Documento de consenso de la Sociedad Española de Infectología Pediátrica sobre el diagnóstico y el tratamiento de la infección congénita por citomegalovirus

Renal Function Impairment in Children With Congenital Cytomegalovirus Infection: A Cross-sectional Study

BACKGROUND

We aimed to determine the prevalence and severity of glomerular and tubular renal dysfunction by means of urinalysis in infants and toddlers with congenital cytomegalovirus infection (cCMV) and their association with cCMV disease, viruria and antiviral treatment.

METHODS

This cross-sectional study was done using the Spanish Registry of Congenital Cytomegalovirus Infection. First-morning urine samples were collected from January 2016 to December 2018 from patients <5 years old enrolled in Spanish Registry of Congenital Cytomegalovirus Infection. Samples were excluded in case of fever or other signs or symptoms consistent with acute infection, bacteriuria or bacterial growth in urine culture. Urinary protein/creatinine and albumin/creatinine ratios, urinary beta-2-microglobulin levels, hematuria and CMV viruria were determined. A 0.4 cutoff in the urinary albumin/protein ratio was used to define tubular (<0.4) or glomerular (>0.4) proteinuria. Signs and symptoms of cCMV at birth, the use of antivirals and cCMV-associated sequelae at last available follow-up were obtained from Spanish Registry of Congenital Cytomegalovirus Infection.

RESULTS

Seventy-seven patients (37 females, 48.1%; median [interquartile range] age: 14.0 [4.4-36.2] months) were included. Symptom-free elevated urinary protein/creatinine and albumin/creatinine ratios were observed in 37.5% and 41.9% of patients, respectively, with tubular proteinuria prevailing (88.3%) over glomerular proteinuria (11.6%). Proteinuria in the nephrotic range was not observed in any patients. In multivariate analysis, female gender was the only risk factor for tubular proteinuria (adjusted odds ratio = 3.339, 95% confidence interval: 1.086-10.268; P = 0.035). cCMV disease at birth, long-term sequelae, viruria or the use of antivirals were not associated with urinalysis findings.

CONCLUSIONS

Mild nonsymptomatic tubular proteinuria affects approximately 40% of infants and toddlers with mostly symptomatic cCMV in the first 5 years of life.

The role of the T-cell mediated immune response to Cytomegalovirus infection in intrauterine transmission

INTRODUCTION

Prognostic markers for fetal transmission of Cytomegalovirus (CMV) infection during pregnancy are poorly understood. Maternal CMV-specific T-cell responses may help prevent fetal transmission and thus, we set out to assess whether this may be the case in pregnant women who develop a primary CMV infection.

METHODS

A multicenter prospective study was carried out at 8 hospitals in Spain, from January 2017 to April 2020. Blood samples were collected from pregnant women at the time the primary CMV infection was diagnosed to assess the T-cell response. Quantitative analysis of interferon producing specific CMV-CD8+/CD4+ cells was performed by intracellular cytokine flow cytometry.

RESULTS

In this study, 135 pregnant women with a suspected CMV infection were evaluated, 60 of whom had a primary CMV infection and samples available. Of these, 24 mothers transmitted the infection to the fetus and 36 did not. No association was found between the presence of specific CD4 or CD8 responses against CMV at the time maternal infection was diagnosed and the risk of fetal transmission. There was no transmission among women with an undetectable CMV viral load in blood at diagnosis.

CONCLUSIONS

In this cohort of pregnant women with a primary CMV infection, no association was found between the presence of a CMV T-cell response at the time of maternal infection and the risk of intrauterine transmission. A detectable CMV viral load in the maternal blood at diagnosis of the primary maternal infection may represent a relevant biomarker associated with fetal transmission.

Cost-effectiveness of a cytomegalovirus screening strategy in neonates born after 34 weeks small for gestational age

INTRODUCTION

Infection by cytomegalovirus (CMV) is one of the most common congenital infections, with a global prevalence of 0.3%-2.4%. In Spain, CMV screening is not performed during pregnancy, but rather in neonates with risk factors, and, in many hospitals, in those born small for gestational age (SGA). Screening is usually performed by measurement of the viral load in urine by polymerase chain reaction (PCR) and/or head ultrasound in search of compatible features. The aim of the study was to assess the yield of the CMV PCR test in urine and head ultrasound examination in asymptomatic neonates born SGA after 34 weeks' gestation. The secondary objective was to assess the cost-effectiveness of this strategy.

