Use of screening dried blood spots for estimation of prevalence, risk factors, and birth outcomes of congenital cytomegalovirus infection

Autism Spectrum Disorder Diagnoses and Congenital Cytomegalovirus

OBJECTIVE

To examine the association between congenital cytomegalovirus (cCMV) and autism spectrum disorder (ASD) administrative diagnoses in US children.

METHODS

Cohort study using 2014 to 2020 Medicaid claims data. We used diagnosis codes to identify cCMV (exposure), ASD (outcome), and covariates among children enrolled from birth through ≥4 to <7 years. Covariates include central nervous system (CNS) anomaly or injury diagnosis codes, including brain anomaly, microcephaly within 45 days of birth, cerebral palsy, epilepsy, or chorioretinitis. We used Cox proportional hazards regression models to estimate hazard ratios and 95% confidence intervals, overall and stratified by sex, birth weight and gestational age outcome (low birth weight or preterm birth), and presence of CNS anomaly or injury.

RESULTS

Among 2 989 659 children, we identified 1044 (3.5 per 10 000) children with cCMV and 74 872 (25.0 per 1000) children with ASD. Of those with cCMV, 49% also had CNS anomaly or injury diagnosis codes. Children with cCMV were more likely to have ASD diagnoses (hazard ratio: 2.5; 95% confidence interval: 2.0-3.2, adjusting for birth year, sex, and region). This association differed by sex and absence of CNS anomaly or injury but not birth outcome.

CONCLUSIONS

Children with (versus without) cCMV diagnoses in Medicaid claims data, most of whom likely had symptomatic cCMV, were more likely to have ASD diagnoses. Future research investigating ASD risk among cohorts identified through universal cCMV screening may help elucidate these observed associations.

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

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

Early childhood outcomes of NICU graduates with cytomegalovirus infection in California

BACKGROUND

To assess demographics and outcomes up to 3 years of age among children with cytomegalovirus (CMV) infection in California neonatal intensive care units (NICUs) during 2010-2021.

METHODS

The California Perinatal Quality Care Collaborative (CPQCC) collects data on all very low birth weight (VLBW, birth weight ≤ 1500 g) and acutely ill infants with birth weight > 1500 g across 92% of NICUs in California. VLBW infants and those with neurological conditions are referred to a statewide high-risk infant follow-up (HRIF) program. CMV infection was defined as a positive culture or PCR identified during the NICU hospitalization.

RESULTS

During 2010-2021, CMV reporting rates averaged 3.5/1000 VLBW infants (n = 205) and 1.1/1000 infants >1500 g (n = 128). Among all 333 infants with CMV, 314 (94%) were discharged home alive, 271 (86%) were referred for HRIF and 205 (65%) had ≥1 visit. Whereas infants born to mothers <20 years of age had highest CMV reporting rates and those born to Hispanic mothers comprised 49% of all infected infants, they had the highest loss of follow-up. At the 12-month visit (n = 152), 19 (13%) infants with CMV had bilateral blindness and 18 (12%) had hearing loss. At the 24-month visit, 5 (5%) of 103 had severe cerebral palsy.

CONCLUSIONS

Among infants admitted to the NICU, those with CMV diagnoses may over represent infants with more severe CMV disease and outcomes. The CPQCC and HRIF program findings may help inform implementation of surveillance for congenital CMV infection in other U.S. states and guide strategies to reduce disparities in access to services.

Update in Pediatric Diagnostic Microbiology

Infants and young children are uniquely susceptible to primary viral and bacterial infections, predisposing them to responses of greater frequency and severity than in adults. Etiologies and manifestations of infections in pediatric patients are often different than those in adults. It can be challenging for clinical laboratories to implement appropriate microbiologic methods for rapid and accurate diagnoses in this population. Laboratorians should be cognizant of the distinctive features of children to provide comprehensive pediatric clinical microbiology services. This article discusses laboratory aspects of several clinically significant pediatric pathogens that cause severe harm to patients and impact public health responses.

Manuscript title: Maternal CMV seroprevalence rate in early gestation and congenital cytomegalovirus infection in a Chinese population

BACKGROUND

Congenital human cytomegalovirus (CMV) infection remains largely unrecognized and underemphasized in medical practice. This study aimed to describe the maternal CMV seroprevalence rate in early gestation and congenital CMV infection in a Chinese population.

METHODS

This was a prospective cohort study that was conducted in three hospitals in China from 2015 through 2018. Pregnant women were enrolled in early gestation and followed up in middle and late gestation with serological testing. CMV serostatus was determined by IgG testing in serum during early gestation. Their newborns were screened and confirmed for cCMV infection by real-time PCR testing in both saliva and urine at two time points. The cCMV prevalence, maternal seroprevalence and associated factors were analyzed.

RESULTS

In China, the CMV seroprevalence was 98.11% (6602/6729, 95% CI: 97.76%-98.41%), and the cCMV prevalence was 1.32% (84/6350, 95% CI: 1.07%-1.64%). Over 98% of cCMV-positive newborns were from pregnant women who were seropositive in early gestation in China. The prevalence of cCMV infection in newborns from seropositive and seronegative pregnant women was similar (crude prevalence: 1.33% vs 0.82%, P=1.00; estimated prevalence: 1.29% vs 1.05%, P=0.42). Pregnant women who were under 25 years old or primiparous had a lower seroprevalence. Newborns from pregnant women under 25 years old or from twin pregnancies had a higher prevalence of cCMV infection.

CONCLUSION

In China, the cCMV prevalence was high, and the rates were similar in newborns from pregnant women who were seropositive and seronegative in early gestation. The vast majority of cCMV newborns were from seropositive mothers.Trial registration: ClinicalTrials.gov identifier: NCT02645396..

Congenital Cytomegalovirus Infection Burden and Epidemiologic Risk Factors in Countries With Universal Screening: A Systematic Review and Meta-analysis

IMPORTANCE

Congenital cytomegalovirus (cCMV) infection is the most common congenital infection and the leading acquired cause of developmental disabilities and sensorineural deafness, yet a reliable assessment of the infection burden is lacking.

OBJECTIVES

To estimate the birth prevalence of cCMV in low- and middle-income countries (LMICs) and high-income countries (HICs), characterize the rate by screening methods, and delineate associated risk factors of the infection.

