Congenital cytomegalovirus infection in a northern Italian region. NEOCMV Group

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.

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

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

Ophthalmological impairment in patients with congenital cytomegalovirus infection

Background

Congenital cytomegalovirus (cCMV) infection is a frequent cause of neurosensory impairment. Ocular abnormalities and visual impairment have been reported in a high percentage of symptomatic infants, whereas they are considered uncommon in asymptomatic ones. The paucity of data has made difficult to reach clear recommendations on the ophthalmological follow-up that should be provided.

Methods

250 patients with cCMV infection (123 symptomatic) were enrolled and underwent a series of age-appropriate ophthalmologic, audiologic, and neurodevelopmental examinations from 2002 to 2022.

Results

Funduscopic abnormalities were identified at onset in 16/123 (13%) symptomatic infants and in none of the asymptomatic ones (p < 0.001). Chorioretinitis lesions were the most common findings (10/16 cases), while the others showed retinal scars. Lesions were bilateral in 4 patients. No later onset retinal lesions were detected, nor in symptomatic or in asymptomatic children. Five of the 16 (31.5%) symptomatic and none of the asymptomatic subjects showed visual impairment al the last evaluation (p < 0.001). All patients with unfavorable outcome had also neurological impairment. Among symptomatic patients, ocular lesions were associated with central nervous system (CNS) pathological findings in prenatal ultrasonography (p 0.05) and with clinical signs of CNS involvement at birth (p 0.046). No correlation was found with the type of maternal infection and pathological neuroimaging.

Conclusions

Chorioretinal lesions are a fairly common finding at birth in neonates with symptomatic cCMV, often associated with long term visual impairment. Asymptomatic infants do not show ophthalmological abnormalities in the short or long term. This information is relevant both to parental counseling and to cost-effective patient management.

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

IMPORTANCE

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

OBJECTIVES

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION AND SYNTHESIS

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

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.

Is Polymerase Chain Reaction in Neonatal Dried Blood Spots Reliable for the Diagnosis of Congenital Cytomegalovirus Infection?

BACKGROUND

Detection of cytomegalovirus (CMV) DNA by real-time polymerase chain reaction (rt-PCR) in dried blood spots (DBSs) collected for newborn screening has been assessed for retrospective diagnosis of congenital CMV (cCMV) infection, with variable results (sensitivities ranging from 34% to 100%). We aimed to assess the accuracy of this technique in Spain in a large patient series.

METHODS

Ambispective, multicenter study including patients with confirmed cCMV from the Spanish Registry of cCMV patients. cCMV was established on the presence of CMV DNA in any body fluid, by positive culture findings or by molecular techniques during the first 2 weeks of life. Children in whom cCMV had been excluded were used as negative controls. Neonatal DBS samples were collected from both groups. The presence of CMV DNA was assessed by rt-PCR (RealStar CMV, Altona, Germany) in a central laboratory.

RESULTS

One-hundred three patients and 81 controls from 10 hospitals were included. The performance of CMV DNA determination in DBS for the diagnosis of cCMV was as follows (95% confidence interval): sensitivity 0.56 (0.47-0.65), specificity 0.98 (0.91-0.99), positive likelihood ratio 22.81 (5.74-90.58) and negative likelihood ratio 0.45 (0.36-0.56). Sensitivity increased with the birth viral load (bVL) log category. In cCMV patients, lower bVL was the single variable associated with a negative DBS rt-PCR result (P = 0.017).

CONCLUSIONS

The sensitivity of CMV rt-PCR in DBS in our series was low and correlated with the bVL. Thus, a negative DBS result would not rule out cCMV infection, especially in patients with a low viremia level at birth.

Recognition, treatment, and sequelae of congenital cytomegalovirus in Australia: An observational study

BACKGROUND AND OBJECTIVES

Australian national surveillance data was used to assess recognition, sequelae, and antiviral therapy for congenital cytomegalovirus (CMV) cases.

STUDY DESIGN

Data from congenital CMV cases reported through the Australian Paediatric Surveillance Unit born January 1999 to December 2016 were described and Chi-square tests used to characterise trends and associations in case reporting, maternal CMV serology testing, and antiviral therapy. Descriptive analyses for hearing loss and developmental delay were reported for cases born ≥2004, following introduction of universal neonatal hearing screening.

