasculature, strong type I interferon (IFN) responses, and interaction of innate immune cells fully protected the ovarian follicles from viral infection. Our work provides fundamental insights into the effect of CMV infection on pregnancy loss and mechanisms protecting fertility.

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.

Associations Between Salivary Bacteriome Diversity and Salivary Human Herpesvirus Detection in Early Childhood: A Prospective Cohort Study

BACKGROUND

The bacteriome is associated with susceptibility to some eukaryotic viruses, but no study has examined associations between the salivary bacteriome and human herpesviruses (HHVs). We provide new prevalence and incidence estimates for salivary herpesviruses detection and estimate associations with bacteriome diversity in young children.

METHODS

Salivary samples collected at ages ~2, 8, 12, and 24 months from 153 children participating in the Center for Oral Health Research in Appalachia cohort 2 (COHRA2) were screened for HHVs using the Fast-Track Neuro9 multiplex PCR assay, and for the bacteriome using 16S rRNA amplicon sequencing. We used Cox proportional hazard models to test for associations between the salivary bacteriome and hazards of cytomegalovirus (CMV) and human herpesvirus-6 (HHV6).

RESULTS

CMV, HHV6, and Epstein-Barr virus (EBV) were detected at all visits. Human herpesvirus-7 (HHV7) was first detected at the 8-month visit and herpes simplex virus 1 (HSV1) was only detected at the 12-month visit. Varicella-zoster virus, herpes simplex virus 2, and human herpesvirus-8 were never detected. HHV6 (24-month cumulative incidence: 73.8%) and CMV (24-month cumulative incidence: 32.3%) were detected most frequently. Increasing salivary bacteriome diversity was associated with longer survival to first detection of CMV (hazard ratio [95% CI]: 0.24 [0.12, 0.49]) and HHV6 (hazard ratio [95% CI]: 0.24 [0.13, 0.44]).

CONCLUSION

CMV, HHV6, EBV, HHV7, and HSV1 were detected in the saliva during the first 2 years of life. Time to first detection of CMV and HHV6 was associated with salivary bacteriome diversity, suggesting a possible interaction between HHVs and the salivary bacteriome.

Cytomegalovirus Infection and Inflammation in Developing Brain

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

Amplification-free Detection of Cytomegalovirus miRNA Using a Modification-free Surface Plasmon Resonance Biosensor

Cytomegalovirus (CMV) is the most frequent cause of congenital infection worldwide; congenital CMV may lead to significant mortality, morbidity, or long-term sequelae, such as sensorineural hearing loss. The current study presents a newly designed surface plasmon resonance (SPR) biosensor for CMV-specific microRNAs that does not involve extra care for receptor immobilization or treatment to prevent fouling on bare gold surfaces. The modification-free approach, which utilizes a poly-adenine [poly(A)]-Au interaction, exhibited a high affinity that was comparable to that of the gold-sulfur (Au-S) interaction. In addition, magnetic nanoparticles (MNPs) were used to separate the analyte from complex sample matrixes that significantly reduced nonspecific adsorption. Moreover, the MNPs also played an important role in SPR signal amplification due to the binding-induced change in the refractive index. Our SPR biosensing platform was used successfully for the multi-detection of the microRNAs, UL22A-5p, and UL112-3p, which were associated with CMV. Our SPR biosensor offered the detection limits of 108 fM and 24 fM for UL22A-5p and UL112-3p, respectively, with an R² of 0.9661 and 0.9985, respectively. The precision of this biosensor has an acceptable CV (coefficient of variation) value of <10%. In addition, our sensor is capable of discriminating between serum samples collected from healthy and CMV-infected newborns. Taken together, we believe that our newly developed SPR biosensing platform is a promising alternative for the diagnosis of CMV-specific microRNA in clinical settings, and its application for the detection of other miRNAs may be extended further.

Changes in Cytomegalovirus Seroprevalence Among U.S. Children Aged 1-5 Years: The National Health and Nutrition Examination Surveys

Data from the cross-sectional National Health and Nutrition Examination Surveys (NHANES) indicate that the seroprevalence of cytomegalovirus immunoglobulin G (IgG) antibodies among US children aged 1-5 years was 20.7% (95% confidence interval [CI]: 14.0, 29.0) in 2011-2012 and 28.2% (95% CI: 23.1-34.0) in 2017-2018 (adjusted prevalence difference, +7.6% [95% CI: -.4, +15.6]).