Spectrum of disease and outcome in children with symptomatic congenital cytomegalovirus infection

Protective capacity of neutralizing and non-neutralizing antibodies against glycoprotein B of cytomegalovirus

Human cytomegalovirus (HCMV) is an important, ubiquitous pathogen that causes severe clinical disease in immunocompromised individuals, such as organ transplant recipients and infants infected in utero. Antiviral chemotherapy remains problematic due to toxicity of the available compounds and the emergence of viruses resistant to available antiviral therapies. Antiviral antibodies could represent a valuable alternative strategy to limit the clinical consequences of viral disease in patients. The envelope glycoprotein B (gB) of HCMV is a major antigen for the induction of virus neutralizing antibodies. However, the role of anti-gB antibodies in the course of the infection in-vivo remains unknown. We have used a murine CMV (MCMV) model to generate and study a number of anti-gB monoclonal antibodies (mAbs) with differing virus-neutralizing capacities. The mAbs were found to bind to similar antigenic structures on MCMV gB that are represented in HCMV gB. When mAbs were used in immunodeficient RAG-/- hosts to limit an ongoing infection we observed a reduction in viral load both with mAbs having potent neutralizing capacity in-vitro as well as mAbs classified as non-neutralizing. In a therapeutic setting, neutralizing mAbs showed a greater capacity to reduce the viral burden compared to non-neutralizing antibodies. Efficacy was correlated with sustained concentration of virus neutralizing mAbs in-vivo rather than their in-vitro neutralizing capacity. Combinations of neutralizing mAbs further augmented the antiviral effect and were found to be as potent in protection as polyvalent serum from immune animals. Prophylactic administration of mAbs before infection was also protective and both neutralizing and non-neutralizing mAbs were equally effective in preventing lethal infection of immunodeficient mice. In summary, our data argue that therapeutic application of potently neutralizing mAbs against gB represent a strategy to modify the outcome of CMV infection in immunodeficient hosts. When present before infection, both neutralizing and non-neutralizing anti-gB exhibited protective capacity.

Congenital Human Cytomegalovirus Infection and the Enigma of Maternal Immunity

Human cytomegalovirus (HCMV) is the most common viral infection acquired by the developing human fetus and can result in damage to the developing central nervous system. Although vaccine development to modify this congenital infection is ongoing, the unique epidemiology of maternal HCMV infections appears discordant with strategies for vaccine development. Several characteristics of congenital HCMV infections suggest that the efficacy of vaccines designed to induce responses similar to those that follow natural infection will be limited.

Long-term outcomes of children with symptomatic congenital cytomegalovirus disease

OBJECTIVE

To assess long-term outcomes of children with symptomatic congenital cytomegalovirus (CMV) disease detected at birth.

STUDY DESIGN

We used Cox regression to assess risk factors for intellectual disability (intelligence quotient <70), sensorineural hearing loss (SNHL; hearing level ⩾25 dB in any audiometric frequency) and vision impairment (best corrected visual acuity >20 or based on ophthalmologist report).

RESULTS

Among 76 case-patients followed through median age of 13 (range: 0-27) years, 56 (74%) had SNHL, 31 (43%, n=72) had intellectual disability and 18 (27%, n=66) had vision impairment; 28 (43%, n=65) had intellectual disability and SNHL with/without vision impairment. Microcephaly was significantly associated with each of the three outcomes. Tissue destruction and dysplastic growth on head computed tomography scan at birth was significantly associated with intellectual disability and SNHL.

CONCLUSION

Infants with symptomatic congenital CMV disease may develop moderate to severe impairments that were associated with presence of microcephaly and brain abnormalities.

Apparent Diffusion Coefficient Value Changes and Clinical Correlation in 90 Cases of Cytomegalovirus-Infected Fetuses with Unremarkable Fetal MRI Results

BACKGROUND AND PURPOSE

Cytomegalovirus is the leading intrauterine infection. Fetal MR imaging is an accepted tool for fetal brain evaluation, yet it still lacks the ability to accurately predict the extent of the neurodevelopmental impairment, especially in fetal MR imaging scans with unremarkable findings. Our hypothesis was that intrauterine cytomegalovirus infection causes diffusional changes in fetal brains and that those changes may correlate with the severity of neurodevelopmental deficiencies.

