Congenital Cytomegalovirus

CMV-induced Hearing Loss

Congenital cytomegalovirus (cCMV) infection is the most common fetal viral infection and contributes to about 25% of childhood hearing loss by the age of 4 years. It is the leading nongenetic cause of sensorineural hearing loss (SNHL). Infants born to seroimmune mothers are not completely protected from SNHL, although the severity of their hearing loss may be milder than that seen in those whose mothers had a primary infection. Both direct cytopathic effects and localized inflammatory responses contribute to the pathogenesis of cytomegalovirus (CMV)-induced hearing loss. Hearing loss may be delayed onset, progressive or fluctuating in nature, and therefore, a significant proportion will be missed by universal newborn hearing screening (NHS) and warrants close monitoring of hearing function at least until 5-6 years of age. A multidisciplinary approach is required for the management of hearing loss. These children may need assistive hearing devices or cochlear implantation depending on the severity of their hearing loss. In addition, early intervention services such as speech or occupational therapy could help better communication, language, and social skill outcomes. Preventive measures to decrease intrauterine CMV transmission that have been evaluated include personal protective measures, passive immunoprophylaxis and valacyclovir treatment during pregnancy in mothers with primary CMV infection. Several vaccine candidates are currently in testing and one candidate vaccine in phase 3 trials. Until a CMV vaccine becomes available, behavioral and educational interventions may be the most effective strategy to prevent maternal CMV infection.

B cells going viral in the CNS: Dynamics, complexities, and functions of B cells responding to viral encephalitis

A diverse number of DNA and RNA viruses have the potential to invade the central nervous system (CNS), causing inflammation and injury to cells that have a limited capacity for repair and regeneration. While rare, viral encephalitis in humans is often fatal and survivors commonly suffer from permanent neurological sequelae including seizures. Established treatment options are extremely limited, predominantly relying on vaccines, antivirals, or supportive care. Many viral CNS infections are characterized by the presence of antiviral antibodies in the cerebral spinal fluid (CSF), indicating local maintenance of protective antibody secreting cells. However, the mechanisms maintaining these humoral responses are poorly characterized. Furthermore, while both viral and autoimmune encephalitis are associated with the recruitment of diverse B cell subsets to the CNS, their protective and pathogenic roles aside from antibody production are just beginning to be understood. This review will focus on the relevance of B cell responses to viral CNS infections, with an emphasis on the importance of intrathecal immunity and the potential contribution to autoimmunity. Specifically, it will summarize the newest data characterizing B cell activation, differentiation, migration, and localization in clinical samples as well as experimental models of acute and persistent viral encephalitis.

Impact of maternal cytomegalovirus seroconversion on newborn and childhood hearing loss

Objectives/hypothesis

The objective of this study is to describe long-term hearing outcomes in infants born to mothers with a known cytomegalovirus (CMV) positivity who were not tested for congenital CMV.

Study type

Clinical research study.

Design

Retrospective cohort study.

Methods

Retrospective chart review was performed for mothers seropositive to CMV. Mother-infant dyads (130) were identified between January 1, 2013 and January 1, 2017. Outcomes data was collected through June 1, 2020. Demographics, risk factors for hearing loss, evidence of CMV infection, other causes of hearing loss, need for speech therapy services, and results of all hearing tests were collected.

Results

All 130 infants were asymptomatic and 5 were tested for congenital CMV. Five were negative for CMV and excluded from analyses. Of the remaining 125, only 1 had low-viral avidity IgG antibodies. None had IgM antibodies. Four children (3.2%) had hearing loss at last audiogram and one child had delayed onset SNHL due to an enlarged vestibular aqueduct. Speech therapy for communication was required for 33 children (26.4%).

Conclusions

Knowledge of maternal perinatal CMV status can allow for education about possible sequelae of cCMV, as well as trigger an alert for testing babies born to mothers with low-viral avidity IgG during the first trimester, when the risk of vertical transmission is highest. Also, babies born to CMV positive mothers may be more at risk for communication delays necessitating intervention. Studies focusing on the impact of maternal CMV related to childhood communication deficits could elucidate any direct relationships.