DESIGN AND METHODS

We conducted an observational and retrospective study between January and December 2019 in a tertiary care hospital. It included neonates delivered after 34 weeks, SGA and without additional risk factors assessed with a CMV PCR test in urine and/or head ultrasound.

RESULTS

The sample included 259 patients. It was divided in 2 groups: group 1, patients with a head circumference, weight and length below the 10th percentile (53 patients; 20.5%), and group 2, patients in whom only the weight was below the 10th percentile (206 patients; 79.5%). The incidence of late preterm birth, twin pregnancy, neonatal admission and exposure to illicit drugs during gestation was higher in group 1. A total of 186 urine PCR tests and 223 head ultrasounds were performed overall, and both tests were performed more frequently in group 1 (P=.002). There was only 1 positive CMV PCR test result in the sample (0.54%), corresponding to a patient in group 2 with no abnormal sonographic findings who remained asymptomatic throughout the follow-up. Two head ultrasound examinations yielded abnormal findings, in both cases unrelated to congenital CMV infection. We performed a cost-effectiveness analysis and determined that the cumulative cost of head ultrasound examinations and urine CMV PCR tests in our sample amounted to Є17 000 for the detection of a single asymptomatic positive case.

CONCLUSION

In our population, screening for congenital CMV infection in asymptomatic late preterm and term newborns whose only risk factor is SGA does not seem to be cost effective. It would be necessary to expand the sample to other populations.

Congenital cytomegalovirus infection in newborns born to HIV-infected mothers

INTRODUCTION

Congenital citomegalovirus (CMVc) infection is more common in children exposed to HIV during pregnancy, with reported rates in pre-ART era from 2 to 7%. The use of combined antiretroviral treatment (ARTc) could be a determining factor in reducing this risk of CMV transmission. The aim of this study was to describe the epidemiology of CMVc infection in newborns of HIV-infected mothers at Hospital Universitario 12 de Octubre, Madrid, Spain, from 2000 to 2017.

MATERIAL AND METHODS

An observational and retrospective study was carried out. Epidemiological and clinical variables were collected. Statistical analysis was performed with the SPSS 24.0 computer program.

RESULTS

288 mother-infant pairs were included in the study. We observed a CMVc rate of 2.1% (95% CI 0.9-4.9).

CONCLUSIONS

The rate of CMVc in HIV-exposed children observed was lower than that reported in pre-ARTc era but seems higher than those described in general population.

Perinatal Cytomegalovirus Infection

PURPOSE OF REVIEW

There have been recent advances in the field of congenital CMV infection (cCMV) related to antiviral treatment of pregnant women and infants, the implementation of newborn CMV screening programs, and the frequency and diagnosis of complications among infected children. In addition, postnatal CMV infection (pCMV) is increasingly recognized as a potential cause of long-term sequelae in addition to acute complications among preterm infants, raising important questions related to treatment, and prevention.

RECENT FINDINGS

High-dose valacyclovir appears to be safe and effective for the prevention of cCMV among women with first-trimester primary CMV infection. New studies reveal high rates of vestibular dysfunction and neuropsychiatric manifestations among children with cCMV. Some studies report associations between pCMV and long-term consequences, including neurodevelopmental delay and bronchopulmonary dysplasia, among very low birth weight infants, in addition to high risk of sepsis and death acutely, which has motivated efforts to eliminate the virus from breast milk by different methods.

SUMMARY

More long-term complications of cCMV are increasingly recognized among children previously thought to be asymptomatic. Although a preventive CMV vaccine may be achievable, strategies to reduce the burden of cCMV disease include maternal education about risk-reduction behaviors, antiviral treatment of pregnant women with primary infection, and newborn screening to allow timely, appropriate care. Similarly, although it remains unclear if pCMV causes long-term problems, there is growing interest in identifying and preventing disease from CMV infections among preterm infants.

Viral infections in stillbirth: a contribution underestimated in Mexico?

OBJECTIVES

To analyze the role of viral infections as etiology of stillbirths in Mexico and their epidemiological impact in the context of the global Every Newborn Initiative.

