[Pilot epidemiologic study of transmission of cytomegalovirus from mother to preterm infant by breastfeeding]

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.

Incidence of Postnatal CMV Infection among Breastfed Preterm Infants: a Systematic Review and Meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis to evaluate the incidence of breast milk-acquired cytomegalovirus (CMV) infection in preterm infants born to CMV-seropositive mothers.

METHODS

PubMed, Embase, and Cochrane Library databases were searched using the terms: ("breast feeding" or "breast milk" or "human milk" or "breast") and ("HCMV" or "cytomegalovirus") and ("infant, extremely premature" or "premature birth" or "newborn" or "neonate" or "low birth weight" or "very low birth weight" or "premature" or "preterm infant"). Studies that had information on CMV status and breast feeding were included in the meta-analysis.

RESULTS

A total of 2,502 newborns from 19 studies were included in this meta-analysis. The rate of postnatally acquired CMV infection among breastfed infants with CMV-seropositive mothers was 16.5% (95% confidence interval [CI], 0.10-0.26; P < 0.001). The infection rate was 26% with fresh breast milk, 8% with a combined diet of fresh and freeze-thawed breast milk, and 11% with freeze-thawed breast milk. Among cases where the CMV status of breast milk was determined, CMV shedding into breast milk occurred in 80.5% (95% CI, 0.71-0.87; P < 0.001) of CMV seropositive mothers. The breast milk-acquired CMV infection rate among infants fed CMV-positive breast milk was 20.7% (95% CI, 0.14-0.30; P < 0.001).

CONCLUSION

This meta-analysis examined the rate of breast milk-acquired CMV infections in preterm infants with CMV-seropositive mothers; the CMV infection rate was higher in preterm infants fed fresh breast milk. Until further data are available, we cautiously suggest the use of freeze-thawed breast milk, rather than fresh breast milk, for preterm infants or very low birth weight infants.

Nutrition of Preterm Infants and Raw Breast Milk-Acquired Cytomegalovirus Infection: French National Audit of Clinical Practices and Diagnostic Approach

Raw breast milk is the optimal nutrition for infants, but it is also the primary cause of acquired cytomegalovirus (CMV) infection. Thus, many countries have chosen to contraindicate to feed raw breast milk preterm infants from CMV-positive mothers before a corrected age of 32 weeks or under a weight of 1500 g. French national recommendations have not been updated since 2005. An audit of the French practices regarding the nutrition with raw breast milk in preterm infants was carried out using a questionnaire sent to all neonatal care units. Diagnosed postnatal milk-acquired CMV infections have been analysed using hospitalisation reports. Seventy-five percent of the neonatal units responded: 24% complied with the French recommendations, 20% contraindicated raw breast milk to all infants before 32 weeks regardless of the mothers' CMV-status, whereas 25% fed all preterm infants unconditionally with raw breast milk. Thirty-five cases of infants with milk-acquired CMV infections have been reported. The diagnosis was undeniable for five patients. In France, a high heterogeneity marks medical practices concerning the use of raw breast milk and the diagnostic approach for breast milk-acquired CMV infection is often incomplete. In this context, updated national recommendations and monitored CMV infections are urgently needed.

Cytomegalovirus infection in HIV-infected versus non-infected infants and HIV disease progression in Cytomegalovirus infected versus non infected infants early treated with cART in the ANRS 12140-Pediacam study in Cameroon

Background

The outcome of CMV/HIV co-infection in infants treated early with combined antiretroviral therapy (cART) in resource-limited settings has not been described.

We aimed to estimate the prevalence and identify factors associated with early CMV infection in HIV-infected and non-infected infants included in a study in Cameroon, and to compare HIV disease progression and survival after 1 year of early cART, following infants’ CMV status.

Methods

HIV-infected infants followed from birth or from HIV diagnosis before 7 months old and HIV-uninfected infants born to HIV-infected or uninfected mothers were tested for CMV at a median age of 4.0 months [Interquartile range (IQR): 3.4–4.9]. Multivariable logistic regression was performed to identify factors associated with CMV infection. Early cART was offered to HIV-infected infants: mortality, immunological and virological outcomes were assessed.

