A Trial of Hyperimmune Globulin to Prevent Congenital Cytomegalovirus Infection

BACKGROUND

Primary cytomegalovirus (CMV) infection during pregnancy carries a risk of congenital infection and possible severe sequelae. There is no established intervention for preventing congenital CMV infection.

METHODS

In this multicenter, double-blind trial, pregnant women with primary CMV infection diagnosed before 24 weeks' gestation were randomly assigned to receive a monthly infusion of CMV hyperimmune globulin (at a dose of 100 mg per kilogram of body weight) or matching placebo until delivery. The primary outcome was a composite of congenital CMV infection or fetal or neonatal death if CMV testing of the fetus or neonate was not performed.

RESULTS

From 2012 to 2018, a total of 206,082 pregnant women were screened for primary CMV infection before 23 weeks of gestation; of the 712 participants (0.35%) who tested positive, 399 (56%) underwent randomization. The trial was stopped early for futility. Data on the primary outcome were available for 394 participants; a primary outcome event occurred in the fetus or neonate of 46 of 203 women (22.7%) in the group that received hyperimmune globulin and of 37 of 191 women (19.4%) in the placebo group (relative risk, 1.17; 95% confidence interval [CI] 0.80 to 1.72; P = 0.42). Death occurred in 4.9% of fetuses or neonates in the hyperimmune globulin group and in 2.6% in the placebo group (relative risk, 1.88; 95% CI, 0.66 to 5.41), preterm birth occurred in 12.2% and 8.3%, respectively (relative risk, 1.47; 95% CI, 0.81 to 2.67), and birth weight below the 5th percentile occurred in 10.3% and 5.4% (relative risk, 1.92; 95% CI, 0.92 to 3.99). One participant in the hyperimmune globulin group had a severe allergic reaction to the first infusion. Participants who received hyperimmune globulin had a higher incidence of headaches and shaking chills while receiving infusions than participants who received placebo.

CONCLUSIONS

Among pregnant women, administration of CMV hyperimmune globulin starting before 24 weeks' gestation did not result in a lower incidence of a composite of congenital CMV infection or perinatal death than placebo. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Center for Advancing Translational Sciences; ClinicalTrials.gov number, NCT01376778.).

A Fully Protective Congenital CMV Vaccine Requires Neutralizing Antibodies to Viral Pentamer and gB Glycoprotein Complexes but a pp65 T-Cell Response Is Not Necessary

A vaccine against congenital cytomegalovirus infection is a high priority. Guinea pig cytomegalovirus (GPCMV) is the only congenital CMV small animal model. GPCMV encodes essential glycoprotein complexes for virus entry (gB, gH/gL/gO, gM/gN) including a pentamer complex (gH/gL/GP129/GP131/GP133 or PC) for endocytic cell entry. The cohorts for protection against congenital CMV are poorly defined. Neutralizing antibodies to the viral glycoprotein complexes are potentially more important than an immunodominant T-cell response to the pp65 protein. In GPCMV, GP83 (pp65 homolog) is an evasion factor, and the GP83 mutant GPCMV has increased sensitivity to type I interferon. Although GP83 induces a cell-mediated response, a GP83-only-based vaccine strategy has limited efficacy. GPCMV attenuation via GP83 null deletion mutant in glycoprotein PC positive or negative virus was evaluated as live-attenuated vaccine strains (GP83dPC+/PC-). Vaccinated animals induced antibodies to viral glycoprotein complexes, and PC+ vaccinated animals had sterilizing immunity against wtGPCMV challenge. In a pre-conception vaccine (GP83dPC+) study, dams challenged mid-2nd trimester with wtGPCMV had complete protection against congenital CMV infection without detectable virus in pups. An unvaccinated control group had 80% pup transmission rate. Overall, gB and PC antibodies are key for protection against congenital CMV infection, but a response to pp65 is not strictly necessary.

The Placental Response to Guinea Pig Cytomegalovirus Depends Upon the Timing of Maternal Infection