Oral Valganciclovir Therapy in Infants Aged ≤2 Months with Congenital Cytomegalovirus Disease: A Multicenter, Single-Arm, Open-Label Clinical Trial in Japan

Our aims were to determine the clinical impact of oral valganciclovir (VGCV) in infants aged ≤2 months with congenital cytomegalovirus (CMV) disease and evaluate the efficacy of VGCV when initiated beyond the neonatal period. The multicenter, single-arm, open-label clinical trial was conducted in Japan. Twenty-five infants aged ≤2 months with congenital CMV disease involving the central nervous system were enrolled and treated with VGCV for 6 months. The primary endpoint was the change in the whole blood CMV load before and after treatment. The secondary endpoint was the change in the auditory brainstem response (ABR) before and after treatment. Changes in ABR were assessed between the younger and older age groups (≤ and >30 days at treatment initiation). Of the 25 patients, one was excluded owing to epilepsy before VGCV administration. The median change in the CMV DNA level in whole blood was −246.0 IU/mL. The best ear and total ear assessments based on ABR were categorized as (improved + unchanged) after treatment for 100% and 93.8%, respectively. No differences in hearing efficacy were observed between the younger and older age groups. Oral VGCV is a potential therapeutic option for treating infants aged ≤2 months with congenital CMV disease.

Congenital Human Cytomegalovirus Infection Inducing Sensorineural Hearing Loss

Human cytomegalovirus (HCMV) is the primary cause of congenital infections. Despite its clinical significance, congenital HCMV infection is frequently overlooked clinically since most affected infants are asymptomatic. Sensorineural hearing loss (SNHL) is one of the most widely known disorders caused by congenital HCMV infection. The potential mechanism, however, remains unknown to date. The mechanism by which congenital HCMV infection induces sensorineural deafness has been partly characterized, leading to advancements in diagnosis, therapy, and prevention strategies. HCMV-induced hearing loss primarily involves immune responses, the release of inflammatory factors by natural killer (NK) cells, apoptosis of cochlear spiral ganglion, and potential changes due to vascular dysfunction. The diagnosis of HCMV induced SNHL includes serological examination to mothers, imaging, and amniotic fluid examination. Ganciclovir, mainly used for antiviral therapy and behavioral prevention, can, to some degree, prevent congenital HCMV infection. The role of HCMV infection in hearing loss needs further investigation since the mechanism of hearing loss caused by cytomegalovirus infection is not well understood. Although some advancement has been made in diagnosing and treating SNHL, more improvement is needed. A comprehensive understanding of cytomegalovirus’s pathogenesis is of key importance for preventing, diagnosing, and treating SNHL.

The prevalence and demographic features of congenital cytomegalovirus infection in an urban area of East Asia: A population-based study

Congenital cytomegalovirus (cCMV) infection is the leading environmental cause of childhood hearing impairment. However, its significance remains largely undocumented in many regions of the world. The purpose of this study was to investigate the prevalence and clinical features of cCMV infection in East Asia. Neonates born at a municipal hospital in Taipei were prospectively recruited and underwent concurrent hearing and CMV screenings. Those who failed the hearing screening or screened positive for CMV were subjected to a focused audiological and/or virological surveillance. The characteristics of the newborns and their mothers were compared between the CMV-positive and CMV-negative groups. Of the 1,532 newborns who underwent concurrent hearing and CMV screenings, seven (0.46%) were positive for cCMV infection. All seven CMV-positive newborns were asymptomatic at birth, and none of them developed hearing or other symptoms during a follow-up period of 14.4±6.3 months. The mothers of the CMV-positive newborns demonstrated higher gravidity (2.4 ± 1.4 vs. 2.1 ± 1.2) and parity (2.0 ± 1.2 vs. 1.6 ± 0.7) than those in the CMV-negative group; however, the difference did not reach statistical significance. The prevalence of cCMV infection in Taipei newborns was 0.46%, which is slightly lower than that of other populations and that of a previous report in the Taiwanese population. The relatively low prevalence in this study might be attributed to the improved public health system and decreased fertility rate in Taiwan.

