Universal newborn screening for congenital cytomegalovirus infection: feasibility and relevance in a French type-III maternity cohort

Implementation of pooled saliva tests for universal screening of cCMV infection

Congenital cytomegalovirus (cCMV) is the most common intrauterine infection, leading to neurodevelopmental disabilities. Universal newborn infant screening of cCMV has been increasingly advocated. In the absence of a high-throughput screening test, which can identify all infected newborn infants, the development of an accurate and efficient testing strategy has remained an ongoing challenge. Here we assessed the implementation of pooled saliva polymerase chain reaction (PCR) tests for universal screening of cCMV, in two hospitals of Jerusalem from April 2022 through April 2023. During the 13-month study period, 15,805 infants (93.6% of all live newborn infants) were screened for cCMV using the pooled approach that has since become our routine screening method. The empirical efficiency of the pooling was six (number of tested newborn infants per test), thereby sparing 83% of the saliva tests. Only a minor 3.05 PCR cycle loss of sensitivity was observed for the pooled testing, in accordance with the theoretical prediction for an eight-sample pool. cCMV was identified in 54 newborn infants, with a birth prevalence of 3.4 per 1,000; 55.6% of infants identified with cCMV were asymptomatic at birth and would not have been otherwise targeted for screening. The study demonstrates the wide feasibility and benefits of pooled saliva testing as an efficient, cost-sparing and sensitive approach for universal screening of cCMV.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Newborn cytomegalovirus screening: is this the new standard?

PURPOSE OF REVIEW

Congenital cytomegalovirus infection (cCMV) is a major cause of childhood hearing loss and neurodevelopmental delay. Early identification of cCMV allows for interventions that improve outcomes, particularly for cCMV-related hearing loss that develops in early childhood. Most cCMV is asymptomatic at birth and is rarely diagnosed without newborn screening. Therefore, various approaches to cCMV screening are increasingly being adopted.

RECENT FINDINGS

Both universal screening (testing all newborns) and targeted screening (testing triggered by failed hearing screening) for cCMV appear valuable, feasible and cost-effective, though universal screening is predicted to have greatest potential overall benefits. CMV PCR testing of newborn oral swabs is sensitive and practical and is therefore widely used in targeted screening programs. In contrast, PCR using dried-blood spots (DBS) is less sensitive but was adopted by current universal cCMV screening initiatives because DBS are already collected from all newborns in high-income countries, which circumvents large-scale oral swab collection.

SUMMARY

Targeted screening is widely recommended as standard of care, while universal screening is less common but is progressively considered as the optimal strategy for identification of children with cCMV. As with all screening programs, cCMV screening requires commitments to equitable and reliable testing, follow-up and services.

Cost-effectiveness of screening and valacyclovir-based treatment strategies for first-trimester cytomegalovirus primary infection in pregnant women in France

OBJECTIVE

To assess the effectiveness, cost and cost-effectiveness of four screening strategies for first-trimester (T1) cytomegalovirus (CMV) primary infection (PI) in pregnant women in France.

METHODS

In a simulated pregnant population of 800 000 (approximate number of pregnancies each year in France), using costs based on the year 2022, we compared four CMV maternal screening strategies: Strategy S1, no systematic screening (current public health recommendations in France); Strategy S2, screening of 25-50% of the pregnant population (current screening practice in France); Strategy S3, universal screening (current medical recommendations in France); Strategy S4, universal screening (as in Strategy S3) in conjunction with valacyclovir in case of T1 PI. Outcomes were total cost, effectiveness (number of congenital infections, number of diagnosed infections) and incremental cost-effectiveness ratio (ICER). Two ICERs were calculated, comparing Strategies S1, S2 and S3 in terms of euros (€) per additional diagnosis, and comparing Strategies S1 and S4 in € per avoided congenital infection.

RESULTS

Compared with Strategy S1, Strategy S3 enabled diagnosis of 536 more infected fetuses and Strategy S4 prevented 375 congenital infections. Strategy S1 was the least expensive strategy (€98.3m total lifetime cost), followed by Strategy S4 (€98.6m), Strategy S2 (€106.0m) and Strategy S3 (€118.9m). In the first analysis, Strategy S2 was dominated and Strategy S3 led to an additional €38 552 per additional in-utero diagnosis, compared with Strategy S1. In the second analysis, Strategy S4 led to an additional €893 per avoided congenital infection compared with Strategy S1, and was cost-saving compared with Strategy S2.

CONCLUSIONS

In France, current screening practice for CMV PI during pregnancy is no longer acceptable in terms of cost-effectiveness because this strategy was dominated by universal screening. Moreover, universal screening in conjunction with valacyclovir treatment would be cost-effective compared with current recommendations and is cost-saving compared with current practice. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

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

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

CONCLUSION

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

TRIAL REGISTRATION

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

WHAT IS NEW

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

Inconsistent Provider Testing Practices for Congenital Cytomegalovirus: Missed Diagnoses and Missed Opportunities

Newborn congenital cytomegalovirus (cCMV) screening programs have been found to increase the rates of early diagnosis and treatment. In North America, newborn cCMV screening programs have not been widely implemented, leaving healthcare providers to rely on clinical suspicion alone to prompt testing. This study sought to examine healthcare providers' cCMV testing practices at a quaternary children's hospital. A retrospective review of the electronic health record was completed for eligible infants over a six-year period. Bivariate calculations and analyses were performed. Between 2014 and 2019, a total of 40,091 infants were cared for at the study institution, of which 178 were tested for cCMV and 10 infants were diagnosed with cCMV. Isolated small-for-gestational age was the most common indication (53/178) to prompt testing. Overall, the cCMV testing rate was 4.5 tests per 1000 infants, with a resulting diagnostic prevalence of 0.2 cases per 1000 infants, which is 15-fold lower than the expected prevalence. Providers relying on clinical suspicion alone are infrequently testing infants for cCMV, resulting in missed diagnoses and missed opportunities for treatment. Systematic cCMV screening practices may improve diagnosis, treatment, and childhood outcomes.