Human cytomegalovirus (HCMV) infects the placenta, and these placental infections can cause fetal injury and/or demise. The timing of maternal HCMV infection during pregnancy is a determinant of fetal outcomes, but how development affects the placenta's susceptibility to infection, the likelihood of placental injury post-infection, and the frequency of transplacental HCMV transmission remains unclear. In this study, guinea pig cytomegalovirus (GPCMV) was used to model primary maternal infection and compare the effects of infection at two different times on the placenta. When guinea pigs were infected with GPCMV at either 21- or 35-days gestation (dGA), maternal and placental viral loads, as determined by droplet digital PCR, were not significantly affected by the timing of maternal infection. However, when the transcriptomes of gestational age-matched GPCMV-infected and control placentas were compared, significant infection-associated changes in gene expression were only observed after maternal infection at 35 dGA. Notably, transcripts associated with immune activation (e.g. Cxcl10, Ido1, Tgtp1, and Tlr8) were upregulated in the infected placenta. A GPCMV-specific in situ hybridization assay detected rare infected cells in the main placenta after maternal infection at either time, and maternal infection at 35 dGA also caused large areas of GPCMV-infected cells in the junctional zone. As GPCMV infection after mid-gestation is known to cause high rates of stillbirth and/or fetal growth restriction, our results suggest that the placenta becomes sensitized to infection-associated injury late in gestation, conferring an increased risk of adverse pregnancy outcomes after cytomegalovirus infection.

Valacyclovir for prevention and treatment of fetal CMV infection: inclusion in the Law 648/96 list and launch of the Italian multicentre observational prospective study "MEGAL-ITALI"

Not available.

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."

The Yield of Targeted Examination for the Detection of Symptomatic Congenital Cytomegalovirus Infection

BACKGROUND

The incidence of congenital cytomegalovirus (CMV) infection in Israel is 0.7%. Only 10-15% are symptomatic. Valganciclovir has been shown to improve hearing and neurodevelopmental outcomes in neonates with symptomatic congenital CMV infection. Targeted examination of infants who fail routine neonatal hearing screening or have clinical or laboratory findings suggestive of symptomatic congenital CMV infection may be a cost-effective approach.

OBJECTIVES

To assess the possibility of targeted examination for the detection of newborns with symptomatic congenital CMV infection.

METHODS

A prospective observational study was conducted in 2014-2015 at two medical centers in northern Israel. Included were all newborns who were tested in the first 3 days of life by polymerase chain reaction (PCR) for urine CMV DNA (n=692), either for failure the hearing screening (n=539, 78%), clinical or laboratory findings suggestive of symptomatic congenital CMV infection, or primary CMV infection during pregnancy (n=153, 22%).

RESULTS

During the study period 15,433 newborns were born. The predicted rate of infection was 10-15% (symptomatic) of 0.7% of newborns, namely 0.07-0.105% or 10-15 infants. In fact, 15 infants (0.11%, 95% confidence interval 0.066-0.175) were diagnosed with symptomatic congenital CMV infection, 2/539 (0.37%) in the failed hearing group and 13/153 (8%) in the clinical/laboratory findings group. The incidence of symptomatic congenital CMV infection was within the predicted range.

CONCLUSIONS

Targeted examination of only 4.5% (n=692) of newborns detected the predicted number of infants with symptomatic congenital CMV infection in whom valganciclovir therapy is recommended.

Outcome of fetuses with congenital cytomegalovirus infection and normal ultrasound at diagnosis: systematic review and meta-analysis

OBJECTIVE

To report the outcome of fetuses with congenital cytomegalovirus (CMV) infection and normal ultrasound at the time of diagnosis, and to evaluate the rate of an additional anomaly detected only on magnetic resonance imaging (MRI).

METHODS

Medline, EMBASE, CINAHL and Cochrane databases were searched for studies reporting on the outcome of fetuses with congenital CMV infection. Inclusion criteria were fetuses with confirmed CMV infection and normal ultrasound assessment at the time of the initial evaluation. The outcomes observed were an anomaly detected on a follow-up ultrasound scan, an anomaly detected on prenatal MRI but missed on ultrasound, an anomaly detected on postnatal assessment but missed prenatally, perinatal mortality, symptomatic infection at birth, neurodevelopmental outcome and hearing and visual deficits. Neurodevelopmental outcome was assessed only in cases of isolated CMV infection confirmed at birth. Subgroup analysis was performed according to the trimester in which maternal infection occurred. Random-effects meta-analysis of proportions was used to analyze the data.