Assessing patient perceptions of cytomegalovirus infection in pregnancy

Pregnant women impacted by cytomegalovirus (CMV) make clinical decisions despite uncertain outcomes. Intolerance of uncertainty score (IUS) is a validated measure of tendency for individuals to find unacceptable that a negative event might occur. We investigated patient perceptions of CMV infection during pregnancy and correlated IUS and knowledge with decision-making. Electronic questionnaire was sent to women from July to August 2017. The questionnaire evaluated knowledge of CMV, IUS, and responses regarding management to three clinical scenarios with escalating risk of CMV including choices for no further testing, ultrasound, amniocentesis, or abortion. For each scenario, logistic regression was used to model IUS on responses. A total of 815 women were included. The majority of participants was white (63.1%) and 42% had a postgraduate degree. Over 70% reported that they had not previously heard of CMV. In the scenario with only CMV exposure, participants with increasing IUS were more likely to choose abortion (odds ratio [OR]  =  1.04; 95% confidence interval [CI]: 1.01, 1.06) and no further testing (OR  =  0.97; 95% CI: 0.95, 0.99). In the scenario with mild ultrasound findings in setting of CMV exposure, increasing IUS was associated with higher odds of choosing no further testing (OR = 0.97; 95% CI, 0.94, 0.99). No significant association was observed between IUS and responses in the scenario with severe ultrasound abnormalities in setting of CMV exposure. The majority of patients had no knowledge of CMV. Higher IUS was associated more intervention in low severity scenarios, but in severe scenarios, IUS was not associated with participants' choices.

Advances in Inner Ear Therapeutics for Hearing Loss in Children

Purpose of review

Hearing loss is a common congenital sensory disorder with various underlying causes. Here, we review and focus on genetic, infectious, and ototoxic causes and recent advances in inner ear therapeutics.

Recent findings

While hearing aids and cochlear implantation are the mainstay of treatment for pediatric hearing loss, novel biological therapeutics are being explored. Recent preclinical studies report positive results in viral-mediated gene transfer techniques and surgical approaches to the inner ear for genetic hearing loss. Novel pharmacologic agents, on the other hand, show promising results in reducing aminoglycoside and cisplatin ototoxicity. Clinical trials are underway to evaluate the efficacy of antivirals for cytomegalovirus-related hearing loss, and its pathogenesis and other potential therapeutics are currently under investigation.

Summary

Individualized therapies for genetic and infectious causes of sensorineural hearing loss in animal models as well as pediatric patients show promising results, with their potential efficacy being active areas of research.

Audiologic Status of Children with Confirmed Cytomegalovirus Infection: a Case Series

BACKGROUND

Congenital cytomegalovirus (CMV) infection is the most common non-genetic cause of sensorineural hearing loss (SHNL) in children. Only about 10% to 15% of children with congenital CMV are symptomatic, and most are not diagnosed at birth. About 7% to 15% of clinically asymptomatic patients may develop later complications, including SNHL, which is the most common sequela in clinically asymptomatic patients. In this study, hearing status was investigated in children with confirmed CMV infection and neonatal hearing screening (NHS) histories were reviewed to explore hearing loss caused by CMV.

METHODS

The medical records of 58 children who were diagnosed with confirmed CMV infection were reviewed for clinical symptoms and signs of CMV infection. Hearing status was evaluated with age-appropriate audiological test batteries.

RESULTS

A total of 58 children (M:F = 32:26 patients; age at study: mean, 5.62 years, range, 1-10 years) were diagnosed serologically with CMV infection (14 patients, 21.1%), or diagnosed via PCR of serum (5, 7.9%) and/or PCR from urine (19, 26.8%). Hearing loss was confirmed in 11 children (19.0%), being bilateral in 6 (54.5%), and unilateral in 5 (45.5%). Note that 7 of 17 ears with hearing loss passed NHS and were diagnosed only after re-evaluation when CMV infection was identified.

CONCLUSION

Hearing loss is a serious complication of CMV infection in children. Our results highlight the importance of timely audiological evaluation in children with clinically symptomatic CMV infection even if they pass NHS.

Where do we Stand after Decades of Studying Human Cytomegalovirus?

Human cytomegalovirus (HCMV), a linear double-stranded DNA betaherpesvirus belonging to the family of Herpesviridae, is characterized by widespread seroprevalence, ranging between 56% and 94%, strictly dependent on the socioeconomic background of the country being considered. Typically, HCMV causes asymptomatic infection in the immunocompetent population, while in immunocompromised individuals or when transmitted vertically from the mother to the fetus it leads to systemic disease with severe complications and high mortality rate. Following primary infection, HCMV establishes a state of latency primarily in myeloid cells, from which it can be reactivated by various inflammatory stimuli. Several studies have shown that HCMV, despite being a DNA virus, is highly prone to genetic variability that strongly influences its replication and dissemination rates as well as cellular tropism. In this scenario, the few currently available drugs for the treatment of HCMV infections are characterized by high toxicity, poor oral bioavailability, and emerging resistance. Here, we review past and current literature that has greatly advanced our understanding of the biology and genetics of HCMV, stressing the urgent need for innovative and safe anti-HCMV therapies and effective vaccines to treat and prevent HCMV infections, particularly in vulnerable populations.