DATA SOURCES

MEDLINE/PubMed, Scopus, and Cochrane Database of Systematic Reviews databases were searched from January 1, 1960, to March 1, 2021, and a total of 1322 studies were identified.

STUDY SELECTION

Studies that provided data on the prevalence of cCMV derived from universal screening of infants younger than 3 weeks were included. Targeted screening studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Extraction was performed independently by 3 reviewers. Quality was assessed using the Newcastle-Ottawa Scale for cohort studies. Random-effects meta-analysis was undertaken. Metaregression was conducted to evaluate the association of sociodemographic characteristics, maternal seroprevalence, population-level HIV prevalence, and screening methods with the prevalence of cCMV.

MAIN OUTCOMES AND MEASURES

Birth prevalence of cCMV ascertained through universal screening of infants younger than 3 weeks for CMV from urine, saliva, or blood samples.

RESULTS

Seventy-seven studies comprising 515 646 infants met the inclusion criteria from countries representative of each World Bank income level. The estimated pooled overall prevalence of cCMV was 0.67% (95% CI, 0.54%-0.83%). The pooled birth prevalence of cCMV was 3-fold greater in LMICs (1.42%; 95% CI, 0.97%-2.08%; n = 23 studies) than in HICs (0.48%; 95% CI, 0.40%-0.59%, n = 54 studies). Screening methods with blood samples demonstrated lower rates of cCMV than urine or saliva samples (odds ratio [OR], 0.38; 95% CI, 0.23-0.66). Higher maternal CMV seroprevalence (OR, 1.19; 95% CI, 1.11-1.28), higher population-level HIV prevalence (OR, 1.22; 95% CI, 1.05-1.40), lower socioeconomic status (OR, 3.03; 95% CI, 2.05-4.47), and younger mean maternal age (OR, 0.85; 95% CI, 0.78-0.92, older age was associated with lower rates) were associated with higher rates of cCMV.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, LMICs appeared to incur the most significant infection burden. Lower rates of cCMV were reported by studies using only blood or serum as a screening method.

Clinical outcome and the role of antivirals in congenital cytomegalovirus infection

Congenital cytomegalovirus (cCMV) infection is a leading cause of hearing loss and neurological disabilities in children worldwide. Although a minority of infants with cCMV will have symptoms at a birth, these children are at high risk of long-term sequelae. Most infants with cCMV have no clinical signs at birth (asymptomatic), but 10-15% will develop hearing loss. The diagnosis of cCMV relies on detection of the virus from urine or saliva within the first three weeks of life, with saliva PCR being the preferred method due to ease of collection and high sensitivity of the assay. Measures to prevent mother-to-child transmission of CMV are limited, and antiviral therapy with valganciclovir for 6 months is the standard of care for infants with symptomatic cCMV. As more infants with cCMV are being identified through newborn screening, studies are urgently needed to address antiviral treatment in asymptomatic infants and the implementation of prevention strategies to prevent fetal infection. This article is part of the symposium "New drugs and vaccines for DNA virus infections: a symposium in memory of Mark Prichard."

Congenital Cytomegalovirus Infection

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

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.

The limited use of US residual newborn screening dried bloodspots for health disparity research

PURPOSE

State-run newborn screening programs screen nearly all babies born in the United States at the time of delivery. After newborn screening has been completed, some states store the residual dried bloodspots. It is unknown how they have been used to address health disparities-related research.

METHODS

In 2017-2018, a scoping review was conducted to evaluate the extent, type, and nature of how residual dried bloodspots. The review included 654 eligible publications, worldwide, published before May 2017. A post hoc analysis of the US-based studies using residual dried bloodspots (n = 192) were analyzed.

RESULTS

There were 32 (16.7%) articles identified that studied a condition of a known health disparity or focused on a key population: 25 studies assessed a disease or condition, 6 expressly enrolled a key population, and 1 study included both (i.e., heart disease and African American/Black).

CONCLUSION

Excluding 12 studies that researched leukemia or a brain tumor, only 20 studies addressed a known health disparity, with 6 stating a specific aim to address a health disparity. This resource could be used to gain further knowledge about health disparities, but is currently underutilized.

Prevalence of cytomegalovirus DNAemia and genotypic distribution among childbearing mothers and neonates in Taiwan

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the leading cause of neurologic disabilities and sensorineural hearing loss in children. However, in Taiwan, there is limited information on the genotypic diversity and prevalence of perinatal CMV infection in both mothers and neonates. The aim of this study was to screen samples from both mothers and umbilical cord blood for CMV at the time of delivery and to determine the CMV genotypic distribution.

METHODS

Between June 2012 and July 2015, residual maternal and umbilical cord blood samples were collected from consenting participants admitted to the Chang Bing Show Chwan Memorial Hospital in central Taiwan. The blood samples were screened for CMV DNA using real-time PCR assay, and the genotypic classification of the CMV UL55, UL144, and US28 genes was determined by sequencing and phylogenetic analysis.

RESULTS

A total of 1282 mother-neonate paired samples were enrolled in the study, 95.3% of whom were Taiwanese. CMV DNA was detectable in 6.2% of the maternal blood samples, with a significantly higher rate noted in non-Taiwanese mothers (11.7%,p=0.027). For the 1,282 umbilical cord blood samples, CMV DNA was detectable in 5.3% of the samples. The presence of CMV DNA in maternal blood was positively associated with the presence of CMV DNA in umbilical cord blood (p=0.01). In addition, the UL55, UL144, and US28 genotypic distribution was similar between mothers and neonates.

CONCLUSION

The prevalence of CMV DNAemia in childbearing mothers and neonates is similar and their genotypic distribution implies potential CMV infection during pregnancy.

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

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

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSIONS

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

Bronchopulmonary Dysplasia in Very Preterm Infants with Symptomatic Congenital Cytomegalovirus Infection: A Propensity Score-Matched Analysis

OBJECTIVE

To assess whether symptomatic congenital cytomegalovirus infection (cCMV) is associated with bronchopulmonary dysplasia (BPD) and mortality in very preterm infants (gestational age ≤32 weeks).

STUDY DESIGN

We performed a retrospective study using the Kids' Inpatient Database for 2003, 2006, 2009, and 2012. Diagnoses of BPD and symptomatic cCMV were determined using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Among patients with in-hospital birth at ≤32 weeks of gestation, cases of symptomatic cCMV were matched with infants without cCMV using propensity score matching at 1:2 ratio. Outcomes of BPD and in-hospital mortality were assessed using conditional logistic regression.