RESULTS

Twenty-six studies were included, comprising 2603 fetuses with congenital CMV infection, of which 1178 (45.3%) had normal ultrasound at the time of diagnosis and were included in the analysis. The overall rate of an associated central nervous system (CNS) anomaly detected on a follow-up ultrasound scan was 4.4% (95% CI, 1.4-8.8%) (32/523; 15 studies), while the rates of those detected exclusively on prenatal MRI or on postnatal imaging were 5.8% (95% CI, 1.9-11.5%) (19/357; 11 studies) and 3.2% (95% CI, 0.3-9.0%) (50/660; 17 studies), respectively. The rate of an associated extra-CNS anomaly detected on a follow-up ultrasound scan was 2.9% (95% CI, 0.8-6.3%) (19/523; 15 studies), while the rates of those detected exclusively on MRI or on postnatal imaging were 0% (95% CI, 0.0-1.7%) (0/357; 11 studies) and 0.9% (95% CI, 0.3-1.8%) (4/660; 17 studies), respectively. Intrauterine death and perinatal death each occurred in 0.7% (95% CI, 0.3-1.4%) (2/824; 23 studies) of cases. In cases without an associated anomaly detected pre- or postnatally, symptomatic infection was found in 1.5% (95% CI, 0.7-2.7%) (6/548; 19 studies) of infants, the overall rate of a neurodevelopmental anomaly was 3.1% (95% CI, 1.6-5.1%) (16/550; 19 studies), and hearing problems affected 6.5% (95% CI, 3.8-10.0%) (36/550; 19 studies) of children. Subanalyses according to the trimester in which maternal infection occurred were affected by the very small number of included cases and lack of comparison of the observed outcomes in the original studies. Compared with fetuses infected in the second or third trimester, those infected in the first trimester had a relatively higher risk of having an additional anomaly detected on follow-up ultrasound or MRI, abnormal neurodevelopmental outcome and hearing problems.

CONCLUSIONS

In fetuses with congenital CMV infection in which no anomalies are detected on prenatal ultrasound or MRI, the risk of adverse postnatal outcome is lower than that reported previously in the published literature when not considering the role of antenatal imaging assessment. The results from this review also highlight the potential role of MRI, even in fetuses with no anomalies detected on ultrasound, as an anomaly can be detected exclusively on MRI in about 6% of cases. The findings from this study could enhance prenatal counseling of pregnancies with congenital CMV infection with normal prenatal imaging. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Pregnant women's knowledge and behaviour to prevent cytomegalovirus infection: an observational study

OBJECTIVES

Congenital cytomegalovirus (cCMV) infection can negatively affect pregnancy outcomes, but may be prevented by simple precautions. Literature suggests that gynaecologists do not always adequately inform about preventive behaviour and most pregnant women have a low-level knowledge regarding cCMV infection. The aim of this study is to evaluate knowledge and risk behaviours related to cCMV infection in an unselected group of pregnant women.

METHODS

An institutional based cross-sectional study was conducted in three Maternal and Fetal Divisions in Rome between November and February 2019 on 296 pregnant women, their knowledge on cCMV was measured using six cytomegalovirus (CMV) related questions.

RESULTS

Out of the 296 respondents, 59.1% had heard, read or seen information about cCMV infection. Regarding the way of transmission, 96/296 (32.4%) correctly recognize children as a potential source of the infection but only 25/296 (8.44%) knew all prevention practices, 28/296 (9.5%) of women reported that they have never performed cCMV test during pregnancy.

CONCLUSIONS

The results of this survey show that knowledge on cCMV infection among pregnant women is poor. This highlights the need to improve counselling on all preventive practices for cCMV infection during perinatal care consultation.

Prenatal cytomegalovirus, rubella, and Zika virus infections associated with developmental disabilities: past, present, and future

Prenatal infections have long been recognized as important, preventable causes of developmental disabilities. The list of pathogens that are recognized to have deleterious effects on fetal brain development continues to grow, most recently with the association between Zika virus (ZIKV) and microcephaly. To answer clinical questions in real time about the impact of a novel infection on developmental disabilities, an historical framework is key. The lessons learned from three historically important pathogens: rubella, cytomegalovirus, and ZIKV, and how these lessons are useful to approach emerging congenital infections are discussed in this review. Congenital infections are preventable causes of developmental disabilities and several public health approaches may be used to prevent prenatal infection. When they cannot be prevented, the sequelae of prenatal infection may be treatable. WHAT THIS PAPER ADDS: The list of prenatal infections associated with developmental disabilities continues to increase. Lessons learned from rubella, cytomegalovirus, and Zika virus have implications for new pathogens. Severity of illness in the mother does not correlate with severity of sequelae in the infant.

Late-onset Hearing Loss From Congenital Cytomegalovirus Infection After Newborn Period in a Highly Immune Population in China

After following 141 children with likely asymptomatic congenital cytomegalovirus infection in a highly immune population in China, four children (2.8%) were found to have late-onset hearing loss. No maternal or childhood factors, except higher saliva cytomegalovirus viral load at birth (P = 0.03), were associated with increased risk of developing a hearing loss.

