Transmission of cytomegalovirus via breast milk in low birth weight and premature infants: a systematic review and meta-analysis

Acquired Cytomegalovirus Retinitis in Preterm Infant Hospitalized in the NICU: A Noteworthy Case Report

BACKGROUND

Acquired human cytomegalovirus (CMV) is a noteworthy disease in infants. This case study will highlight the influence of early diagnosis of CMV retinitis (CMVR) on avoid visual impairment.

CLINICAL FINDINGS

We describe a preterm female infant with a birth weight of 2060 gr that was admitted for tracheostomy placement due to hypoxic-ischemic encephalopathy. There were no signs of CMV infection or sepsis in laboratory results upon admission such as serology (IgG, IgM antibodies), Toxoplasma gondii , Rubella virus, Herpes simplex virus, CMVR and urine polymerase chain reaction (PCR).

PRIMARY DIAGNOSIS

Incidentally, upon screening for retinopathy of prematurity, diffuse occlusive vasculitis was detected in the retinal image on the 112th day of life.

INTERVENTION

Intravenous and intraocular ganciclovir were administered for 4 weeks.

OUTCOMES

In the follow-up visit 6 weeks after discharge from the hospital, visual impairment was detected on both sides.

PRACTICE RECOMMENDATIONS

This is a report of a case of acquired CMVR, a silent finding, as an uncommon complication in preterm neonates during the hospital stay. This diagnosis should be taken into consideration in preterm infants, since early diagnosis and treatment are crucial to avoid visual impairment.

Association between viral infection and bronchopulmonary dysplasia in preterm infants: a systematic review and meta-analysis

Bronchopulmonary dysplasia (BPD) is the most common serious complication of very preterm infants (VPI) or very low birth weight (VLBW) infants. Studies implicate viral infections in etiopathogenesis. The aim of this study was to summarize the relationship between viral infections and BPD through a systematic review and meta-analysis. We searched PubMed, Embase, the Web of Science Core Collection, and the Cochrane Database on December 19, 2023. We included observational studies that examined the association between viral infections and BPD in preterm infants. We extracted data on study methods, participant characteristics, exposure assessment, and outcome measures. We assessed study risk of bias using the Newcastle-Ottawa Scale (NOS). We included 17 and 15 studies in the qualitative review and meta-analysis, respectively. The meta-analysis showed a significant association between viral infection and BPD diagnosed at 36 weeks postmenstrual age (odds ratio (OR): 2.42, 95% confidence interval: 1.89-3.09, 13 studies, very low certainty of evidence). In a subgroup analysis of specific viruses, cytomegalovirus (CMV) proved to be significantly associated with BPD diagnosed at 36 weeks postmenstrual age (OR: 2.34, 95% confidence interval: 1.80-3.05, 11 studies). We did not find an association between viral infection and BPD diagnosed on the 28th day of life, probably due to the small sample size of the included prospective studies.  Conclusion: Viral infections, especially CMV, are associated with an increased risk of BPD in preterm infants. Methodologically reliable prospective studies with large samples are needed to validate our conclusions, and high-quality randomized controlled studies are needed to explore the effect of prevention or treatment of viral infections on the incidence of BPD. What is Known: • Studies have attempted to identify viral infections and bronchopulmonary dysplasia in preterm infants; however, results have been inconsistent. What is New: • Systematic demonstration that viral infections, particularly cytomegalovirus, are positively associated with bronchopulmonary dysplasia diagnosed in preterm infants at the 36th week of postmenstrual age. • The importance of screening for viral infections in preterm infants, especially cytomegalovirus. More high-quality studies should be produced in the future to investigate the causal relationship between viral infections and bronchopulmonary dysplasia.

Congenital and Postnatal Cytomegalovirus: Case Series and State of the Science for Neonatal Providers

Cytomegalovirus (CMV), a beta-herpes virus, is the most common viral infection in infants. Transmission may occur congenitally (cCMV) or postnatally (pCMV). Early detection and intervention are crucial in reducing morbidities, notable developmental delays, and sensorineural hearing loss. However, more than 90% of infants are asymptomatic at birth. Treatment involves intravenous ganciclovir or the oral prodrug, valganciclovir, drugs usually reserved for use with symptomatic infants because of the toxicity profile. Research currently supports standardized antenatal CMV screening and treatment of affected pregnant patients with hyperimmune globulin as well as vaccination against CMV in unaffected pregnant patients, although widespread adoption is lacking. Standardized postnatal CMV screening is a proven, cost-effective way to detect and diagnose CMV and optimize outcomes across the lifespan. This article presents a case series of cCMV and pCMV and a review of the state of science of CMV as well as promising scientific advances that are on the horizon.

Cytomegalovirus and Pregnancy: A Narrative Review

Cytomegalovirus (CMV) infection is the most common congenital infection worldwide, affecting between 0.7% and 1% of all live births. Approximately 11% of infected newborns are symptomatic at birth, and between 30% and 40% of these are at risk of developing long-term neurological sequelae. Until recently, the lack of an effective treatment did not justify universal testing of pregnant women. In recent years, however, valacyclovir at a dose of 8 g/day has been shown to be effective in preventing vertical transmission, and ganciclovir has been shown to be effective in preventing long-term sequelae in the treatment of symptomatic neonates. The aim of this article is to review congenital CMV infection, from its epidemiology to its treatment, using the most recent studies in the literature, and to help in the decision to modify protocols for universal testing of pregnant women according to the possibilities of each locality.