RESULTS

Of 204 818 in-hospital births with gestational age ≤32 weeks, we identified 208 cases of symptomatic cCMV, 177 of which underwent matching. Symptomatic cCMV was associated with higher odds of BPD (OR, 2.34; 95% CI, 1.41-3.87), but was not significantly associated with in-hospital all-cause mortality (OR, 1.18, 95% CI, 0.64-2.17).

CONCLUSIONS

Symptomatic cCMV was associated with BPD but not with in-hospital mortality among very preterm infants. Further study is needed to determine the risk of BPD among infants with cCMV to allow for evaluation of possible preventive measures.

Racial and Ethnic Differences in the Prevalence of Congenital Cytomegalovirus Infection

OBJECTIVE

To evaluate the impact of race and ethnicity upon the prevalence and clinical spectrum of congenital cytomegalovirus infection (cCMV).

STUDY DESIGN

From 2007 to 2012, 100 332 infants from 7 medical centers were screened for cCMV while in the hospital. Ethnicity and race were collected and cCMV prevalence rates were calculated.

RESULTS

The overall prevalence of cCMV in the cohort was 4.5 per 1000 live births (95% CI, 4.1-4.9). Black infants had the highest cCMV prevalence (9.5 per 1000 live births; 95% CI, 8.3-11.0), followed by multiracial infants (7.8 per 1000 live births; 95% CI, 4.7-12.0). Significantly lower prevalence rates were observed in non-Hispanic white infants (2.7 per 1000 live births; 95% CI, 2.2-3.3), Hispanic white infants (3.0 per 1000 live births; 95% CI, 2.4-3.6), and Asian infants (1.0 per 1000 live births; 95% CI, 0.3-2.5). After adjusting for socioeconomic status and maternal age, black infants were significantly more likely to have cCMV compared with non-Hispanic white infants (adjusted prevalence OR, 1.9; 95% CI, 1.4-2.5). Hispanic white infants had a slightly lower risk of having cCMV compared with non-Hispanic white infants (adjusted prevalence OR, 0.7; 95% CI, 0.5-1.0). However, no significant differences in symptomatic cCMV (9.6%) and sensorineural hearing loss (7.8%) were observed between the race/ethnic groups.

CONCLUSIONS

Significant racial and ethnic differences exist in the prevalence of cCMV, even after adjusting for socioeconomic status and maternal age. Although once infected, the newborn disease and rates of hearing loss in infants are similar with respect to race and ethnicity.

Viral Loads in Congenital Cytomegalovirus Infection From a Highly Immune Population

Among newborns with congenital cytomegalovirus (CMV) infection from China, there was no difference in CMV viral load in saliva specimens dried and stored at room temperature compared with those kept wet and stored cold, even after longer storage time for the former than the later (74 vs 58 days, P = .02).

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

Background

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

Methods

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

Results

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

Conclusions

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

Risk Factors, Geographic Distribution, and Healthcare Burden of Symptomatic Congenital Cytomegalovirus Infection in the United States: Analysis of a Nationally Representative Database, 2000-2012

OBJECTIVE

To assess risk factors, geographic distribution, length of stay, and total charges per case of symptomatic congenital cytomegalovirus infection (cCMV).

STUDY DESIGN

We performed retrospective analyses of serial cross-sectional data using the Kids' Inpatient Database, a nationally representative sample of US pediatric hospital discharges, from 2000, 2003, 2006, 2009, and 2012. Symptomatic cCMV was identified via use of the International Classification of Diseases, Ninth Revision, Clinical Modification code 771.1 among records with in-hospital birth that were accompanied by 1 or more characteristic symptoms. Demographic characteristics were compared with multivariable logistic regression. Temporal trend was assessed using linear regression. Charges were adjusted for inflation to 2012 US dollars.

RESULTS

We identified 1349 cases of symptomatic cCMV (SE 56). Symptomatic cCMV was associated with non-Hispanic black race (OR 1.70; 95% CI 1.37-2.10), government-sponsored insurance (OR 1.95; 95% CI 1.34-2.83), and birth in the American South and West (OR 1.68, 95% CI 1.35-2.09 and OR 1.61, 95% CI 1.23-2.09, respectively). In-hospital mortality and preterm birth rate ranged from 3.2%-6.8% and 50.4%-59.2%, respectively, without temporal changes. The geometric mean of total charges per case doubled from $45 771 (SE $8509) in 2000 to $89 846 (SE $10 358) in 2006 (P = .002) but did not change from 2006 to 2012. Length of stay in days was 15 (IQR 8-22) in 2000, 27 (IQR, 9-51) in 2009, and 18 (IQR, 8-47) in 2012.

CONCLUSIONS

Symptomatic cCMV was associated with non-Hispanic black race, low socioeconomic status, and birth in the American South and West and resulted in substantial healthcare burden.

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.

Congenital Cytomegalovirus Infection: Maternal-Child HLA-C, HLA-E, and HLA-G Affect Clinical Outcome

Congenital CMV infection (cCMV) is the most common congenital infection causing permanent long-term impairments (LTI). cCMV immunopathogenesis is largely unknown due to the complex interplay between viral, maternal, placental, and child factors. In this study, a large retrospective nationwide cohort of children with cCMV and their mothers was used. HLA-C, HLA-E, and HLA-G were assessed in 96 mother–child pairs in relation to symptoms at birth and LTI at 6 years of age. The mothers were additionally typed for killer cell immunoglobulin-like receptors. The maternal HLA-G 14 bp deletion/deletion polymorphism was associated with a worse outcome, as the immunomodulation effect of higher protein levels may induce less CMV control, with a direct impact on placenta and fetus. The absence of maternal HLA-C belonging to the C2 group was associated with symptoms at birth, as activating signals on decidual NK may override inhibitory signals, contributing to a placental pro-inflammatory environment. Here, the increased HLA-E*0101 and HLA-C mismatches, which were associated with symptoms at birth, may enhance maternal allo-reactivity to fetal Ags, and cause suboptimal viral clearance. Finally, HLA-C non-inherited maternal antigens (NIMAs) were associated with LTI. The tolerance induced in the fetus toward NIMAs may indirectly induce a suboptimal CMV antiviral response throughout childhood. In light of our findings, the potential role of maternal–child HLA in controlling CMV infection and cCMV-related disease, and the clinical value as predictor for long-term outcome certainly deserve further evaluation.