MATERIALS AND METHODS

A retrospective analysis was performed on 90 fetal MR imaging scans of cytomegalovirus-infected fetuses with unremarkable results and compared with a matched gestational age control group of 68 fetal head MR imaging scans. ADC values were measured and averaged in the frontal, parietal, occipital, and temporal lobes; basal ganglia; thalamus; and pons. For neurocognitive assessment, the Vineland Adaptive Behavior Scales, Second Edition (VABS-II) was used on 58 children in the cytomegalovirus-infected group.

RESULTS

ADC values were reduced for the cytomegalovirus-infected fetuses in most brain areas studied. The VABS-II showed no trend for the major domains or the composite score of the VABS-II for the cytomegalovirus-infected children compared with the healthy population distribution. Some subdomains showed an association between ADC values and VABS-II scores.

CONCLUSIONS

Cytomegalovirus infection causes diffuse reduction in ADC values in the fetal brain even in unremarkable fetal MR imaging scans. Cytomegalovirus-infected children with unremarkable fetal MR imaging scans do not deviate from the healthy population in the VABS-II neurocognitive assessment. ADC values were not correlated with VABS-II scores. However, the lack of clinical findings, as seen in most cytomegalovirus-infected fetuses, does not eliminate the possibility of future neurodevelopmental pathology.

Congenital Cytomegalovirus infection: advances and challenges in diagnosis, prevention and treatment

Cytomegalovirus (CMV) is the most frequent cause of congenital infection worldwide, with an estimated incidence in developing countries of 0.6-0.7% of all live births. The burden of disease related to congenital CMV in substantial, as it is the leading non-genetic cause of sensorineural hearing loss and an important cause of neurodevelopmental disabilities in children. Despite its clinical significance, congenital CMV infection often goes undetected because the majority of infected infants are asymptomatic at birth and screening programs have not been substantially implemented. Other than behavioral measures, effective interventions aimed at the prevention of maternal infection and of mother-to-child transmission are lacking. Due to a convergence of recent advances in both diagnostic and therapeutic strategies in infants with congenital CMV, though, the field likely will be changing rapidly over just the next few years. Specifically, a highly-sensitive screening test with high throughput potential has been developed, and treatment of infants symptomatically infected with congenital CMV has proven to be well-tolerated and effective in improving long-term hearing and neurodevelopmental outcomes.This review highlights the clinical importance of congenital CMV infection, the developments in laboratory diagnostics, and the benefits of antiviral therapy. It also identifies the global efforts still required in the prevention of maternal infection and in the optimization of antiviral therapy to further reduce the burden of congenital CMV disease.

Cytomegalovirus infection in pregnancy

Cytomegalovirus (CMV) is a DNA herpesvirus that is common worldwide. The two known main sources of primary CMV infection during pregnancy are through sexual activity and contact with young children. Primary infection occurs in approximately 1 to 4% of pregnancies, and is mostly asymptomatic in immunocompetent adults. However, primary infection may manifest as a mild mononucleosis or flu-like syndrome with persistent fever and fatigue. CMV can be transmitted from mother-to-child in utero, intrapartum, or during breastfeeding. Intrauterine transmission can lead to congenital CMV infection, a leading cause of permanent hearing and vision loss and neurological disability among children. Congenital CMV transmission rates are as high as 50% in women who acquire primary CMV infection during pregnancy, and less than 2% in women with nonprimary infection. There is no licensed CMV vaccine. Good hygiene practices and avoiding intimate contact with young children (e.g., kissing on the mouth and sharing utensils) have been suggested as an approach to prevent maternal primary CMV infection during pregnancy, but remains an unproven method of reducing the risk of congenital CMV infection. Approximately 1 in 10 infants who acquire CMV in utero will have clinical signs at birth, and an additional 10 to 15% will go on to develop late-onset sequelae. Antiviral treatment prenatally and postnatally has not proven effective at preventing congenital or postnatal CMV infection, and is not recommended for routine clinical care. However, antiviral treatment when initiated in the first month of life for symptomatic congenital CMV infection is recommended for improved neurodevelopmental and audiologic outcomes. Birth Defects Research 109:336-346, 2017. © 2017 Wiley Periodicals, Inc.

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.

Primary versus non-primary maternal cytomegalovirus infection as a cause of symptomatic congenital infection - register-based study from Finland

BACKGROUND

Both primary and non-primary maternal cytomegalovirus (CMV) infection during pregnancy can lead to vertical transmission. We evaluated the proportion of maternal primary/non-primary infections among 26 babies with symptomatic congenital CMV infection born in Finland from 2000 to 2012.

