Vertically transmitted cytomegalovirus infection in newborn preterm infants

Handling of human milk to prevent acquired cytomegalovirus infection in Japanese neonatal intensive care units: The first nationwide survey

BACKGROUND

Human milk (HM) has been proven to provide immunological and nutritional advantages to neonates; however, acquired cytomegalovirus (CMV) infection can be associated with raw HM. In Japan, there are no standardized guidelines concerning HM handling. This cross-sectional survey was performed to reveal specific trends in HM handling in neonatal intensive care units (NICUs) in Japan.

METHODS

A questionnaire was sent to 255 NICUs participating in the Japanese Neonatologist Association in May 2020. It involved HM handling practices, such as maternal screening, pasteurization, storage, and the workforce.

RESULTS

Of 255 NICUs, 174 (67.8%) responded to the survey. Maternal CMV screening was carried out in 37 units (22.2%), and CMV inactivation in HM was performed in 44 units (26.5%). For CMV inactivation, a freeze-thawing method was employed in about 90% of units. In 70% of units providing CMV inactivation, CMV inactivation was conducted regardless of bodyweight and corrected gestational age of infants until the infants' discharge. Acquired CMV infection in preterm neonates was observed in 43 units (25.7%) in the survey period.

CONCLUSION

A wide range of HM handling practices are used in Japanese NICUs. A national guideline for handling HM in NICUs should be created to promote the infection control of CMV.

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.

Diagnosis of congenital infections in premature, low-birthweight newborns with intrauterine growth restriction caused by cytomegalovirus (CMV), herpes simplex virus (HSV), Parvo-B 19, and Zika virus: a systematic review

OBJECTIVES

To identify the prevalence of viral congenital infections in newborns classified as premature, low-birthweight, small for gestational age or intrauterine growth restriction.

METHODS

The definition considered for selecting papers were: P as newborns younger than 28 days; V as low-birthweight, prematurity and intrauterine growth restriction; O as frequency of congenital infections with Cytomegalovirus, Parvovirus B19, Herpes Simplex, and Zika virus. The research was performed using EMBASE, LILACS, SCOPUS and MEDLINE databases, with no limitations on date and language.

RESULTS

Eight studies were included. Manuscripts including Herpes Simplex, Zika virus or Parvovirus B19 did not fulfill the defined criteria. A wide variation in the frequency of CMV congenital infection (0-4.8%) was found, which might be attributed to regional and methodological differences between investigations.

CONCLUSIONS

Newborn characteristics associated with CMV congenital infections may direct investigations towards these patients with a higher probability of infection. However, as data are controversial, studies concerning screening of infection are important to define recommendations of diagnosis.

Literature Review and an Italian Hospital Experience about Post-Natal CMV Infection Acquired by Breast-Feeding in Very Low and/or Extremely Low Birth Weight Infants

Breastfeeding is recommended for all neonates due to a known variety of beneficial effects, but infants can be infected by cell-associated bacteria and viruses from breast milk, such as cytomegalovirus (CMV). The majority of CMV-seropositive breastfeeding women have a viral, self-restricted reactivation, can shed the virus in the milk for about 12 weeks after delivery, and can transmit the infection to their offspring. Post-natal CMV-infected term infants are mainly asymptomatic, while very low birth weight (VLBW, <1500 g) and extremely low birth weight (ELBW, <1000 g) infants may present with severe disease, short-term sequelae ranging from abnormalities in laboratory indexes to sepsis-like syndrome, and long-term sequelae such as developmental problems. Thus, the use of thermally treated maternal milk for VLBW/ELBW infants may be indicated to prevent/reduce the risk of CMV transmission. Different techniques, with varying efficacy in eradicating CMV and maintaining the activity of biological compounds in milk are available: long/short pasteurization, freeze-thawing, the use of microwaves, and ultraviolet-C irradiation. In our NICU, the use of maternal raw milk is always strongly recommended for term/preterm infants, but to reduce risk of CMV transmission, freeze-thawing mother's own milk is used in neonates with GA ≤ 30 weeks or/and weight ≤ 1000 g, usually regardless of serological maternal condition, as CMV screening is not routinely offered to pregnant women and the milk of seroimmune mothers is not evaluated for CMV reactivation, as its rate is similar to seroprevalence. Over the last 4 years, we had 10 VLBW/ELBW newborns in our NICU with late-onset sepsis and negative cultures. In these cases, the research of CMV DNA in neonatal urine or saliva, for the diagnosis of post-natal symptomatic infection (once congenital transmission has been excluded) may be useful and not invasive. The take-home message we would like to share is that acquired CMV infection should be considered in VLBW/ELBW infants breastfed by seropositive mothers and presenting severe symptoms-particularly sepsis with negative cultures. This could allow pediatricians to make better-quality diagnoses, perform supportive therapy, provide antiviral treatment if needed, or establish a "pre-emptive" therapy for these high-risk neonates.