Detection of congenital cytomegalovirus in newborns using nucleic acid amplification techniques and its public health implications

Human cytomegalovirus (HCMV), a herpesvirus, is an important human pathogen that causes asymptomatic infections in healthy or immunocompetent individuals but can lead to severe and potentially life-threatening complications in immune-immature individuals such as neonates or immune-compromised patients such as organ-transplant recipients and HIV-positive individuals. Congenital HCMV infection represents a significant public health issue and poses substantial healthcare and economic burden to society. This virus causes the most common viral congenital infection worldwide, and is the leading non-genetic cause of sensorineural hearing loss in children in developed countries. Congenital HCMV infection is believed to fulfill the criteria of the American College of Medical Genetics to be considered as a condition targeted for a newborn screening program. This is because congenital HCMV infection can be identified during a time (within 2 days after birth) at which it would not ordinarily be detected clinically, and there are demonstrated benefits of early detection, timely intervention, and efficacious treatment of the condition. Recent progresses in developing polymerase chain reaction-based approaches to detect HCMV in samples obtained from newborns have generated much excitement in the field. In this review, we highlight the recent progress in diagnostic techniques that could potentially be used for the detection of HCMV infection in neonates and its direct implications in public health settings for diagnosing congenital HCMV infection.

Cohort study on maternal cytomegalovirus seroprevalence and prevalence and clinical manifestations of congenital infection in China

Congenital cytomegalovirus (CMV) infection is the leading viral cause of birth defects and developmental disabilities in developed countries. However, CMV seroprevalence and burden of congenital CMV infection are not well defined in China.Cohort of newborns from 5 birthing hospitals in 2 counties of Shandong Province, China, were enrolled from March 2011 to August 2013. Dried blood spots (DBS) and saliva were collected within 4 days after birth for IgG testing for maternal seroprevalence and real-time PCR testing for congenital CMV infection, respectively.Among 5020 newborns tested for CMV IgG, 4827 were seropositive, resulting in CMV maternal seroprevalence of 96.2% (95% confidence interval [CI]:95.6%-96.7%). Of the 10,933 newborns screened for congenital CMV infection, 75 had CMV detected, resulting in an overall prevalence of 0.7% (95% CI: 0.5%-0.9%), with prevalences of 0.4% (14/3995), 0.6% (66/10,857), and 0.7% (52/7761) for DBS, wet saliva, and dried saliva specimens screened, respectively. Prevalence of congenital CMV infection decreased with increasing maternal age (0.9%, 0.6%, and 0.3% among newborns delivered from mothers aged 16-25, 26-35, and >35 years, respectively; P = 0.03), and was higher among preterm infants than full term infants (1.3% vs 0.6%, P = 0.04), infants with intrauterine growth restriction (IUGR) than those without (1.8% vs 0.7%, P = 0.03), and twins or triplets than singleton pregnancies (2.8% vs 0.7%, P = 0.04). None of the 75 newborns exhibited symptomatic congenital CMV infection, and there was no difference in clinical characteristics and newborn hearing screening results between infants with and without congenital CMV infection at birth.Congenital CMV infection prevalence was lower and the clinical manifestations were milder in this relatively developed region of China compared to populations from other countries with similarly high maternal seroprevalence. Follow-up on children with congenital CMV infection will clarify the burden of disabilities from congenital CMV infection in China.

Vertically transmitted cytomegalovirus infection in newborn preterm infants

OBJECTIVE

To determine the epidemiology of congenital and acquired cytomegalovirus (CMV) infections in preterm infants and to analyze the efficacy of breast milk freezing in decreasing the vertical transmission rate of CMV.

STUDY DESIGN

During 2013 and 2014, preterm newborns who weighed ≤1500 g and were admitted to 22 Spanish neonatal units were included and screened for CMV infection according to the Spanish Neonatology Society recommendations. Each hospital treated the breast milk according to its own protocols.

RESULTS

Among the 1236 preterm neonates included, 10 had a congenital infection (0.8%) and 49 had an acquired infection (4.0%) (82% demonstrated positive PCR-CMV in breast milk). The neonates who received only frozen milk presented less frequently with acquired infection (1.2%) than those fed fresh milk (5.5%) (RR=0.22; 95% CI 0.05-0.90; P=0.017). The newborns who received bank milk followed by frozen or fresh breast milk more frequently had an acquired infection (2.1% or 2.2%, respectively) than those fed only frozen breast milk.

CONCLUSIONS

The incidence of congenital CMV infection in our sample is low, as described in the literature. To reduce acquired CMV infection, freezing breast milk might be an advisable procedure for preterm neonates born from seropositive mothers, either from the beginning of lactation or after a period of bank milk administration.

Cytomegalovirus infection and neonatal outcome in extremely preterm infants after freezing of maternal milk

BACKGROUND

Cytomegalovirus (CMV) infection acquired from breast milk can cause serious illness in extremely preterm (EPT) infants (<28 weeks). Some neonatal centers freeze maternal milk (MM) to prevent CMV transmission; however, this practice is controversial. In this study, we assessed the CMV transmission rate and neonatal outcome in EPT infants after routine freezing of all MM.

METHODS

EPT infants (n = 140) and their mothers were randomized to the intervention group (only freeze-thawed MM) or the control group (combined fresh and freeze-thawed MM). Freeze-thawed MM was frozen at -20°C for ≥3 days before thawing. Mothers had serological tests for CMV, and MM was analyzed for CMV by polymerase chain reaction and CMV culture. Infants underwent CMV screening with urine analysis by CMV-polymerase chain reaction and CMV culture until 12 weeks of age.

RESULTS

Congenital CMV infection was detected in 2% of screened infants. The CMV transmission rate in infants fed with CMV-DNA positive milk was 8% (3 of 37) in the intervention group and 6% (2 of 33) in controls. All infants infected by CMV were asymptomatic. The final per-protocol analysis included 56 infants in the intervention group and 65 controls. Neonatal mortality was comparable between the groups (7% vs. 6%). Neonatal morbidity was similar, except for late onset Candida sepsis, which was more frequent in the controls (12% vs. 0%).

CONCLUSIONS

Routine freezing of all MM did not affect the rate of CMV transmission but may help to prevent fungal sepsis in EPT infants. This observation merits further investigation.

