Detection of cytomegalovirus DNA in dried blood spots of Minnesota infants who do not pass newborn hearing screening

Congenital Cytomegalovirus Testing Outcomes From the ValEAR Trial

OBJECTIVE

To determine the positivity rate of congenital cytomegalovirus (cCMV) testing among universal, hearing-targeted CMV testing (HT-cCMV) and delayed targeted dried blood spot (DBS) testing newborn screening programs, and to examine the characteristics of successful HT-cCMV testing programs.

STUDY DESIGN

Prospective survey of birth hospitals performing early CMV testing.

SETTING

Multiple institutions.

METHODS

Birth hospitals participating in the National Institutes of Health ValEAR clinical trial were surveyed to determine the rates of cCMV positivity associated with 3 different testing approaches: universal testing, HT-cCMV, and DBS testing. A mixed methods model was created to determine associations between successful HT-cCMV screening and specific screening protocols.

RESULTS

Eighty-two birth hospitals were surveyed from February 2019 to December 2021. Seven thousand six hundred seventy infants underwent universal screening, 9017 infants HT-cCMV and 535 infants delayed DBS testing. The rates of cCMV positivity were 0.5%, 1.5%, and 7.3%, respectively. The positivity rate for universal CMV screening was less during the COVID-19 pandemic than that reported prior to the pandemic. There were no statistically significant drops in positivity for any approach during the pandemic. For HT-cCMV testing, unique order sets and rigorous posttesting protocols were associated with successful screening programs.

CONCLUSION

Rates of cCMV positivity differed among the 3 approaches. The rates are comparable to cohort studies reported in the literature. Universal CMV prevalence decreased during the pandemic but not significantly. Institutions with specific order set for CMV testing where the primary care physician orders the test and the nurse facilitates the testing process exhibited higher rates of HT-cCMV testing.

Impact of Cytomegalovirus (CMV) on an Academic Pediatric Infectious Diseases Outpatient Clinic Referral Population, 2005-2020: Will the Advent of Universal Congenital CMV (cCMV) Screening Change Clinical Practice Referral Patterns?

Cytomegalovirus (CMV) infections exert a substantial impact on the practice of pediatric infectious diseases. Although most infections in children are minimally symptomatic, several populations are at risk for CMV-associated disease, including immunosuppressed children, children with HIV infection, and, most significantly, children with congenital CMV (cCMV) infection. In spite of the ubiquitous nature of CMV infection, few studies have quantified the impact of CMV-associated care in a pediatric outpatient clinic setting. We evaluated the impact of CMV on clinical care in an outpatient clinic setting over a fifteen-year period at the University of Minnesota (UMN) Masonic Children's Hospital Pediatric Infectious Diseases (PID) Clinic. A retrospective review of clinic appointments identified 253 unique patients specifically evaluated over this time period for consideration of CMV infection. Of these, 242 were pediatric patients. The majority of the pediatric patients evaluated in the PID clinic were referred for either confirmed or suspected cCMV infection, including children referred for consideration of CMV as a potential reason for a failed newborn hearing screen (NHS) and/or for evaluation of CMV as a possible etiology for documented hearing loss. In total, 116 of the children evaluated during this time period (48%) were unequivocally confirmed as having cCMV infection, with an additional 37 (15%) presenting with presumed, probable, or possible cCMV infection. A total of 16 (7%) of the pediatric CMV cases were confirmed to be post-natally acquired infections. Of the 253 total patients, 11 (4%) of the referrals were for pregnant patients seeking advice about potential therapies in the setting of a known or suspected primary maternal infection during their pregnancies, with an attendant risk of fetal CMV infection. This overview of the demographics and referral patterns for patients evaluated for known or suspected CMV infections in a tertiary care center outpatient PID clinic will serve as a useful baseline assessment, even as future patterns of outpatient care are highly likely to evolve. We predict that PID clinic referrals for newborns identified by universal cCMV screening programs will result in a shift of the CMV outpatient population to healthier infants with clinically inapparent infections, and care will need to be taken by practitioners not to over-medicalize management for these asymptomatic newborns.

Diagnosing congenital cytomegalovirus infections using archived dried blood spots: A 15-year observational study, Portugal

BACKGROUND

Cytomegalovirus (CMV) is a leading cause of congenital infections. Dried blood spots (DBS) collected in the first week of life (Guthrie cards) have been used in the diagnosis of CMV infection outside the three-week window period following birth. The present work summarizes the results of a 15-year observational study in which DBS from 1388 children were used for a late diagnosis of congenital CMV infection.

METHODS

Three groups of children were studied: (i) symptomatic (with symptoms at birth or late sequelae) (N = 779); (ii) born to mothers with serological profile of primary CMV infection (N = 75); (iii) without any information (N = 534). A highly sensitive method of DNA extraction (heat-induced) from the DBS was used. CMV DNA was detected by a nested PCR.