METHODS

A comprehensive literature search was performed in electronic databases related to stillbirth and viral infections published prior to January 19th 2021. Stillbirths records and causes from National Mexican databases, during 2008-2019 period were also computed.

RESULTS

Only two articles with a direct relationship between viral infection and stillbirth were found, and one article with an indirect serological association was identified. During the analyzed period there were 198,076 stillbirths, with a National stillbirth rate (SBR) ranging from 6.9 to 6.5 between 2008 and 2014, with a subsequent increase to reach 7.7 in 2019. Only 19 cases were attributed to viral causes and a specific virus was identified in 11. The main causes of early stillbirth were a fetus with premature rupture of membranes and light for gestational age, and for late stillbirth these were fetus affected by oligohydramnios and slow fetal growth. The percentage classified as unspecified deaths varied from 34.4-41.9%.

CONCLUSIONS

In Mexico, there has been an increase in SBR during last years, but the goals of the Every Newborn Initiative is met. More than 14,500 stillbirths with at least 5,100 unspecified cases have been reported per year, and only 11 cases were attributable to a specific virus, highlighting the serious underestimation of cases and the need of implementation of routine viral diagnosis methods to improve the care of this global health problem.

Assessment of mitochondrial toxicity in newborns and infants with congenital cytomegalovirus infection treated with valganciclovir

BACKGROUND

Ganciclovir/valganciclovir is currently indicated during the first 6 months of life in symptomatic children with congenital cytomegalovirus (CMV) infection. However, this treatment may have the potential to induce mitochondrial toxicity due to off-target inhibition of DNA-polymerases. Similar anti-HIV drugs have been associated with mitochondrial toxicity but this has never been explored in CMV.

OBJECTIVE

To determine the potential mitochondrial toxicity profile at the genetic, functional and biogenesis level in peripheral blood mononuclear cells from a cohort of newborns and infants with symptomatic congenital CMV infection (treated with valganciclovir, untreated and uninfected controls).

DESIGN

Longitudinal, observational and controlled study.

SETTING AND PATIENTS

Subjects were recruited at the tertiary referral Hospital Sant Joan de Déu and experiments were conducted at IDIBAPS-Hospital Clínic of Barcelona, Spain. CMV-infected newborns underwent comprehensive monthly clinical follow-up.

METHODS

Mitochondrial parameters, audiometry and neurological assessment were measured at baseline, 3-6 and 12 months after inclusion in the study. The Kruskal-Wallis test for k-independent samples and Friedman tests for repeated measurements were applied.

RESULTS

Complex IV, citrate synthase enzymatic activities and mtDNA remained preserved in congenital CMV-infected infants treated with valganciclovir compared with controls (p>0.05 in all cases).

CONCLUSIONS

No evidence of mitochondrial toxicity was found in infants treated with valganciclovir for congenital CMV.

Association between neuroimaging findings and neurological sequelae in patients with congenital cytomegalovirus infection

BACKGROUND

Congenital cytomegalovirus (CMV) infection is an important cause of disability. There is little evidence on the prognostic value of lesions identified in neuroimaging studies.

AIM

The study aimed to assess the severity of lesions detected with brain MRI and transfontanellar ultrasound and their relationship with long-term neurological deficits.

PATIENTS AND METHODS

We performed a retrospective, analytical, observational study of 36 patients with congenital CMV infection. Neuroimaging studies were reviewed and classified according to the modified Noyola' scale. Imaging findings were compared with neurological alterations in the patients' most recent follow-up evaluation at the paediatric neurology department.

RESULTS

Thirty-six patients were studied (transfontanellar ultrasound: 30; brain MRI: 29). Twenty of 30 patients showed ultrasound abnormalities; of these, 11 showed alterations on brain MR images (P=.04) and 10 had neurological impairment (P=.008). Transfontanellar ultrasound had a sensitivity of 83.3%, 90% CI: 58-100 and a specificity of 44.4%, 90% CI: 18.7-70.2 for predicting neurological sequelae. Brain MRI displayed abnormalities in 20 of 29 patients, of whom 16 had neurological impairment (P<.001). MRI had a sensitivity of 94%, 95% CI: 80-100 and a specificity of 66.6%, 95% CI: 36-97.5 for predicting neurological sequelae. Modified Noyola' scale values >2 were correlated with psychomotor retardation (P<.001).

