Vaccine value profile for cytomegalovirus

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

Clinical Utility of SARS-CoV-2 Serological Testing and Defining a Correlate of Protection

Herein, we review established clinical use cases for SARS-CoV-2 antibody measures, which include diagnosis of recent prior infection, isolating high titer convalescent plasma, diagnosing multisystem inflammatory syndrome in children (MIS-C), and booster dosing in the immunosuppressed and other populations. We then address whether an antibody correlate of protection (CoP) for SARS-CoV-2 has been successfully defined with the following considerations: Antibody responses in the immunocompetent, vaccine type, variants, use of binding antibody tests vs. neutralization tests, and endpoint measures. In the transition from the COVID-19 pandemic to endemic, there has been much interest in defining an antibody CoP. Due to the high mutability of respiratory viruses and our current knowledge of SARS-CoV-2 variants defining a CoP for prevention of infection is unrealistic. However, a CoP may be defined for prevention of severe disease requiring hospitalization and/or death. Most SARS-CoV-2 CoP research has focused on neutralization measurements. However, there can be significant differences in neutralization test methods, and disparate responses to new variants depending on format. Furthermore, neutralization assays are often impractical for high throughput applications (e.g., assessing humoral immune response in populations or large cohorts). Nevertheless, CoP studies using neutralization measures are reviewed to determine where there is consensus. Alternatively, binding antibody tests could be used to define a CoP. Binding antibody assays tend to be highly automatable, high throughput, and therefore practical for large population applications. Again, we review studies for consensus on binding antibody responses to vaccines, focusing on standardized results. Binding antibodies directed against the S1 receptor binding domain (S1-RBD) of the viral spike protein can provide a practical, indirect measure of neutralization. Initially, a response for S1-RBD antibodies may be selected that reflects the peak response in immunocompetent populations and may serve as a target for booster dosing in the immunocompromised. From existing studies reporting peak S1-RBD responses in standardized units, an approximate range of 1372-2744 BAU/mL for mRNA and recombinant protein vaccines was extracted that could serve as an initial CoP target. This target would need to be confirmed and potentially adjusted for updated vaccines, and almost certainly for other vaccine formats (i.e., viral vector). Alternatively, a threshold or response could be defined based on outcomes over time (i.e., prevention of severe disease). We also discuss the precedent for clinical measurement of antibodies for vaccine-preventable diseases (e.g., hepatitis B). Lastly, cellular immunity is briefly addressed for its importance in the nature and durability of protection.

Risk factors for community acquired pediatric urinary tract infection with extended-spectrum-β-lactamase Escherichia coli - A case-control study

INTRODUCTION

Community-acquired (CA) infections caused by extended-spectrum β-lactamase (ESBL) producing Escherichia coli urinary tract infections (UTI) have become increasingly prevalent, posing a serious threat to public health. Risk factors for ESBL UTI have not been extensively studied in the pediatric population. We report findings from a case control study to identify risk factors for CA ESBL-producing E. coli UTI in children.

MATERIALS AND METHOD

A cohort of children with CA ESBL Escherichia coli UTI evaluated at a tertiary referral hospital from January 2014 through April 2021, were matched 1:3 with control group of non-ESBL CA E. coli UTI based on age at first episode of non-ESBL UTI. To identify potential risk factors for ESBL E. coli UTI, conditional logistic regression model was utilized accounting for age matching. Univariate models were fitted for each clinical risk factor. Factors found to be significantly associated with ESBL UTI were simultaneously included in a single model to check for associations adjusted for all other factors.

RESULTS

On conditional multivariate analyses for univariate testing, male sex (P = 0.021), history of Urology care (P = 0.001), and antibiotic treatment within 30 days prior to positive culture (P = 0.004) were identified as independent risk factors for CA ESBL E. coli UTI. Comorbidity scores were assigned to each patient according to pediatric comorbidity index (PCI); children with ESBL UTI were more likely to have higher morbidity risk than non-ESBL UTI children (P < 0.001). From the logistic model, the higher the morbidity scores, the more likely children will have CA ESBL UTI (P < 0.001).

DISCUSSION

Identifying risk factors for ESBL-producing E. coli UTI in children is important because of limited therapeutic options. This knowledge is essential for clinical decision making and to develop intervention strategies to reduce disease burden. Our study found that although females have an increased predisposition to UTIs, we observed that the male sex is an independent risk factor for ESBL E. coli UTI. This finding warrants further investigation to determine underlying cause. Because of the retrospective design of the study, collection of data from a single center, and differences in characteristics between patient populations, treatments, and prescribing patterns in the community, this study may not be generalizable.

CONCLUSIONS

Findings from our case-control study suggest that the male sex, history of Urology care, and previous antibiotic exposure are independent risk factors for CA ESBL-GNB UTI. Children with ESBL E. coli UTI are more likely to have longer admission duration and higher comorbidity index.

Mission, Organization and Future Direction of the Serological Sciences Network for COVID-19 (SeroNet) Epidemiologic Cohort Studies

Global efforts are needed to elucidate the epidemiology of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the underlying cause of coronavirus disease 2019 (COVID-19) including seroprevalence, risk factors and long-term sequelae, as well as immune responses following vaccination across populations and the social dimensions of prevention and treatment strategies. In the U.S., the National Cancer Institute in partnership with the National Institute of Allergy and Infectious Diseases, established the SARS-CoV-2 Serological Sciences Network (SeroNet) as the nation’s largest coordinated effort to study COVID-19. The network is comprised of multidisciplinary researchers bridging gaps and fostering collaborations between immunologists, epidemiologists, virologists, clinicians and clinical laboratories, social and behavioral scientists, policy makers, data scientists, and community members. In total, 49 institutions form the SeroNet consortium to study individuals with cancer, autoimmune disease, inflammatory bowel diseases, cardiovascular diseases, HIV, transplant recipients, as well as otherwise healthy pregnant women, children, college students, and high-risk occupational workers (including health care workers and first responders). Several studies focus on underrepresented populations, including ethnic minorities and rural communities. To support integrative data analyses across SeroNet studies, efforts are underway to define common data elements for standardized serology measurements, cellular and molecular assays, self-reported data, treatment, and clinical outcomes. In this paper, we discuss the overarching framework for SeroNet epidemiology studies, critical research questions under investigation, and data accessibility for the worldwide scientific community. Lessons learned will help inform preparedness and responsiveness to future emerging diseases.

Congenital and Perinatal Varicella Infections

Varicella-zoster virus (VZV) is a human pathogen of the α-herpesvirus family. Some fetuses infected in utero around 8-20 weeks of pregnancy show signs of congenital varicella syndrome (CVS). Infants born to mothers who develop varicella within 5 days before and 2 days after delivery can experience severe disease with increased mortality. The best diagnostic modality is polymerase chain reaction (PCR), which can be done using vesicular swabs or scrapings, scabs from crusted lesions, tissue from biopsy samples, and cerebrospinal fluid. The prevention and management of varicella infections include vaccination, anti-VZV immunoglobulin, and specific antiviral drugs. In this article, we have reviewed the characteristics of VZV, clinical manifestations, management of perinatal infections, and short- and long-term prognosis.