Evaluation of DNA extraction methods for the detection of Cytomegalovirus in dried blood spots

BACKGROUND

Dried blood spots (DBS) are collected universally from newborns and may be valuable for the diagnosis of congenital Cytomegalovirus (CMV) infection. The reported analytical sensitivity for DBS testing compared to urine or saliva varies greatly across CMV studies. The purpose of this study was to directly compare the performance of various DNA extraction methods for identification of CMV in DBS including those used most often in CMV studies.

STUDY DESIGN

Whatman(®) Grade 903 filter paper cards were spotted with blood samples from 25 organ transplant recipients who had confirmed CMV viremia. Six DNA extraction methods were compared for relative yield of viral and cellular DNA: 2 manual solution-based methods (Gentra Puregene, thermal shock), 2 manual silica column-based methods (QIAamp DNA Mini, QIAamp DNA Investigator), and 2 automated methods (M48 MagAttract Mini, QIAcube Investigator). DBS extractions were performed in triplicate followed by real-time quantitative PCR (qPCR).

RESULTS

For extraction of both viral and cellular DNA, two methods (QIAamp DNA Investigator and thermal shock) consistently gave the highest yields, and two methods (M48 MagAttract Mini and QIAamp DNA Mini) consistently gave the lowest yields. There was an average 3-fold difference in DNA yield between the highest and lowest yield methods.

CONCLUSION

The choice of DNA extraction method is a major factor in the ability to detect low levels of CMV in DBS and can largely account for the wide range of DBS sensitivities reported in studies to date.

Screening for and treatments of congenital immunodeficiency diseases

Although newborn screening (NBS) for inborn errors of metabolism has been successfully utilized in the US for decades, only recently has this screening program expanded to include disorders of immunity. Severe combined immunodeficiency (SCID) became the first disorder of immunity to be screened on a population wide basis in 2008. While NBS for SCID has been successful, the implementation of population-based screening programs is not without controversy, and there remain barriers to the nationwide implementation of this test. In addition, as the program has progressed we have learned of new challenges in the management of newborns that fail this screen.

Repeated measures study of weekly and daily cytomegalovirus shedding patterns in saliva and urine of healthy cytomegalovirus-seropositive children

Background

To better understand potential transmission risks from contact with the body fluids of children, we monitored the presence and amount of CMV shedding over time in healthy CMV-seropositive children.

Methods

Through screening we identified 36 children from the Atlanta, Georgia area who were CMV-seropositive, including 23 who were shedding CMV at the time of screening. Each child received 12 weekly in-home visits at which field workers collected saliva and urine. During the final two weeks, parents also collected saliva and urine daily.

Results

Prevalence of shedding was highly correlated with initial shedding status: children shedding at the screening visit had CMV DNA in 84% of follow-up saliva specimens (455/543) and 28% of follow-up urine specimens (151/539); those not shedding at the screening visit had CMV DNA in 16% of follow-up saliva specimens (47/303) and 5% of follow-up urine specimens (16/305). Among positive specimens we found median viral loads of 82,900 copies/mL in saliva and 34,730 copies/mL in urine (P = 0.01), while the viral load for the 75th percentile was nearly 1.5 million copies/mL for saliva compared to 86,800 copies/mL for urine. Younger age was significantly associated with higher viral loads, especially for saliva (P < 0.001). Shedding prevalence and viral loads were relatively stable over time. All children who were shedding at the screening visit were still shedding at least some days during weeks 11 and 12, and median and mean viral loads did not change substantially over time.

Conclusions

Healthy CMV-seropositive children can shed CMV for months at high, relatively stable levels. These data suggest that behavioral prevention messages need to address transmission via both saliva and urine, but also need to be informed by the potentially higher risks posed by saliva and by exposures to younger children.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0569-1) contains supplementary material, which is available to authorized users.

Cross-sectional study of cytomegalovirus shedding and immunological markers among seropositive children and their mothers

Background

Congenital cytomegalovirus (CMV) is the leading infectious cause of birth defects in the United States. To better understand factors that may influence CMV transmission risk, we compared viral and immunological factors in healthy children and their mothers.

Methods

We screened for CMV IgG antibodies in a convenience sample of 161 children aged 0-47 months from the Atlanta, Georgia metropolitan area, along with 32 mothers of children who screened CMV-seropositive. We assessed CMV shedding via PCR using saliva collected with oral swabs (children and mothers) and urine collected from diapers using filter paper inserts (children only).

Results

CMV IgG was present in 31% (50/161) of the children. Half (25/50) of seropositive children were shedding in at least one fluid. The proportion of seropositive children who shed in saliva was 100% (8/8) among the 4-12 month-olds, 64% (9/14) among 13-24 month-olds, and 40% (6/15) among 25-47 month-olds (P for trend = 0.003). Seropositive mothers had a lower proportion of saliva shedding (21% [6/29]) than children (P < 0.001). Among children who were shedding CMV, viral loads in saliva were significantly higher in younger children (P <0.001); on average, the saliva viral load of infants (i.e., <12 months) was approximately 300 times that of two year-olds (i.e., 24-35 months). Median CMV viral loads were similar in children's saliva and urine but were 10-50 times higher (P < 0.001) than the median viral load of the mothers' saliva. However, very high viral loads (> one million copies/mL) were only found in children's saliva (31% of those shedding); children's urine and mothers' saliva specimens all had fewer than 100,000 copies/mL. Low IgG avidity, a marker of primary infection, was associated with younger age (p = 0.03), higher viral loads in saliva (p = 0.02), and lower antibody titers (p = 0.005).

Conclusions

Young CMV seropositive children, especially those less than one year-old may present high-risk CMV exposures to pregnant women, especially via saliva, though further research is needed to see if this finding can be generalized across racial or other demographic strata.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0568-2) contains supplementary material, which is available to authorized users.

Cytomegalovirus viral and antibody correlates in young children

Background

Young, healthy children shedding cytomegalovirus (CMV) in urine and saliva appear to be the leading source of CMV in primary infection of pregnant women.