CONCLUSIONS

Our findings validate previous studies reporting a statistical significant correlation between the extension of neuroimaging lesions and severity of neurological deficits.

Mitochondrial changes associated with viral infectious diseases in the paediatric population

Infectious diseases occur worldwide with great frequency in both adults and children, causing 350,000 deaths in 2017, according to the latest World Health Organization reports. Both infections and their treatments trigger mitochondrial interactions at multiple levels: (i) incorporation of damaged or mutated proteins into the complexes of the electron transport chain; (ii) impact on mitochondrial genome (depletion, deletions and point mutations) and mitochondrial dynamics (fusion and fission); (iii) membrane potential impairment; (iv) apoptotic regulation; and (v) generation of reactive oxygen species, among others. Such alterations may result in serious adverse clinical events with considerable impact on the quality of life of the children and could even cause death. Herein, we use a systematic review to explore the association between mitochondrial alterations in paediatric infections including human immunodeficiency virus, cytomegalovirus, herpes viruses, various forms of hepatitis, adenovirus, T-cell lymphotropic virus and influenza. We analyse how these paediatric viral infectious processes may cause mitochondrial deterioration in this especially vulnerable population, with consideration for the principal aspects of research and diagnosis leading to improved disease understanding, management and surveillance.

Association between neuroimaging findings and neurological sequelae in patients with congenital cytomegalovirus infection

BACKGROUND

Congenital cytomegalovirus (CMV) infection is an important cause of disability. There is little evidence on the prognostic value of lesions identified in neuroimaging studies.

AIM

The study aimed to assess the severity of lesions detected with brain MRI and transfontanellar ultrasound and their relationship with long-term neurological deficits.

PATIENTS AND METHODS

We performed a retrospective, analytical, observational study of 36 patients with congenital CMV infection. Neuroimaging studies were reviewed and classified according to the modified Noyola' scale. Imaging findings were compared with neurological alterations in the patients' most recent follow-up evaluation at the paediatric neurology department.

RESULTS

Thirty-six patients were studied (transfontanellar ultrasound: 30; brain MRI: 29). Twenty of 30 patients showed ultrasound abnormalities; of these, 11 showed alterations on brain MR images (P = .04) and 10 had neurological impairment (P = .008). Transfontanellar ultrasound had a sensitivity of 83.3%, 90% CI: 58-100 and a specificity of 44.4%, 90% CI: 18.7-70.2 for predicting neurological sequelae. Brain MRI displayed abnormalities in 20 of 29 patients, of whom 16 had neurological impairment (P < .001). MRI had a sensitivity of 94%, 95% CI: 80-100 and a specificity of 66.6%, 95% CI: 36-97.5 for predicting neurological sequelae. Modified Noyola' scale values > 2 were correlated with psychomotor retardation (P < .001).

CONCLUSIONS

Our findings validate previous studies reporting a statistical significant correlation between the extension of neuroimaging lesions and severity of neurological deficits.

Growth Patterns in Children With Congenital Cytomegalovirus Infection

BACKGROUND

Congenital cytomegalovirus infection (CMVc) affects 0.7%-6% of recent births. Among its clinical manifestations are low weight and length at birth.

OBJECTIVE

Describe the growth patterns of children with CMVc in their early years.

METHODS

Observational, multicenter study of patients with CMVc. Anthropometric data were collected during the first 2 years of life and compared with World Health Organization standards.

RESULTS

Anthropometric characteristics of 383 children with CMVc were studied, of which 198 (51%) were symptomatic at birth. At birth, 9% were small for gestational age (SGA) in terms of their weight and length and 17% had microcephaly. At 24 ± 3 months, 10% had a weight and length ≤2 SD, and 13% a head circumference ≤2 SD. Of those who were SGA at birth, at 24 ± 3 months >20% remained at ≤2 SD of their weight and length. Conversely, 75% of children with low weight or length at 24 ± 3 had not been SGA at birth. 20% of infants with microcephaly at birth remained with microcephaly, and 10% of those without microcephaly developed it at 24 ± 3 months. The average growth rate in length and weight was normal. Patients who were symptomatic at birth, premature and with motor and neurocognitive impairment had a significantly higher risk of low weight and length at 24 ± 3 months.