Comparing Nasopharyngeal and Midturbinate Nasal Swab Testing for the Identification of Severe Acute Respiratory Syndrome Coronavirus 2

Testing of paired mid-turbinate (MT) nasal and nasopharyngeal (NP) swabs, collected by trained personnel from 40 patients with COVID-19 showed more NP (76/95, 80%) than MT swabs tested positive (61/95, 64%; p=0.02). Among samples collected a week after study enrollment, fewer MT than NP samples were positive (45% vs 76%; p=0.001).

Clinical Diagnostic Testing for Human Cytomegalovirus Infections

Human cytomegalovirus (HCMV) infections are among the most common complications arising in transplant patients, elevating the risk of various complications including loss of graft and death. HCMV infections are also responsible for more congenital infections worldwide than any other agent. Congenital HCMV (cCMV) infections are the leading nongenetic cause of sensorineural hearing loss and a source of significant neurological disabilities in children. While there is overlap in the clinical and laboratory approaches to diagnosis of HCMV infections in these settings, the management, follow-up, treatment, and diagnostic strategies differ considerably. As yet, no country has implemented a universal screening program for cCMV. Here, we summarize the issues, limitations, and application of diagnostic strategies for transplant recipients and congenital infection, including examples of screening programs for congenital HCMV that have been implemented at several centers in Japan, Italy, and the United States.

Recent Approaches and Strategies in the Generation of Anti-human Cytomegalovirus Vaccines

Human cytomegalovirus is the largest human herpesvirus and shares many core features of other herpesviruses such as tightly regulated gene expression during genome replication and latency as well as the establishment of lifelong persistence following infection. In contrast to stereotypic clinical syndromes associated with alpha-herpesvirus infections, almost all primary HCMV infections are asymptomatic and acquired early in life in most populations in the world. Although asymptomatic in most individuals, HCMV is a major cause of disease in hosts with deficits in adaptive and innate immunity such as infants who are infected in utero and allograft recipients following transplantation. Congenital HCMV is a commonly acquired infection in the developing fetus that can result in a number of neurodevelopmental abnormalities. Similarly, HCMV is a major cause of disease in allograft recipients in the immediate and late posttransplant period and is thought to be a major contributor to chronic allograft rejection. Even though HCMV induces robust innate and adaptive immune responses, it also encodes a vast array of immune evasion functions that are thought aid in its persistence. Immune correlates of protective immunity that prevent or modify intrauterine HCMV infection remain incompletely defined but are thought to consist primarily of adaptive responses in the pregnant mother, thus making congenital HCMV a potentially vaccine modifiable disease. Similarly, HCMV infection in allograft recipients is often more severe in recipients without preexisting adaptive immunity to HCMV. Thus, there has been a considerable effort to modify HCMV specific immunity in transplant recipient either through active immunization or passive transfer of adaptive effector functions. Although efforts to develop an efficacious vaccine and/or passive immunotherapy to limit HCMV disease have been underway for nearly six decades, most have met with limited success at best. In contrast to previous efforts, current HCMV vaccine development has relied on observations of unique properties of HCMV in hopes of reproducing immune responses that at a minimum will be similar to that following natural infection. However, more recent findings have suggested that immunity following naturally acquired HCMV infection may have limited protective activity and almost certainly, is not sterilizing. Such observations suggest that either the induction of natural immunity must be specifically tailored to generate protective activity or alternatively, that providing targeted passive immunity to susceptible populations could be prove to be more efficacious.

Contribution of Congenital Cytomegalovirus Infection to Permanent Hearing Loss in a Highly Seropositive Population: The Brazilian Cytomegalovirus Hearing and Maternal Secondary Infection Study

BACKGROUND

The exact contribution of congenital cytomegalovirus infection (cCMVI) to permanent hearing loss (HL) in highly seropositive populations is unknown. We determined the contribution of cCMVI to HL and estimated the effectiveness of newborn hearing screening (HS) in identifying neonates with CMV-related HL.

METHODS

A total of 11 900 neonates born from a population with ≥97% maternal seroprevalence were screened for cCMVI and HL. cCMVI was confirmed by detection of CMV-DNA in saliva and urine at age <3 weeks.

RESULTS

Overall, 68 (0.6%; 95% confidence interval [CI], 0.4-0.7) neonates were identified with cCMVI. Of the 91 (0.8%) newborns who failed the HS, 24 (26.4%) were confirmed with HL, including 7 (29.2%; 95% CI, 17.2-59.3) with cCMVI. Another newborn with cCMVI passed the HS but was confirmed with HL at age 21 days. Of the 62 neonates with cCMVI who underwent a complete hearing evaluation, 8 (12.9%; 95% CI, 6.7-23.4) had HL and most (7/8; 87.5%; 95% CI, 46.6-99.7) were identified by HS. The rate of CMV-related HL was 8 per 11 887 neonates (0.7 per 1000 live births). The prevalence ratio of HL among neonates with cCMVI compared to CMV-uninfected neonates was 89.5 (95% CI, 39.7-202.0). No late-onset cCMVI-related HL was detected during a median follow-up of 36 months.

CONCLUSIONS

cCMVI is an important cause of HL in childhood in all settings. Integrating targeted cCMVI screening among neonates who fail a HS could be a reasonable, cost-effective strategy to identify newborns with early-onset cCMVI-related HL.

Cytomegalovirus Genetic Diversity Following Primary Infection

BACKGROUND

Infection with multiple cytomegalovirus (CMV) strains (mixed infection) was reported in a variety of hosts. As the virus genetic diversity in primary CMV infection and the changes over time remain incompletely defined, we examined CMV diversity and changes in diversity over time in healthy adolescent females who participated in a phase 2 CMV gB/MF59 vaccine trial.

METHODS

CMV genetic diversity was determined by genotyping of 5 genes-gB (UL55), gH (UL75), gN (UL73), US28, and UL144-in urine, saliva, and plasma samples from 15 study subjects.

RESULTS

At the time of primary infection, 5 of 12 (42%) urine samples had multiple virus strains, and 50% of vaccine recipients were infected with gB1 genotype (vaccine strain). Mixed infection was documented in all 15 subjects within 3 months after primary infection, and the majority had different CMV genotypes in different compartments. Changes in genotypes over time were observed in all subjects.

CONCLUSIONS

Infection with multiple CMV genotypes was common during primary infection and further diversification occurred over time. Infection with gB1 genotype in vaccine recipients suggests a lack of strain-specific protection from the vaccine. As only 5 polymorphic genes were assessed, this study likely underestimated the true genetic diversity in primary CMV infection.

Association of CMV genomic mutations with symptomatic infection and hearing loss in congenital CMV infection

Background

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and a leading cause of long-term neurological and sensory sequelae, the most common being sensorineural hearing loss (SNHL). Despite extensive research, clinical or laboratory markers to identify CMV infected children with increased risk for disease have not been identified. This study utilizes viral whole-genome next generation-sequencing (NGS) of specimens from congenitally infected infants to explore viral diversity and specific viral variants that may be associated with symptomatic infection and SNHL.

Methods

CMV DNA from urine specimens of 30 infants (17 asymptomatic, 13 symptomatic) was target enriched and next generation sequenced resulting in 93% coverage of the CMV genome allowing analysis of viral diversity.