RESULTS

There were 302 congenital CMV cases (214 symptomatic, 88 asymptomatic). Congenital CMV was suspected in 70.6% by 30 days of age, with no differences across birth cohorts. Maternal CMV serology testing was associated with maternal illness during pregnancy but not birth cohort. There was increasing antiviral use for symptomatic cases, being used in 14% born 1999-2004, 19.6% born 2005-2010, and 44.4% born 2011-2016 (p < 0.001). For those born ≥2004, hearing loss was reported in 42.1% of symptomatic and 26.6% of asymptomatic cases; while developmental delay was reported in 16.9% of symptomatic and 1.3% of asymptomatic cases.

CONCLUSION

There appears to be under-reporting and under-recognition of congenital CMV despite increasing use of antiviral therapy. Universal newborn CMV screening should be considered to facilitate follow-up of affected children and targeted linkage into hearing and developmental services, and to provide population-level infant CMV epidemiology to support research and evaluation of antiviral and adjunctive therapies.

Hearing and neurodevelopmental outcomes for children with asymptomatic congenital cytomegalovirus infection: A systematic review

INTRODUCTION

Congenital CMV is one of the commonest congenital infections and a recognised cause of sensorineural hearing loss and neurodevelopmental impairment. Ninety percent are clinically inapparent at birth but are reported to be at risk of developing such abnormalities throughout childhood, the extent of which requires further elucidation.

METHODS

A systematic literature review was conducted using Medline and Embase databases, manual citation review, and personal libraries for articles reporting primary data on hearing and neurodevelopmental outcomes for children with asymptomatic congenital CMV. PROSPERO registration number CRD42015025407.

RESULTS

Thirty-seven of 480 articles identified between 1969 and 2016 met the eligibility criteria. Twenty-nine of these contributed primary data on hearing outcomes and 20 on neurodevelopmental outcomes (12 of the 37 studies contributed data on both). Cumulative incidence of sensorineural hearing loss with follow-up to at least 5 years was 7% to 11%, which is more than healthy controls but less than children with symptomatic congenital CMV (34%-41%). The onset, course, and severity of hearing loss was variable with no reliable virological prognostic marker. In comparison to controls, children with asymptomatic congenital CMV did not perform worse than controls in neurodevelopmental assessments and performed better than children with symptomatic congenital CMV.

CONCLUSIONS

Studies show children with asymptomatic congenital CMV are at increased risk of developing hearing loss but perform equally well on neurodevelopmental assessments when compared with healthy controls. There is no reliable virological marker to determine which infants will develop sequelae. Regular follow-up until school entry is supported by the literature.

Polymorphisms and features of cytomegalovirus UL144 and UL146 in congenitally infected neonates with hepatic involvement

Human cytomegalovirus is a significant agent of hepatic involvement in neonates. In this study, we investigated the polymorphisms and features of the viral genes UL144 and UL146 as well as their significance to congenital hepatic involvement. In 79 neonates with congenital cytomegalovirus infection and hepatic involvement, full length UL144 and UL146 were successfully amplified in 73.42% and 60.76% of cases, respectively. Sequencing indicated that both genes were hypervariable. Notably, UL144 genotype B was highly associated with aspartate aminotransferase (P = 0.028) and lactate dehydrogenase (P = 0.046). Similarly, UL146 genotype G1 and G13 were significantly associated with CMV IgM (P = 0.026), CMV IgG (P = 0.034), alanine aminotransferase (P = 0.019), and aspartate aminotransferase (P = 0.032). In conclusion, dominant UL144 (genotype B) and UL146 (genotype G1 and G13) genotypes are associated with elevated levels of enzymes and CMV IgM and IgG of cytomegalovirus infection.

Molecular Detection of Human Cytomegalovirus (HCMV) Among Infants with Congenital Anomalies in Khartoum State, Sudan

Human Cytomegalovirus (HCMV) infection still represents the most common potentially serious viral complication in humans and is a major cause of congenital anomalies in infants. This study is aimed to detect HCMV in infants with congenital anomalies.

Study subjects consisted of infants born with neural tube defect, hydrocephalus and microcephaly.