CONCLUSION

Around 10% of children with CMVc are at ≤2 SD in weight, length and head circumference at 24 ± 3 months. The lack of adequate growth is associated with symptoms at birth, prematurity and motor and neurocognitive impairment. Growth impairment could be incorporated into the symptomatic spectrum of CMVc.

Human Breast Milk-acquired Cytomegalovirus Infection: Certainties, Doubts and Perspectives

Breast Milk (BM) is the best source of nutrition for newborns, especially if premature. In fact, its beneficial impact on short- and the long-term neonatal outcome has was deeply described. Unfortunately, BM could not be always so safe, especially due to the possible presence of maternal viruses that can be shed and transferred to the breastfed neonate. Among these, Cytomegalovirus (CMV) can potentially lead to a serious and acute illness, mostly in case of low gestational age. Some studies also report the association of CMV-acquired infection to an increased risk of structural and functional brain modifications and neurological impairment. Due to these reasons, a strategy to remove CMV from BM with a minimal or absent impact on its beneficial components would be desirable. Up to now, pasteurization, freezing, ultraviolet- C or microwave irradiation are the available techniques; they show different levels of efficacy and variable effects on BM composition, even if many studies are still needed to fully clarify these implications. In this review, we provide an update of the current evidence about these topics. We focus on the factors promoting CMV shedding through BM; moreover, the possible occurrence of a severe disease in preterm neonates is also described. Finally, we investigate the potential effects showed on BM properties by the strategies that prevent or reduce viral transmission, therefore influencing newborns' health, and the new techniques which could show a relevant role in the next future, such as metabolomics.

Congenital cytomegalovirus, parvovirus and enterovirus infection in Mozambican newborns at birth: A cross-sectional survey

Background

Congenital cytomegalovirus (cCMV) infection is the most prevalent congenital infection acquired worldwide, with higher incidence in developing countries and among HIV-exposed children. Less is known regarding vertical transmission of parvovirus B19 (B19V) and enterovirus (EV). We aimed to assess the prevalence of CMV, B19V and EV vertical transmission and compare results of screening of congenital CMV obtained from two different specimens in a semirural Mozambican maternity.

Methods

A cross sectional study was conducted among pregnant mothers attending Manhiça District Hospital upon delivery. Information on maternal risk factors was ascertained. Dried umbilical cord (DUC) samples were collected in filter paper for CMV, B19V and EV detection by real-time polymerase chain reaction (RT-PCR), and nasopharyngeal aspirates (NPA) to test for CMV by RT-PCR. Maternal blood samples and placental biopsy samples were also obtained to investigate CMV maternal serology, HIV status and immunopathology.

Results

From September 2014 to January 2015, 118 mothers/newborn pairs were recruited. Prevalence of maternal HIV infection was 31.4% (37/118). CMV RT-PCR was positive in 3/115 (2.6%) of DUC samples and in 3/96 (6.3%) of NPA samples obtained from neonates. The concordance of the RT-PCR assay through DUC with their correspondent NPA sample was moderate (Kappa = 0.42 and p<0.001. No differences on cCMV prevalence were found among HIV-exposed and unexposed. All (100%) mothers were seropositive for CMV IgG. RT-PCR of EV and B19V in DUC were both negative in all screened cases. No histological specific findings were found in placental tissues. No risk factors associated to vertical transmission of these viral infections were found.

Conclusions

This study indicates the significant occurrence of vertical transmission of CMV in southern Mozambique. Larger studies are needed to evaluate the true burden, clinical relevance and consequences of congenital infections with such pathogens in resource-constrained settings.

Cytomegalovirus DNA Detection by Polymerase Chain Reaction in Cerebrospinal Fluid of Infants With Congenital Infection: Associations With Clinical Evaluation at Birth and Implications for Follow-up

Background

DNA detection of human cytomegalovirus (hCMV) in cerebrospinal fluid (CSF) by polymerase chain reaction (PCR) is a marker of central nervous system (CNS) involvement in congenital hCMV infection (cCMV), but its prognostic value is unknown.

Methods

A multicenter, retrospective study was performed using the Spanish Congenital Cytomegalovirus Infection Database (REDICCMV; http://www.cmvcongenito.es). Newborns with cCMV and a lumbar puncture performed were included and classified according to their hCMV-PCR in CSF result (positive/negative). Clinical characteristics, neuroimaging abnormalities, plasma viral load, and audiological and neurological outcomes of both groups were compared.