Efficacy and safety of valganciclovir in patients with symptomatic congenital cytomegalovirus disease: Study Protocol Clinical Trial (SPIRIT Compliant)

BACKGROUND

Congenital cytomegalovirus (CMV) disease, a common mother-to-child infection, can lead to neurological sequelae. Some clinical trials have shown that oral valganciclovir (VGCV) can improve hearing and neurodevelopmental impairment in infants with congenital CMV disease. However, VGCV has neither been approved in Japan nor other countries as a treatment for this disease by the government health insurance.

METHODS

This study is a non-randomized, prospective, open-label, multicenter, single-arm clinical trial and will include subjects meeting the following criteria: confirmation of positive CMV-DNA amplification in urine by an in vitro diagnostic test within 21 days of age; congenital CMV disease with one or more central nervous system disorders-microcephaly, hydrocephalus or ventricular enlargement, periventricular calcification, cortical hypoplasia or white matter injury, retinal choroiditis, and abnormal auditory brainstem response (ABR); and infants within 2 months of age with a gestational age ≥32 weeks at birth and weighing ≥1800 g at the time of registration. Subjects will be orally administered 16 mg/kg VGCV twice daily for 6 months. The target number of cases for enrollment between February 3, 2020 and July 31, 2021 is 25. Primary endpoint is the change in whole blood CMV loads before and after 6 months of treatment. The important secondary endpoint is the change in ABR (both best and total ear hearing assessments) before and after 6 months of treatment. The safety endpoints are adverse events and drug side effects.

DISCUSSION

To the best of our knowledge, this multicenter, open-label, single-arm study will be the first well-designed clinical trial to evaluate the efficacy of oral VGCV in infants with congenital CMV diseases. The findings will reveal the efficacy and safety of oral VGCV treatments and enable the approval of oral VGCV as a treatment for infants with congenital CMV disease by the government health insurance of Japan.

Mevalonate kinase deficiency masked by cytomegalovirus infection and obscure liver disease

BACKGROUND

Chronic liver disease with conjugated hyperbilirubinaemia and failure to thrive can have multifactorial aetiologies. Investigations can be complex and difficult especially when obscured by a viral infection affecting liver function.

METHODS

A 5 month old male infant was referred for investigation of chronic liver disease and a history of jaundice with multiple febrile episodes. Liver function tests were performed followed by a liver biopsy and microbiological workup for infectious disease. In addition, urine analysis of organic acids was also performed.

RESULTS

There was marked conjugated hyperbilirubinaemia with markedly elevated hepatocellular enzymes and normal ductal enzymes. Proteinuria and near normal renal function suggested early renal impairment. There was also leukocytosis and bicytopenia. An extensive bacteriological investigation including TB workup was negative. CMV infection was confirmed by viral load and antibody reactivity. There was prolonged PT and PTT and high INR. The liver biopsy showed giant cell transformation of hepatocytes with mild cholestasis, portal and peri-cellular fibrosis with alpha-1-antitrypsin positive granules in the hepatocyte cytoplasm suggesting alpha-1-antitrypsin deficiency. Urine organic acids revealed significantly elevated mevalonolactone.

CONCLUSIONS

We confirmed the genetic diagnosis of mevalonic aciduria caused by MVK deficiency which had been masked by liver disease and the possible misdiagnosis of alpha-1-antitrypsin deficiency.

Fetal, neonatal, and infant death in central China (Hubei): A 16-year retrospective study of forensic autopsy cases

Data based on forensic autopsy in neonates and infants in China are rare in the literature. The purpose of this study is to evaluate the characteristics of fetal, neonatal, and infant death and to determine the main cause of death among them.A retrospective analysis of fetal and infant forensic autopsies referred to the Tongji Forensic Medical Center (TFMC) in Hubei, central China, during a 16-year period between January 1999 and December 2014, was performed.In this period, there were 1111 males and 543 females; the total male-to-female ratio (MFR) was 2.05:1. There were 173 fetal and infant autopsies conducted, comprised of 43 fetal, 84 neonatal (<28 days) and 46 infant (4 weeks to 1 year) cases. The annual case number ranged from 5 in 2004 to 18 in 2014 (annual mean of 10.8). MFR was 1.75:1. About 94% of these deaths (163/173) resulted from natural causes, 6 cases (3.5%) were accidental deaths, and 4 (2.3%) resulted from homicide (4 abandoned babies). Among fetuses, the most common causes of death were placental and umbilical cord pathologies (28%, 12/43), followed by intrapartum asphyxia resulting from amniotic fluid aspiration (AFA) or meconium aspiration syndrome (MAS) (18.6%, 8/43), congenital malformation (14%, 6/43), and intrapartum infection (9.3%, 4/43). A majority of neonatal deaths (66.7%, 56/84) died within 24 hours of birth. The main causes of neonatal death were asphyxia resulting from AFA, MAS, or hyaline membrane disease, and congenital malformation. The main causes of infant (1-12 months) death were infectious diseases, including pneumonia, meningitis, and viral brainstem encephalitis.This study was the 1st retrospective analysis of autopsies of fetal, neonatal, and infant death in TFMC and central China. We delineate the common causes of early demise among cases referred for autopsy, and report a male preponderance in this population. Our data observed that placental and/or umbilical cord pathology, asphyxia due to AFA, and/or MAS, and pneumonia were the leading causes of fetal, neonatal, and infant death, respectively. And it can inform clinical practitioners about the underlying causes of some of the most distressing cases in their practices.