Cytomegalovirus Specific Serological and Molecular Markers in a Series of Pregnant Women With Cytomegalovirus Non Primary Infection

(1) Background: In a period where systematic screening of CMV during pregnancy is still debated, diagnosis of non primary infection (NPI) remains challenging and an obstacle to systematic screening. Our aim is to report kinetics of serological and molecular CMV markers of NPI. (2) Methods: We identified immunocompetent pregnant women with CMV NPI as women known to be seropositive for CMV before pregnancy who gave birth to cCMV infected infants. We performed CMV-IgG, CMV-IgM, CMV-IgG avidity and CMV PCR retrospectively on sequential serum samples collected during pregnancy. (3) Results: We collected 195 serum samples from 53 pregnant women with NPI during pregnancy. For 29/53 (55%) patients, no markers of active infection were observed (stable IgG titers, negative IgM and negative PCR). CMV PCR was positive in at least one serum for 18/53 (34%) patients and median viral load was 46 copies/mL, IQR (21-65). (4) Conclusions: For more than half of patients with confirmed CMV NPI during pregnancy, available diagnostic tools are liable to fail in detecting an active infection. These should therefore not be used and universal neonatal screening for CMV remains the only way to detect all cCMV infections.

Universal Newborn Screening for Congenital Cytomegalovirus Infection - From Infant to Maternal Infection: A Prospective Multicenter Study

INTRODUCTION

Most infants at risk for cytomegalovirus (CMV)-associated sensorineural hearing loss (SNHL) are unrecognized because of the absence of a universal neonatal CMV screening. The search of CMV-DNA by molecular methods in salivary swabs was demonstrated to be a reliable approach. This study describes the results obtained by carrying out a universal screening for congenital CMV (cCMV) infection including all live-born newborns in three Italian sites, as well as the therapeutic interventions and clinical outcome of the CMV-infected neonates. Moreover, CMV maternal infection's characteristics were evaluated.

METHODS

To confirm or exclude cCMV infection, a CMV-DNA-positive result on a first salivary swab was followed by repeated saliva and urine samples collected within 21 days of age. Breast milk samples were also collected. The search of CMV-DNA was performed with a single automated quantitative commercial real-time PCR assay, regardless of the type of samples used.

RESULTS

A total of 3,151 newborns were enrolled; 21 (0.66%) of them were congenitally infected (median saliva viral load at screening, 6.65 [range, 5.03-7.17] log₁₀ IU/ml). Very low/low viral load in screening saliva samples (median value, 1.87 [range, 1.14-2.59] log₁₀ IU/ml) was associated with false-positive results (n = 54; 1.7%). CMV-DNA was detected in almost half of the breast milk samples of mother-infant pairs with a false-positive result, suggesting that contamination from breast milk may not be the only explanation in the study population. cCMV infection confirmation with the search of CMV-DNA in a urine sample proved to be the gold standard strategy, since false-positive results were observed in 4/54 (7.5%) of the repeated saliva samples. Symptomatic cCMV infection was observed in 3/21 (14.3%) infants; notably, one (4.7%) developed moderate unilateral SNHL at 5 months after birth. Finally, two symptomatic cCMV infections were associated with primary maternal infection acquired in the first trimester of gestation; one newborn with severe cCMV symptoms was born to a mother with no CMV checkups in pregnancy.

CONCLUSION

Without universal neonatal CMV screening, some infected infants who develop late neurological sequelae may not be recognized and, consequently, they are not able to benefit early from instrumental and therapeutic interventions to limit and/or treat CMV disease.

Congenital Cytomegalovirus Knowledge, Practices, and Beliefs Among Primary Care Physicians and Newborn Hospitalists

BACKGROUND

Congenital cytomegalovirus (cCMV) affects 1 in every 200 United States infants, at present there are 9 states which mandate newborn cCMV screening. With more infants being diagnosed, more children will need continuing care from providers who are knowledgeable about cCMV.

OBJECTIVES

To examine pediatric provider knowledge, practices, and beliefs around cCMV.

METHODS

Primary care and newborn hospitalist pediatricians (N = 103) from Michigan, who "regularly care for infants" were invited to participate in a survey about their cCMV-related knowledge, clinical practices, and beliefs.

RESULTS

Respondents had low knowledge of typical cCMV presentation and sequelae, with mixed knowledge of screening and testing standards. Most (68%) reported rarely/never screening for cCMV, though 71% strongly agreed/agreed that primary care providers should test for cCMV. Most (90%) strongly agreed/agreed that infants who fail/refer on their newborn hearing screen should be tested for cCMV, yet 81% expressed not being comfortable diagnosing and managing cCMV. Most (72%) felt that cCMV was not sufficiently covered in their medical training; almost all respondents endorsed interest in learning more.

CONCLUSIONS

Primary care and newborn hospitalists in this study expressed mixed knowledge about, infrequent practice of and low comfort with screening and caring for children with cCMV. This may present a prime opportunity for education and clinician support by professional organizations.