Findings

We screened 48 children 6 months – 5 years old for CMV IgG and measured levels of CMV IgG, IgM and IgG avidity antibodies, frequency of CMV shedding, and viral loads in blood, urine, and saliva. Thirteen of the 48 children (27%) were CMV IgG positive, among whom 3 were also CMV IgM positive with evidence of recent primary infection. Nine of the 13 seropositive children (69%) were shedding 10²-10⁵ copies/ml of CMV DNA in one or more bodily fluid. Among seropositive children, low IgG antibody titer (1:20–1:80) was associated with the absence of shedding (p = 0.014), and enrollment in daycare was associated with the presence of CMV shedding (p = 0.037).

Conclusions

CMV antibody profiles correlated with CMV shedding. The presence of CMV IgM more often represents primary infection in children than in adults. Correlating antibodies with primary infection and viral shedding in healthy children adds to the understanding of CMV infection in children that can inform the prevention of CMV transmission to pregnant women.

Universal newborn screening for congenital CMV infection: what is the evidence of potential benefit?

Congenital CMV infection is a leading cause of childhood disability. Many children born with congenital CMV infection are asymptomatic or have nonspecific symptoms and therefore are typically not diagnosed. A strategy of newborn CMV screening could allow for early detection and intervention to improve clinical outcomes. Interventions might include antiviral drugs or nonpharmaceutical therapies such as speech-language therapy or cochlear implants. Using published data from developed countries, we analyzed existing evidence of potential benefit that could result from newborn CMV screening. We first estimated the numbers of children with the most important CMV-related disabilities (i.e. hearing loss, cognitive deficit, and vision impairment), including the age at which the disabilities occur. Then, for each of the disabilities, we examined the existing evidence for the effectiveness of various interventions. We concluded that there is good evidence of potential benefit from nonpharmaceutical interventions for children with delayed hearing loss that occurs by 9 months of age. Similarly, we concluded that there is fair evidence of potential benefit from antiviral therapy for children with hearing loss at birth and from nonpharmaceutical interventions for children with delayed hearing loss occurring between 9 and 24 months of age and for children with CMV-related cognitive deficits. We found poor evidence of potential benefit for children with delayed hearing loss occurring after 24 months of age and for children with vision impairment. Overall, we estimated that in the United States, several thousand children with congenital CMV could benefit each year from newborn CMV screening, early detection, and interventions.

A diagnostic paradigm including cytomegalovirus testing for idiopathic pediatric sensorineural hearing loss

OBJECTIVES/HYPOTHESIS

To determine the feasibility and cost effectiveness of incorporating cytomegalovirus (CMV) testing to determine the etiology of pediatric hearing loss.

STUDY DESIGN

Retrospective study of children presenting with sensorineural hearing loss (SNHL) at one institution from 2008 to 2013.

METHODS

Children aged 3 years or younger who presented to the senior author (A.P.) between May 2008 and September 2013 with confirmed SNHL were evaluated. These children underwent a sequential diagnostic paradigm that incorporated CMV testing if no obvious etiology could be determined from the history or physical examination.

RESULTS

One hundred eleven children with SNHL were evaluated between 2008 and 2013. Eighty-three children underwent CMV testing, imaging, and a genetic evaluation. Those with confirmed or probable CMV-induced SNHL made up 30% of all children tested (n = 25), the largest group identified. CMV screening had the lowest cost compared to genetic testing or imaging for all types of hearing loss, except for those with auditory neuropathy spectrum disorder.

CONCLUSION

We present the first sequential diagnostic paradigm utilizing CMV testing for children presenting with SNHL. The relatively high incidence of CMV-induced SNHL, the low cost for this assay, and the indirect benefits from early diagnosis support the role of early CMV testing for these patients.

LEVEL OF EVIDENCE

4.

Feasibility and acceptability of targeted screening for congenital CMV-related hearing loss

BACKGROUND

Congenital cytomegalovirus (cCMV) is the most common non-genetic cause of sensorineural hearing loss (SNHL) in children. Ganciclovir has been shown to prevent the continued deterioration in hearing of children with symptomatic cCMV, but some children with cCMV-related SNHL are unidentified in the neonatal treatment period. Neonatal cCMV screening provides an opportunity to identify infants with cCMV-related SNHL who might benefit from early treatment.

OBJECTIVES

To assess the feasibility (ability to take samples before 3 weeks of age and clinical assessment by 30 days of age) and acceptability (maternal anxiety) of targeted CMV testing of infants who are 'referred' for further audiological testing after routine newborn hearing screening programme (NHSP).

METHODS

Parents of infants who have 'no clear responses' on routine NHSP before 22 days of life in London and North East England were approached. Salivary and urine samples were tested by CMV PCR. At recruitment and 3 months, the short form Spielberger State-Trait Anxiety Inventory measured maternal anxiety.

RESULTS

411 infants were recruited. 99% (407/411) returned a sample; 98% (404/411) successfully yielded a CMV result, 6 had cCMV, all diagnosed on salivary samples taken <22 days of age (1.5%; 95% CI 0.6% to 3.2%). Only 50% returned urine samples compared with 99% returning salivary samples (p<0.001). Using saliva swabs 98% were successfully screened for CMV within 3 weeks. All positive screening CMV results were known by day 23, and 5/6 infants with cCMV were assessed within 31 days. Anxiety was not increased in mothers of infants screened for cCMV.

CONCLUSIONS

Targeted salivary screening for cCMV within the NHSP is feasible, acceptable and detects infants with cCMV-related SNHL who could benefit from early treatment.

Cytomegalovirus infection among infants in California neonatal intensive care units, 2005-2010

AIM

To assess the burden of congenital and perinatal cytomegalovirus (CMV) disease among infants hospitalized in neonatal intensive care units (NICUs).

METHODS

CMV infection was defined as a report of positive CMV viral culture or polymerase chain reaction at any time since birth in an infant hospitalized in a NICU reporting to California Perinatal Quality Care Collaborative during 2005-2010.

RESULTS

One hundred and fifty-six (1.7 per 1000) infants were reported with CMV infection, representing an estimated 5% of the expected number of live births with symptomatic CMV disease. Prevalence was higher among infants with younger gestational ages and lower birth weights. Infants with CMV infection had significantly longer hospital stays and 14 (9%) died.

CONCLUSIONS

Reported prevalence of CMV infection in NICUs represents a fraction of total expected disease burden from CMV in the newborn period, likely resulting from underdiagnosis and milder symptomatic cases that do not require NICU care. More complete ascertainment of infants with congenital CMV infection that would benefit from antiviral treatment may reduce the burden of CMV disease in this population.