Fifty serum specimens (20 males, 30 females) were collected from different hospitals in Khartoum State. The sera were investigated for cytomegalovirus specific immunoglobin M (IgM) antibodies using enzyme-linked immunosorbent assay (ELISA), and for Cytomegalovirus DNA using polymerase chain reaction (PCR).

Out of the 50 sera tested, one patient’s (2%) sample showed HCMV IgM, but with no detectable DNA, other 4(8.2 %) sera were positive for HCMV DNA but with no detectable IgM.

Various diagnostic techniques should be considered to evaluate HCMV disease and routine screening for HCMV should be introduced for pregnant women in this setting. It is vital to initiate further research work with many samples from different area to assess prevalence and characterize HCMV and evaluate its maternal health implications.

Dried blood spots PCR assays to screen congenital cytomegalovirus infection: a meta-analysis

The performance of dried blood spots (DBS) polymerase chain reaction (PCR) assays in screening for congenital cytomegalovirus (cCMV) infection varies between different studies. To determine whether the DBS PCR assay has sufficient accuracy to be used as a screening test for cCMV infection, we performed a meta-analysis of 15 studies (n = 26007 neonates) that evaluated the performance of DBS PCR tests in screening for cCMV infection and that met our inclusion criteria. The pooled sensitivity and specificity were 0.844 (95% CI = 0.812–0.872) and 0.999 (95% CI = 0.998–0.999), respectively, and the diagnostic odds ratio was 1362.10 (95%CI = 566.91–3272.60). As sensitivity analysis showed that the results were robust. In conclusion, the performance of DBS PCR assays for testing cCMV was more suitable for retrospective diagnosis than screening.

Hearing loss and congenital CMV infection: a systematic review

BACKGROUND AND OBJECTIVE

Hearing loss caused by congenital cytomegalovirus (cCMV) infection was first observed in 1964. Today cCMV is the most common cause of nonhereditary sensorineural hearing loss in childhood. Our objective was to provide an overview of the prevalence of cCMV-related hearing loss, to better define the nature of cCMV-associated hearing loss, and to investigate the importance of cCMV infection in hearing-impaired children.

METHODS

Two reviewers independently used Medline and manual searches of references from eligible studies and review articles to select cohort studies on children with cCMV infection with audiological follow-up and extracted data on population characteristics and hearing outcomes.

RESULTS

Thirty-seven studies were included: 10 population-based natural history studies, 14 longitudinal cohort studies, and 13 retrospective studies. The prevalence of cCMV in developed countries is 0.58% (95% confidence interval, 0.41-0.79). Among these newborns 12.6% (95% confidence interval, 10.2-16.5) will experience hearing loss: 1 out of 3 symptomatic children and 1 out of 10 asymptomatic children. Among symptomatic children, the majority have bilateral loss; among asymptomatic children, unilateral loss predominates. In both groups the hearing loss is mainly severe to profound. Hearing loss can have a delayed onset, and it is unstable, with fluctuations and progression. Among hearing-impaired children, cCMV is the causative agent in 10% to 20%. Despite strict selection criteria, some heterogeneity was found between selected studies.

CONCLUSIONS

This systematic review underscores the importance of cCMV as a cause of sensorineural hearing loss in childhood.

Analysis of the shedding of three β-herpesviruses in urine and saliva of children with renal disease

Cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and 7 (HHV-7) are important pathogens in immunocompromised patients. To elucidate the kinetics of the three β-herpesviruses in saliva and urine samples were collected serially from children with renal diseases. Twenty children with renal diseases were enrolled in this study. A total of 240 saliva and urine samples were collected monthly from the patients over a 1-year period. Viral DNAs loads were measured by real-time PCR. In 10 CMV seropositive patients CMV DNA was detected rarely in saliva and CMV DNA load was lower than the other two β-herpesviruses DNA loads. All patients were seropositive for HHV-6B and the virus was detected frequently in saliva. Two of 20 patients were HHV-7 seronegative. High copies of viral DNA were detected continuously in saliva of the HHV-7 seropositive patients. Although neither CMV nor HHV-6B DNA load was different among the three renal diseases, HHV-7 DNA load was different among the diseases (P = 0.039). HHV-6B DNA loads were significantly higher in patients with immunosuppressive treatment compared to those without treatment (P = 0.013). Although CMV DNA was detected in urine samples collected from 5 of 10 CMV seropositive patients, HHV-6B and HHV-7 DNA were detected at relatively low frequencies in urine. No remarkable temporal associations between viral DNA excretion and proteinuria or immunosuppressive treatment were demonstrated. The pattern of viral DNA excretion in saliva and urine were different among the three viruses. No temporal correlation was observed between viral infection and renal diseases.