RESULTS

In total CMV DNA was detected in 7.5% (104/1388) of children. Symptomatic children showed a low rate of CMV DNA detection (6.7%) than children born to mothers with serological profile of primary CMV infection (13.3%) (p = 0.034). Sensorial hearing loss and encephalopathy were the two clinical manifestations with the highest CMV detection rate (18.3% and 11.1%, respectively). Children whose mothers had a confirmed primary infection showed a higher rate of CMV detection (35.3%) when compared with children whose mothers had a not confirmed primary infection (6.9%) (p = 0.007).

CONCLUSION

The present work emphasises the importance of testing DBS in symptomatic children even a long time after symptoms onset and in children born to mothers with serologic diagnosis of maternal primary CMV infection when they miss the diagnosis during the three-week window following birth.

Evaluation of the Association Between Congenital Cytomegalovirus Infection and Pediatric Acute Lymphoblastic Leukemia

IMPORTANCE

Acute lymphoblastic leukemia (ALL) is the most common form of pediatric cancer, and a leading cause of death in children. Understanding the causes of pediatric ALL is necessary to enable early detection and prevention; congenital cytomegalovirus (cCMV) has recently been identified as a potential moderate-to-strong factor associated with risk for ALL.

OBJECTIVE

To compare the prevalence of cCMV infection between ALL cases and matched controls.

DESIGN, SETTING, AND PARTICIPANTS

In this population-based case-control study of ALL cases and matched controls, cases consisted of children aged 0 to 14 years between 1987 and 2014 with an ALL diagnosis identified through the Michigan Cancer Surveillance Program and born in Michigan on or after October 1, 1987. Cancer-free controls were identified by the Michigan BioTrust for Health and matched on age, sex, and mother's race and ethnicity. Data were analyzed from November to May 2022.

EXPOSURES

cCMV infection measured by quantitative polymerase chain reaction in newborn dried blood spots.

MAIN OUTCOMES AND MEASURES

ALL diagnosed in children aged 0 to 14 years.

RESULTS

A total of 1189 ALL cases and 4756 matched controls were included in the study. Bloodspots were collected from participants at birth, and 3425 (57.6%) participants were male. cCMV was detected in 6 ALL cases (0.5%) and 21 controls (0.4%). There was no difference in the odds of cCMV infection comparing ALL cases with controls (odds ratio, 1.30; 95% CI, 0.52-3.24). Immunophenotype was available for 536 cases (45.1%) and cytogenetic data for 127 (27%). When stratified by subtype characteristics, hyperdiploid ALL (74 cases) was associated with 6.26 times greater odds of cCMV infection compared with unmatched controls (95% CI, 1.44-27.19).

CONCLUSIONS AND RELEVANCE

In this case-control study of cCMV and pediatric ALL, cCMV was associated with increased risk of hyperdiploid ALL. These findings encourage continued research.

[Childhood hearing screening: achievements, difficulties, and possible ways to improve]

Hearing impairment is the most common sensory impairment that is seen among adults and children. The frequency of congenital hearing loss is well-known due to implementation of newborn hearing screening. Hearing may change throughout a lifetime due to different factors and, therefore, the number of hearing impaired children increases with age. Introduction of universal newborn hearing screening has enabled earlier detection of hearing loss including unilateral and minimal disorders. Nevertheless, despite significant progress made in this field, there is still a group of hearing impairments that stay undiagnosed timely. Auditory neuropathy spectrum disorders, late-onset hearing loss, low-frequency and minimal hearing impairment are sometimes missed in newborn hearing screening or they manifest later. These types of hearing disorders are covered in detail in this review as well as possible ways of increasing the effectiveness of early diagnosis.

Timing of newborn hearing screening in the neonatal intensive care unit: implications for targeted screening for congenital cytomegalovirus infection

OBJECTIVE

To determine when infants in the neonatal intensive care unit (NICU) have the first hearing screen performed, and thus inform targeted testing for cytomegalovirus (CMV)-related hearing loss.

STUDY DESIGN

Retrospective review of electronic health records of infants admitted to a Level 4 outborn NICU and had a first hearing screen performed from 8/2016-8/2018.

RESULT

Among 1498 infants, 546 (36%) had a first hearing screen performed at age >21 days when a positive CMV PCR test cannot distinguish congenital from postnatal CMV acquisition. While most infants tested at >21 days of age were <34 weeks' gestational age (71%), 18% (n = 100) and 11% (n = 59) were ≥34 and ≥37 weeks' gestation, respectively.

CONCLUSION

Targeted CMV testing for failed hearing screen in the NICU is problematic as 36% of infants did not have a hearing screen performed before 21 days of age, supporting the need for CMV screening at NICU admission.

Etiology of Prelingual Hearing Loss in the Universal Newborn Hearing Screening Era: A Scoping Review

OBJECTIVE

To conduct a scoping review on etiologic investigation of prelingual hearing loss among children <2 years of age in the era of universal newborn hearing screening (UNHS).

DATA SOURCES

PubMed, Embase, PsycInfo, CINAHL, and Cochrane Library databases.