Results

Variant frequency distribution was compared between children with symptomatic and asymptomatic cCMV and those with (n = 13) and without (n = 17) hearing loss. The CMV genes UL48A, UL88, US19 and US22 were found to have an increase in nucleotide diversity in symptomatic children; while UL57, UL20, UL104, US14, UL115, and UL35 had an increase in diversity in children with hearing loss. An analysis of single variant differences between symptomatic and asymptomatic children found UL55 to have the highest number, while the most variants associated with SNHL were in the RL11 gene family. In asymptomatic infants with SNHL, mutations were observed more frequently in UL33 and UL20.

Conclusion

CMV genomes from infected newborns can be mapped to 93% of the genome at a depth allowing accurate and reproducible analysis of polymorphisms for variant and gene discovery that may be linked to symptomatic and hearing loss outcomes.

Contribution of Breastfeeding to False-Positive Saliva Polymerase Chain Reaction for Newborn Congenital Cytomegalovirus Screening

Real-time polymerase chain reaction (PCR) of saliva is highly sensitive for newborn congenital cytomegalovirus (CMV) screening. This study uses nationally published CMV seroprevalence and breastfeeding rates to estimate the contribution of CMV DNA in breast milk to false-positive saliva PCR results. The false-positive rates adjusted for breastfeeding ranged from 0.03% in white Hispanic persons to 0.14% in white non-Hispanic persons. Saliva CMV PCR for newborn screening is highly sensitive, and the low false-positive rates in this study suggest that saliva PCR results are unlikely to be significantly influenced by breastfeeding or other perinatal exposures.

Pathogenesis of Non-Zika Congenital Viral Infections

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 from South and Central America and the Caribbean. Although the full spectrum of ZIKV infection of the newborn has yet to be determined, other maternal viral infections resulting in transmission to the fetus provide instructive lessons that can be applied to the prospective evaluation of individuals with ZIKV infection. This review focuses on those other congenital infections, including rubella, congenital cytomegalovirus, human immunodeficiency virus, hepatitis B virus, and neonatal herpes simplex virus, from which lessons for the evaluation of ZIKV in the newborn can be applied.

Vaccination against the human cytomegalovirus

The human cytomegalovirus (HCMV) is the most important infectious cause of congenital abnormalities and also of infectious complications of transplantation. The biology of the infection is complex and acquired immunity does not always prevent reinfection. Nevertheless, vaccine development is far advanced, with numerous candidate vaccines being tested, both live and inactivated. This article summarizes the status of the candidate vaccines.

Congenital cytomegalovirus infection

Each year, thousands of children are born with or develop permanent disabilities such as hearing loss, vision loss, motor and cognitive deficits from congenital CMV infection (cCMV). However, awareness of cCMV and its associated sequelae is very low in pregnant women and healthcare providers. Both targeted and universal approaches to screen newborns for CMV infection are now achievable due to recent scientific advances including the development of a rapid, high-throughput method for detecting CMV in saliva, the efficacy of antiviral treatment in symptomatic infants, and the demonstration of cost effectiveness of CMV screening. Future studies are needed to address gaps in our understanding on the role of non-primary maternal CMV infections, the evaluation of antiviral treatment in asymptomatic infants, and the implementation of prevention strategies for cCMV.

Breast Milk Human Cytomegalovirus (CMV) Viral Load and the Establishment of Breast Milk CMV-pp65-Specific CD8 T Cells in Human CMV Infected Mothers

The role of human cytomegalovirus (HCMV)-specific T-cell responses in breast milk of HCMV-seropositive mothers is not well defined. In these studies, we demonstrate that the frequency of cytomegalovirus (CMV)-pp65-specific T-cell responses in peripheral blood mononuclear cells (PBMCs) and breast milk cells (BMCs) is increased for CD8+ T cells in both sample sources when compared with CD4+ T cells. The frequency of pp55-specific CD8 T cells producing interferon γ (IFN-γ) alone or dual IFN-γ/granzyme rB producers is increased in breast milk compared with PBMCs. Lastly, we observed a positive correlation between breast milk viral load and the CD8 pp65-specific response, suggesting that local virus replication drives antigen-specific CD8 T cells into the breast.

Newborn Dried Blood Spot Polymerase Chain Reaction to Identify Infants with Congenital Cytomegalovirus-Associated Sensorineural Hearing Loss

OBJECTIVE

To determine the utility of dried blood spot (DBS) polymerase chain reaction (PCR) in identifying infants with cytomegalovirus (CMV) infection-associated sensorineural hearing loss (SNHL).

STUDY DESIGN

Newborns at 7 US hospitals between March 2007 and March 2012 were screened for CMV by saliva rapid culture and/or PCR. Infected infants were monitored for SNHL during the first 4 years of life to determine sensitivity, specificity, and positive and negative likelihood ratios of DBS PCR for identifying CMV-associated SNHL.

RESULTS

DBS at birth was positive in 11 of 26 children (42%) with SNHL at age 4 years and in 72 of 270 children (27%) with normal hearing (P = .11). The sensitivity (42.3%; 95% CI, 23.4%-63.1%) and specificity (73.3%; 95% CI, 67.6%-78.5%) was low for DBS PCR in identifying children with SNHL at age 4 years. The positive and negative likelihood ratios of DBS PCR positivity to detect CMV-associated SNHL at age 4 years were 1.6 (95% CI, 0.97-2.6) and 0.8 (95% CI, 0.6-1.1), respectively. There was no difference in DBS viral loads between children with SNHL and those without SNHL.

CONCLUSIONS

DBS PCR for CMV has low sensitivity and specificity for identifying infants with CMV-associated hearing loss. These findings, together with previous reports, demonstrate that DBS PCR does not identify either the majority of CMV-infected newborns or those with CMV-associated SNHL early in life.

Congenital cytomegalovirus infection in pregnancy and the neonate: consensus recommendations for prevention, diagnosis, and therapy

Congenital cytomegalovirus is the most frequent, yet under-recognised, infectious cause of newborn malformation in developed countries. Despite its clinical and public health importance, questions remain regarding the best diagnostic methods for identifying maternal and neonatal infection, and regarding optimal prevention and therapeutic strategies for infected mothers and neonates. The absence of guidelines impairs global efforts to decrease the effect of congenital cytomegalovirus. Data in the literature suggest that congenital cytomegalovirus infection remains a research priority, but data are yet to be translated into clinical practice. An informal International Congenital Cytomegalovirus Recommendations Group was convened in 2015 to address these questions and to provide recommendations for prevention, diagnosis, and treatment. On the basis of consensus discussions and a review of the literature, we do not support universal screening of mothers and the routine use of cytomegalovirus immunoglobulin for prophylaxis or treatment of infected mothers. However, treatment guidelines for infected neonates were recommended. Consideration must be given to universal neonatal screening for cytomegalovirus to facilitate early detection and intervention for sensorineural hearing loss and developmental delay, where appropriate. The group agreed that education and prevention strategies for mothers were beneficial, and that recommendations will need continual updating as further data become available.

