Congenital and acquired cytomegalovirus infection and hearing evaluation in children

Congenital human cytomegalovirus infection and neurologic diseases in newborns

Objective:

This review aimed to summarize research progress regarding congenital cytomegalovirus (cCMV) infection-related nervous system diseases and their mechanisms.

Data sources:

All literature quoted in this review was retrieved from PubMed and Web of Science using the keywords “Cytomegalovirus” and “Neurologic disease” in English. To identify more important information, we did not set time limits.

Study selection:

Relevant articles were selected by carefully reading the titles and abstracts. Then, different diagnosis and clinical treatment methods for human CMV infection-related neurologic diseases were compared, and the main mechanism and pathogenesis of neurologic damage caused by CMV were summarized from the selected published articles.

Results:

cCMV infection is a major cause of neonatal malformation. cCMV can infect the fetal encephalon during early gestation and compromise neurodevelopment, resulting in varying degrees of neurologic damage, mainly including hearing impairment, central nervous system (CNS) infection, neurodevelopmental disorders, ophthalmic complications, cerebral neoplasms, infantile autism, epilepsy, and other neurologic abnormalities.

Conclusions:

cCMV infection-induced neurodevelopmental abnormalities, which were directly caused by fetal encephalon infection, thus inducing neuroimmune responses to damage nerve cells. Such abnormalities were also caused by suppression of the proliferation and differentiation of neural progenitor cells by CMV's gene products. cCMV infection in the fetal encephalon can also inhibit neuronal migration and synapse formation and indirectly trigger placental inflammation and thus disrupt the oxygen supply to the fetus.

Symptomatic Congenital Cytomegalovirus Infection in Children of Seropositive Women

Cytomegalovirus (CMV) is the most frequent congenital virus infection worldwide. The risk of congenital CMV (cCMV) transmission is highest in seronegative women who acquire primary CMV infection during pregnancy. A growing body of evidence indicates that secondary CMV infections in pregnant women with preconceptual immunity (either through reactivation of latent virus or re-infection with a new strain of CMV) contribute to a much greater proportion of symptomatic cCMV than was previously thought. Here, we describe a case of symptomatic cCMV infection in the newborn of a woman with proven immunity prior to pregnancy. Diagnosis was confirmed by CMV PCR from amniotic fluid and fetal MR imaging. The newborn presented with typical cCMV symptoms including jaundice, hepatosplenomegaly, cholestasis, petechiae, small head circumference, and sensorineural hearing loss, the most common neurologic sequela. CMV was detected in infant blood and urine by PCR, and intravenous ganciclovir was initiated and continued orally for 6 weeks totally. Apart from persisting right-sided deafness, the child exhibited normal neurological development up through the last follow-up at 4.5 years. To date, the most effective strategy to prevent vertical CMV transmission is hygiene counseling for women of childbearing age, which, in our case, and in concordance with recent literature, applies to seronegative, as well as seropositive, women. Once an expecting mother shows seroconversion or signs of an active CMV infection, there are no established procedures to reduce the risk of transmission, or therapeutic options for the fetus with signs of infection. After birth, symptomatic infants can be treated with ganciclovir to inhibit viral replication and improve hearing ability and neurodevelopmental outcome. A comprehensive review of the literature, including our case study, reveals the most current and significant diagnostic and treatment options available. In conclusion, the triad of maternal hygiene counseling, postnatal hearing screening of all newborns, followed by CMV PCR in symptomatic infants, and antiviral therapy of infants with symptomatic cCMV provides an outline of best practice to reduce the burden of CMV transmission sequelae.

Aetiological diagnosis of child deafness: CODEPEH recommendations

Important progress in the fields of molecular genetics (principally) and diagnostic imaging, together with the lack of a consensus protocol for guiding the diagnostic process after confirming deafness by neonatal screening, have led to this new work document drafted by the Spanish Commission for the Early Detection of Child Deafness (Spanish acronym: CODEPEH). This 2015 Recommendations Document, which is based on the most recent scientific evidence, provides guidance to professionals to support them in making decisions regarding aetiological diagnosis. Such diagnosis should be performed without delay and without impeding early intervention. Early identification of the causes of deafness offers many advantages: it prevents unnecessary trouble for the families, reduces health system expenses caused by performing different tests, and provides prognostic information that may guide therapeutic actions.

Discrepancy in impact of maternal milk on vertical transmission between Hepatitis B virus and Human cytomegalovirus

OBJECTIVES

This study aims to elucidate the role of breastfeeding on vertical transmission of HCMV and HBV and to investigate the difference in perinatal transmission via breast milk between HBV and HCMV.

METHODS

This detailed study monitored the kinetics of viral DNA load in maternal milk for both HBV and HCMV, demonstrated the rate of transmission to infants, and compared HBV infection rate with that of HCMV.

RESULTS

There was no difference in overall DNAlactia+ between HBV (23.86%) and HCMV (29.54%, P=0.140) for seropositive mothers, while HBsAg prevalence (0.75%) was significantly lower than HCMV IgG+ (27.44%, P<0.001) for the breast-fed babies. Between breast-fed babies of seropositive mothers and those of seronegative mothers, HBV infection rate had no difference (HBsAg+: 0.75% vs 0%, P=0.538; DNAemia+: 0.38% vs 0%, P=0.664), but HCMV infection rate of the former was significantly higher than that of the latter (IgG+: 27.07% vs 18.00%, P=0.045; DNAemia+: 15.79% vs 4.00%, P=0.027).

CONCLUSIONS

Breastfeeding is not a risk factor for maternal-to-infant transmission of HBV after the recommended prophylaxis is implemented. However, viral DNA positive breast milk is a main source for vertical transmission of HCMV to infants who are not protected by a standard immunoprophylaxis protocol.