Accuracy of prenatal ultrasound screening to identify fetuses infected by cytomegalovirus which will develop severe long-term sequelae

OBJECTIVES

To compare the ability of detailed routine ultrasound examination, performed without knowledge of maternal serology and fetal status, with that of targeted prenatal imaging performed in prenatal diagnostic units in cases of known fetal infection to identify cytomegalovirus (CMV)-infected fetuses that will develop long-term sequelae.

METHODS

All prenatal imaging reports were collected for 255 children with congenital CMV in a registered cohort between 2013 and 2017 (NCT01923636). All women had undergone detailed routine fetal ultrasound examination at 20-24 and 30-34 weeks as part of routine antenatal care. All cases of known fetal CMV infection had also undergone targeted prenatal ultrasound examination. Postnatal structured follow-up for up to 48 months of age involved clinical, audiological and neurological assessment, including Brunet-Lezine scoring. Long-term sequelae (> 12 months) were considered to be mild in cases with isolated unilateral hearing loss and/or vestibular disorders, and severe in cases with bilateral hearing loss and/or neurological sequelae. All imaging reports were analyzed retrospectively with the knowledge of congenital CMV infection, searching for reference to findings that were, or could have been, related to fetal infection. Findings were analyzed in relation to whether the cases were diagnosed with CMV in utero or only postnatally.

RESULTS

There were 237 children with complete follow-up data (> 12 months), for a median of 24 (range, 12-48) months. Of these, 30% (71/237) were diagnosed with CMV prenatally and 70% (166/237) were diagnosed within 3 weeks after birth. 72.5% (29/40) of children with long-term sequelae, including 74% (14/19) with severe long-term sequelae, were not identified in the prenatal period. Among those diagnosed prenatally, the sensitivity of prenatal imaging for predicting long-term sequelae and severe long-term sequelae was 91% and 100%, respectively, while, in the group diagnosed only postnatally, non-specific infection-related ultrasound findings had been reported without raising suspicion in 48% of cases with long-term sequelae and 64% of those with severe long-term sequelae.

CONCLUSIONS

Routine detailed ultrasound examination in pregnancy is not an appropriate screening tool for congenital CMV infection that leads to long-term sequelae, in contrast with the high performance of targeted prenatal imaging in known cases of fetal infection. The non-specific nature of ultrasound features of CMV and their evolution, and a lack of awareness of caregivers about congenital CMV, are likely explanations. Awareness of the sonologist regarding congenital CMV and knowledge of the maternal serological status in the first trimester seem key to the performance of prenatal ultrasound. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Mixed cytomegalovirus genotypes in HIV-positive mothers show compartmentalization and distinct patterns of transmission to infants

Cytomegalovirus (CMV) is the commonest cause of congenital infection and particularly so among infants born to HIV-infected women. Studies of congenital CMV infection (cCMVi) pathogenesis are complicated by the presence of multiple infecting maternal CMV strains, especially in HIV-positive women, and the large, recombinant CMV genome. Using newly developed tools to reconstruct CMV haplotypes, we demonstrate anatomic CMV compartmentalization in five HIV-infected mothers and identify the possibility of congenitally transmitted genotypes in three of their infants. A single CMV strain was transmitted in each congenitally infected case, and all were closely related to those that predominate in the cognate maternal cervix. Compared to non-transmitted strains, these congenitally transmitted CMV strains showed statistically significant similarities in 19 genes associated with tissue tropism and immunomodulation. In all infants, incident superinfections with distinct strains from breast milk were captured during follow-up. The results represent potentially important new insights into the virologic determinants of early CMV infection.

Congenital cytomegalovirus infections in Poland - a national hospital register-based study

INTRODUCTION AND OBJECTIVE

Congenital cytomegalovirus (cCMV) infections are common worldwide. CCMV infected newborns are mostly asymptomatic at birth. However, cCMV remains the major infectious cause of congenital abnormalities in the developing foetus and newborns. The aim of the study was to provide recent data on cCMV in Poland.

MATERIAL AND METHODS

Aretrospective, population-based study was conducted using data from hospital discharge records of patients hospitalized from 2009-2018. CCMV incidence rates were estimated on the basis of data taken from a Polish hospital morbidity study, carried out by the National Institute of Public Health.

RESULTS

The study group consisted of 1,916 hospitalized patients with the first-time diagnosis of cCMV. Among them, 52% were patients up to 30 days of age. The median age was 28 days. The average annual incidence of cCMV was 48 per 100,000 live births (95% CI 23.5-73.4). A significantly higher cCMV incidence rate was observed in patients from more urban than rural regions of Poland (55 per 100,000 vs 39 per 100,000; P<0.001). In the study period, 9 hospital deaths (0.5 % of all patients) were reported. The coexistence of nervous system diseases was observed in 26% of cases and hearing loss in 6% of cases.