A Targeted Approach for Congenital Cytomegalovirus Screening Within Newborn Hearing Screening

BACKGROUND AND OBJECTIVE

Congenital cytomegalovirus (cCMV) infection remains a leading cause of childhood hearing loss. Currently universal CMV screening at birth does not exist in the United States. An alternative approach could be testing infants who do not pass their newborn hearing screening (NHS) for cCMV. This study was undertaken to evaluate whether a targeted approach will identify infants with CMV-related sensorineural hearing loss (SNHL).

METHODS

Infants born at 7 US medical centers received NHS and were also screened for cCMV while in the newborn nursery. Infants who tested positive for CMV received further diagnostic audiologic evaluations to identify or confirm hearing loss.

RESULTS

Between 2007 and 2012, 99 945 newborns were screened for both hearing impairment and cCMV. Overall, 7.0% of CMV-positive infants did not pass NHS compared with 0.9% of CMV-negative infants (P < .0001). Among the cCMV infants who failed NHS, diagnostic testing confirmed that 65% had SNHL. In addition, 3.6% of CMV-infected infants who passed their NHS had SNHL confirmed by further evaluation during early infancy. NHS in this cohort identified 57% of all CMV-related SNHL that occurred in the neonatal period.

CONCLUSIONS

A targeted CMV approach that tests newborns who fail their NHS identified the majority of infants with CMV-related SNHL at birth. However, 43% of the infants with CMV-related SNHL in the neonatal period and cCMV infants who are at risk for late onset SNHL were not identified by NHS.

Cost-effectiveness of Universal and Targeted Newborn Screening for Congenital Cytomegalovirus Infection

IMPORTANCE

Congenital cytomegalovirus (cCMV) infection is a major cause of childhood deafness. Most cCMV infections are not diagnosed without newborn screening, resulting in missed opportunities for directed care.

OBJECTIVE

To estimate the cost-effectiveness of universal and targeted newborn cCMV screening programs compared with no cCMV screening.

DESIGN, SETTING, AND PARTICIPANTS

Models were constructed using rates and outcomes from prospective cohort studies of newborn cCMV screening in US postpartum care and early hearing programs. Costs of laboratory testing, treatment, and hearing loss were drawn from Medicaid data and published estimates. The benefits of cCMV screening were assumed to come from antiviral therapy for affected newborns to reduce hearing loss and from earlier identification of hearing loss with postnatal onset. Analyses were performed from July 2014 to March 2016.

INTERVENTIONS

Models compared universal or targeted cCMV screening of newborns with a failed hearing screen, with standard care for cCMV infection.

MAIN OUTCOMES AND MEASURES

The incremental costs of identifying 1 cCMV infection, identifying 1 case of cCMV-related hearing loss, and preventing 1 cochlear implant; the incremental reduction in cases of severe to profound hearing loss; and the differences in costs per infant screened by universal or targeted strategies under different assumptions about the effectiveness of antiviral treatment.

RESULTS

Among all infants born in the United States, identification of 1 case of cCMV infection by universal screening was estimated to cost $2000 to $10 000; by targeted screening, $566 to $2832. The cost of identifying 1 case of hearing loss due to cCMV was as little as $27 460 by universal screening or $975 by targeted screening. Assuming a modest benefit of antiviral treatment, screening programs were estimated to reduce severe to profound hearing loss by 4.2% to 13% and result in direct costs of $10.86 per newborn screened. However, savings of up to $37.97 per newborn screened were estimated when costs related to functionality were included.

CONCLUSIONS AND RELEVANCE

Newborn screening for cCMV infection appears to be cost-effective under a wide range of assumptions. Universal screening offers larger net savings and the greatest opportunity to provide directed care. Targeted screening also appears to be cost-effective and requires testing for fewer newborns. These findings suggest that implementation of newborn cCMV screening programs is warranted.

Congenital cytomegalovirus infection: clinical outcome

Congenital cytomegalovirus (CMV) infection is a leading cause of hearing loss and neurologic disabilities in children worldwide. Infants with symptomatic congenital CMV infection at birth are at significantly increased risk for developing adverse long-term outcomes. The vast majority of infants with congenital CMV infection have no clinical findings at birth (asymptomatic infants), and about 10%-15% of these children develop long-term sequelae. Currently, predictors of adverse outcome in asymptomatic congenital CMV infection are not known, and it is important that future studies address this issue.

Detection of congenital cytomegalovirus infection by real-time polymerase chain reaction analysis of saliva or urine specimens

Viral culture of urine or saliva has been the gold standard technique for the diagnosis of congenital cytomegalovirus (CMV) infection. Results of rapid culture and polymerase chain reaction (PCR) analysis of urine and saliva specimens from 80 children were compared to determine the clinical utility of a real-time PCR assay for diagnosis of congenital CMV infection. Results of urine PCR were positive in 98.8% of specimens. Three PCR-positive urine samples were culture negative. Results of saliva PCR and culture were concordant in 78 specimens (97.5%). Two PCR-positive saliva samples were culture negative. These findings demonstrate that PCR performs as well as rapid culture of urine or saliva specimens for diagnosing congenital CMV infection and saliva specimens are easier to collect. Because PCR also offers more rapid turnaround, is unlikely to be affected by storage and transport conditions, has lower cost, and may be adapted to high-throughput situations, it is well suited for targeted testing and large-scale screening for CMV.

Spectrum of disease and outcome in children with symptomatic congenital cytomegalovirus infection

OBJECTIVE

To evaluate differences in presentation and outcomes in children with symptomatic congenital cytomegalovirus (cCMV) identified on newborn screening (screened group) and those identified based on clinical findings at birth (referred group).

STUDY DESIGN

Data on 178 infants with symptomatic cCMV were analyzed. Demographic characteristics, clinical and laboratory findings documented in the nursery, and sequelae data were compared between the screened and the referred groups using χ(2) or Fisher exact test.

RESULTS

Two or more clinical findings were detected at birth in 91% of referred infants, and only 58% of screened infants (P < .001). Significantly more children in the referred group had hearing loss compared with screened infants (P = .009). Fifty-one percent of screened children were free of sequelae compared with only 28% of the referred group (P < .003).

CONCLUSIONS

Infants with symptomatic cCMV identified based on clinical suspicion have more severe disease at birth and more commonly have sequelae than those identified on newborn screening. Inclusion of referral infants in many previous reports may have overestimated the severity of disease because of selection bias. Defining the complete spectrum of symptomatic disease due to cCMV and providing precise estimates of disease burden can only be gathered from large newborn screening studies.

Incidence and impact of CMV infection in very low birth weight infants

BACKGROUND AND OBJECTIVES

Congenital cytomegalovirus (CMV) is the leading cause of nongenetic deafness in children in the United States and can cause neurodevelopmental impairment in term infants. Limited data exist regarding congenital CMV infections in preterm infants. We aimed to determine the incidence and association with outcomes of congenital CMV in very low birth weight (VLBW) preterm infants.

METHODS

VLBW infants born in 1993 to 2008 and admitted to the University of Alabama in Birmingham Regional Neonatal ICU were screened on admission for congenital CMV. CMV status and clinical outcomes were identified by using internal patient databases and hospital-based medical records. The primary outcome was death. Secondary outcomes included evidence of neurologic injury in the form of abnormal cranial ultrasound findings, sensorineural hearing loss, or abnormal motor development. Multivariate analysis was performed.