Transmission of cytomegalovirus in fresh and freeze-thawed mother's own milk to very preterm infants: a cohort study

OBJECTIVES

The objectives of the study were to clarify: (i) the frequency of human cytomegalovirus (HCMV) transmission, (ii) the association between the viral load in mother's own milk (MOM), the amount of fresh MOM and transmission, and (iii) the frequency of sepsis-like-symptoms (SLS) among infants born to seropositive mothers compared to infants born to seronegative mothers.

STUDY DESIGN

This prospective cohort study enrolled very preterm infants (gestational age <32 weeks) from Denmark. Weekly samples of fresh MOM and urine were analyzed for HCMV-DNA.

RESULTS

Twenty-six very preterm infants were enrolled. Four acquired an HCMV infection, of which two developed SLS. HCMV-infected infants received MOM with a significant higher viral load compared to the HCMV-uninfected infants.

CONCLUSION

A combination of a high viral load and an increased amount of fresh MOM increased the risk of HCMV transmission. SLS was only slightly more common among infants exposed to HCMV positive MOM.

Timing of primary maternal cytomegalovirus infection and rates of vertical transmission and fetal consequences

OBJECTIVE

Cytomegalovirus infection is the most frequent congenital infection and a major cause of long-term neurologic morbidity. The aim of this meta-analysis was to calculate the pooled rates of vertical transmission and fetal impairments according to the timing of primary maternal infection.

DATA SOURCES

From inception to January 2020, MEDLINE, Scopus, Cochrane Library, and gray literature sources were used to search for related studies.

STUDY ELIGIBILITY CRITERIA

Cohort and observational studies reporting the timing of maternal cytomegalovirus infections and rate of vertical transmission or fetal impairments were included. The primary outcomes were vertical transmission and fetal insult, defined as either prenatal findings from the central nervous system leading to termination of pregnancy or the presence of neurologic symptoms at birth. The secondary outcomes included sensorineural hearing loss or neurodevelopmental delay at follow-up and prenatal central nervous system ultrasonography findings.

STUDY APPRAISAL AND SYNTHESIS METHODS

The pooled rates of the outcomes of interest with their 95% confidence intervals (CI) were calculated for primary maternal infection at the preconception period, periconception period, first trimester, second trimester, and third trimester.

RESULTS

A total of 17 studies were included. The pooled rates of vertical transmission (10 studies, 2942 fetuses) at the preconception period, periconception period, first trimester, second trimester, and third trimester were 5.5% (95% CI, 0.1-10.8), 21.0% (95% CI, 8.4-33.6), 36.8% (95% CI, 31.9-41.6), 40.3% (95% CI, 35.5-45.1), and 66.2% (95% CI, 58.2-74.1), respectively. The pooled rates of fetal insult in case of transmission (10 studies, 796 fetuses) were 28.8% (95% CI, 2.4-55.1), 19.3% (95% CI, 12.2-26.4), 0.9% (95% CI, 0-2.4%), and 0.4% (95% CI, 0-1.5), for maternal infection at the periconception period, first trimester, second trimester, and third trimester, respectively. The pooled rates of sensorineural hearing loss for maternal infection at the first, second, and third trimester were 22.8% (95% CI, 15.4-30.2), 0.1% (95% CI, 0-0.8), and 0% (95% CI, 0-0.1), respectively.

CONCLUSION

Vertical transmission after maternal primary cytomegalovirus infection increases with advancing pregnancy, starting from the preconception period. However, severe fetal impairments are rare after infection in the first trimester of pregnancy.

Prevalence and Clinical Manifestations of Congenital Cytomegalovirus Infection in a Screening Program in Madrid (PICCSA Study)

BACKGROUND

Cytomegalovirus (CMV) is the leading cause of congenital infection worldwide. Up to 15%-20% of infected newborns will develop long-term sequelae such as hearing loss and neurologic abnormalities. The aim of this study was to investigate the prevalence of congenital CMV infection (cCMV) and associated clinical abnormalities in Spain.

METHODS

A prospective screening for cCMV by viral load in saliva was performed. Saliva samples were obtained within the first 72 hours of life in a maternity ward in Madrid (Spain), during a 1-year period. All positive screening tests were confirmed with viral load in urine. Clinical, laboratory, auditory, visual and cerebral imaging assessments were performed in all children with cCMV.

RESULTS

Of the 4097 neonates born during the study period, 3190 (78%) were included. CMV viral load in saliva was detectable in 24/3190 (0.75%) children, and congenital infection was confirmed in 15/3190 (0.47%, CI 95%: 0.29%-0.77%). Positive predictive value was 62.5% (CI 95%: 46.5%-76.1%). Two infants presented symptoms at birth. Eight (53.3%) children showed abnormalities in magnetic resonance imaging; most of them isolated white matter abnormalities. Newborns with abnormalities in magnetic resonance imaging showed higher viral loads in blood and saliva (P = 0.04).

