Screening for Congenital Cytomegalovirus After Newborn Hearing Screening: What Comes Next?

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Improved Dried Blood Spot PCR Assay for Universal Congenital Cytomegalovirus Screening in Newborns

Congenital cytomegalovirus (cCMV) is the most common perinatal infection, the leading cause of nongenetic sensorineural hearing loss, and one of the leading causes of neurodevelopmental impairment in the developed world. Early identification via newborn screening (NBS) would benefit the many undiagnosed infants who are either asymptomatic or mildly to moderately symptomatic, of whom 20% develop sequelae. The sensitivity of a recently developed PCR-based method to detect CMV in dried blood spots (DBS) is less than 80% and requires significantly more specimen than any other NBS test. We sought to improve the analytical sensitivity of the screening method by using droplet digital PCR and direct PCR and decreasing the amount of specimen utilized. The methods were tested with CMV-spiked filters, DBS from CMV-spiked cord blood, and DBS from neonates with cCMV. The results showed that the analytical sensitivity of all modified methods was equivalent to that of the reference method, with consistent CMV detection at high viral loads and inconsistent detection at low viral loads. IMPORTANCE Implementation of screening for cCMV in public health programs is hindered by feasibility challenges, including limited specimen availability and an insufficiently sensitive DBS-based screening assay. We report on efforts to improve the currently available DBS-based molecular assay to increase its feasibility of implementation in newborn screening programs. Although the analytical sensitivity of the modified methods was similar at the lower IU, equivalent CMV detection was achieved using one punch instead of the required three punches for the reference method. This reduction in sample size has the potential to substantially improve feasibility of NBS for cCMV. A population-based study is needed to further evaluate the clinical sensitivity of the improved assay.

Economic assessments of the burden of congenital cytomegalovirus infection and the cost-effectiveness of prevention strategies

OBJECTIVE

This is a critical review of published economic analyses on congenital cytomegalovirus infection and strategies for its detection and prevention.

FINDINGS

The review identified four cost-of-illness studies and nine cost-effectiveness analyses: three of vaccination of young women, two of prenatal screening, and four of newborn screening. All reported either large economic costs or favorable cost-effectiveness of interventions. However, sensitivity analyses did not address some of the most critical assumptions.

CONCLUSIONS

Reviewed economic analyses overattributed certain adverse long-term outcomes to congenital cytomegalovirus infection, while other long-term costs were not included. Overall, limited conceptual frameworks, unrepresentative data sources, and unsupported or inadequately documented assumptions regarding outcomes and costs hinder the ability of policymakers to draw conclusions. A major challenge is the limited information on long-term outcomes and costs for representative cohorts of individuals with congenital cytomegalovirus, which further research could helpfully address.

Assessment of Risk Indicators for Targeted Cytomegalovirus Screening in Neonates

BACKGROUND

In the absence of universal screening for congenital cytomegalovirus (cCMV) infection, the aim of this study was to assess the outcomes of a targeted screening protocol based on maternal and neonatal risk indicators.

METHODS

The medical records of 2,623 neonates born in our maternal hospital between June 2016 and December 2018 and screened for cCMV infection were reviewed. Among those of the included neonates, the records of 380 CMV-negative and 19 CMV-positive neonates were randomly assigned to obtain additional comparative data.

RESULTS

During the study period, a total of 63 neonates were identified as positive for cCMV, comprising 0.2% of the total birth cohort (63/28,982) and 2.4% of all neonates screened for cCMV (63/2,623). The comparative data analysis showed that suspected or confirmed CMV infection during pregnancy, maternal age, and maternal diabetes mellitus were found to be significantly associated with a positive cCMV diagnosis. Although symmetric small for gestational age and hearing screening failure contributed to the detection of some of the CMV-positive infants, these factors were not specific to this group. The results of the logistic regression model showed that the only factor that was significantly associated with an increased risk for a cCMV diagnosis was maternal serology suspected of CMV infection during pregnancy, with a regression coefficient estimate of 2.657 (adjusted p < 0.001).

CONCLUSIONS

A targeted neonatal screening protocol based on multiple maternal and neonatal risk indicators is feasible but provides limited information. Our study emphasizes the importance of universal neonatal screening for the detection of neonates with cCMV.

Diagnóstico tardio de Citomegalovirose em recém-nascido pré-termo, por carência de triagem no período gestacional: uma realidade do Brasil - Relato de Caso

O citomegalovírus pertence à família do Herpes vírus, e está presente na maior parte da população. A citomegalovirose no período neonatal pode estar associada à transmissão intra-útero por via transplacentária, ou ainda, perinatal.  No caso apresentado, destaca-se a demora no diagnóstico e na efetivação da conduta terapêutica visto que, no Brasil, o rastreamento de infecção por citomegalovírus em gestante não faz parte da rotina de pré-natal. O diagnóstico da citomegalovirose neonatal é obtido por meio da realização da cultura do vírus na urina entre o terceiro e o quinto dia de vida, ou ainda, pela realização da Reação em Cadeia de Polimerase. No relato de caso, o tratamento utilizado para a citomegalovirose baseou-se no uso de Ganciclovir (500 mg/10ml por via endovenosa durante três semanas). A dificuldade de estabelecer um diagnóstico precoce da citomegalovirose neonatal ainda representa um dos principais desafios para se alcançar um melhor prognóstico da doença.