RESULTS

Eighteen of 4594 VLBW infants had congenital CMV (0.39%; 95% confidence interval, 0.25%-0.62%). An additional 16 infants (0.35%; 95% confidence interval, 0.21%-0.57%) were identified who acquired CMV postnatally. Congenital CMV was not associated with death. Compared with controls, congenitally infected VLBW infants were more likely to have hearing loss at initial screening (67% vs. 9%, P < .0001) and confirmed at follow-up (83% vs. 2.1%, P < .0001). Congenital CMV was also associated with abnormal neuroimaging (72% vs. 25%, P < .0001) and adverse developmental motor outcomes (43% vs. 9%, P = .02). Acquired CMV was not associated with any adverse outcomes.

CONCLUSIONS

Congenital CMV in VLBW infants is associated with high rates of neurologic injury and hearing loss but not death.

Birth prevalence of congenital cytomegalovirus among infants of HIV-infected women on prenatal antiretroviral prophylaxis in South Africa

BACKGROUND

A high rate of congenital cytomegalovirus (CMV) has been documented in human immunodeficiency virus (HIV)-exposed infants in industrialized settings, both in the pre- and post-highly active antiretroviral therapy (HAART) era. Only limited data on the birth prevalence of congenital CMV among infants of HIV-infected women on prenatal antiretroviral (ARV) prophylaxis are available from sub-Saharan Africa, despite a high prevalence of both infections. We evaluated the prevalence of congenital CMV in HIV-exposed infants in the Western Cape, South Africa.

METHODS

HIV-infected mothers were recruited in the immediate postnatal period at a referral maternity hospital between April and October 2012. Maternal and infant clinical data and newborn saliva swabs were collected. Saliva swabs were assayed by real-time polymerase chain reaction for CMV. Data were analyzed using univariate and multivariate logistic regression analyses to determine specific demographic, maternal, and newborn characteristics associated with congenital CMV.

RESULTS

CMV was detected in 22 of 748 newborn saliva swabs (2.9%; 95% confidence interval [CI], 1.9%-4.4%). Overall, 96% of mothers used prenatal ARV prophylaxis (prenatal zidovudine, 43.9%; HAART, 52.1%). Maternal age, gestational age, prematurity (<37 weeks' gestation), type of ARV prophylaxis, length of ARV prophylaxis, birth weight, small for gestational age, and infant feeding choice were not significantly different between CMV-infected and -uninfected infants. Maternal CD4 count <200 cells/μL during pregnancy was independently associated with congenital CMV (adjusted odds ratio, 2.9; 95% CI, 1.2-7.3). A negative correlation between CMV load in saliva and maternal CD4 count was observed (r = -0.495, n = 22, P = .019).

CONCLUSIONS

The birth prevalence of congenital CMV was high despite prenatal ARV prophylaxis, and was associated with advanced maternal immunosuppression.

The "silent" global burden of congenital cytomegalovirus

Human cytomegalovirus (CMV) is a leading cause of congenital infections worldwide. In the developed world, following the virtual elimination of circulating rubella, it is the commonest nongenetic cause of childhood hearing loss and an important cause of neurodevelopmental delay. The seroprevalence of CMV in adults and the incidence of congenital CMV infection are highest in developing countries (1 to 5% of births) and are most likely driven by nonprimary maternal infections. However, reliable estimates of prevalence and outcome from developing countries are not available. This is largely due to the dogma that maternal preexisting seroimmunity virtually eliminates the risk for sequelae. However, recent data demonstrating similar rates of sequelae, especially hearing loss, following primary and nonprimary maternal infection have underscored the importance of congenital CMV infection in resource-poor settings. Although a significant proportion of congenital CMV infections are attributable to maternal primary infection in well-resourced settings, the absence of specific interventions for seronegative mothers and uncertainty about fetal prognosis have discouraged routine maternal antibody screening. Despite these challenges, encouraging results from prototype vaccines have been reported, and the first randomized phase III trials of prenatal interventions and prolonged postnatal antiviral therapy are under way. Successful implementation of strategies to prevent or reduce the burden of congenital CMV infection will require heightened global awareness among clinicians and the general population. In this review, we highlight the global epidemiology of congenital CMV and the implications of growing knowledge in areas of prevention, diagnosis, prognosis, and management for both low (50 to 70%)- and high (>70%)-seroprevalence settings.

Overview of the diagnosis of cytomegalovirus infection

Cytomegalovirus (CMV) is recognized as the most common congenital viral infection in humans and an important cause of morbidity and mortality in immunocompromised hosts. This recognition of the clinical importance of invasive CMV disease in the setting of immunodeficiency and in children with congenital CMV infection has led to the development of new diagnostic procedures for the rapid identification of CMV. Diagnosis of acute maternal CMV infection by the presence of immunoglobulin (Ig)M and low-avidity IgG requires confirmation of fetal infection, which is typically performed using polymerase chain reaction (PCR) assays for CMV on amniotic fluid. Viral culture of the urine and saliva obtained within the first two weeks of life continues to be the gold standard for diagnosis of congenitally-infected infants. PCR assays of dried blood spots from newborns have been shown to lack sufficient sensitivity for the identification of most neonates with congenital CMV infection for universal screening purposes. However, saliva PCR assays are currently being assessed as a useful screening method for congenital CMV infection. In the immunocompromised host, newer rapid diagnostic assays, such as phosphoprotein 65 antigenemia and CMV real-time PCR of blood or plasma have allowed for preemptive treatment, reducing morbidity and mortality. However, lack of standardized real-time PCR protocols hinders the comparison of data from different centers and the development of uniform guidelines for the management of invasive CMV infections in immunocompromised individuals.

Mixed infection and strain diversity in congenital cytomegalovirus infection

BACKGROUND

Cytomegalovirus (CMV), the most common cause of congenital infection, exhibits extensive genetic variability. We sought to determine whether multiple CMV strains can be transmitted to the fetus and to describe the distribution of genotypes in the saliva, urine, and blood.

METHODS

Study subjects consisted of a convenience sampling of 28 infants found to be CMV-positive on newborn screening as part of an ongoing study. Genotyping was performed on saliva specimens obtained during newborn screening and urine, saliva, and blood obtained at a later time point within the first 3 weeks of life.

RESULTS

Six (21.4%) of the 28 saliva samples obtained within the first 2 days of life contained >1 CMV genotype. Multiple CMV genotypes were found in 39% (5/13) of urine, saliva, and blood samples obtained within the first 3 weeks of life from 13 of the 28 newborns. There was no predominance of a CMV genotype at a specific site; however, 4 infants demonstrated distinct CMV strains in different compartments.

CONCLUSIONS

Infection with multiple CMV strains occurs in infants with congenital CMV infection. The impact of intrauterine infection with multiple virus strains on the pathogenesis and long-term outcome remains to be elucidated.