REVIEW METHODS

We searched for articles published from January 1, 1998, to February 19, 2020. We reviewed studies that (1) included children identified with either congenital or delayed-onset hearing loss before 2 years of age among cohorts who had undergone UNHS and (2) investigated ≥1 etiologies of hearing loss. We defined hearing loss as congenital when confirmed after UNHS failure and as delayed onset when diagnosed after ≥1 assessments with normal hearing.

RESULTS

Among 2069 unique citations, 115 studies met criteria for full-text assessment, and 20 met our inclusion criteria. Six studies tested children diagnosed with hearing loss for genetic etiology, 9 for congenital cytomegalovirus (CMV) infection, and 5 for both. Among 1787 children with congenital hearing loss and etiologic investigation, 933 (52.2%) were tested for genetic mutations and 1021 (57.1%) for congenital CMV infection. The proportion of congenital hearing loss cases attributable to genetic etiology ranged between 7.7% and 83.3% and to congenital CMV infection between 0.0% and 32.0%.

CONCLUSION

Data are lacking on the identification and etiology of delayed-onset hearing loss in children <2 years of age in the UNHS era. The proportion of congenital hearing loss cases attributable to genetic etiologies and congenital CMV infection appears to vary widely.

Implications of dried blood spot testing for congenital CMV on management of children with hearing loss: A preliminary report

INTRODUCTION

Non-genetic, congenital sensorineural hearing loss (cSNHL) is commonly caused by congenital CMV infection (cCMV). Hearing loss related to cCMV is variable in degree, often progressive, and can affect one or both ears.

OBJECTIVES

We sought to examine the outcomes of DBS testing in California, and the hearing outcomes of cCMV-positive children.

METHODS

This is a retrospective study of patients with SNHL of unknown etiology aged 6 months to 17 years old presenting to a tertiary care pediatric center and evaluated for cCMV by DBS testing.

RESULTS

114 children (228 ears) with SNHL of unknown origin were included. 6/114 (5.3%) tested positive for cCMV versus 108/114 (94.7%), who tested negative. None of the cCMV-positive children had symmetric bilateral hearing loss, compared with 56.5% (61/108) of cCMV-negative children (p < 0.05). cCMV-positive children were more likely to have profound SNHL in the worse-hearing ear (5/6 (83%) vs 16/108 (14.9%) of cCMV-negative children, p < 0.001). 86% (5/6) exhibited progressive hearing loss, including progression or new-onset hearing loss in the previously better hearing ear. 3 of the 6 children with cCMV underwent CI.

CONCLUSION

A small proportion of patients presenting with SNHL tested positive on DBS. Of cCMV-positive children, most presented with profound hearing loss in the worse-hearing ear, and 50% of cCMV-positive children developed progressive hearing loss in the initially better-hearing ear. Prognostic information afforded by etiologic confirmation of cCMV infection informed decision-making concerning cochlear implantation in these cases.

Congenital cytomegalovirus infection inducing non-congenital sensorineural hearing loss during childhood; a systematic review

BACKGROUND

Congenital cytomegalovirus (CMV) infection is one of the most important risk factors for delayed onset and progressive hearing loss in children. However, the relevant literature is limited, heterogeneous and currently insufficient to provide guidance toward the effective monitoring of hearing acuity in these children.

OBJECTIVES

The aim of this study was to provide a systematic review focused on types of hearing loss that may escape diagnosis through universal neonatal hearing screening and/or present significant changes during childhood, such as progressive, fluctuating and late-onset hearing loss.

DATA SOURCES

A review of the present literature was conducted via the PubMed database of the US National Library of Medicine (www.pubmed.org) and Scopus database (www.scopus.com) with the search terms "late-onset hearing loss cytomegalovirus", "progressive hearing loss cytomegalovirus" and "fluctuating hearing loss cytomegalovirus".

STUDY ELIGIBILITY CRITERIA

Prospective or retrospective clinical studies were included if they presented a detailed audiological assessment, for a follow-up period of >2years.

METHODS

The prevalence and time of diagnosis of progressive, fluctuating and late-onset hearing loss were considered as primary outcomes. Results were recorded separately for symptomatic and asymptomatic children, when possible.

RESULTS

This analysis refers to a population of 181 children with CMV-induced hearing loss, who were diagnosed among 1089 with congenital CMV infection. The prevalence of CMV-induced hearing loss was significantly higher among symptomatic children (p < 0.0001), who were also significantly more likely to develop bilateral hearing loss (p = 0.001). There was not sufficient information on the prevalence, laterality, degree and time of diagnosis of progressive, fluctuating and late-onset hearing loss that could constitute the basis toward the report of specific follow-up guidelines.

CONCLUSIONS

Further studies are needed in order to understand and quantify the potential effects of congenital CMV infection in the inner ear and hearing acuity. The results presented in the relative studies should be very carefully evaluated and compared to each other, since they correspond to substantially different cohorts, study designs, and result elaboration. Infants with congenital CMV infection should be closely monitored, regarding their hearing acuity at least during their preschool years, although substantial changes in hearing thresholds have been reported as late as the 16th year of age. Parental counseling is of outmost importance in order to minimize the numbers of children lost to follow-up.