METHODS

We executed a database search on hospital records from all five university hospitals in Finland to identify infants with congenital CMV infection. The preserved maternal serum samples drawn at the end of the first trimester were analysed for CMV antibodies. Maternal infection was classified to be non-primary, if there was high avidity CMV immunoglobulin G (IgG) in the early pregnancy samples. Infection was considered primary in the case of either low avidity IgG (primary infection in the first trimester or near conception) or absent CMV IgG at the end of the first trimester (primary infection in the second or third trimester).

RESULTS

The majority of the symptomatic congenital CMV infections (54%) were due to maternal non-primary infection, 27% due to maternal primary infection in the first trimester or near conception, and 19% during the second or third trimester. Long-term sequelae occurred in 59% of patients: in 6/7 after primary infection in the first trimester, in 0/5 after primary infection in the second or third trimester, and in 9/14 after non-primary infection.

CONCLUSIONS

In this register-based cohort, non-primary infections caused the majority of symptomatic congenital CMV infections, and resulted in significant morbidity.

Screening for seemingly healthy newborns with congenital cytomegalovirus infection by quantitative real-time polymerase chain reaction using newborn urine: an observational study

OBJECTIVE

Approximately 8-10% of newborns with asymptomatic congenital cytomegalovirus (cCMV) infection develop sensorineural hearing loss (SNHL). However, the relationship between CMV load, SNHL and central nervous system (CNS) damage in cCMV infection remains unclear. This study aimed to examine the relationship between urinary CMV load, SNHL and CNS damage in newborns with cCMV infection.

STUDY DESIGN

The study included 23 368 newborns from two maternity hospitals in Saitama Prefecture, Japan. Urine screening for cCMV infection (quantitative real-time PCR) and newborn hearing screening (automated auditory brainstem response (AABR) testing) were conducted within 5 days of birth to examine the incidence of cCMV infection and SNHL, respectively. CNS damage was assessed by MRI of cCMV-infected newborns.

RESULTS

The incidence of cCMV infection was 60/23 368 (0.257%; 95% CI 0.192% to 0.322%). The geometric mean urinary CMV DNA copy number in newborns with cCMV was 1.79×10⁶ copies/mL (95% CI 7.97×10⁵ to 4.02×10⁶). AABR testing revealed abnormalities in 171 of the 22 229 (0.769%) newborns whose parents approved hearing screening. Of these 171 newborns, 22 had SNHL (12.9%), and 5 of these 22 were infected with cCMV (22.7%). Newborns with both cCMV and SNHL had a higher urinary CMV DNA copy number than newborns with cCMV without SNHL (p=0.036). MRI revealed CNS damage, including white matter abnormalities, in 83.0% of newborns with cCMV. Moreover, newborns with CNS damage had a significantly greater urinary CMV load than newborns without CNS damage (p=0.013).

CONCLUSIONS

We determined the incidence of cCMV infection and urinary CMV DNA copy number in seemingly healthy newborns from two hospitals in Saitama Prefecture. SNHL and CNS damage were associated with urinary CMV DNA copy number. Quantification of urinary CMV load may effectively predict the incidence of late-onset SNHL and neurodevelopmental disorders.

Congenital cytomegalovirus related intestinal malrotation: a case report

Background

Cytomegalovirus is the most common cause of congenital infection in the developed countries. Gastrointestinal involvement has been extensively described in both adult and paediatric immunocompromised patients but it is infrequent in congenital or perinatal CMV infection.

Case presentation

We report on a case of coexistent congenital Cytomegalovirus infection with intestinal malrotation and positive intestinal Cytomegalovirus biopsy. At birth the neonate showed clinical and radiological evidence of intestinal obstruction. Meconium passed only after evacuative nursing procedures; stooling pattern was irregular; gastric residuals were bile-stained. Laparatomy revealed a complete intestinal malrotation and contextually gastrointestinal biopsy samples of the appendix confirmed the diagnosis of CMV gastrointestinal disease. Intravenous ganciclovir was initiated for 2 weeks, followed by oral valgancyclovir for 6 month.