Saliva polymerase-chain-reaction assay for cytomegalovirus screening in newborns

BACKGROUND

Congenital cytomegalovirus (CMV) infection is an important cause of hearing loss, and most infants at risk for CMV-associated hearing loss are not identified early in life because of failure to test for the infection. The standard assay for newborn CMV screening is rapid culture performed on saliva specimens obtained at birth, but this assay cannot be automated. Two alternatives--real-time polymerase-chain-reaction (PCR)-based testing of a liquid-saliva or dried-saliva specimen obtained at birth--have been developed.

METHODS

In our prospective, multicenter screening study of newborns, we compared real-time PCR assays of liquid-saliva and dried-saliva specimens with rapid culture of saliva specimens obtained at birth.

RESULTS

A total of 177 of 34,989 infants (0.5%; 95% confidence interval [CI], 0.4 to 0.6) were positive for CMV, according to at least one of the three methods. Of 17,662 newborns screened with the use of the liquid-saliva PCR assay, 17,569 were negative for CMV, and the remaining 85 infants (0.5%; 95% CI, 0.4 to 0.6) had positive results on both culture and PCR assay. The sensitivity and specificity of the liquid-saliva PCR assay were 100% (95% CI, 95.8 to 100) and 99.9% (95% CI, 99.9 to 100), respectively, and the positive and negative predictive values were 91.4% (95% CI, 83.8 to 96.2) and 100% (95% CI, 99.9 to 100), respectively. Of 17,327 newborns screened by means of the dried-saliva PCR assay, 74 were positive for CMV, whereas 76 (0.4%; 95% CI, 0.3 to 0.5) were found to be CMV-positive on rapid culture. Sensitivity and specificity of the dried-saliva PCR assay were 97.4% (95% CI, 90.8 to 99.7) and 99.9% (95% CI, 99.9 to 100), respectively. The positive and negative predictive values were 90.2% (95% CI, 81.7 to 95.7) and 99.9% (95% CI, 99.9 to 100), respectively.

CONCLUSIONS

Real-time PCR assays of both liquid- and dried-saliva specimens showed high sensitivity and specificity for detecting CMV infection and should be considered potential screening tools for CMV in newborns. (Funded by the National Institute on Deafness and Other Communication Disorders.).

Cytomegalovirus viruria and DNAemia in healthy seropositive women

Viruria and DNAemia patterns were investigated in 205 seroimmune women enrolled in a prospective cytomegalovirus (CMV) reinfection study. CMV DNA was detected at least once in urine and blood specimens from 83% and 52% of patients, respectively. At baseline, 39% of patients had viruria, and 24% had DNAemia. Intermittent viruria and viremia was observed throughout the study. There were no differences in baseline CMV positivity by polymerase chain reaction or in longitudinal DNAemia and viruria between the women with and without serological evidence of reinfection. In young seropositive women, CMV DNAemia and viruria are common, which suggests that naturally acquired immunity to CMV does not alter shedding patterns.

Dried blood spot real-time polymerase chain reaction assays to screen newborns for congenital cytomegalovirus infection

CONTEXT

Reliable methods to screen newborns for congenital cytomegalovirus (CMV) infection are needed for identification of infants at increased risk of hearing loss. Since dried blood spots (DBS) are routinely collected for metabolic screening from all newborns in the United States, there has been interest in using DBS polymerase chain reaction (PCR)-based methods for newborn CMV screening.

OBJECTIVE

To determine the diagnostic accuracy of DBS real-time PCR assays for newborn CMV screening.

DESIGN, SETTING, AND PARTICIPANTS

Between March 2007 and May 2008, infants born at 7 US medical centers had saliva specimens tested by rapid culture for early antigen fluorescent foci. Results of saliva rapid culture were compared with a single-primer (March 2007-December 2007) and a 2-primer DBS real-time PCR (January 2008-May 2008). Infants whose specimens screened positive on rapid culture or PCR had congenital infection confirmed by the reference standard method with rapid culture testing on saliva or urine.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative likelihood ratios (LRs) of single-primer and 2-primer DBS real-time PCR assays for identifying infants with confirmed congenital CMV infection.

RESULTS

Congenital CMV infection was confirmed in 92 of 20,448 (0.45%; 95% confidence interval [CI], 0.36%-0.55%) infants. Ninety-one of 92 infants had positive results on saliva rapid culture. Of the 11,422 infants screened using the single-primer DBS PCR, 17 of 60 (28%) infants had positive results with this assay, whereas, among the 9026 infants screened using the 2-primer DBS PCR, 11 of 32 (34%) screened positive. The single-primer DBS PCR identified congenital CMV infection with a sensitivity of 28.3% (95% CI, 17.4%-41.4%), specificity of 99.9% (95% CI, 99.9%-100%), positive LR of 803.7 (95% CI, 278.7-2317.9), and negative LR of 0.7 (95% CI, 0.6-0.8). The positive and negative predictive values of the single-primer DBS PCR were 80.9% (95% CI, 58.1%-94.5%) and 99.6% (95% CI, 99.5%-99.7%), respectively. The 2-primer DBS PCR assay identified infants with congenital CMV infection with a sensitivity of 34.4% (95% CI, 18.6%-53.2%), specificity of 99.9% (95% CI, 99.9%-100.0%), positive LR of 3088.9 (95% CI, 410.8-23 226.7), and negative LR of 0.7 (95% CI, 0.5-0.8). The positive and negative predictive values of the 2-primer DBS PCR were 91.7% (95% CI, 61.5%-99.8%) and 99.8% (95% CI, 99.6%-99.9%), respectively.

CONCLUSION

Among newborns, CMV testing with DBS real-time PCR compared with saliva rapid culture had low sensitivity, limiting its value as a screening test.

Human cytomegalovirus reinfection is associated with intrauterine transmission in a highly cytomegalovirus-immune maternal population

OBJECTIVE

To determine contribution of reinfection with new strains of cytomegalovirus in cytomegalovirus seromimmune women to incidence of congenital cytomegalovirus infection.

STUDY DESIGN

In 7848 women studied prospectively for congenital cytomegalovirus infection from a population with near universal cytomegalovirus seroimmunity, sera from 40 mothers of congenitally infected infants and 109 mothers of uninfected newborns were analyzed for strain-specific anticytomegalovirus antibodies.

RESULTS

All women were cytomegalovirus seroimmune at first prenatal visit. Reactivity for 2 cytomegalovirus strains was found in 14 of 40 study mothers and in 17 of 109 control mothers at first prenatal visit (P = .009). Seven of 40 (17.5%) study women and 5 of 109 (4.6%) controls (P = .002) acquired antibodies reactive with new cytomegalovirus strains during pregnancy. Evidence of infection with more than 1 strain of cytomegalovirus before or during current pregnancy occurred in 21 of 40 study mothers and 22 of 109 controls (P < .0001).

CONCLUSION

Maternal reinfection by new strains of cytomegalovirus is a major source of congenital infection in this population.

Cytomegalovirus reinfections in healthy seroimmune women

Cytomegalovirus (CMV) reinfections have been associated with damaging congenital infection and adverse outcomes in transplant recipients. To determine the frequency of and risk factors for CMV reinfections, 205 seropositive women were followed up prospectively. The appearance of new antibody specificity against 1 of 4 polymorphic epitopes was considered as evidence of CMV reinfection. Approximately one-third of the study participants (59 [29%] of 205) were noted to have CMV reinfection during follow-up. None of the exposure factors were associated with CMV reinfection. Women with antibodies against at least 1 of the 4 antigens at baseline had a 63% decreased risk of reinfection, suggesting a protective role for strain-specific immunity.