Results

A total of 136 neonates were included in the study: 21 (15.4%) with positive CSF hCMV-PCR and 115 (84.6%) with negative results. Seventeen patients (81%) in the positive group were symptomatic at birth compared with 52.2% of infants in the negative group (odds ratio [OR], 3.86; 95% confidence interval [CI], 1.28-14.1; P = .01). Only 4 asymptomatic newborns (6.8%) had a positive CSF hCMV-PCR. There were no differences between groups regarding the rate of microcephaly, neuroimaging abnormalities, neurological sequelae at 6 months of age, or plasma viral load. Sensorineural hearing loss (SNHL) at birth was associated with a positive CSF hCMV-PCR result (OR, 3.49; 95% CI, 1.08-11.27; P = .04), although no association was found at 6 months of age.

Conclusions

A positive hCMV-PCR result in CSF is associated with symptomatic cCMV and SNHL at birth. However, no differences in neuroimaging studies, plasma viral load, or outcomes at 6 months were found. These results suggest that hCMV-PCR in CSF may not be a useful prognostic marker in cCMV.

Prevention and treatment of fetal cytomegalovirus infection with cytomegalovirus hyperimmune globulin: a multicenter study in Madrid

INTRODUCTION

Cytomegalovirus (CMV) is the leading cause of congenital infection worldwide. Data about the management of CMV infection in pregnant women are scarce, and treatment options are very limited. The aim of the study is to investigate the effectiveness of cytomegalovirus hyperimmune globulin (CMV-HIG) for the prevention and treatment of congenital CMV (cCMV) infection.

MATERIALS AND METHODS

A retrospective observational study was conducted in three tertiary hospitals in Madrid. In the period 2009-2015, CMV-HIG (Cytotect^® CP Biotest, Biotest) treatment was offered to all pregnant women with primary CMV infection and/or detection of CMV-DNA in amniotic fluid in participating centers. Women were divided into prevention and treatment groups (PG and TG, respectively). Those with primary CMV infection who had not undergone amniocentesis comprised the PG and received monthly CMV-HIG (100 UI/kg). If CMV-DNA was subsequently detected in amniotic fluid, one extra dose of CMV-HIG (200 UI/kg) was given 4 weeks after the last dose. Those women were considered to be part of the PG group despite detection of CMV-DNA in amniotic fluid. In the case of a negative result in CMV-DNA detection in amniotic fluid or if amniocentesis was not performed, monthly HIG was given up to the end of the pregnancy.

RESULTS

Thirty-six pregnant women were included. Median gestational age at birth was 39 weeks (interquartile range: 38-40) and two children (5.5%) were premature (born at 28 and 34 weeks' gestation). Amniocentesis was performed in 30/36 (83.4%) pregnancies and CMV PCR was positive in 21 of them (70%). One fetus with a positive PCR in amniotic fluid that received one dose of HIG after amniocentesis presented a negative CMV-PCR in urine at birth, and was asymptomatic at 12 months of age. Twenty-four children were infected at birth, and 16/21 (76.2%) presented no sequelae at 12 months, while two (9.5%) had a mild unilateral hearing loss and three (14.3%) severe hearing loss or neurological sequelae. Seventeen women were included in the PG and 19 in the TG. In the PG 7/17 (41%) fetuses were infected, one pregnancy was terminated due to abnormalities in cordocentesis and one showed a mild hearing loss at 12 months of age. In the TG, 18/19 children (95%) were diagnosed with cCMV, while the remaining neonate had negative urine CMV at birth. Eight out of the 19 fetuses (42.1%) showed CMV related abnormalities in the fetal US before HIG treatment. Complete clinical assessment in the neonatal period and at 12 months of age was available in 16 and 15 children, respectively. At birth 50% were symptomatic and at 12 months of age, 4/15 (26.7%) showed a hearing loss and 3/15 (20%) neurologic impairment. Fetuses with abnormalities in ultrasonography before HIG presented a high risk of sequelae (odds ratios: 60; 95%CI: 3-1185; p = .007).