Results

Three hundred and sixty-nine infants were tested. The proportion of infants infected with CMV at baseline was significantly higher in HIV-infected than in HIV-uninfected groups (58.9% (86/146) vs 30.0% (67/223), p < 0.001). At baseline, median CMV viral load was higher in HIV-infected (3.7 log copies/ml [IQR; 3.1–4.3]) than in HIV-uninfected infants (2.8 log copies [IQR; 2.1–3.4], p < 0.001). cART was initiated in 90% of HIV-infected infants (132/146) at a median age of 4.0 months (IQR; 3.2–5.9); in this sub-group CMV infection was independently associated with being followed from the time of HIV diagnosis rather than from birth (aOR = 3.1, 95%CI [1.2–8.0]), born to a non-single mother (aOR = 3.4[1.4–8.1]), and breastfeeding (aOR = 7.3 [2.7–19.4]). HIV-infected infants were retested after a median of 7.1 months [4.8–9.5]: CMV was undetectable in 37 of the 61 (60.7%) initially CMV-infected cases and became detectable in 8 of the 38 (21.1%) initially CMV-negative cases. After 1 year of cART, the probability of death (0.185 vs 0.203; p = 0.75), the proportion of cases with HIV RNA viral load <400 copies/ml (75.5% vs 61.5%; p = 0.17) and the mean CD4 percentage increase (10.97% vs 6.88%; p = 0.15) did not differ between CMV+ and CMV- infants.

Conclusions

We observed a high prevalence of CMV infection among HIV-infected infants. Early initiation of cART may have limited the negative impact of CMV even in the absence of specific anti-CMV treatment.

Breast milk-acquired cytomegalovirus infection and disease in VLBW and premature infants

BACKGROUND

Very low birth weight (VLBW) and premature infants are at risk for developing postnatal cytomegalovirus (CMV) disease, including CMV-related sepsis-like syndrome (CMV-SLS) for which estimates [corrected] in the United States are lacking.

METHODS

We performed a systematic review and meta-analysis to estimate the pooled proportions (and 95% confidence intervals) of VLBW and premature infants born to CMV-seropositive women with breast milk-acquired CMV infection and CMV-SLS. We combined these proportions with population-based rates of CMV seropositivity, breast milk feeding, VLBW, and prematurity to estimate annual rates of breast milk-acquired CMV infection and CMV-SLS in the United States.

RESULTS

In our meta-analysis, among 299 infants fed untreated breast milk, we estimated 19% (11%-32%) acquired CMV infection and 4% (2%-7%) developed CMV-SLS. Assuming these proportions, we estimated a rate of breast milk-acquired CMV infection among VLBW and premature infants in the United States of 6.5% (3.7%-10.9%) and 1.4% (0.7%-2.4%) of CMV-SLS, corresponding to 600 infants with CMV-SLS in 2008. Among 212 infants fed frozen breast milk, our meta-analysis proportions were 13% (7%-24%) for infection and 5% (2%-12%) for CMV-SLS, yielding slightly lower rates of breast milk-acquired CMV infection (4.4%; 2.4%-8.2%) but similar rates of CMV-SLS (1.7%; 0.7%-4.1%).

CONCLUSIONS

Breast milk-acquired CMV infection presenting with CMV-SLS is relatively rare. Prospective studies to better define the burden of disease are needed to refine guidelines for feeding breast milk from CMV-seropositive mothers to VLBW and premature infants.

Human milk donation is an alternative to human milk bank

BACKGROUND AND AIMS

Human milk bank is a source of human milk supply in many neonatal intensive care units. However, there are some hospitals without this facility because of financial or religious impediments, such as the Muslim community.

METHODS

We introduced human milk donation as an alternative to human milk banking based on Islamic principles. The suitable donor is a healthy rooming-in mother whose expressed breastmilk is in excess of her baby's demand. The milk is used after 72 hours of freezing at -20°C. The donor must fulfill the criteria for selection of donors and be nonreactive to human immunodeficiency virus and syphilis. Once the recipient's family and the donor state their desire for the human milk donation, a meeting with both parties is made. Unpasteurized frozen-thawed donor's milk will be provided to the recipient after written consents are obtained from both parties.

RESULTS

This study was carried out in the Duchess of Kent Hospital (Sandakan, Sabah, Malaysia) between January 2009 and December 2010. A total of 48 babies received donated breastmilk. Forty-two infants were from the special care nursery, and the remaining six were from the pediatric ward. Eighty-eight percent of the donors and 77% of the recipients were Muslims. Sixty percent of the infants who received donated human milk were premature. Two infants died because of the underlying nature of their disease.

CONCLUSION

Human milk donation is an option for hospitals without a human milk bank or in the Muslim community.