CONCLUSIONS

The significantly more cCMV cases were observed in patients from more urban than rural regions of Poland may suggest the presence of territorial factors related to the cCMV incidence in Poland. The relatively high percentage of newborns with hearing loss or neurologic diseases may require activities aimed at reducing the cCMV incidence. The epidemiological data presented may be useful for comparisons with other geographical regions.

Of "Cotton Balls" and "Owl's eyes"

Report of a 3-month old girl child who died due to multi-systemic infection of cytomegalovirus (CMV) involving the lungs, liver and kidneys along with pneumocystis jiroveci pneumonia (PJP). The mother of the child tested positive for CMV IgG and HIV with a very low CD4 count (160/ μl). Co-infection of cytomegalovirus and pneumocystis jiroveci always occurs in the setting of immunocompromise. Congenital CMV infection is transmitted through the placenta, especially during the first trimester and causes severe multi-systemic disease whereas perinatal infection is acquired during childbirth/ breastfeeding where the babies have maternal protective antibodies leading to much milder or asymptomatic infection. PJP is more common in infancy and presents as hypoxic pneumonia. CMV causes cyto-nucleomegaly and classic "owl's eye" inclusions on histology while PJP presents with characteristic fluffy "cotton ball" alveolar exudates.

Association Between Congenital Cytomegalovirus and the Prevalence at Birth of Microcephaly in the United States

Importance

Congenital cytomegalovirus (cCMV) has received far less clinical and public health attention as a teratogenic infection than the Zika virus epidemic. However, cCMV may be responsible for a large fraction of microcephaly cases in the United States.

Objective

To evaluate the association between cCMV and the prevalence at birth of microcephaly in the United States.

Design, Setting, and Participants

This population-based cohort study included pregnant women and their newborns identified in 2 insurance claims databases from the United States: Medicaid Analytic eXtract (January 1, 2000, to December 31, 2013) and IBM Research MarketScan, a database for employer-sponsored private health insurance (January 1, 2011, to September 30, 2015). All pregnancies that resulted in live births in women with full health benefits were included. Analysis began June 2016 and ended May 2020.

Exposures

Congenital cytomegalovirus infection documented in inpatient or outpatient newborn claims records.

Main Outcomes and Measures

The primary outcome was microcephaly at birth documented in inpatient or outpatient newborn and/or maternal claims records. Cases with chromosomal abnormalities or neural tube defects were excluded. The association between cCMV and microcephaly was estimated in the pooled cohort using prevalence ratios (PRs) and 95% CIs.

Results

In the pooled cohort of 2 338 580 pregnancies (2 075 410 pregnancies [88.7%] were among women younger than 35 years), 336 infants (0.014%) had a cCMV diagnosis. The prevalence of microcephaly among newborns with and without a cCMV diagnosis was 655 and 2.8 per 10 000 live births, respectively (PR, 232; 95% CI, 154-350). After restricting to CMV-tested newborns (572 [0.024%]) to correct for preferential testing of infants with microcephaly, the PR was 15 (95% CI, 5.2-41). However, this PR is biased if other cCMV-related outcomes (eg, hearing loss) trigger testing because cCMV prevalence in tested infants, with ([46%]) or without microcephaly (22 of 559 [3.9%]), would overestimate that in the source population. Therefore, the prevalence of cCMV in overall infants with microcephaly (22 of 669 [3.2%]) was compared with that from an external unbiased sample of US infants screened at birth (449 of 100 332 [0.45%]) to estimate a PR of 7.4 (95% CI, 4.8-11.5) as a conservative lower bound.

Conclusions and Relevance

Congenital cytomegalovirus infection increases the prevalence of microcephaly at birth by at least 7-fold. Prevention of CMV infection during pregnancy might substantially reduce the number of newborns with microcephaly and other cCMV-related outcomes in the United States.

Estimated Cost-effectiveness of Newborn Screening for Congenital Cytomegalovirus Infection in China Using a Markov Model

IMPORTANCE

Congenital cytomegalovirus infection (cCMVi) is one of the most common infections associated with childhood hearing loss. Prevention and mitigation of cCMVi-related hearing loss will require an increase in newborn screening, which is not yet available in China.

OBJECTIVE

To estimate the cost-effectiveness of newborn screening strategies for cCMVi from the perspective of the Chinese health care system.