Seroprevalence of cytomegalovirus antibodies amongst normal pregnant women in Nigeria

OBJECTIVE

Cytomegalovirus (CMV), a ubiquitous virus belonging to the herpes family, is known to be transmitted frequently to developing fetuses in pregnancy. In an immunocompromised state like pregnancy, primary infection through blood transfusion or reactivation of a latent CMV infection can cause severe illness. The study was carried out to determine the seroprevalence of the immunoglobulin G (IgG) antibody to cytomegalovirus amongst pregnant women in correlation with previous exposure to blood transfusion.

METHODS

A cross sectional study was carried out amongst 179 HIV negative pregnant women attending the antenatal clinic of Lagos State University Teaching Hospital (LASUTH), Ikeja, Nigeria. Five mL of blood was collected and stored in a plain bottle, centrifuged on the same day and the serum stored at -20°C. All samples were screened for anti-CMV IgG antibodies using the enzyme linked immunosorbent assay (ELISA). Consenting participants were instructed to fill a semi-structured questionnaire to obtain demographic and other related information. Statistical analysis of the results was done using Pearson's chi squared test for analytical assessment.

RESULTS

A total of 97.2% of the pregnant women recruited for this study were anti-CMV IgG positive. Out of the 179 recruited for the study 174 responded to the question on previous history of blood transfusion, 14.9% of the respondents (26 of 174) had a previous history of blood transfusion and all tested positive to the anti-CMVIgG antibody. However, past history of blood transfusion and educational level were found to be insignificant to the risk of acquiring CMV infection.

CONCLUSION

The seroprevalence of the CMV antibody amongst pregnant women in this environment is high in relation to findings in other developing countries. There is the need to assess anti-CMV immunoglobulin M antibodies in pregnant women, which is a determinant of active infection.

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

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

Dried blood spot real-time polymerase chain reaction assays to screen newborns for congenital cytomegalovirus infection

CONTEXT

Reliable methods to screen newborns for congenital cytomegalovirus (CMV) infection are needed for identification of infants at increased risk of hearing loss. Since dried blood spots (DBS) are routinely collected for metabolic screening from all newborns in the United States, there has been interest in using DBS polymerase chain reaction (PCR)-based methods for newborn CMV screening.

OBJECTIVE

To determine the diagnostic accuracy of DBS real-time PCR assays for newborn CMV screening.

DESIGN, SETTING, AND PARTICIPANTS

Between March 2007 and May 2008, infants born at 7 US medical centers had saliva specimens tested by rapid culture for early antigen fluorescent foci. Results of saliva rapid culture were compared with a single-primer (March 2007-December 2007) and a 2-primer DBS real-time PCR (January 2008-May 2008). Infants whose specimens screened positive on rapid culture or PCR had congenital infection confirmed by the reference standard method with rapid culture testing on saliva or urine.

MAIN OUTCOME MEASURES

Sensitivity, specificity, and positive and negative likelihood ratios (LRs) of single-primer and 2-primer DBS real-time PCR assays for identifying infants with confirmed congenital CMV infection.

RESULTS

Congenital CMV infection was confirmed in 92 of 20,448 (0.45%; 95% confidence interval [CI], 0.36%-0.55%) infants. Ninety-one of 92 infants had positive results on saliva rapid culture. Of the 11,422 infants screened using the single-primer DBS PCR, 17 of 60 (28%) infants had positive results with this assay, whereas, among the 9026 infants screened using the 2-primer DBS PCR, 11 of 32 (34%) screened positive. The single-primer DBS PCR identified congenital CMV infection with a sensitivity of 28.3% (95% CI, 17.4%-41.4%), specificity of 99.9% (95% CI, 99.9%-100%), positive LR of 803.7 (95% CI, 278.7-2317.9), and negative LR of 0.7 (95% CI, 0.6-0.8). The positive and negative predictive values of the single-primer DBS PCR were 80.9% (95% CI, 58.1%-94.5%) and 99.6% (95% CI, 99.5%-99.7%), respectively. The 2-primer DBS PCR assay identified infants with congenital CMV infection with a sensitivity of 34.4% (95% CI, 18.6%-53.2%), specificity of 99.9% (95% CI, 99.9%-100.0%), positive LR of 3088.9 (95% CI, 410.8-23 226.7), and negative LR of 0.7 (95% CI, 0.5-0.8). The positive and negative predictive values of the 2-primer DBS PCR were 91.7% (95% CI, 61.5%-99.8%) and 99.8% (95% CI, 99.6%-99.9%), respectively.