DISCUSSION

Prophylactic HIG administration in pregnant women after CMV primary infection seems not to reduce significantly the rate of congenital infection, but is safe and it could have a favorable effect on the symptoms and sequelae of infected fetuses. The risk of long-term sequelae in fetuses without US abnormalities before HIG is low, so it could be an option in infected fetuses with normal imaging. On the other hand, the risk of sequelae among infected fetuses with abnormalities in fetal ultrasonography before HIG despite treatment is high.

Diagnosis, gB genotype distribution and viral load of symptomatic congenitally infected CMV patients in Cuba

OBJECTIVE

Cytomegalovirus (CMV) is the leading cause of viral congenital infection. Some viral factors have been proposed to be CMV pathogenicity markers. The objective of this study was to investigate the frequency of congenital CMV infection in symptomatic patients and the possible association with the CMV glycoprotein B (gB) genotype and viral load.

STUDY DESIGN

A total of 361 newborns (NB) and 158 pregnant women (PW) with clinically suspected CMV infection were enrolled. Studied samples included urine, saliva, serum, vaginal swabs and amniotic fluid. CMV infection was diagnosed by multiplex nested PCR. CMV gB genotyping was performed on infected samples, followed by viral load determination.

RESULTS

Overall, 18.7% of the tested patients were positive for CMV infection, 19.7% of NB were congenitally infected and 16.5% of PW showed active CMV infection. gB-2 was the most prevalent genotype detected (39/97 patients). gB CMV mixed infections were detected in 12 patients. gB-2 was associated with mono-infections (P<0.01). Mixed infections showed higher levels of viral load compared with gB mono-infection (P=0.03). Hepatomegaly, splenomegaly, jaundice, sepsis-like syndrome and malformations were the most prevalent clinical findings. gB-4 was more frequently associated with sepsis-like syndrome than other gB genotypes (P=0.04, odds ratio=4.3, confidence interval: 0.9 to 21.6). The difference in medians of CMV load was statistically significant among patients presenting different clinical signs (P=0.04).

CONCLUSIONS

This study showed that CMV is a frequent cause of congenital infection in symptomatic Cuban patients. Despite gB2 being the most frequently detected, gB-4 was the only genotype associated with clinical features (sepsis-like syndrome in NB). No other associations among specific genotypes and clinical characteristics were found. Further studies are needed to clarify the role that viral load and genotype play in the outcome of congenital infection.

Congenital and perinatally-acquired infections in resource-constrained settings

INTRODUCTION

Congenital and perinatal infections are a leading cause of neonatal and infant morbidity and mortality. Maternal screening, vaccines or treatment where available, constitute effective prevention strategies to reduce the burden of these diseases. Data on the burden of congenital and perinatal infections are very limited for low and middle-income regions.

AREAS COVERED

This review aims to summarize the burden of congenital and perinatal infections and the main challenges for their control in resource-limited settings. Articles were identified through the main electronic databases and cover the period 1971-2016. Expert commentary: Estimates from low and middle-income countries indicate that the burden of congenital infections may be higher in these regions than in industrialized countries. As preventive and curative strategies are available to tackle some of these infections, efforts at the international and national levels must be made to implement those and thus reduce their burden in resource-limited countries.

High Cytomegalovirus (CMV) DNAemia Predicts CMV Sequelae in Asymptomatic Congenitally Infected Newborns Born to Women With Primary Infection During Pregnancy

OBJECTIVE

We investigated the kinetics of cytomegalovirus (CMV) clearance in blood and urine and the relationship between the viral load in blood at birth and the development of late-onset sequelae in asymptomatic congenital CMV infection.

METHODS

Thirty-three newborns with congenital asymptomatic CMV infection born to women with primary CMV infection during pregnancy were enrolled. CMV infection was monitored by polymerase chain reaction analysis of blood and urine. The follow-up examination was concluded at 6 years of age.

RESULTS

Ten infants developed postnatal sequelae, whereas twenty-three infants remained asymptomatic. Fifty percent of babies cleared CMV in blood and urine within 3 and 36 months, respectively. Logistic multivariate regression revealed that the risk of neonatal clinical disease crossed the level of 50% with a DNAemia at birth of ≥ 12,000 copies/mL (P = .0002). The risk of hearing deficit crossed the level of 50% with a DNAemia at birth of ≥ 17,000 copies/mL (P = .0001). No significant difference was found between the kinetics of CMV clearance in asymptomatic children as compared to babies with late-onset disease.