DESIGN, SETTING, AND PARTICIPANTS

A decision tree for a simulated cohort population of 15 000 000 live births was developed to compare the costs and health effects of 3 mutually exclusive interventions: (1) no screening, (2) targeted screening using CMV polymerase chain reaction assay for newborns who fail a universal hearing screening, and (3) universal screening for CMV among all newborns. Markov diagrams were used to evaluate the lifetime horizon (76 years).

MAIN OUTCOMES AND MEASURES

Cost, hearing-related health outcomes, and incremental cost-effectiveness ratios (ICERs) were estimated based on a direct medical costs perspective. Costs and ICERs were reported in 2018 US dollars.

RESULTS

Incidence of cCMVi among newborns was reported to be approximately 0.7% in China. Targeted screening was less costly but also less effective than universal screening, identifying 41% of cases needing antiviral treatment and preventing nearly half of less severe or profound hearing loss. To avoid 1 CMV-related severe or profound hearing loss, 13 and 16 newborns need to be treated by targeted and universal screening, respectively. The ICERs of targeted and universal screening vs no screening were $79 and $2087 per quality-adjusted life-year gained, respectively, at the discounted rate of 3.5%. Both screening options were cost-effective for the Chinese health care system based on the willingness-to-pay threshold of 3 × gross domestic product per capita. The sensitivity analysis showed that the prevalence of cCMVi, as well as diagnosis and treatment costs, were key factors that may be associated with decision-making.

CONCLUSIONS AND RELEVANCE

To achieve cost-effectiveness and best health outcomes, universal screening could be considered for the Chinese population. While the results are specific to China, the model may easily be adapted for other countries.

Timing of primary maternal cytomegalovirus infection and rates of vertical transmission and fetal consequences

OBJECTIVE

Cytomegalovirus infection is the most frequent congenital infection and a major cause of long-term neurologic morbidity. The aim of this meta-analysis was to calculate the pooled rates of vertical transmission and fetal impairments according to the timing of primary maternal infection.

DATA SOURCES

From inception to January 2020, MEDLINE, Scopus, Cochrane Library, and gray literature sources were used to search for related studies.

STUDY ELIGIBILITY CRITERIA

Cohort and observational studies reporting the timing of maternal cytomegalovirus infections and rate of vertical transmission or fetal impairments were included. The primary outcomes were vertical transmission and fetal insult, defined as either prenatal findings from the central nervous system leading to termination of pregnancy or the presence of neurologic symptoms at birth. The secondary outcomes included sensorineural hearing loss or neurodevelopmental delay at follow-up and prenatal central nervous system ultrasonography findings.

STUDY APPRAISAL AND SYNTHESIS METHODS

The pooled rates of the outcomes of interest with their 95% confidence intervals (CI) were calculated for primary maternal infection at the preconception period, periconception period, first trimester, second trimester, and third trimester.

RESULTS

A total of 17 studies were included. The pooled rates of vertical transmission (10 studies, 2942 fetuses) at the preconception period, periconception period, first trimester, second trimester, and third trimester were 5.5% (95% CI, 0.1-10.8), 21.0% (95% CI, 8.4-33.6), 36.8% (95% CI, 31.9-41.6), 40.3% (95% CI, 35.5-45.1), and 66.2% (95% CI, 58.2-74.1), respectively. The pooled rates of fetal insult in case of transmission (10 studies, 796 fetuses) were 28.8% (95% CI, 2.4-55.1), 19.3% (95% CI, 12.2-26.4), 0.9% (95% CI, 0-2.4%), and 0.4% (95% CI, 0-1.5), for maternal infection at the periconception period, first trimester, second trimester, and third trimester, respectively. The pooled rates of sensorineural hearing loss for maternal infection at the first, second, and third trimester were 22.8% (95% CI, 15.4-30.2), 0.1% (95% CI, 0-0.8), and 0% (95% CI, 0-0.1), respectively.

CONCLUSION

Vertical transmission after maternal primary cytomegalovirus infection increases with advancing pregnancy, starting from the preconception period. However, severe fetal impairments are rare after infection in the first trimester of pregnancy.

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.