Potential Benefit of Selective CMV Testing after Failed Newborn Hearing Screening

Evidence-based guidelines for the prevention, diagnosis and treatment of congenital cytomegalovirus (cCMV) were recently released by two independent expert groups. Of particular emphasis was the relationship between cCMV and sensorineural hearing loss (SNHL), a major component of the virus' overall disease burden. In this study, a literature review was performed to estimate the proportion of cCMV-related SNHL cases, which might be identified through selective cCMV testing following failed newborn hearing screening. Furthermore, it was of interest to estimate the potential benefit of emerging antiviral therapies. Currently, at most 10% of cCMV-related SNHL is likely to be identified clinically. Through use of a selective cCMV testing protocol, however, a significant improvement in the identification rate can be achieved. Recent expert group statements strongly recommend antiviral therapy in cases of moderate-to-severe disease, especially in the presence of central nervous system involvement. Though differences exist between recommendations in instances of isolated SNHL or SNHL in combination with only mild symptoms, the majority of experts in both groups offered at least a weak recommendation for antiviral treatment. Available results suggest antiviral treatment could therefore benefit a meaningful proportion of newborns referred for cCMV testing following failed newborn hearing screening.

Disparities in access to pediatric hearing health care

PURPOSE OF REVIEW

There are significant disparities in care facing children with hearing loss. The objective of this review is to assess the current disparities in pediatric hearing healthcare delivery, describe the barriers of efficient and effective pediatric hearing health care, and explore the innovations to improve pediatric hearing healthcare delivery.

RECENT FINDINGS

Children with hearing loss from certain geographic regions or ethnic background are significantly delayed in diagnosis and treatment. Multiple patient characteristics (presentation of hearing loss), parental factors (insurance status, socioeconomic status, educational status, and travel distance to providers), and provider barriers (specialist shortage and primary care provider challenges) prevent the delivery of timely hearing health care. Advances, such as improved screening programs and the expansion of care through remote services, may help to ameliorate these disparities.

SUMMARY

Timely identification and treatment of pediatric hearing loss is critical to prevent lifelong language complications. Children from vulnerable populations, such as rural residents, face significant disparities in care. Careful assessment of these barriers and implementation of culturally acceptable interventions are paramount to maximize communication outcomes of children with hearing loss.

Contribution of targeted saliva screening for congenital CMV-related hearing loss in newborns who fail hearing screening

BACKGROUND

We previously reported a 2.2% rate of infants born with sensorineural hearing loss (SNHL) due to congenital cytomegalovirus (cCMV) infection identified by universal neonatal screen for cCMV using saliva.

OBJECTIVE

To evaluate the contribution of targeted saliva screening for cCMV to the detection of infants born with cCMV-related SNHL who failed universal newborn hearing screening (UNHS).

METHODS

We retrospectively reviewed the audiological and medical records of infants who failed UNHS and were tested for cCMV using saliva sample prior to discharge at Sheba Medical Center between 2014 and 2015. Positive cases were confirmed by urine sample.

RESULTS

Two hundred (1%) of the 19 830 infants tested during the study period failed in-hospital hearing screening. A saliva specimen was obtained prior to discharge in 187 infants (93.5% of those who failed UNHS). In 178 infants saliva testing was performed at ≤21 days of chronological age and yielded results. cCMV infection was identified in 4/178 tested infants (2.25%, 95% CI 0.8% to 5.3%), of whom three were diagnosed with SNHL (1.7%, 95% CI 0.5% to 4.4%) and offered antiviral treatment. Two of the tested infants (1.12%, 95% CI 0.2% to 3.6%) were diagnosed with cCMV solely due to failure in UNHS. Occult central nervous system (CNS) symptoms of cCMV infection were detected in 2/4 infants following targeted investigation.

CONCLUSIONS

Targeted cCMV screening in newborns who failed UNHS contributed to the early detection of infants born with cCMV-related isolated SNHL or with occult CNS symptoms who could potentially benefit from antiviral treatment.

Analysis of archived newborn dried blood spots (DBS) identifies congenital cytomegalovirus as a major cause of unexplained pediatric sensorineural hearing loss

PURPOSE

Congenital cytomegalovirus (cCMV) infection is the most common non-genetic cause of sensorineural hearing loss (SNHL). However, accurate diagnosis of cCMV as the etiology of SNHL is problematic beyond the neonatal period. This study therefore examined whether cCMV infection could be identified retrospectively in children presenting with unexplained SNHL to a multidisciplinary diagnostic outpatient otolaryngology clinic at an academic medical center in Minnesota.

METHODS

Over a 4-year period, 57 patients with an age range of 3months to 10years with unexplained SNHL were recruited to participate in this study. Informed consent was obtained to test the archived dried blood spots (DBS) of these patients for cCMV infection by real-time PCR, targeting a highly conserved region of the CMV UL83 gene. Results were normalized to recovery of an NRAS gene control. Chart review was conducted to identify subjects who underwent genetic testing and/or neurodiagnostic imaging to investigate possible genetic, syndromic, or anatomical causes of SNHL.