Hearing loss in children with congenital cytomegalovirus infection born to mothers with preexisting immunity

OBJECTIVE

To define hearing outcomes in children with congenital cytomegalovirus (CMV) infection born to mothers with non-primary CMV infection.

STUDY DESIGN

A cohort of 300 children with congenital CMV infection identified by newborn virologic screening at the University of Alabama Hospital and a private community hospital in which the type of maternal infection could be classified constituted the study population. Maternal infections were categorized by analyzing serum samples. Children were followed prospectively and underwent serial audiologic evaluations.

RESULTS

The frequency of hearing loss was not different between children born to mothers with non-primary infection (10%) and those with primary infection (11%). Significantly more children in the primary infection group had progressive and severe/profound hearing loss compared with children in the non-primary group. The frequency of bilateral, delayed onset, high-frequency, and fluctuating hearing loss was not different between the 2 groups. The mean age of diagnosis of hearing loss was 39 +/- 53 months for children born to mothers with non-primary infection and 13 +/- 21 months for the primary infection group (P = .16).

CONCLUSIONS

Maternal preexisting seroimmunity to CMV does not provide complete protection against hearing loss in infants with congenital CMV infection.

Congenital cytomegalovirus infection following first trimester maternal infection: Symptoms at birth and outcome

BACKGROUND

The relationship between gestational age at time of maternal cytomegalovirus (CMV) infection and outcome of fetal infection is not well defined because the timing of maternal infection is usually not known.

OBJECTIVE

To determine whether congenital cytomegalovirus (CMV) infection following primary maternal infection during the first trimester of pregnancy is more likely to lead to central nervous system (CNS) sequelae than fetal infection due to maternal infection later in pregnancy.

STUDY DESIGN

Using serum collected during pregnancy from mothers of newborns with congenital CMV infection, maternal infection was categorized as first trimester (<13 weeks) or later based on dates and results of IgG and IgM assays for CMV antibody. Outcome of congenital CMV infection was assessed by longitudinal fotlow-up of the infected cohort.

RESULTS

Sensorineural hearing loss was found in 8/34 (24%) of children in the first trimester group, compared with 1/40 (2.5%) in the later infection group (P=0.01, relative risk, 9.6). Considering any CNS sequela (hearing loss, mental retardation, cerebral palsy, seizures, chorioretinitis) 11/34 (32%) first trimester cases were affected compared with 6/40 (15%) in the later infection group (P=0.07, relative risk 2.2). None of the later group had more than one sequela, compared with 4 (12%) of the first trimester group (P=0.04).

CONCLUSIONS

Children with congenital CMV infection following first trimester maternal infection are more likely to have CNS sequelae, especially sensorineural hearing loss, than are those whose mothers were infected later in pregnancy. However, some degree of CNS impairment can follow even late gestational infection.

Congenital cytomegalovirus (CMV) infection and hearing deficit

BACKGROUND

The association between congenital cytomegalovirus (CMV) infection and sensorineural hearing loss (SNHL) was first described in 1964. Studies over the past four decades have further described the relationship between congenital CMV infection and SNHL in children.

OBJECTIVES

This manuscript will review the current knowledge of CMV-related SNHL and summarize the studies completed at the University of Alabama at Birmingham (UAB).

STUDY DESIGN

A review of the series of studies at UAB that has led to a more detailed characterization of hearing loss due to congenital CMV infection.

RESULTS

Approximately, 22%-65% of symptomatic and 6%-23% of asymptomatic children will have hearing loss following congenital CMV infection. CMV-related SNHL may be present at birth or occur later in childhood. Variability in the severity of CMV-related hearing loss ranges from unilateral high frequency losses to profound bilateral losses.

CONCLUSIONS

Congenital CMV infection significantly contributes to SNHL in many infant populations. Although, most children with congenital CMV infection do not develop hearing loss, it is difficult to predict which children with congenital CMV infection will develop hearing loss and, among those who do develop loss, whether or not the loss will continue to deteriorate.

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

OBJECTIVE

To determine the relationship between the virus burden in infancy and hearing loss in congenital CMV infection.

STUDY DESIGN

A cohort of 76 infants with congenital cytomegalovirus (CMV) infection identified by means of newborn virologic screening was monitored for outcome. The amount of infectious CMV was analyzed in urine specimens obtained during early infancy. Peripheral blood (PB) samples obtained during early infancy were available from 75 children and CMV DNA was quantitated with a real-time quantitative polymerase chain reaction.

RESULTS

Infants with clinical abnormalities at birth (symptomatic congenital CMV infection) had higher amounts of CMV in urine (P = .005) and CMV DNA in PB (P = .001) than infants with no symptoms. Eight children with and 4 children without symptoms had hearing loss. Among children without symptoms, those with hearing loss had a significantly greater amount of CMV in urine (P = .03) and PB virus burden (P = .02) during infancy than those with normal hearing. Infants with < 5 x 10(3) pfu/mL of urine CMV and infants with < 1 x 10(4) copies/mL of viral DNA in PB were at a lower risk for hearing loss.

CONCLUSION

In children with asymptomatic congenital CMV infection, hearing loss was associated with increased amounts of urine CMV and PB CMV DNA during early infancy.

Congenital cytomegalovirus infection: outcome and diagnosis

Cytomegalovirus (CMV) is the most common congenital infection in humans and an important cause of morbidity and mortality in immunocompromised hosts. Congenital CMV infection occurs in approximately 0.5 to 1 percent of all newborns in the United States and can result in significant neurological sequelae. The gold standard for diagnosing congenital CMV infection is isolation of the virus from infants within the first 2 weeks of life through conventional or rapid cell culture techniques. Newer molecular diagnostic methods to diagnose congenital CMV infection, including the nucleic acid amplification of viral DNA from the peripheral blood of infants, are being investigated, and the preliminary results show promise. However, more work must be done to standardize and validate these methods before they can be used routinely in establishing the diagnosis of congenital CMV infection.

Predictors of hearing loss in children with symptomatic congenital cytomegalovirus infection

OBJECTIVE

Congenital cytomegalovirus (CMV) infection is a major cause of sensorineural hearing loss (SNHL) and neurologic impairment in children. Although the majority of children with symptomatic congenital CMV infection develop hearing loss, many symptomatic infants have normal hearing. The purpose of this study was to identify indicators present in the newborn period that have predictive value for the development of hearing loss in children with symptomatic congenital CMV infection.

METHODS

Of the 190 children who had symptomatic congenital CMV infection and were born between 1966 and 1997 and enrolled in a follow-up study, hearing outcome was known for 180 children. Follow-up data were analyzed using univariate and multivariate logistic regression analyses to determine the specific demographic, newborn clinical, and laboratory findings predictive of hearing loss. The amount of infectious CMV in urine was quantified in a subset of 21 children who were born between 1994 and 1998.