Cytomegalovirus infection during pregnancy: state of the science

Cytomegalovirus is the most common congenital infection, affecting 0.5-2% of all live births and the main nongenetic cause of congenital sensorineural hearing loss and neurological damage. Congenital cytomegalovirus can follow maternal primary infection or nonprimary infection. Sensorineurological morbidity is confined to the first trimester with up to 40-50% of infected neonates developing sequelae after first-trimester primary infection. Serological testing before 14 weeks is critical to identify primary infection within 3 months around conception but is not informative in women already immune before pregnancy. In Europe and the United States, primary infection in the first trimester are mainly seen in young parous women with a previous child younger than 3 years. Congenital cytomegalovirus should be evoked on prenatal ultrasound when the fetus is small for gestation and shows echogenic bowel, effusions, or any cerebral anomaly. Although the sensitivity of routine ultrasound in predicting neonatal symptoms is around 25%, serial targeted ultrasound and magnetic resonance imaging of known infected fetuses show greater than 95% sensitivity for brain anomalies. Fetal diagnosis is done by amniocentesis from 17 weeks. Prevention consists of both parents avoiding contact with body fluids from infected individuals, especially toddlers, from before conception until 14 weeks. Candidate vaccines failed to provide more than 75% protection for >2 years in preventing cytomegalovirus infection. Medical therapies such as cytomegalovirus hyperimmune globulins aim to reduce the risk of vertical transmission but 2 randomized controlled trials have not found any benefit. Valaciclovir given from the diagnosis of primary infection up to amniocentesis decreased vertical transmission rates from 29.8% to 11.1% in the treatment group in a randomized controlled trial of 90 pregnant women. In a phase II open-label trial, oral valaciclovir (8 g/d) given to pregnant women with a mildly symptomatic fetus was associated with a higher chance of delivering an asymptomatic neonate (82%), compared with an untreated historical cohort (43%). Valganciclovir given to symptomatic neonates is likely to improve hearing and neurological symptoms, the extent of which and the duration of treatment are still debated. In conclusion, congenital cytomegalovirus infection is a public health challenge. In view of recent knowledge on diagnosis and pre- and postnatal management, health care providers should reevaluate screening programs in early pregnancy and at birth.

An observational study to assess Italian obstetrics providers' knowledge about preventive practices and diagnosis of congenital cytomegalovirus

OBJECTIVES

Congenital cytomegalovirus (cCMV) infection can be easily prevented by hygienic measures. Up to date the majority of the studies in literature highlighted a reduction in cCMV antenatal counseling and its prevention. Our purpose was to evaluate obstetrics providers' knowledge about cCMV infection, management and the behavioral practices to avoid it.

METHODS

This is a cross-sectional survey carried out in Umberto I Hospital, "Sapienza" University of Rome between November 2019 and January 2020. We recruited 148 specialists and residents in Obstetrics and Gynecology through online anonymous multiple-choice 13-questions, 10 min-survey comparing responses between the two groups.

RESULTS

A total of 94.6% of all participants said they always prescribe cytomegalovirus (CMV) serum screening: 73.6% of them regularly counsel about preventive practices, with specialists recording higher percentages (85.4 vs. 65.1%, p<0.005). We identified a good knowledge about the diagnostic pathway, but only 58.1% of our population knows the correct time of late amniocentesis. 12.2% of providers do not consider magnetic resonance (MRI) as a complementary exam.

CONCLUSIONS

Prevention of maternal seroconversion is crucial: even if our data show an acceptable knowledge about antenatal counseling, we encourage clinicians to firmly inform and educate women about behavioral measures.

Convalescent Immunity to Guinea Pig Cytomegalovirus Induces Limited Cross Strain Protection against Re-Infection but High-Level Protection against Congenital Disease

The guinea pig is the only small animal model for congenital cytomegalovirus (cCMV) but requires guinea pig cytomegalovirus (GPCMV). Current GPCMV research utilizes prototype strain 22122, which limits the translational impact of GPCMV as numerous human CMV strains exist and cCMV is possible in the setting of re-infection. A novel strain of GPCMV (TAMYC) exhibited differences to 22122 in various glycoproteins with GP74 (gO homolog) the most variable (25% difference). Antibody ELISAs for TAMYC-convalescent animals evoked similar immune response to viral glycoprotein complexes (gB, gH/gL, gM/gN, pentamer) and cell-mediated response to pp65 homolog (GP83). Convalescent sera from TAMYC-infected animals neutralized GPCMV infection on fibroblasts but was less effective on epithelial cells. TAMYC-convalescent animals were not protected from dissemination of heterogenous virus challenge (22122). However, in a cCMV protection study, TAMYC-convalescent animals challenged mid-pregnancy (22122) exhibited high-level protection against cCMV compared to seronegative animals with pup transmission reduced from 80% (control) to 12%. Overall, pre-existing immunity in guinea pigs provides limited ability to prevent GPCMV re-infection by a different viral strain but provides a high level of protection against cCMV in heterogenous strain challenge. This level of cross protection against cCMV should be a prerequisite of any CMV vaccine.