CONCLUSION

Among newborns, CMV testing with DBS real-time PCR compared with saliva rapid culture had low sensitivity, limiting its value as a screening test.

Congenital cytomegalovirus infection in high-risk Canadian infants: Report of a pilot screening study

OBJECTIVES

Congenital cytomegalovirus (cCMV) is the most common congenital infection; however, the epidemiology in Canada has not been recently examined. The present prospective study pilots tools for a population-based study of cCMV infection in Canada by determining the maternal seroprevalence and risk factors, the clinical characteristics and the incidence of cCMV using a variety of diagnostic tests in a cohort of high-risk infants in northern Alberta.

METHODS

All infants born at the Royal Alexandra Hospital in Edmonton, Alberta, from June 1, 2003, to May 31, 2004, were screened for the study. Eligible infants were those with very low birth weights (VLBWs) or small for gestational age (SGA). Maternal CMV serostatus was determined, and chart review and parental interviews were completed. Neonatal urine and throat cultures, and polymerase chain reaction (PCR) were performed. Dried blood spots (DBS) were tested for CMV by PCR.

RESULTS

In total, 213 infants were eligible for the study. Of these, 137 entered the study (79 VLBW and 58 SGA). Some families were not contacted for participation in the study due to neonatal deaths or early discharge. The mean age of the mothers was 27.6 years; 68% of the mothers were Caucasian and 16% were Aboriginal. The maternal CMV seroprevalence was 55%. Seropositivity was significantly associated with ethnicity (First Nations [100%]; Caucasian [34%]) and country of birth (outside Canada [94%]; Canadian born [45%]). The rate of cCMV was two in 137 (1.5%), with a rate of one in 79 (1.3%) for the VLBW infants and one in 58 (1.7%) for the SGA infants. Both had positive throat or urine specimens, but only the symptomatic infant was positive on DBS.

CONCLUSIONS

A cCMV screening program should be universal and routine to successfully screen all newborns. Maternal CMV seropositivity varies widely within the Canadian population. In the present pilot study, DBS PCR was not a sensitive screening tool and throat swab was the best screening specimen.

Incidence and risk of cytomegalovirus infection during pregnancy in an urban area of Northern Italy

The fetal consequences of CMV infection make it one of the most serious infections contracted during pregnancy, but the scientific community is divided over the proposed implementation of preventive screening for anti-CMV antibodies. The aim of this study was to assess the incidence and risk of infection during pregnancy in 2817 women who underwent anti-CMV IgG and IgM antibody screening during the period 2005–2007. The prevalence of anti-CMV IgG antibodies was 68.3% (95% CI: 66.6–70.0); the seroconversion rate in the 892 seronegative women was 0.32%; the results of IgG avidity testing revealed an cumulative incidence of 1.4% (95% CI: 0.97–1.83), density incidence of 0.8% (as cases/pregnant woman-trimester) (95% CI: 0.47–1.13), and a risk of infection of 0.5% (95% CI: 0.24–0.76). The screening identified 13 cases of primary infection (84.6% of which occurred in the first trimester of pregnancy). The possibility to identify these cases and consequently to plan appropriate interventions, supports the use of screening during pregnancy, especially in the first trimester when the risk of infection is greater.