CONCLUSIONS

Asymptomatic newborns with a CMV DNAemia at birth of ≥ 12,000 copies/mL were more likely to experience CMV-related sequelae. The risk of hearing deficit increased with a viral load in blood of ≥ 17,000 copies/mL.

Role of cytomegalovirus (CMV) IgG avidity testing in diagnosing primary CMV infection during pregnancy

The risk of intrauterine transmission of cytomegalovirus (CMV) during pregnancy is much greater for women who contract primary CMV infection after conception than for women with evidence of infection (circulating CMV antibodies) before conception. Thus, laboratory tests that aid in the identification of recent primary CMV infection are important tools for managing the care of pregnant women suspected of having been exposed to CMV. CMV IgM detection is a sensitive marker of primary CMV infection, but its specificity is poor because CMV IgM is also produced during viral reactivation and persists following primary infection in some individuals. Studies conducted over the last 20 years convincingly demonstrate that measurement of CMV IgG avidity is both a sensitive and a specific method for identifying pregnant women with recent primary CMV infection and thus at increased risk for vertical CMV transmission. IgG avidity is defined as the strength with which IgG binds to antigenic epitopes expressed by a given protein; it matures gradually during the 6 months following primary infection. Low CMV IgG avidity is an accurate indicator of primary infection within the preceding 3 to 4 months, whereas high avidity excludes primary infection within the preceding 3 months. In this minireview, we summarize published data demonstrating the clinical utility of CMV IgG avidity results for estimating time since primary infection in pregnant women, describe commercially available CMV IgG avidity assays, and discuss some of the issues and controversies surrounding CMV IgG avidity testing during pregnancy.

[Can we rule out a congenital cytomegalovirus infection when the result of polymerase chain reaction in dried blood spots is negative?]

INTRODUCTION

The detection of cytomegalovirus (CMV) DNA by real time polymerase chain reaction (rt-PCR) in dried blood spots collected routinely for metabolic screening has been assessed for the retrospective diagnosis of congenital CMV (cCMV) infection in many studies, but not in Spain. The aim of this study is to analyze the diagnostic accuracy of this technique in our hospital.

METHODS

A cross-sectional retrospective observational study was conducted including all patients born between January, 2007 and September, 2012 with confirmed cCMV infection. The assessment of CMV DNA was made by using rt-PCR in dried blood spots of these patients.

RESULTS

Fourteen patients were included: 4/14 were symptomatic and 4/14 had sequelae. The detection of CMV DNA by rt-PCR was positive in only 7 patients. A statistically significant relationship between low viral load at birth and negative rt-PCR in dried blood spots was demonstrated.

CONCLUSIONS

Despite the low number of patients included, our data highlight an important amount of false negative results in the DNA CMV detection by rt-PCR in these samples for the retrospective diagnosis of cCMV infection, especially in cases with low viral load at birth.

[Review and guidelines on the prevention, diagnosis and treatment of post-natal cytomegalovirus infection]

Postnatal cytomegalovirus (CMV) infection in the newborn can occur from exposure to maternal cervical secretions during birth, ingestion of breast milk, transfusion of blood products or transmission by body fluids of infected people. Breast milk is the main source of infection, given the high rate of CMV-positive mothers excreting CMV in milk. Freezing reduces the risk of CMV transmission by breastfeeding, although it does not eliminate it completely. Pasteurisation prevents such transmission, but it can alter the immunological properties of breast milk. Postnatal CMV infection is usually asymptomatic, as it normally results from viral reactivation in the mother, and the neonate is born with protective antibodies. However, in the very low birth weight premature infant the amount of transferred antibodies is smaller and a symptomatic infection can occur. Symptomatic post-natal CMV infection in the newborn typically causes hepatitis, neutropenia, thrombocytopenia or sepsis-like syndrome. Pneumonitis and enteritis are less common, but very characteristic. Diagnosis is based on urine virus detection at the time of onset of symptoms. Postnatal CMV infection in the newborn generally resolves spontaneously without antiviral treatment. Ganciclovir should be reserved for severe cases. Unlike congenital CMV disease, post-natal CMV infection in the preterm infant does not seem to be associated with hearing loss or abnormal neuro-development in long term follow-up.