Neonatal Blood Banking Practices

There is little formal guidance to direct neonatal blood banking practices and, as a result, practices vary widely across institutions. In this vulnerable patient population with a high transfusion burden, considerations for blood product selection include freshness, extended-storage media, pathogen inactivation, and other modifications. The authors discuss the potential unintended adverse impacts in the neonatal recipient. Concerns such as immunodeficiency, donor exposures, cytomegalovirus transmission, volume overload, transfusion-associated hyperkalemia, and passive hemolysis from ABO incompatibility have driven modifications of blood components to improve safety.

Viruses and Human Milk: Transmission or Protection?

Human milk (HM) is considered the best source of nutrition for infant growth and health. This nourishment is unique and changes constantly during lactation to adapt to the physiological needs of the developing infant. It is also recognized as a potential route of transmission of some viral pathogens although the presence of a virus in HM rarely leads to a disease in an infant. This intriguing paradox can be explained by considering the intrinsic antiviral properties of HM. In this comprehensive and schematically presented review, we have described what viruses have been detected in HM so far and what their potential transmission risk through breastfeeding is. We have provided a description of all the antiviral compounds of HM, along with an analysis of their demonstrated and hypothesized mechanisms of action. Finally, we have also analyzed the impact of HM pasteurization and storage methods on the detection and transmission of viruses, and on the antiviral compounds of HM. We have highlighted that there is currently a deep knowledge on the potential transmission of viral pathogens through breastfeeding and on the antiviral properties of HM. The current evidence suggests that, in most cases, it is unnecessarily to deprive an infant of this high-quality nourishment and that the continuation of breastfeeding is in the best interest of the infant and the mother.

Routine breast milk monitoring using automated molecular assay system reduced postnatal CMV infection in preterm infants

Human cytomegalovirus (CMV) transmitted through breast milk poses fatal risks to preterm infants. However, current molecular assay systems often do not accommodate breast milk samples. In this study, we evaluated the analytical and clinical performance of the measurement procedure of CMV load in breast milk utilizing the Cobas CMV test on the Cobas 6,800 system. This was enabled by incorporating a simple independent sample preparation procedure before the application of samples on the automated assay system. Clinical data from electronic medical records were retrospectively analyzed. Breast milk samples from mothers of preterm infants born before 33 weeks of gestation were screened for CMV using the automated assay system. CMV positivity rates in breast milk and neonatal samples and the CMV transmission rate were calculated. Furthermore, to validate the analytical accuracy of the overall measurement procedure with newly obtained residual breast milk samples, the linearity of the measurement procedure was assessed, and a simplified sample preparation method was validated against a conventional method. The CMV positivity rates in maternal breast milk and neonatal samples were 57.8 and 5.2%, respectively. The CMV transmission rate through breast milk was 7.7%. No significant differences in gestational age or birth weight were found between the CMV-negative and CMV-positive neonates. The linearity of the procedure was observed within a range of 1.87-4.73 log IU/mL. The simplified sample preparation method had an equivalent or even improved CMV detection sensitivity than the conventional method. Incorporating a simple independent sample preparation procedure effectively resolved any potential issues regarding the application of breast milk on the automated assay system. Our approach contributed to reduced vertical transmission of CMV by providing a convenient and reliable method for the monitoring of breast milk CMV positivity for clinicians.

Prevention of human milk-acquired cytomegalovirus infection in very-low-birth-weight infants

BACKGROUND

The aim of the study was to determine the rate of cytomegalovirus virolactia in the human milk (HM) of mothers of VLBW infants, compare the CMV infection rates and the changes in CMV DNA viral load and nutrient profile among different HM preparation methods.

METHODS

A prospective randomized controlled study was performed in infants with gestational age < 32 weeks or birth-weight < 1500 g admitted to neonatal intensive care unit of Asan Medical Center and Haeundae Paik Hospital who were given mother's own milk. Enrolled infants were randomized into three groups according to the HM preparation methods: freezing-thawing (FT), FT + low-temperature Holder pasteurization (FT + LP), and FT + high-temperature short-term pasteurization (FT + HP). Urine CMV culture and PCR were obtained at birth and at 4, 8, and 12 weeks. HM CMV culture and PCR were obtained at birth and at 3, 6, 9, and 12 weeks. Changes in macronutrients in HM was obtained at 4 ~ 6 weeks.

RESULTS

Of 564 infants, 217 mothers (38.5%) produced CMV PCR positive milk. After exclusion, a total of 125 infants were randomized into the FT (n = 41), FT + LP (n = 42), and FT + HP (n = 42) groups, whose rate of HM-acquired CMV infection was 4.9% (n = 2), 9.5% (n = 4), and 2.4% (n = 1), respectively. Out of seven CMV infected infants, two infants fed with FT + LP HM developed CMV infection- associated symptoms. Ages at diagnoses were earlier (28.5 days after birth) and at younger post conceptional age (< 32 weeks) in comparison to infants with asymptomatic CMV infection. CMV DNA viral load significantly decreased after pasturizations, especially in FT + HP group.

CONCLUSIONS

HM-acquired symptomatic CMV infection rate is low and its impact on clinical course was not serious in our VLBW infants. However, evidences showing poor neurodevelopmental outcome in later life, we need to generate a guideline to protect VLBW infant form HM transmitted CMV infection. Based on our small sized study, we did not find any superiority in pasteurizing HM with frequently used LP in comparison to frozen or HP HM. More research is needed to determine the method and duration of pasteurization to reduce the HM-acquired CMV infection.