[Can we rule out a congenital cytomegalovirus infection when the result of polymerase chain reaction in dried blood spots is negative?]

INTRODUCTION

The detection of cytomegalovirus (CMV) DNA by real time polymerase chain reaction (rt-PCR) in dried blood spots collected routinely for metabolic screening has been assessed for the retrospective diagnosis of congenital CMV (cCMV) infection in many studies, but not in Spain. The aim of this study is to analyze the diagnostic accuracy of this technique in our hospital.

METHODS

A cross-sectional retrospective observational study was conducted including all patients born between January, 2007 and September, 2012 with confirmed cCMV infection. The assessment of CMV DNA was made by using rt-PCR in dried blood spots of these patients.

RESULTS

Fourteen patients were included: 4/14 were symptomatic and 4/14 had sequelae. The detection of CMV DNA by rt-PCR was positive in only 7 patients. A statistically significant relationship between low viral load at birth and negative rt-PCR in dried blood spots was demonstrated.

CONCLUSIONS

Despite the low number of patients included, our data highlight an important amount of false negative results in the DNA CMV detection by rt-PCR in these samples for the retrospective diagnosis of cCMV infection, especially in cases with low viral load at birth.

Risk factors for poor outcome in congenital cytomegalovirus infection and neonatal herpes on the basis of a nationwide survey in Japan

BACKGROUND

Congenital cytomegalovirus (CMV) infection and neonatal herpes are major mother-to-child infections, and analyses of the important clinical issues, including risk factors for prognosis, are essential.

METHODS

A secondary survey of congenital CMV infection and neonatal herpes was performed using questionnaires for cases reported in the primary survey between 2006 and 2008.

RESULTS

Univariate analysis of 71 cases of congenital CMV infection showed that intrauterine growth restriction (IUGR) or other specific findings on fetal ultrasonography (US), microcephaly, intracranial calcification, disseminated intravascular coagulation, abnormal findings on computed tomography, and the use of i.v. gammaglobulin were all significantly correlated with poor outcome (death or severe sequelae). Multivariate analysis showed that only IUGR was significantly associated with poor outcome. Hearing impairment is one of the major abnormalities associated with congenital CMV infection. Automatic auditory brainstem response (automatic ABR) appeared to be useful for detection of hearing impairment in comparison with conventional ABR. Moreover, univariate analysis showed that specific fetal US or abnormal magnetic resonance imaging findings were correlated with sensorineural hearing loss. In 24 cases of neonatal herpes, fever and seizure were correlated with poor outcome on univariate analysis. All patients received acyclovir treatment, although substantial numbers of patients in severe clinical categories (disseminated or central nervous system diseases) received a low dose of acyclovir (<60 mg/kg per day).

CONCLUSIONS

This secondary survey has identified the risk factors associated with outcome and important issues in diagnosis and treatment of two mother-to-child infections: congenital CMV and neonatal herpes, in Japan.

Laboratory testing and diagnostic coding for cytomegalovirus among privately insured infants in the United States: a retrospective study using administrative claims data

BACKGROUND

Rates of laboratory testing and diagnostic practices for congenital CMV in the United States are unknown. We determined rates of CMV testing and diagnostic coding for CMV among insured infants in the United States using a national healthcare claims database.

METHODS

We analyzed medical claims from 2011 Truven Health MarketScan® Commercial databases for infants who were ≤30 days of age. We used ICD-9-CM codes to identify infants with CMV and CMV-associated conditions. We computed frequencies of infants with CPT codes for CMV testing.

RESULTS

A total of 368,266 infants met the study criteria. We identified 61 (0.02%) infants with a diagnostic code for CMV. Among the 368,266 infants, 229 (0.1%) infants had a code for CMV-specific testing, of which 43% had codes for CMV polymerase chain reaction (PCR) and/or CMV direct florescent antibody (DFA) testing, 44% for CMV serologic testing alone, and 13% for CMV serology and non-specific PCR and/or culture. Over 80% (187/229) with CMV testing had a code for ≥1 CMV-associated conditions. Although infrequently coded for, CMV testing was more common among infants with a code for a condition possibly associated with CMV than infants without these conditions (0.14% (187/ 136,857) vs. 0.02% (42/231,409)).

CONCLUSIONS

The low rates of CMV testing among infants with symptoms suggestive of congenital CMV infection and the substantial proportion of infants tested with only serologic assays instead of PCR or viral culture suggests gaps in awareness and knowledge of congenital CMV and its diagnosis among healthcare providers. Although claims databases presumably do not capture all diagnosed CMV cases or CMV-specific testing, healthcare claims are a potential source for surveillance and monitoring practices of CMV-specific testing and diagnostic coding for CMV among infants.

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.

Ophthalmological findings in congenital cytomegalovirus infection: when to screen, when to treat?

Cytomegalovirus (CMV) is the leading cause of known congenital viral infections. Approximately 90% of congenitally infected newborns exhibit no clinical abnormalities at birth. In 5% to 15%, a wide spectrum of clinical signs is present at birth. Ophthalmological signs are seen in a large percentage of symptomatic patients but rarely in otherwise asymptomatic infants. Chorioretinitis, optic atrophy, and cortical visual impairment are the most frequent causes of visual problems in congenitally infected infants. There is no clear consensus in the literature on screening or treatment modalities concerning the ophthalmological aspects of congenital CMV. Further prospective studies are needed to set up guidelines for ophthalmological screening and treatment of infants with congenital CMV.

Real-time PCR-based testing of saliva for cytomegalovirus at birth

Evaluation of: Boppana SB, Ross SA, Shimamura M et al. Saliva polymerase-chain-reaction assay for cytomegalovirus screening in newborns. N. Engl. J. Med. 364, 2111-2118 (2011). Cytomegalovirus (CMV) commonly causes congenital infection. As such, CMV is a prominent etiology for nongenetic sensori-neural hearing loss. However, screening examination in the perinatal and early infant period fails to identify most children at risk for CMV-produced hearing loss because of the absence of symptoms early in life. Furthermore, generalized screening for congenital CMV infection has yet to be implemented. Currently, newborns are tested via means of a rapid saliva culture but large-scale automation of this test would be difficult. Fortunately, newer potential replacement tests have been created. An important advance includes testing newborns via means of PCR using liquid or dried saliva samples. In a large-scale, prospective, multi-institutional study both types of salivary samples were compared with the gold standard of saliva culture. Of the 34,989 neonates tested, 0.5% or 177 samples tested positive for CMV. Testing of both liquid and dried saliva were sensitive (>97%) as well as specific (>98%) when measured against CMV culture. PCR testing of dried saliva has the potential benefit of adapting to generalized screening of neonates for congenital CMV infection. The advantages of early detection, intervention for and treatment of cases that are not clinically apparent needs to be carefully evaluated before proposing universal newborn screening for CMV infection as a valuable public health strategy.