CONCLUSIONS

One in 200 neonates born in our hospital presented a cCMV infection. CMV viral load in saliva has been shown to be a simple and highly accepted screening method but should be confirmed by CMV detection in urine. In spite of the fact that half of infected children had abnormalities in cerebral imaging, diagnosis during the neonatal period would have been impossible without a screening program in most cases.

Targeted and universal screen in term and preterm infants for congenital CMV infection

Background: The aims of this study were to evaluate the incidence of congenital cytomegalovirus (CMV) in term and near-term infants who fail hearing screen (target screening), the incidence of congenital CMV infections in infants born before 33 weeks of gestation (universal screening) and the incidence of infants who need pharmacologic treatment for congenital CMV associated sensorineural hearing loss (SNHL).Methods: This was a retrospective cohort study that assessed two groups of infants born between 2014 and 2017. The first group consisted of infants born between 33 and 42 weeks gestation and the second group, of infants born before 33 weeks gestation. Targeted CMV screening was performed in the first group who either failed neonatal hearing screen or were growth retarded. Universal screen was performed in the second group of infants. CMV DNA was tested in urine samples using real time PCR soon after birth.Results: In the first group, 2078 infants were assessed, 19 (0.9%) were found to be CMV positive and in 9 (42%) valganciclovir treatment was initiated. In the second group, out of 549 urine samples/infants, none was positive for CMV DNA soon after birth.Conclusions: A joint strategy of targeted CMV screening in infants who fail hearing screen test with universal screen of premature infants can select infants at risk of hearing impairment due to congenital CMV soon after birth, allows for timely initiation of treatment and prevents dilemmas regarding congenital CMV diagnosis in infants who fail hearing screen in a later age until universal screen will be widely adopted.

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.

Sequence analyses of variable cytomegalovirus genes for distinction between breast milk- and transfusion-transmitted infections in very-low-birth-weight infants

BACKGROUND

Cytomegalovirus (CMV) transmission to very-low-birth-weight infants (VLBWIs) sometimes induces serious clinical symptoms. Although breast milk is considered a major source of transmission, transfusion-transmitted CMV (TT-CMV) infection is often suspected when CMV disease develops after transfusion. Thus, it is clinically important to distinguish between transfusion-transmitted and breast milk-transmitted CMV infections.

STUDY DESIGN AND METHODS

Study A: The incidence of acquired CMV transmission was prospectively investigated in 65 VLBWIs. Study B: To determine the transmission routes in 18 TT-CMV-suspected VLBWIs who had been reported in our hemovigilance system, we performed polymerase chain reaction for CMV DNA in fed breast milk and/or repository blood samples related to transfused leukoreduced blood products. Furthermore, we evaluated the identity of CMV strains in patients' urine/blood samples and fed breast milk by sequence analyses of variable CMV genes UL139 and UL146.

RESULTS

Study A: Acquired CMV infection was found in 4 of 65 VLBWIs (6.2%). Study B: CMV DNA was detected in fed breast milk for 12 of 14 TT-CMV-suspected cases, for which breast milk was available. Furthermore, CMV DNA sequence-matching rates between fed breast milk and patients' urine/blood for both UL139 and UL146 genes were 100% or nearly 100% in 11 patients. In contrast, repository blood samples for 11 of 14 patients were CMV DNA negative.

CONCLUSION

CMV is principally transmitted through breast milk in VLBWIs. The risk of TT-CMV seems to be extremely low when using leukoreduced blood products. Sequence analyses of the variable CMV genes are useful for evaluating CMV transmission routes.

Controversies in Breastfeeding

When addressing the compatibility of breastfeeding with certain maternal conditions, we need to differentiate between "contraindication" and "obstacle." Failure to distinguish between the two confuses new mothers and their families, and engenders misconceptions about breastfeeding advice by health professionals. Health conditions that may simply impede the initiation and duration of breastfeeding are often wrongly referred to as true contraindications to breastfeed, under the assumption that they might harm the health of the mother and/or that of the nursing infant. Here, we discuss several topics, including breast surgery, prolactinoma, concurrent new pregnancy, hormonal contraception, and use of medications and contrast agents, that continue to raise controversy. While most conditions appear to be compatible with breastfeeding, the major determinants of a woman's final choice of whether to nurse her infant or not are the attitude of health professionals and the state of mind of being an informed mother.

Parent Misidentification Leading to the Breastfeeding of the Wrong Baby in a Neonatal Intensive Care Unit

Patient: Male, 2 month

Final Diagnosis: 2 month old 32 weeks’ gestational age preterm infant

Symptoms: Prematurity

Medication: —

Clinical Procedure: Accidental breastfeeding of the wrong baby

Specialty: Pediatrics and Neonatology