Conclusion

CMV-induced proinflammatory process may be responsible of the interruption of the normal development of the gut or could in turn lead to a disruption in the normal development of the gut potentiating the mechanism causing malrotation. We suggest the hypothesis that an inflammatory process induced by CMV congenital infection may be responsible, in the early gestation, of the intestinal end-organ disease, as the intestinal malrotation. CMV infection should always be excluded in full-term infants presenting with colonic stricture or malrotation.

Activation of Innate and Adaptive Immunity by a Recombinant Human Cytomegalovirus Strain Expressing an NKG2D Ligand

Development of an effective vaccine against human cytomegalovirus (HCMV) is a need of utmost medical importance. Generally, it is believed that a live attenuated vaccine would best provide protective immunity against this tenacious pathogen. Here, we propose a strategy for an HCMV vaccine that aims at the simultaneous activation of innate and adaptive immune responses. An HCMV strain expressing the host ligand ULBP2 for the NKG2D receptor was found to be susceptible to control by natural killer (NK) cells, and preserved the ability to stimulate HCMV-specific T cells. Infection with the ULBP2-expressing HCMV strain caused diminished cell surface levels of MHC class I molecules. While expression of the NKG2D ligand increased the cytolytic activity of NK cells, NKG2D engagement in CD8+ T cells provided co-stimulation and compensated for lower MHC class I expression. Altogether, our data indicate that triggering of both arms of the immune system is a promising approach applicable to the generation of a live attenuated HCMV vaccine.

Human cytomegalovirus (CMV) is a major cause of morbidity and mortality in congenitally infected newborns and immunocompromised individuals, indicating an utmost need for a vaccine to protect these vulnerable groups. Recent experimental studies in animal models, including non-human primates, have shown that attenuated CMVs trigger a potent immune response and are attractive vaccine candidates. However, an effective CMV vaccine is still not available. Here, we demonstrate that rational engineering of a live attenuated human CMV vaccine candidate is feasible. We equipped a CMV strain with an immunostimulatory molecule that is a ligand for an activating receptor present on both Natural Killer cells and CD8+ T cells. Moreover, we deleted several immunoevasins involved in downregulation of MHC class I molecules and of a ligand for Natural Killer cells in order to elicit stronger immune responses. In vitro assays using human immune cells and a first assessment in a humanized mouse model in vivo suggest that the generated CMV strain is attenuated and has the ability to induce a virus-specific immune response. Our study proposes this novel approach for the development of a rationally engineered CMV vaccine.

Prospects of a vaccine for the prevention of congenital cytomegalovirus disease

Congenital human cytomegalovirus (HCMV) infection is one leading cause of childhood disabilities. Prevention of congenital HCMV disease by vaccination has consequently been identified as a priority public healthcare goal. Several vaccine candidates have been introduced in the past that aimed at the prevention of primary HCMV infection in pregnancy. None of these has provided complete protection, and no licensed vaccine is thus far available. An additional level of complexity has been reached by recent studies indicating that the burden of HCMV transmission and disease following non-primary infections in pregnancy may be higher than previously anticipated. Substantial progress in our understanding of the immunobiology of HCMV infection in pregnancy has fostered studies to test revised or novel vaccine strategies. Preventing HCMV transmission has been identified a surrogate endpoint, rendering the conduction of vaccine studies feasible with reasonable effort. Identification of the glycoprotein complex gH/gL/UL128-131 as a mediator of HCMV host cell tropism and evaluation of that complex as a major target of the neutralizing antibody response made manufacturers consider vaccine candidates that include these proteins. Detailed structural analyses of the neutralizing determinants on HCMV glycoprotein B (gB) have revived interest in using this protein in its pre-fusion conformation for vaccine purposes. Studies in pregnant women and in animal models have provided evidence that addressing the T lymphocyte response by vaccination may be crucial to prevent HCMV transmission to the offspring. CD4 T lymphocytes may be of particular importance in this respect. A simultaneous targeting of both the humoral and cellular immune response against HCMV by vaccination thus appears warranted in order to prevent congenital HCMV infection. There is, however, still need for further research to be able to define an immunological correlate of protection against HCMV transmission during pregnancy. This brief review will highlight recent developments in our understanding of the natural history and immunobiology of HCMV infection in pregnancy and their possible impact on the strategies for the development of an HCMV vaccine.