RESULTS

In total, 15 of the 57 children with unexplained SNHL tested positive for CMV DNA in their DBS (26%). A mean viral load of 8.3×10⁴ (±4.1×10⁴) [range, 1×10³-6×10⁵] copies/μg DNA was observed in subjects retrospectively diagnosed with cCMV. No statistically significant correlation was found between viral load and SNHL severity.

CONCLUSIONS

A retrospective DBS analysis demonstrated that 26% of patients presenting with unexplained SNHL in childhood had cCMV. DBS testing is useful in the retrospective diagnosis of cCMV, and may provide definitive diagnostic information about the etiology of SNHL.

Hearing Loss in Children With Asymptomatic Congenital Cytomegalovirus Infection

OBJECTIVES

To assess the prevalence, characteristics, and risk of sensorineural hearing loss (SNHL) in children with congenital cytomegalovirus infection identified through hospital-based newborn screening who were asymptomatic at birth compared with uninfected children.

METHODS

We included 92 case-patients and 51 controls assessed by using auditory brainstem response and behavioral audiometry. We used Kaplan-Meier survival analysis to estimate the prevalence of SNHL, defined as ≥25 dB hearing level at any frequency and Cox proportional hazards regression analyses to compare SNHL risk between groups.

RESULTS

At age 18 years, SNHL prevalence was 25% (95% confidence interval [CI]: 17%-36%) among case-patients and 8% (95% CI: 3%-22%) in controls (hazard ratio [HR]: 4.0; 95% CI: 1.2-14.5; P = .02). Among children without SNHL by age 5 years, the risk of delayed-onset SNHL was not significantly greater for case-patients than for controls (HR: 1.6; 95% CI: 0.4-6.1; P = .5). Among case-patients, the risk of delayed-onset SNHL was significantly greater among those with unilateral congenital/early-onset hearing loss than those without (HR: 6.9; 95% CI: 2.5-19.1; P < .01). The prevalence of severe to profound bilateral SNHL among case-patients was 2% (95% CI: 1%-9%).

CONCLUSIONS

Delayed-onset and progression of SNHL among children with asymptomatic congenital cytomegalovirus infection continued to occur throughout adolescence. However, the risk of developing SNHL after age 5 years among case-patients was not different than in uninfected children. Overall, 2% of case-patients developed SNHL that was severe enough for them to be candidates for cochlear implantation.

Cytomegalovirus (CMV) Infection Causes Degeneration of Cochlear Vasculature and Hearing Loss in a Mouse Model

Cytomegalovirus (CMV) infection is one of the most common causes of congenital hearing loss in children. We have used a murine model of CMV infection to reveal functional and structural cochlear pathogenesis. The cerebral cortex of Balb/c mice (Mus musculus) was inoculated with 2000 pfu (plaque forming units) of murine CMV on postnatal day 3. At 6 weeks of age, cochlear function was monitored using auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) measures. Histological assessment of cochlear vasculature using a corrosion cast technique was made at 8 weeks. Vascular casts of mCMV-damaged cochleas, and those of untreated control animals, were examined using scanning electron microscopy. We find very large variations in the degree of vascular damage in animals given identical viral injections (2000 pfu). The primary lesion caused by CMV infection is to the stria vascularis and to the adjacent spiral limbus capillary network. Capillary beds of the spiral ligament are generally less affected. The initial vascular damage is found in the mid-apical turn and appears to progress to more basal cochlear regions. After viral migration to the inner ear, the stria vascularis is the primary affected structure. We suggest that initial auditory threshold losses may relate to the poor development or maintenance of the endocochlear potential caused by strial dysfunction. Our increased understanding of the pathogenesis of CMV-related hearing loss is important for defining methods for early detection and treatment.

Aetiological diagnosis of child deafness: CODEPEH recommendations

Important progress in the fields of molecular genetics (principally) and diagnostic imaging, together with the lack of a consensus protocol for guiding the diagnostic process after confirming deafness by neonatal screening, have led to this new work document drafted by the Spanish Commission for the Early Detection of Child Deafness (Spanish acronym: CODEPEH). This 2015 Recommendations Document, which is based on the most recent scientific evidence, provides guidance to professionals to support them in making decisions regarding aetiological diagnosis. Such diagnosis should be performed without delay and without impeding early intervention. Early identification of the causes of deafness offers many advantages: it prevents unnecessary trouble for the families, reduces health system expenses caused by performing different tests, and provides prognostic information that may guide therapeutic actions.

Ethical issues in DNA sequencing in the neonate

With the recognition of genetic disorders in the newborn, there is the potential to offer new lifesaving therapies. For other conditions such as hypothyroidism in Down syndrome or hypercalemia in the 22q11 microdeltion syndrome, the early identification of an untreatable condition permits prompt screening for potential comorbid conditions. DNA testing for disorders and DNA-based screening are rapidly evolving. With new more powerful tests, there is an increasing ability to see into a potential future and change the outcome for newborns. However, there remain significant ethical and structural issues to be considered before routine implementation of DNA testing.