Membranous nephritis associated with acquired cytomegalovirus infection in a 19-month-old baby

Membranous nephritis (MN) is a rare form of glomerulonephritis in childhood, with an incidence of 0.8 to 6.7% based on renal biopsy specimens. Although the disease is considered to be idiopathic in the majority of cases, especially in adults, MN has been associated with various infectious agents, such as hepatitis Beta virus. The natural history of MN in childhood remains unknown because of its rarity, and to the best of our knowledge, no case of MN linked to cytomegalovirus (CMV) infection in an immunocompetent child has been described to date. We report here a 19-month-old female infant who presented with a maculopapular rash, fever, and nephritic-nephrotic syndrome. Virology tests for infectious diseases revealed a recent CMV infection. The renal biopsy findings were compatible with MN, while PCR analysis of the renal tissue specimen was positive for CMV DNA. Antiviral treatment (ganciclovir) resulted in full remission of proteinuria and hematuria. Two years after the initial diagnosis, the child remains well and asymptomatic without clinical or laboratory evidence of the disease.

New estimates of the prevalence of neurological and sensory sequelae and mortality associated with congenital cytomegalovirus infection

Congenital CMV is a major cause of neurological and sensory impairment in children. Reliable estimates of the prevalence of permanent sequelae and mortality associated with congenital CMV are needed to guide development of education and prevention programmes and to gauge the financial costs associated with this disease. To calculate such estimates, this review used data solely from studies in which children with congenital CMV were identified through universal screening. Based on 15 studies with a total of 117 986 infants screened, the overall CMV birth prevalence estimate was 0.7%. The percentage of infected children with CMV-specific symptoms at birth was 12.7%. The percentage of symptomatic children with permanent sequelae was 40-58%. The percentage of children without symptoms at birth who developed permanent sequelae was estimated to be 13.5%. The true burden of congenital CMV infection is unclear because data on important outcomes, such as visual impairment, are lacking and follow-up of infected children has been too short to fully identify late-onset sequelae. Therefore, the estimates of permanent sequelae associated with congenital CMV presented here are likely underestimates. Future studies should extend follow-up of CMV-infected children identified through universal screening and include the evaluation of visual impairment.

Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection

We reviewed studies that reported results of systematic cytomegalovirus (CMV) screening on fetuses and/or live-born infants. The overall birth prevalence of congenital CMV infection was 0.64%, but varied considerably among different study populations. About 11% of live-born infants with congenital CMV infection were symptomatic, but the inter-study differences in definitions of symptomatic cases limit the interpretation of these data. Non-white race, low socioeconomic status (SES), premature birth, and neonatal intensive care unit admittance were risk factors for congenital CMV infection. Birth prevalence increased with maternal CMV seroprevalence. Maternal seroprevalence accounted for 29% of the variance in birth prevalence between study populations. Maternal seroprevalence and birth prevalence were both higher in study populations that were ascertained at birth rather than in the prenatal period. Thus, timing of ascertainment should be considered when interpreting birth prevalence estimates. Birth prevalence was inversely correlated with mean maternal age, but this relationship was not significant when controlling for maternal seroprevalence. The rate of transmission to infants born to mothers who had a primary infection or a recurrent infection during pregnancy was 32% and 1.4%, respectively. Possible maternal primary infections (i.e. seropositive mother with CMV IgM) resulted in congenital infections about 20% of the time, but are likely to represent a mixture of primary and recurrent infections. In summary, CMV is a common congenital infection worldwide that can lead to permanent disabilities. There is an urgent need for interventions that can reduce the substantial burden of this often overlooked disease.

Clinical findings and adverse outcome in neonates with symptomatic congenital cytomegalovirus (SCCMV) infection

INTRODUCTION

Congenital cytomegalovirus (CCMV) infection is a common neonatal infection affecting 1% of all live births, 10% of which are symptomatic. Many of these infants have long-term sequelae. The objective is to document the clinical presentation of SCCMV infection in neonates, the frequency of sequelae and severity of adverse neurologic outcomes and risk factors.

METHODS

A review and analysis of all symptomatic infants diagnosed with SCCMV infection are given. SCCMV was defined as a diagnosis of CCMV infection in the first three weeks of life in the presence of any clinical manifestations. Outcome data from 2 years of age and later are analyzed.

RESULTS

There were 104 patients identified as having SCCMV infection and of these 42 cases had definite infection. The common findings at presentation were hepatosplenomegaly 19/42 (45%), thrombocytopenia 21/42 (50%), elevated transaminases 21/42(50%), abnormal cranial US scan 24/41(56%), abnormal head CT scan 29/41(71%) and abnormal brain MRI 17/19(89%). The risk factors for an adverse outcome including death or deafness or blindness or moderate to severe neurological deficits included an abnormal cranial US scan (OR 8.5), abnormal head CT scan (OR 21) and abnormal brainstem auditory evoked responses (BAER) (OR 8.7).