Clinical Predictors of Sensorineural Hearing Loss and Cognitive Outcome in Infants with Symptomatic Congenital Cytomegalovirus Infection

The objective of this study was to determine newborn clinical findings predictive of adverse clinical outcomes in infants with symptomatic congenital cytomegalovirus infection. Of 160 infants, significantly more children with central nervous system involvement had sensorineural hearing loss (P = 0.0007) and an IQ ≤70 (P < 0.0001) compared with infants with transient findings or only a petechial rash.

Hearing in Children with Congenital Cytomegalovirus Infection: Results of a Longitudinal Study

OBJECTIVES

To evaluate hearing outcome, to characterize the nature of symptomatic and asymptomatic congenital cytomegalovirus (cCMV) infection and associated hearing loss, and to compare results with data from previous studies.

STUDY DESIGN

A prospective multicenter registry was set up in 2007. Six centers participated in the development of a standardized protocol for diagnosis, treatment, and follow-up. Data were gathered in an online registry. Children (n = 379) with a documented cCMV infection and at least 2 separate audiologic evaluations were included. Audiometric results from a multicenter cohort study of children with cCMV infection with longitudinal observation were examined.

RESULTS

Results from 123 children with a symptomatic and 256 children with an asymptomatic cCMV infection were analyzed. In the group with symptomatic cCMV, 63% had hearing loss, compared with 8% in the group with asymptomatic cCMV. Delayed-onset hearing loss occurred in 10.6% of symptomatic cCMV and in 7.8% of asymptomatic cCMV. In the group with symptomatic cCMV, 29.3% of children used some kind of hearing amplification; 1.6% in the group with asymptomatic cCMV used hearing amplification.

CONCLUSIONS

Symptomatic and asymptomatic cCMV infections are a major cause of hearing loss in childhood. Reliable estimates of the long-term outcome of cCMV infection are mandatory to increase vigilance, especially among pregnant women and to draw attention to preventive measures, vaccine development, and prenatal and postnatal therapy. Universal screening of newborns for cCMV infection should be initiated and combined with longitudinal audiometric follow-up.

Neurological outcomes in symptomatic congenital cytomegalovirus-infected infants after introduction of newborn urine screening and antiviral treatment

BACKGROUND

Newborn screening for urinary cytomegalovirus (CMV) and early introduction of antiviral treatment are expected to improve neurological outcomes in symptomatic congenital CMV-infected infants. This cohort study prospectively evaluated neurological outcomes in symptomatic congenital CMV-infected infants following the introduction of hospital-based newborn urinary CMV screening and antiviral treatment.

SUBJECTS/METHODS

Following institutional review board approval and written informed consent from their parents, newborns were prospectively screened from 2009 to 2014 for urinary CMV-DNA by PCR within 1 week after birth at Kobe University Hospital and affiliated hospitals. CMV-positive newborns were further examined at Kobe University Hospital, and those diagnosed as symptomatic were treated with valganciclovir for 6 weeks plus immunoglobulin. Clinical neurological outcomes were evaluated at age ⩾12 months and categorized by the presence and severity of neurologic sequelae.

RESULTS

Urine samples of 6348 newborns were screened, with 32 (0.50%) positive for CMV. Of these, 16 were diagnosed with symptomatic infection and 12 received antiviral treatment. Four infants developed severe impairment (33%), three developed mild impairment (25%), and five developed normally (42%).

CONCLUSIONS

This is the first Japanese report of neurological assessments in infants with symptomatic congenital CMV infection who received early diagnosis and antiviral treatment. Urinary screening, resulting in early diagnosis and treatment, may yield better neurological outcomes in symptomatic congenital CMV-infected infants.

Symptomatic Congenital Cytomegalovirus Infection Is Underdiagnosed in British Columbia

Records were reviewed from all infants tested for congenital cytomegalovirus infection in British Columbia, Canada from 2006 to June 2014. Fourteen of 701 infants, or approximately 4.2 per 100,000 live births, had a positive test, indicating that >90% of expected symptomatic congenital cytomegalovirus infection cases were not diagnosed using clinician-initiated testing.