RESULTS

The presence of intrauterine growth retardation, petechiae, hepatosplenomegaly, hepatitis, thrombocytopenia, and intracerebral calcifications was associated with the development of hearing loss on univariate analysis. The presence of microcephaly and other neurologic abnormalities was not predictive of hearing loss. Logistic regression analysis revealed that only petechiae and intrauterine growth retardation independently predicted hearing loss. None of the demographic and other newborn findings predicted progressive hearing loss. The children who developed hearing loss had higher urine CMV titers during infancy than those with normal hearing.

CONCLUSION

In children with symptomatic congenital CMV infection, evidence of disseminated infection with or without the presence of neurologic involvement at birth was predictive of the development of hearing loss. However, it was not possible to identify factors that are independently predictive of the development of progressive hearing loss.

Intrauterine transmission of cytomegalovirus to infants of women with preconceptional immunity

BACKGROUND

Preconceptional immunity against cytomegalovirus (CMV) provides only partial protection against intrauterine transmission of the virus. Whether congenital CMV infection in the offspring of women who are seropositive for CMV can occur after maternal reinfection with a different strain of CMV is unknown.

METHODS

Serum specimens from 46 women with preconceptional immunity against CMV that were obtained during the previous pregnancy and the current pregnancy were analyzed for antibodies against the strain-specific epitopes of CMV glycoprotein H. Virus-neutralizing activity in maternal serum samples was measured against the AD169 laboratory strain of CMV and the CMV isolates available from seven infected infants. In addition, the nucleotide sequences of the glycoprotein H gene from the seven CMV isolates were determined.

RESULTS

Eleven of the 16 mothers with infected infants (69 percent) had antibodies against the glycoprotein H epitopes present on two laboratory strains of CMV, AD169 and Towne. Ten of the 16 mothers with infected children (62 percent) acquired new antibody specificities against glycoprotein H, as compared with only 4 of the 30 mothers of uninfected infants (13 percent, P<0.001). The samples obtained at the time of the current delivery from four of the seven mothers contained at least twice as many neutralizing antibodies against the CMV isolated from their infants as were present in the samples obtained at the previous delivery. The specificity of the newly acquired maternal antibodies reflected the amino acid sequence of the glycoprotein H epitope of CMV from these four infants.

CONCLUSIONS

In women who are seropositive for CMV, reinfection with a different strain of CMV can lead to intrauterine transmission and symptomatic congenital infection.

Longitudinal investigation of hearing disorders in children with congenital cytomegalovirus

This investigation consisted of a longitudinal study of the effects of congenital cytomegalovirus (CMV) infection on hearing sensitivity in 860 children with documented asymptomatic or symptomatic congenital CMV infection. Of the 651 children with asymptomatic CMV infection, 48 (7.4%) developed sensorineural hearing loss (SNHL), compared to 85 (40.7%) of the children with symptomatic CMV infection. Children in both groups experienced latent effects consisting of delayed onset of loss, threshold fluctuations, and/or progressive loss of hearing. It can be concluded that congenital CMV infection is a leading cause of SNHL in children. The late onset and progression of loss necessitates continued monitoring of hearing sensitivity in this population.

High prevalence of complement component C6 deficiency among African-Americans in the south-eastern USA

Complement component C6 is a part of the membrane attack complex that forms a pore-like structure in cell membranes following complement activation. Deficiency of terminal complement components including C6 predisposes individuals to infection with Neisseriae. Using polymerase chain reaction/single-strand conformation polymorphism analysis followed by DNA sequencing, we screened genomic DNA from 200 randomly chosen blacks and an equal number from whites for three loss-of-function C6 mutations. Ten blacks and two whites were found to be heterozygous for one of the mutations. Two of the mutations, 1195delC and 1936delG, were found exclusively in black individuals. A third previously undescribed mutation, 878delA, was found at equal frequency among the two groups. The difference between the two groups was significant (P = 0.027), indicating that C6 deficiency due to these three mutations is more common among blacks than whites in the local area, principally Jefferson County, Alabama. In addition, three previously undescribed point mutations, two of which result in amino acid substitutions, were identified within exon 6. A review of the county health department records over the past 6 years revealed a higher incidence of meningococcal meningitis in blacks due to serogroups Y and W-135 which paralleled the difference in the estimated prevalence of C6 deficiency. Among black residents of the county (n = 235 598) there were 15 cases of meningitis due to these two serogroups, compared with two cases in the white population (n = 422 604) (P = 0.002). We conclude that C6 deficiency is more common among blacks than whites in the south-eastern United States, with a frequency approaching 1 in 1600 black individuals.

Asymptomatic primary cytomegalovirus infection: virologic and immunologic features

We followed 45 seronegative adolescents for acquisition of cytomegalovirus (CMV); 6 (5 female, 1 male) seroconverted after a median of 7.5 months. All were free of signs and symptoms. CMV was isolated from 32 (59.2%) of 54 urines, 2-80 weeks after infection; viruria was less frequent after 6 months. CMV was isolated from saliva of 3 subjects, vaginal swabs of 2 of 5, and 1 white blood cell (WBC) sample. CMV DNA was detected by polymerase chain reaction in WBCs and plasma from all subjects tested. The proportion of WBC samples with CMV DNAemia was 75%-80% within 16 weeks of infection, declining to 0%-25% after 48 weeks. The rate of plasma DNAemia was 25%-40% at 8-16 weeks, declining with time. IgG antibody to CMV, glycoprotein B (gB), and neutralizing antibody were present after 6-8 weeks. Lymphocyte proliferative responses to CMV and to gB were low, compared with those of controls. CMV shedding was of shorter duration than expected. Although antibody response was prompt and vigorous, CMV DNA could be detected in blood for months.

Symptomatic congenital cytomegalovirus infection in infants born to mothers with preexisting immunity to cytomegalovirus

OBJECTIVES

To determine the frequency of symptomatic congenital cytomegalovirus (CMV) infection in the offspring of women with a recurrent maternal CMV infection and to characterize the demographic and newborn findings.

METHODS

Study subjects consisted of infants with symptomatic congenital CMV infection identified by a newborn virologic screening program at the University of Alabama Hospital between 1991 and 1997 and were enrolled in a long-term follow-up study. Maternal infections were categorized by an analysis of archival serum specimens collected before pregnancy and at the time of delivery. Demographic data and clinical findings at birth were collected from maternal and newborn hospital records and from parents at the time of initial evaluation.

RESULTS

Of the 47 infants with symptomatic congenital CMV infection identified during the study period, 8 were born to mothers with a confirmed nonprimary or recurrent CMV infection. The type of maternal infection could be ascertained in only approximately 43% (20/47) of the children with symptomatic congenital CMV infection born at the University of Alabama Hospital during the study period. There were no significant differences in demographic characteristics of the recurrent infection group and the infants who were born to mothers with either primary CMV infection during pregnancy or unclassified maternal infection. Similarly, the range of severity of clinical abnormalities during the newborn period did not differ in the two groups of children. Furthermore, there were no significant differences in the incidence of sequelae at long-term follow-up in the two groups of children.

CONCLUSIONS

Symptomatic congenital CMV infection can occur after a nonprimary or recurrent maternal infection. However, the exact incidence of symptomatic congenital CMV infection among children born to women with preexisting immunity remains to be defined.