CONCLUSIONS

There was only three (7%) patients without any deficits and severely affected infants have been identified with a diverse clinical presentation, reinforcing the importance of CMV as a major public health problem.

Cytomegalovirus-related congenital nephrotic syndrome with diffuse mesangial sclerosis

This case report describes congenital nephrotic syndrome in a 2-month-old girl associated with cytomegalovirus infection. Histological examination on renal biopsy showed diffuse mesangial sclerosis and cytomegalic inclusion bodies in the tubular cells and in some glomeruli. Cytomegalovirus (CMV) polymerase chain reaction (PCR) titer in serum was high. Remission of pulmonary and renal symptoms was achieved with ganciclovir in 3 weeks. No recurrence of proteinuria was observed during the follow-up period of 14 months. These finding suggested a causal relationship between congenital nephrotic syndrome and cytomegalovirus infection.

Multicity Italian study of congenital cytomegalovirus infection

BACKGROUND

Cytomegalovirus (CMV) infection is the most frequent congenital infection in humans. Its prevalence and the frequency of disabling sequelae must be assessed in different populations to permit the formulation or assessment of preventive measures.

OBJECTIVES

To check the prevalence of congenital infection and seroprevalence in Italy; to verify the rate of sensorineural hearing loss (SNHL) in infected infants; and to assess the proportion of children with SNHL attributable to congenital CMV infection.

METHODS

Diagnosis of congenital CMV infection was sought in 9032 children born between March 2002 and February 2003 by testing for viral DNA [CMV dried blood spot (DBS) test] in each newborn's Guthrie card and confirmation by isolation of CMV from urine collected in the first 3 weeks of life; CMV IgG testing in 1200 women of childbearing age; clinical and audiologic tests in the first 24 months for infected children; CMV DBS tests on the Guthrie cards collected from screening centers for 77 children (3 months-5 years) presenting SNHL of 40 dB or more.

RESULTS

CMV infection was diagnosed in 14 asymptomatic and 2 symptomatic newborns (0.18%). CMV seroprevalence was 80%. In 2 infected infants, transient, unilateral SNHL was found. Nineteen of the 71 children with SNHL >70 dB were congenitally infected.

CONCLUSIONS

The prevalence of congenital CMV infection is low in Italy. Population characteristics limiting the circulation of CMV strains in adult women might explain this. The fact that CMV contributes to significant SNHL highlights the need for preventive measures.

Congenital cytomegalovirus infection after recurrent infection: case reports and review of the literature

Cytomegalovirus (CMV) is one of the most common causes of congenital infections in developed countries with reported incidences varying between 0.15% and 2.0%. The effects of congenital CMV infection may vary from a congenital syndrome to an asymptomatic course. Infants that are asymptomatic at birth may still present handicaps at a later age. It is generally accepted that symptoms of congenitally infected children are more severe after primary infection than after recurrent infection. In this article, we present two case reports which demonstrate that the outcome of recurrent maternal CMV infection may be severe. In the first case, early pregnancy serology showed positive IgG and IgM, but negative IgA, whereas at the time of diagnosed fetal death, 5 weeks later, there was only positive IgG. The second case showed positive IgG and negative IgM and IgA both in early pregnancy and after delivery. Since in both cases CMV was isolated from several organs, these findings are compatible with recurrent rather than primary CMV infection. In the reported patients, fetal death and necrotising enterocolitis occurred after a congenital CMV infection, with mothers having pre-existing immunity to CMV. In conclusion, these case reports and review of the literature emphasise that the outcome of recurrent maternal CMV infection may be severe and that congenital CMV infection should be considered in cases of pregnancy loss and necrotising enterocolitis with recurrent maternal CMV infection.

Congenital cytomegalovirus infection in San Luis Potosi, Mexico

The incidence of congenital cytomegalovirus infection in Mexico is unknown. We evaluated the presence of cytomegalovirus infection in 560 newborn infants at a public general hospital. There were five (0.89%) infected newborns. Infants with congenital infection were more likely to be born to primigravid mothers (P = 0.01) and were more often from rural areas (P = 0.058) than were noninfected newborns.