Time-Series Analysis Comparing the Prevalence of Antibodies against Nine Viral Species Found in Umbilical Cord Blood in Japan

In this study, we investigated the prevalence of antibodies against 9 viral species found in umbilical cord blood from 561 neonates in 2013. Serum IgG antibodies against the following viruses were measured: herpes simplex virus (HSV), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus 6 (HHV-6), measles virus (MV), rubella virus (RV), mumps virus (MuV), and human parvovirus B19 (HPV B19). A survey questionnaire regarding past medical history and maternal immunization status for the vaccine-preventable diseases of varicella, measles, rubella, and mumps was simultaneously administered. The results were compared with previous data collected in 2001-2002 from 378 umbilical cord blood samples. Viral seroprevalence data were: HSV, 54%; VZV, 96%; EBV, 96%; CMV, 67%; HHV-6, 100%; MV, 95%; RV, 94%; MuV, 64%; and HPV B19, 55%. The seroprevalence of CMV, MV, and MuV were significantly lower in 2013 than in 2001-2002 (CMV, 76%; MV, 98%; MuV, 93%). Compared with the 2001-2002 data, the mean IgG antibody values of the 4 vaccine-preventable diseases were significantly lower, and vaccination coverage for those diseases among mothers was significantly higher. Thus, attention should be paid to antibody levels in women of childbearing age in the future.

Cytomegalovirus Genotype Distribution Among Congenitally and Postnatally Infected Patients: Association of Particular Glycoprotein (g)B and gN Types With Symptomatic Disease

Background. Human cytomegalovirus is a leading cause of congenital infection, and there are limited data on prognosis markers in disease development. We aimed to study 3 virology targets (glycoprotein [g]B, gN, and UL144) to assess their correlation with congenital infection and various organ system involvement.

Methods. Forty-eight congenital cases and 58 postnatally infected children were included (2003–2014). Genotyping for the 3 targets and distribution among the cohorts were investigated, and the relationship between the gB, gN, and UL144 types with clinical manifestations in congenital infection was also studied.

Results. All of the genotypes were similarly represented among cohorts, and the most prevalent were the UL144B, gB1, and gN1 genotypes. The gB2 genotype was associated with abnormal image findings by ultrasound and/or magnetic resonance in congenital infection (odds ratio [OR], 6.2; 95% confidence interval [CI], 1.1–34.3; P = .036); the gN1 genotype was associated with an elevated risk of developing neurological disorders (OR, 7.0; 95% CI, 1.1–45.9; P = .043). Both gN1 and gB2 were independent factors for symptomatic infection. Statistical analyses showed no association between any UL144 genotype and disease severity.

Conclusions. All of the genotypes can be involved in congenital infection, although the gB2 and gN1 genotypes might be associated with a more serious illness.

Hepatic involvement in congenital cytomegalovirus infection - infrequent yet significant

Congenital cytomegalovirus (cCMV) infection can reside in many organ systems; however, the virus has a particular predilection towards inhabiting the reticuloendothelial system, especially the liver. Specific studies focusing only on hepatic involvement in infants with cCMV are lacking. We report our experience with a large cohort of infants treated in our hospital clinic due to cCMV and hepatic involvement. Hepatic involvement was defined either as hepatitis (elevated alanine transaminases (ALT) >80 units/L without cholestatic disease) or cholestatic disease (elevated ALT >80 units/L combined with direct bilirubin >2 mg/dL). During the study period, 198 infants were diagnosed with symptomatic cCMV in our clinic. Hepatic involvement was observed in 13 infants (6.6%); 7 (3.5%) with hepatitis and 6 (3%) with cholestatic disease. Maternal primary infection with cytomegalovirus during pregnancy was diagnosed in 7 (53.8%) of the 13 infants, nonprimary in 3 (23.1%) and unknown in 3 (23.1%). Among these 13 infants, central nervous system (CNS) involvement was observed in 11 (84.6%) and hearing impairment in 7 (53.8%). Treatment with an antiviral agent was initiated in all cases. Gradual improvement of hepatic enzymes and cholestasis was observed over a prolonged period. We found that the incidence of hepatic involvement in infants with cCMV is much less frequent than previously reported. The hepatic involvement in these infants may manifest in two different ways, and thus, a high index of suspicion and a stepwise approach will help in correctly diagnosing these infants. Antiviral treatment due to CNS involvement is warranted and prognosis is excellent.