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.

[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.

Asymptomatic DNAemia heralds CMV-associated NEC: case report, review, and rationale for preemption

Human cytomegalovirus (CMV) infection may be acquired in very low birth weight and extremely low birth weight (ELBW) infants from breast milk. The clinical relevance of such infections is uncertain. There is no consensus on whether screening breast milk for CMV, freezing/pasteurizing milk before feeding, or performing virological monitoring on at-risk infants is warranted. We describe an ELBW infant who acquired CMV postnatally from breast milk and developed CMV sepsis syndrome and clinical evidence of necrotizing enterocolitis (NEC) at ≈ 5 weeks of age. The availability of serial dried blood spots from day of life (DOL) 4 to 21, coincidentally obtained for a metabolic study, provided the novel opportunity to retrospectively test for and quantify the magnitude of CMV DNAemia. DNAemia was present for several weeks before the onset of severe CMV disease, first being noted on DOL 18 and increasing in magnitude daily to 4.8 log10 genomes/mL on DOL 21, approximately 8 days before the onset of abdominal distension and 15 days before the onset of CMV sepsis syndrome and NEC. After surgical resection, supportive care, and ganciclovir therapy, the infant recovered. This case underscores the importance of including CMV infection in the differential diagnosis of sepsis and NEC in premature infants. This case also suggests the value of prospective virological monitoring in at-risk low birth weight and ELBW infants. Future studies should examine the potential utility of preemptive monitoring for, and possibly treatment of, CMV DNAemia in premature infants, which may herald the onset of serious disease.

A pilot study using residual newborn dried blood spots to assess the potential role of cytomegalovirus and Toxoplasma gondii in the etiology of congenital hydrocephalus

BACKGROUND

Congenital hydrocephalus is a condition characterized by accumulation of cerebrospinal fluid in the ventricles of the brain. Prenatal infections are risk factors for some birth defects. This pilot study investigated whether residual dried blood spots (DBS) could be used to assess infections as risk factors for birth defects by examining the associations between prenatal infection with Toxoplasma gondii (T. gondii) or cytomegalovirus (CMV) with congenital hydrocephalus.

METHODS

Case-infants with hydrocephalus (N=410) were identified among live-born infants using birth defects surveillance systems in California, North Carolina, and Texas. Control-infants without birth defects were randomly selected from the same geographic areas and time periods as case-infants (N=448). We tested residual DBS from case- and control-infants for T. gondii immunoglobulin M and CMV DNA. When possible, we calculated crude odds ratios (cORs) and confidence intervals (CIs).

RESULTS

Evidence for prenatal T. gondii infection was more common among case-infants (1.2%) than control-infants (0%; p=0.11), and evidence for prenatal CMV infection was higher among case-infants (1.5%) than control-infants (0.7%; cOR: 2.3; 95% CI: 0.48, 13.99).

CONCLUSIONS

Prenatal infections with T. gondii and CMV occurred more often among infants with congenital hydrocephalus than control-infants, although differences were not statistically significant. This pilot study highlighted some challenges in using DBS to examine associations between certain infections and birth defects, particularly related to reduced sensitivity and specimen storage conditions. Further study with increased numbers of specimens and higher quality specimens should be considered to understand better the contribution of these infections to the occurrence of congenital hydrocephalus.

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.

Cytomegalovirus DNA detection in dried blood spots and perilymphatic fluids from pediatric and adult cochlear implant recipients with prelingual deafness

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the leading cause of non-genetic congenital hearing loss. The contribution of congenital CMV to prelingual deafness and the pathophysiology is largely unknown.

OBJECTIVE

(1) To analyze the prevalence of congenital CMV among cochlear implant (CI) recipients with prelingual deafness. (2) To genotype CMV present in dried blood spots (DBS) and in the inner ear years after birth.

STUDY DESIGN

Children and adults with prelingual deafness who received a CI in 2010-2011 were included prospectively. Perilymphatic fluids were collected during CI surgery and, in the pediatric cases, DBS were retrieved for CMV DNA detection. Furthermore, a cohort of children with prelingual deafness who received a CI between 2003 and 2008 were included retrospectively. CMV detection in DBS and perilymph was followed by gB and gH genotyping.

RESULTS

Seventysix pediatric CI recipients were included. Seventy DBS were tested for CMV DNA, resulting in a prevalence of congenital CMV of 14% (10/70). Perilymphatic fluid was available from 29 pediatric CI recipients. One perilymph fluid, of a 21-month old girl with congenital CMV, asymptomatic at birth, was CMV DNA positive. The CMV strain in the perilymph was genotypically identical to the strain present in her DBS (gB1/gH2). Perilymph samples from 21 adult CI recipients were CMV DNA negative.

CONCLUSIONS

Our study stresses the important contribution of congenital CMV among pediatric CI recipients. Furthermore, our genotyping data support the hypothesis that CMV-related hearing loss is associated with ongoing viral replication in the inner ear up to years after birth.