US28: HCMV's Swiss Army Knife

US28 is one of four G protein coupled receptors (GPCRs) encoded by human cytomegalovirus (HCMV). The US28 protein (pUS28) is a potent signaling molecule that alters a variety of cellular pathways that ultimately alter the host cell environment. This viral GPCR is expressed not only in the context of lytic replication but also during viral latency, highlighting its multifunctional properties. pUS28 is a functional GPCR, and its manipulation of multiple signaling pathways likely impacts HCMV pathogenesis. Herein, we will discuss the impact of pUS28 on both lytic and latent infection, pUS28-mediated signaling and its downstream consequences, and the influence this viral GPCR may have on disease states, including cardiovascular disease and cancer. We will also discuss the potential for and progress towards exploiting pUS28 as a novel therapeutic to combat HCMV.

Evaluation and management of cytomegalovirus-associated congenital hearing loss

PURPOSE OF REVIEW

The current article reviews the current literature related to congenital cytomegalovirus (CMV)-related hearing loss. The discussion will focus on the epidemiology, pathogenesis, and clinical presentation of human CMV infection as it pertains to hearing loss. Current methods of CMV diagnosis with a focus on the evolving trend toward broader neonatal screening protocols will also be explored. Discussion of medical, surgical, and audiologic management of the condition will also be addressed.

RECENT FINDINGS

Much of the current research on this topic is focused on improving detection of CMV through screening programs. Some advances in understanding cochlear pathogenesis have also been made.

SUMMARY

Congenital CMV infection remains an important cause of hearing loss in infants and children. Early detection of CMV infection can broaden treatment options and allow for improved hearing and language outcome for patients with CMV-associated sensorineural hearing loss.

Knowledge of congenital cytomegalovirus (cCMV) among physical and occupational therapists in the United States

Congenital cytomegalovirus (cCMV) infections cause more children to have permanent disabilities than Down Syndrome, Fetal Alcohol Syndrome, Spina Bifida, and pediatric HIV/AIDS combined. The risk of infection during pregnancy can be significantly decreased using universal precautions, such as thorough handwashing and cleansing of surfaces and objects that have come into contact with infected body fluids. Children under 3 years of age are commonly asymptomatic excretors of CMV, with the highest viral loads present in saliva. Pediatric therapists have regular close contact with young children, and are thus likely at elevated occupational risk of acquiring CMV. Our objective was to evaluate therapist knowledge of cCMV and its transmission. We recruited American Occupational Therapy Association (AOTA) and American Physical Therapy Association (APTA) members via electronic newsletters and printed flyers from April to September 2015. Participants completed an online, anonymous 24-question survey using Survey Monkey. We compared responses between groups and previously published CMV awareness data using binomial tests of difference of proportions and multiple logistic regression. Our study identified both a low level of therapist awareness and poor demonstrated understanding of cCMV. Self-reported cCMV awareness amongst therapists was greater than awareness in the general population, and equivalent to awareness amongst health care professionals. Whereas 52% of participants self-reported awareness of cCMV, only 18% demonstrated understanding of the behavioral modes of CMV transmission. Fewer therapists reported awareness of cCMV than other, less prevalent conditions. Higher levels of health risk knowledge were associated with greater contact with children. Most participants reported learning about cCMV from the workplace. The knowledge gaps between self-reported awareness of cCMV and demonstrated understanding of modes of transmission described by our results emphasize the need for additional training of therapists. cCMV is preventable, and accurate knowledge of modes of transmission is crucial for the health of practitioners and clients.