Current controversies in diagnosis, management, and prevention of congenital cytomegalovirus: updates for the pediatric practitioner

Congenital cytomegalovirus (CMV) infection has been called "the elephant in our living room" because it is a major public health problem that for decades has been unrecognized and unaddressed. Congenital CMV infection is a common cause of sensorineural hearing loss, vision loss, neurodevelopment disabilities, liver disease, and growth failure. Diagnostic tests are now widely available to identify newborns with congenital CMV infection, congenitally infected newborns now can be easily assessed for evidence of organ involvement, and there are now antiviral treatments and other interventions available to improve the outcome in children with congenital CMV disease. A licensed vaccine to prevent CMV infection is not yet available; however, a "CMV knowledge vaccine," composed of "an ounce of CMV awareness and three simple precautions" and that is endorsed by the Centers for Disease Control and Prevention is available for pregnant women who wish to reduce their contact with potentially CMV-infected secretions and therefore reduce their risk of acquiring CMV during pregnancy. Medical experts in the field of congenital CMV have been called upon for a consensus statement for diagnosis and treatment, and nonprofit organizations of families affected by congenital CMV from around the world have formed a collaborative coalition to facilitate the spread of CMV knowledge and awareness.

Murine CMV-induced hearing loss is associated with inner ear inflammation and loss of spiral ganglia neurons

Congenital human cytomegalovirus (HCMV) occurs in 0.5–1% of live births and approximately 10% of infected infants develop hearing loss. The mechanism(s) of hearing loss remain unknown. We developed a murine model of CMV induced hearing loss in which murine cytomegalovirus (MCMV) infection of newborn mice leads to hematogenous spread of virus to the inner ear, induction of inflammatory responses, and hearing loss. Characteristics of the hearing loss described in infants with congenital HCMV infection were observed including, delayed onset, progressive hearing loss, and unilateral hearing loss in this model and, these characteristics were viral inoculum dependent. Viral antigens were present in the inner ear as were CD3+ mononuclear cells in the spiral ganglion and stria vascularis. Spiral ganglion neuron density was decreased after infection, thus providing a mechanism for hearing loss. The lack of significant inner ear histopathology and persistence of inflammation in cochlea of mice with hearing loss raised the possibility that inflammation was a major component of the mechanism(s) of hearing loss in MCMV infected mice.

Congenital infection with human cytomegalovirus (HCMV) is the most common viral infection of the fetus and occurs in 0.5–2.0% of all live births in most regions in the world. Infection of the fetus can result in a spectrum of end-organ disease, including long term damage to the central nervous system (CNS). Although less than 10% of infected infants exhibit clinical evidence of end-organ disease, up to 10% of the total number of infected infants develop hearing loss. Mechanisms of disease leading to hearing loss are poorly understood because of the limited availability of pathological specimens and accessibility of the inner ear. Existing small animal models fail to recapitulate many features of this infection of the inner ear. In this report we describe a mouse model in which newborn animals infected peripherally with murine CMV develop hearing loss following hematogenous spread of virus to the inner ear. Hearing loss occurs in 30–50% of animals and characteristics of hearing loss in infants with congenital HCMV infection, including delayed onset of hearing loss, progressive hearing loss, and unilateral hearing loss were present in infected mice. Our findings suggest that host derived inflammatory responses and not direct virus-mediated cytopathology are responsible for hearing loss. Findings from this study provide insight into potential mechanisms of hearing loss in infants with congenital HCMV infection.

Immunobiology of congenital cytomegalovirus infection of the central nervous system—the murine cytomegalovirus model

Congenital human cytomegalovirus infection is a leading infectious cause of long-term neurodevelopmental sequelae, including mental retardation and hearing defects. Strict species specificity of cytomegaloviruses has restricted the scope of studies of cytomegalovirus infection in animal models. To investigate the pathogenesis of congenital human cytomegalovirus infection, we developed a mouse cytomegalovirus model that recapitulates the major characteristics of central nervous system infection in human infants, including the route of neuroinvasion and neuropathological findings. Following intraperitoneal inoculation of newborn animals with mouse cytomegalovirus, the virus disseminates to the central nervous system during high-level viremia and replicates in the brain parenchyma, resulting in a focal but widespread, non-necrotizing encephalitis. Central nervous system infection is coupled with the recruitment of resident and peripheral immune cells as well as the expression of a large number of pro-inflammatory cytokines. Although infiltration of cellular constituents of the innate immune response characterizes the early immune response in the central nervous system, resolution of productive infection requires virus-specific CD8(+) T cells. Perinatal mouse cytomegalovirus infection results in profoundly altered postnatal development of the mouse central nervous system and long-term motor and sensory disabilities. Based on an enhanced understanding of the pathogenesis of this infection, prospects for novel intervention strategies aimed to improve the outcome of congenital human cytomegalovirus infection are proposed.