Dried urine spots for detection and quantification of cytomegalovirus in newborns

Dried urine spots (DUS) have been reported to provide a simple screening tool for congenital cytomegalovirus (CMV) infection. We developed a standardized method for CMV quantification from DUS. Two applications of 20 μL urine remained within the rim of the filter paper disc and were used to determine the analytical performance of Towne CMV spiked into urine and applied on the discs. The measurable range spanned 3.7 to ≥8.0 log(10) copies/mL. The detection limit was 22 DNA copies/disc. Urine samples from congenitally infected newborns and negative controls were either diluted 1:10 or applied on filter paper at the same volume. DNA copy number from DUS correlated well with copy number from 1:10 diluted urine, although there was a trend for lower levels from DUS (0.3 log(10) difference). Our standardized method for CMV detection and quantification may facilitate CMV studies in resource-limited areas and allow for longitudinal monitoring of viral loads in treated infants.

Post-extraction stabilization of HIV viral RNA for quantitative molecular tests

Two approaches to stabilize viral nucleic acid in processed clinical specimens were evaluated. HIV-1 RNA extracted from clinical specimens was stabilized in a dry matrix in a commercial product (RNAstable, Biomatrica, San Diego, CA, USA) and in a reverse-transcription reaction mixture in liquid form as cDNA. As few as 145 HIV-1 genome copies of viral RNA are reliably stabilized by RNAstable at 45°C for 92 days and in the cDNA format at 45°C for 7 days as determined by real-time PCR. With RNAstable the R(2) at days 1, 7, and 92 were 0.888, 0.871, and 0.943 when compared to baseline viral load values. The cDNA generated from the same clinical specimens was highly stable with an R(2) value of 0.762 when comparing viral load determinations at day 7 to baseline values. In conclusion viral RNA stabilized in a dry RNAstable matrix is highly stable for long periods of time at high temperatures across a substantial dynamic range. Viral RNA signal can also be stabilized in liquid in the form of cDNA for limited periods of time. Methods that reduce reliance on the cold chain and preserve specimen integrity are critical for extending the reach of molecular testing to low-resource settings. Products based on anhydrobiosis, such as the RNAstable should be evaluated further to support viral pathogen diagnosis.

Rapid genotyping of cytomegalovirus in dried blood spots by multiplex real-time PCR assays targeting the envelope glycoprotein gB and gH genes

Genotyping of cytomegalovirus (CMV) is useful to examine potential differences in the pathogenicity of strains and to demonstrate coinfection with multiple strains involved in CMV disease in adults and congenitally infected newborns. Studies on genotyping of CMV in dried blood spots (DBS) are rare and have been hampered by the small amount of dried blood available. In this study, two multiplex real-time PCR assays for rapid gB and gH genotyping of CMV in DBS were developed. Validation of the assays with 39 CMV-positive plasma samples of transplant recipients and 21 urine specimens of congenitally infected newborns was successful in genotyping 100% of the samples, with gB1 and gB3 being the most prevalent genotypes. Multiple gB and gH genotypes were detected in 36% and 33% of the plasma samples, respectively. One urine sample from a newborn with symptomatic congenital CMV was positive for gB1 and gB2. DBS of congenitally infected newborns (n = 41) were tested using 9 μl of dried blood, and genotypes were detected in 81% (gB) and 73% (gH) of the samples, with gB3 being the most prevalent genotype. No clear association of specific genotypes with clinical outcome was observed. In conclusion, the CMV gB and gH PCR assays were found to be rapid, sensitive for detecting mixed infections, and suitable for direct usage on DBS. These assays are efficient tools for genotyping of CMV in DBS of congenitally infected newborns.

Differentiating inherited human herpesvirus type 6 genome from primary human herpesvirus type 6 infection by means of dried blood spot from the newborn screening card

To differentiate active human herpesvirus type 6 (HHV-6) infection from inherited HHV-6 (iHHV-6), we analyzed dried blood spots from archived newborn screening cards in 3 patients with high HHV-6 DNA copy numbers. Two patients were positive for HHV-6 DNA as neonates suggesting iHHV-6. In 1 patient, the absence of HHV-6 DNA excluded iHHV-6.

Clinical profile of hearing loss in children with congenital cytomegalovirus (CMV) infection: CMV DNA diagnosis using preserved umbilical cord

Conclusions:

Congenital cytomegalovirus (CMV) infection is a major cause of bilateral and unilateral sensorineural hearing loss (SNHL) in children, accounting for 9.0% of SNHL cases. The diagnostic rate using combined genetic deafness test and CMV DNA detection test was determined to be 46.4% in bilateral profound SNHL.

Objectives.

The present study investigated the prevalence of congenital CMV infection diagnosed retrospectively by detection of CMV DNA in dried umbilical cord specimens from children with unilateral or bilateral SNHL up to the age of 12 years.

Methods:

Preserved dried umbilical cords were collected from 134 children with bilateral (46 children) or unilateral (88 children) SNHL. DNA was extracted from the dried umbilical cords and CMV DNA was detected by quantitative PCR. Genetic deafness tests based on the invader assay were performed in children with bilateral SNHL.