Onset of valganciclovir resistance in two infants with congenital cytomegalovirus infection

Ganciclovir and its prodrug valganciclovir are elective treatments for cCMV. Neonates with important symptoms undergo 6 months of therapy to ameliorate/prevent symptoms and late sequelae, but evidence of resistance is emerging. Over the last 5 years, we took care of 59 cCMV infants and experienced two cases of resistance among nine cCMV infants receiving long-term valganciclovir therapy. In the first case, valganciclovir therapy was prolonged beyond 6 months due to severity of symptoms, control of viral load, and absence of adverse events. Resistance was detected in the 8th month of therapy. In the second case, after a significant reduction following valganciclovir administration and no adverse events, CMV viral load suddenly increased in the 6th month of therapy due to resistance. Both events were associated with UL97 gene mutation. The cCMV infants, affected by severe symptoms, remained in a steady state during treatment, and their later neurological development was coherent with initial seriousness of diagnosis. Prolonged therapeutic exposure may therefore be a risk for resistance, suggesting that constant dosage/weight adjustments, monthly surveillance of viral load, and therapeutic drug monitoring could be proposed to monitor resistance onset and optimize the therapy regime. The risk-benefit ratio for long-term therapy, including the possibility of resistance onset, alongside SNHL and neurodevelopmental improvement, should also be evaluated.

A cross-sectional study exploring disease characteristics and phylogenetic nature of human cytomegalovirus among infected neonates with congenital nephrotic syndrome

BACKGROUND

Congenital nephrotic syndrome (CNS) is a rare but serious condition which affects neonates and is caused by monogenic defects of glomerular structural proteins or congenital viral infections. Several reports have established a causal relationship between human cytomegalovirus (HCMV) intrauterine infection and CNS, but thorough study assessing parameters has not yet been done.

METHODS

This study aimed to ascertain significant demographic, biochemical, serological, inflammatory and etiological parameters with 12 months follow-up to clinically identify and monitor neonates with HCMV-associated CNS and sought to decipher the phylogenetic nature of infecting strains. Differences between four patient groups (neonates < 4 weeks old) with or without CNS and HCMV infection were compared by unpaired t testing and one-way analysis of variance (ANOVA). Linear regression was performed to assess statistical significance among individual groups. Maximum-likelihood-based phylogenetic analysis was performed with HCMV gH gene sequences to compare clinically isolated and referenced NCBI strains. This was further supported by analysis of effective number of codons (ENc), codon adaptation index (CAI) and mRNA structural variation.

RESULTS

Patients with HCMV-associated CNS were found to have significant variations in many studied parameters compared with controls. The majority of clinical strains formed a separate phylogenetic cluster defining them as somewhat distinct from standard reference strains, which was supported by the other analyses.

CONCLUSION

This study defined parameters for monitoring cases of HCMV-associated CNS, which suggest the possible existence of a selection force acting and rendering these HCMV strains able to infect selective host tissues and cause specific disease types.

Middle Ear Effusion in Children With Congenital Cytomegalovirus Infection

BACKGROUND

Sensorineural hearing loss (SNHL) is well described in children with congenital cytomegalovirus (CMV) infection, but limited data are available on middle ear effusion (MEE) occurrence in this population. We assessed the prevalence of MEE and the degree of transient hearing change associated with MEE among children with congenital CMV infection.

METHODS

Children with congenital CMV infection enrolled in a longitudinal study received hearing and tympanometric testing during scheduled follow-up visits annually up to 6 years of age. We used a generalized linear mixed-effect logistic regression model to compare the odds of MEE, defined as type B tympanogram (normal ear canal volume with little tympanic membrane movement) among patients categorized as symptomatic or asymptomatic based on the presence of congenital CMV-associated signs in the newborn period.

RESULTS

Forty-four (61%) of 72 symptomatic and 24 (28%) of 87 asymptomatic patients had ≥1 visit with MEE. After controlling for the number of visits, symptomatic patients had significantly higher odds of MEE (odds ratio: 2.09; 95% confidence interval: 1.39-3.14) than asymptomatic patients. Transient hearing decrease associated with a type B tympanogram ranged from 10 to 40 dB, as measured by audiometric air-bone gap in 11 patients.

CONCLUSIONS

Among children with congenital CMV, MEE can result in transient hearing decrease, which can reduce the efficacy of a hearing aid in those with SNHL. It is warranted that children with congenital CMV infection and SNHL receive routine audiologic and tympanometric testing to better manage hearing aid amplification levels.