[Review and guidelines on the prevention, diagnosis and treatment of post-natal cytomegalovirus infection]

Postnatal cytomegalovirus (CMV) infection in the newborn can occur from exposure to maternal cervical secretions during birth, ingestion of breast milk, transfusion of blood products or transmission by body fluids of infected people. Breast milk is the main source of infection, given the high rate of CMV-positive mothers excreting CMV in milk. Freezing reduces the risk of CMV transmission by breastfeeding, although it does not eliminate it completely. Pasteurisation prevents such transmission, but it can alter the immunological properties of breast milk. Postnatal CMV infection is usually asymptomatic, as it normally results from viral reactivation in the mother, and the neonate is born with protective antibodies. However, in the very low birth weight premature infant the amount of transferred antibodies is smaller and a symptomatic infection can occur. Symptomatic post-natal CMV infection in the newborn typically causes hepatitis, neutropenia, thrombocytopenia or sepsis-like syndrome. Pneumonitis and enteritis are less common, but very characteristic. Diagnosis is based on urine virus detection at the time of onset of symptoms. Postnatal CMV infection in the newborn generally resolves spontaneously without antiviral treatment. Ganciclovir should be reserved for severe cases. Unlike congenital CMV disease, post-natal CMV infection in the preterm infant does not seem to be associated with hearing loss or abnormal neuro-development in long term follow-up.

Infectious disease and reproductive health: a review

Human reproduction provides unique opportunities for the transmission of infectious agents. Furthermore, the mother and her offspring have distinct susceptibilities to infection at each stage of reproduction, from conception and gestation to parturition and the neonatal period. The impact of pathogens on reproduction can be mitigated or exacerbated depending on timing of acquisition during pregnancy. Similarly, factors such as maternal immune response, nutritional status, or concurrent infection may modify the effect of an infectious agent. In this review, we discuss the evidence--or lack thereof--for associations between infectious agents and reproductive problems at each stage of reproduction. We focus on well-substantiated associations, and consider several emerging or controversial associations. We discuss the challenges, limitations, and opportunities related to epidemiologic research on infectious disease and reproductive outcomes.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the potential mechanisms by which infectious agents may impact productive health, explain the public health impact of infectious diseases on reproductive health, and summarize the perinatal risks of infectious disease and relate this to treatment and prevention strategies in practice.

Incidence and clinical outcome of cytomegalovirus transmission via breast milk in preterm infants </=31 weeks

AIM

To evaluate incidence, timing and clinical relevance of acquired human cytomegalovirus (HCMV) infection in preterm infants.

METHODS

The prospective longitudinal study included preterm infants </=31 weeks. Congenital HCMV infection was excluded by negative HCMV culture from urine or by HCMV-PCR-negative umbilical cord blood. Infants from HCMV-IgG-positive mothers received thawed frozen breast milk until 33 weeks. Urine samples were obtained weekly for HCMV culture. Data were collected regarding clinical course and milk-intake.

RESULTS

Twenty-nine mothers (29/48, 60%) of 35 infants were HCMV-IgG-positive. Five of 35 infants (14%) excreted HCMV in urine. Three of five children remained asymptomatic. One child developed a respirator-dependent HCMV pneumonia, the other child an upper airway infection and a transient thrombocytopenia. HCMV infected children had a significant longer hospital stay (median 96 vs. 73 days, p = 0.025) and received more formula milk (89 vs. 44 mL/kg/day, p = 0.04). Mothers of infected children had significantly higher HCMV-IgG levels than those of non-infected children (mean 1557 vs. 921 AU/mL, p = 0.048). Nineteen of 48 mothers (40%) with 23 infants were HCMV-IgG-negative. These children remained HCMV negative.

CONCLUSION

Feeding preterm infants </=31 weeks of HCMV-IgG-positive mothers with thawed frozen breast milk until 33 completed weeks does not prevent symptomatic HCMV infection in all cases. These infections can be associated with a prolonged hospital stay.

Cytomegalovirus transmission to preterm infants during lactation

Breastfeeding has a major impact on HCMV epidemiology. The incidence of postnatal HCMV reactivation during lactation equals the maternal seroprevalence. Infectious virus, viral DNA and RNA can be isolated easily from cell and fat-free milk whey. Early onset of viral DNAlactia and virolactia as well as high viral load in milk whey are maternal risk factors for virus transmission. The dynamics of HCMV reactivation can be described by unimodal kinetics with interindividual variation. Virus reactivation during lactation is a self-limiting local process in the absence of systemic HCMV infection. Preterm infants below 1000g birthweight and a gestational age below 30 weeks may be at high risk of acquiring a symptomatic HCMV infection. Several recent studies described low transmission rates and mostly asymptomatically infected neonates using frozen milk. Despite different freeze-storing procedures, HCMV transmissions occurred, and severe HCMV infections were observed. Few data exist on the long-term outcome of postnatally acquired HCMV infection via breast milk. To substantiate the international debate on the use of native or inactivated milk for feeding of preterm infants, additional data are necessary for better identification of mother-infant-pairs at risk for viral transmission and symptomatic infection early after birth.