Results:

CMV DNA from the dried umbilical cords was detected in 8.7% of the bilateral SNHL and 9.1% of unilateral SNHL. Deafness gene mutations were identified in 21.7% (10/46) of children with bilateral SNHL.

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.

Human cytomegalovirus infection and clinical status of infants born to human immunodeficiency virus type 1 infected mothers

OBJECTIVE

Human cytomegalovirus (HCMV) is one of the most common congenital infections worldwide and a frequent opportunistic infection that aggravates the condition of human immunodeficiency virus (HIV)-infected patients. The aim of the study was to evaluate the frequency and factors influencing HCMV infection among infants of HIV-positive women.

METHODS

The study included 35 infants born to HIV-1-infected mothers examined for congenital infections. Children were evaluated for human immunodeficiency virus type 1 (HIV-1), HCMV, and HCV infection by serological and molecular methods.

RESULTS

HIV-1 infection was found in one child whose mother did not receive antiretroviral treatment during pregnancy, and HCV infection in another infant. HCMV-DNA in the urine was present in 13/35 infants (37.14%) on the 10th day and 24/35 infants (68.57%) in the 4th week of life. The majority of HCMV-infected infants were asymptomatic, although they manifested microcephaly and low birth weight significantly more frequently (p = 0.006 and p = 0.02, respectively). Type HIV prophylaxis did not influence HCMV transmission.

CONCLUSIONS

Although often asymptomatic, HCMV infection in infants born to HIV-infected mothers is frequent and may be associated with prematurity, low birth weight, and microcephaly. Diagnostic procedures in children of HIV-infected mothers should involve HCMV.

Congenital cytomegalovirus infection in pediatric hearing loss

OBJECTIVES

To compare the prevalence of congenital cytomegalovirus (CMV) infection in Washington State in children with hearing loss (HL) and the general population and to compare the characteristics of HL in children with and without congenital CMV infection.

DESIGN

Matched case-control; case cohort.

SETTING

Regional pediatric hospital, Washington State Department of Health (WSDOH).

PATIENTS

Cases were children 4 years and older with HL born in Washington State. Control individuals matched for demographic characteristics were identified at random through the WSDOH.

MAIN OUTCOME MEASURES

Congenital CMV status determined using quantitative polymerase chain reaction testing on newborn heel stick blood spots archived by the WSDOH. Audiologic data were used to characterize HL.

RESULTS

Congenital CMV testing was performed for 222 matched cases and controls. Congenital CMV infection was detected in 1.4% of controls and in 9.9% of cases (odds ratio, 10.5; 95% confidence interval, 2.6-92.4). An estimated 8.9% of HL in children in Washington can be attributed to CMV infection. After inclusion of an additional 132 children with HL (for a total of 354 cases in the case cohort), we observed that children with congenital CMV had more severe HL (P < .001) and higher proportions of progressive (P = .02) and unilateral (P = .002) HL compared with children without congenital CMV infection. In the 35 children with congenital CMV infection, there was no relationship between neonatal CMV load and severity of HL.

CONCLUSIONS

In Washington State, children with HL had a far higher prevalence of congenital CMV viremia than did the general pediatric population, and CMV infection seems to be responsible for an appreciable fraction of pediatric HL in Washington State.

Public health and laboratory considerations regarding newborn screening for congenital cytomegalovirus

Congenital cytomegalovirus (CMV) infection is the most common infection in newborns worldwide and causes hearing loss and other neurological disability in 15-20% of infected infants. Only about half of the hearing loss resulting from congenital CMV infection is currently detected by universal newborn hearing screening because of late-onset hearing loss. Thus, much of the hearing loss and the majority of other CMV-associated disabilities remain undetected for years after birth and are never connected to CMV infection. Congenital CMV may be appropriate to include in national newborn screening (NBS) programs because it is more common than other disorders tested for by NBS programs and is a major cause of disability. Significant obstacles to the implementation of screening for congenital CMV include the lack of a standardized, high-throughput screening test and a protocol for follow-up of CMV-infected children. Nonetheless, screening newborns for congenital CMV infection merits further consideration.

Prevention of maternal cytomegalovirus infection: current status and future prospects

Human cytomegalovirus (CMV) infection is the most common cause of perinatal viral infection in the developed world, resulting in approximately 40,000 congenitally infected infants in the United States each year. Congenital CMV infection can produce varying degrees of neurodevelopmental disabilities. The significant impact of congenital CMV has led the Institute of Medicine to rank development of a CMV vaccine as a top priority. Vaccine development has been ongoing; however no licensed CMV vaccine is currently available. Treatment of pregnant women with CMV hyperimmune globulin has shown promising results, but has not been studied in randomized controlled trials. Education on methods to prevent CMV transmission, particularly among young women of child-bearing age, should continue until a CMV vaccine becomes available. The epidemiology, clinical manifestations, prevention strategies, and treatment of CMV infections are reviewed.