Hearing Trajectory in Children with Congenital Cytomegalovirus Infection

Objectives To compare hearing trajectories among children with symptomatic and asymptomatic congenital cytomegalovirus infection through age 18 years and to identify brain abnormalities associated with sensorineural hearing loss (SNHL) in asymptomatic case patients. Study Design Longitudinal prospective cohort study. Setting Tertiary medical center. Subjects and Methods The study included 96 case patients (4 symptomatic and 92 asymptomatic) identified through hospital-based newborn cytomegalovirus screening from 1982 to 1992 and 72 symptomatic case patients identified through referrals from 1993 to 2005. We used growth curve modeling to analyze hearing thresholds (0.5-8 kHz) by ear with increasing age and Cox regression to determine abnormal findings on head computed tomography scan associated with SNHL (hearing threshold ≥25 dB in any audiometric frequency) among asymptomatic case patients. Results Fifty-six (74%) symptomatic and 20 (22%) asymptomatic case patients had SNHL: congenital/early-onset SNHL was diagnosed in 78 (51%) and 10 (5%) ears, respectively, and delayed-onset SNHL in 25 (17%) and 20 (11%) ears; 49 (32%) and 154 (84%) ears had normal hearing. In affected ears, all frequency-specific hearing thresholds worsened with age. Congenital/early-onset SNHL was significantly worse (severe-profound range, >70 dB) than delayed-onset SNHL (mild-moderate range, 26-55 db). Frequency-specific hearing thresholds were significantly different between symptomatic and asymptomatic case patients at 0.5 to 1 kHz but not at higher frequencies (2-8 kHz). Among asymptomatic case patients, white matter lucency was significantly associated with SNHL by age 5 years (hazard ratio, 4.4; 95% CI, 1.3-15.6). Conclusion Congenital/early-onset SNHL frequently resulted in severe to profound loss in symptomatic and asymptomatic case patients. White matter lucency in asymptomatic case patients was significantly associated with SNHL by age 5 years.

Results of a Targeted Screening Program for Congenital Cytomegalovirus Infection in Infants Who Fail Newborn Hearing Screening

BACKGROUND

Congenital cytomegalovirus (CMV) infection is a major cause of sensorineural hearing loss. By law, newborns in Connecticut who fail newborn hearing screening are tested for infection with CMV. This targeted screening is controversial, because most children with congenital CMV infection are asymptomatic, and CMV-related hearing loss can have a delayed onset. Our hospital uses a saliva polymerase chain reaction (PCR) assay (confirmed by a urine PCR assay) to detect CMV. Here, we report the results of the first year of our screening program.

METHODS

We reviewed the medical records of newborns in the Yale New Haven Health System who failed the newborn hearing screening test between January 1 and December 31, 2016.

RESULTS

Of 10964 newborns, 171 failed newborn hearing screening, and 3 of these newborns had positive saliva CMV PCR test results. Of these 3 newborns, 2 had positive results on the confirmatory test (for 1 of them the confirmatory test was not performed until the infant was 10 weeks old), and 1 had a negative result on the confirmatory test. Three additional newborns with congenital CMV infection were tested because of clinical indications (1 for ventriculomegaly on prenatal ultrasound and 2 for CMV infection of the mother). Results of audiology follow-up were available for 149 (87.1%) of the 171 newborns who failed newborn hearing screening; 127 (85.2%) had normal results.

CONCLUSION

Our targeted screening program for congenital CMV infection had a low yield. Consideration should be given to other strategies for identifying children at risk of hearing loss as a result of congenital CMV infection.

Intelligence and Academic Achievement With Asymptomatic Congenital Cytomegalovirus Infection

OBJECTIVES

To examine intelligence, language, and academic achievement through 18 years of age among children with congenital cytomegalovirus infection identified through hospital-based newborn screening who were asymptomatic at birth compared with uninfected infants.

METHODS

We used growth curve modeling to analyze trends in IQ (full-scale, verbal, and nonverbal intelligence), receptive and expressive vocabulary, and academic achievement in math and reading. Separate models were fit for each outcome, modeling the change in overall scores with increasing age for patients with normal hearing (n = 78) or with sensorineural hearing loss (SNHL) diagnosed by 2 years of age (n = 11) and controls (n = 40).

RESULTS

Patients with SNHL had full-scale intelligence and receptive vocabulary scores that were 7.0 and 13.1 points lower, respectively, compared with controls, but no significant differences were noted in these scores among patients with normal hearing and controls. No significant differences were noted in scores for verbal and nonverbal intelligence, expressive vocabulary, and academic achievement in math and reading among patients with normal hearing or with SNHL and controls.

CONCLUSIONS

Infants with asymptomatic congenital cytomegalovirus infection identified through newborn screening with normal hearing by age 2 years do not appear to have differences in IQ, vocabulary or academic achievement scores during childhood, or adolescence compared with uninfected children.