Cytomegalovirus and Epstein-Barr virus may be associated with some cases of cerebral palsy

OBJECTIVE

Intrauterine infection is a risk factor for cerebral palsy. Previous work reported a high frequency of viral DNA in newborn screening cards from cerebral palsy cases and controls possibly due to contamination.

METHODS

Retrospective case-control study using improved methodologies to minimize contamination during PCR-based detection of viral DNA sequences. Newborn screening cards of 339 Caucasian children with cerebral palsy and 594 controls were examined. Viruses tested were herpes simplex viruses 1 and 2 (HSV1 and 2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes viruses 6, 7 and 8 (HHV6, HHV7 and HHV8), and parvovirus B19. Genotyping was performed on DNA extracted from dried blood spots.

RESULTS

CMV and EBV were detected in 5 (1.5%) and 3 (0.9%) of 339 cases, respectively, but not in controls (p = 0.047 and 0.006). Frequencies of detection of the other viruses examined were similar for cases and controls. DNA from at least one of the nine viruses tested was found in 4.4% of cases and 3.1% of controls [OR 1.4 95% CI (0.71-2.76)].

CONCLUSION

Evidence of congenital viral infection was uncommon in cases of cerebral palsy and controls. However, CMV and EBV were significantly associated with cerebral palsy.

Screening newborns for primary T-cell immunodeficiencies: consensus and controversy

Newborn screening for early identification of T-cell lymphopenia and severe combined immunodeficiency has recently been recommended as an addition to the newborn screening programs in all states. This article will review the evidence supporting the use of this newborn screening test, and will outline the barriers to nationwide implementation, which include issues specific to this test and controversies regarding newborn screening in general.

Extraction of DNA from dried blood in the diagnosis of congenital CMV infection

Viral DNA detection in dried blood spotted on filter paper, dried blood spots (DBS), is valuable in the diagnosis of viral infections, with at the moment congenital cytomegalovirus (CMV) being the most common application. CMV detection in clinical samples taken within the first 2-3 weeks after birth differentiates congenital CMV infection from the in general harmless postnatal acquired cytomegalovirus infection. DBS render the possibility to diagnose congenital CMV infection retrospectively, e.g., when late-onset hearing loss, the most frequently encountered symptom of congenital CMV infection, becomes manifest. Additionally, CMV DNA detection in DBS can be of usage in recently advocated newborn screening on congenital CMV infection. The procedure of CMV DNA detection in DBS consists of two separate steps: (1) DNA extraction from the DBS, followed by (2) CMV DNA amplification. Here, we describe two efficient methods for the extraction of DNA from DBS. Sensitivity, specificity, and applicability of the methods for high-throughput usage are discussed.

Prevalence of congenital cytomegalovirus infection in Slovenia: a study on 2,841 newborns

Human cytomegalovirus (CMV) is the most frequent cause of congenital infection in humans. In the first prevalence study of congenital CMV infection in Eastern and Central Europe, all neonates born in a 22-month period in two Slovenian maternity units (total of 2,841 newborns) were screened prospectively for congenital CMV infection by a real-time polymerase chain reaction (PCR) in urine. In all newborns with positive screening results, plasma and dried blood spots (DBS) collected at birth were tested additionally for CMV DNA. Congenital CMV infection was confirmed by virus isolation from a urine sample collected within the first 2 weeks of life. Congenital CMV infection was identified in four out of 2,841 newborns tested (incidence 0.14%; 95% CI, 0.05-0.39%). In four newborns with confirmed congenital infection, the concentration of CMV DNA in urine ranged from 4.68 to 8.18 log(10)  copies/ml, all four newborns had detectable CMV DNA in plasma taken at birth (1.26-3.34 log(10)  copies/ml) and two out of four had detectable CMV DNA in DBS collected during newborn metabolic screening. None of the four newborns with confirmed congenital CMV infection was symptomatic. The study showed that the prevalence of congenital CMV infection at birth in Slovenia is among the lowest in the world and that CMV DNA PCR testing of urine is a suitable and affordable real-time screening strategy for congenital CMV infection. If it is performed in 24 mini-pools, the cost of screening is 1.4 €/newborn and the cost of detecting a single newborn with congenital CMV infection 1,000 €.

Prospective identification of congenital cytomegalovirus infection in newborns using real-time polymerase chain reaction assays in dried blood spots

BACKGROUND

Congenital cytomegalovirus (CMV) infection is a public health issue, and implementation of neonatal screening has been debated. Detection of CMV DNA by polymerase chain reaction (PCR) of dried blood spots (DBS) routinely collected for metabolic screening from all newborns has been proposed for congenital CMV infection screening. The goal of this study was to prospectively assess the performance of 2 CMV PCR assays of DBS for CMV neonatal screening in a selected population of neonates.

METHODS

We studied prospective congenital CMV screening in a population of neonates either born with symptoms compatible with congenital CMV or born to mothers with a history of primary infection during pregnancy. For each neonate, 2 CMV PCR assays of DBS were blindly performed in parallel with a gold standard technique (ie, CMV PCR of a urine sample).

RESULTS

Two hundred seventy-one neonates were studied, and CMV infection, defined by a positive urine sample in the first week of life, was confirmed in 64 (23.6%). Nineteen infected (29.7%) neonates were symptomatic, and 45 (70.3%) were asymptomatic. The ranges of sensitivity, specificity, positive predictive value, and negative predictive value for the 2 CMV PCR assays of DBS were 95.0%-100%; 98.1%-99.0%; 94.1%-96.9%, and 98.5%-100%, respectively.

CONCLUSIONS

The sensitivity and specificity of both CMV PCR assays of DBS to identify congenital CMV were very high in this population of neonates with a high risk of sequelae. These new data should be considered in the ongoing debate on the appropriateness of the use of DBS as a sample to screen for congenital CMV infection.