Transmission of Cytomegalovirus (CMV) through Human Milk. In: Pickering LK, Morrow AL, Ruiz-palacios GM, Schanler RJ, editors. Protecting Infants through Human Milk. Boston: Springer US; 2004. pp. 489-94. [DOI: 10.1007/978-1-4757-4242-8_70]

Effects of different CMV-heat-inactivation-methods on growth factors in human breast milk

Preterm infants can inoculate virulent cytomegalovirus (CMV) through their mothers' raw breast milk. Complete virus inactivation is achieved only by heat treatment, but the effect on growth factors has never been assessed systematically. Insulin-like-growth-factor-1-, IGF-2-, insulin-like-growth-factor-binding-protein-2-, and IGFBP-3-concentrations were measured, before and after heating, in 51 breast-milk-samples from 28 mothers, and epidermal-growth-factor-concentrations in a subgroup of 35 samples from 22 mothers. Two heating methods were applied: Short-term (5 s) pasteurisation at 62, 65, and 72 degrees C, and long-term Holder-Pasteurisation (30 min) at 63 degrees C. IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were measured by RIA, and EGF by ELISA. Heating for 30 min decreased significantly IGF-1 by 39.4%, IGF-2 by 9.9%, IGFBP-2 by 19.1%, and IGFBP-3 by 7.0%. In contrast, IGF-1, IGF-2, IGFBP-2, and IGFBP-3 were not altered significantly when using a short heating duration of 5 s, irrespective of the level of temperature, except for IGF-2 at 62 degrees C for 5 s (p = 0.041) and IGFBP-2 at 72 degrees C for 5 s (p = 0.025). Neither long- nor short-time heating methods changed the concentration of EGF. Only short heating methods (5 s, 62-72 degrees C) can preserve, almost completely, the concentrations of IGFs in human milk, whereas Holder-Pasteurization does not.

Manifestations of human cytomegalovirus infection: proposed mechanisms of acute and chronic disease

Infections with human cytomegalovirus (HCMV) are a major cause of morbidity and mortality in humans with acquired or developmental deficits in innate and adaptive immunity. In the normal immunocompetent host, symptoms rarely accompany acute infections, although prolonged virus shedding is frequent. Virus persistence is established in all infected individuals and appears to be maintained by both a chronic productive infections as well as latency with restricted viral gene expression. The contributions of the each of these mechanisms to the persistence of this virus in the individual is unknown but frequent virus shedding into the saliva and genitourinary tract likely accounts for the near universal incidence of infection in most populations in the world. The pathogenesis of disease associated with acute HCMV infection is most readily attributable to lytic virus replication and end organ damage either secondary to virus replication and cell death or from host immunological responses that target virus-infected cells. Antiviral agents limit the severity of disease associated with acute HCMV infections, suggesting a requirement for virus replication in clinical syndromes associated with acute infection. End organ disease secondary to unchecked virus replication can be observed in infants infected in utero, allograft recipients receiving potent immunosuppressive agents, and patients with HIV infections that exhibit a loss of adaptive immune function. In contrast, diseases associated with chronic or persistent infections appear in normal individuals and in the allografts of the transplant recipient. The manifestations of these infections appear related to chronic inflammation, but it is unclear if poorly controlled virus replication is necessary for the different phenotypic expressions of disease that are reported in these patients. Although the relationship between HCMV infection and chronic allograft rejection is well known, the mechanisms that account for the role of this virus in graft loss are not well understood. However, the capacity of this virus to persist in the midst of intense inflammation suggests that its persistence could serve as a trigger for the induction of host-vs-graft responses or alternatively host responses to HCMV could contribute to the inflammatory milieu characteristic of chronic allograft rejection.

The 3 M's of breast-feeding the preterm infant

Mother's own milk is considered best for preterm infants. Given the often protracted period between birth and breast-feeding for most preterm newborns, a number of challenges exist for mothers and neonatal intensive care unit nurses in establishing lactation, providing mother's own milk, and achieving breast-feeding. This article conceptualizes breast-feeding the preterm infant in the context of the neonatal intensive care unit as a 3-phase process, the 3 M's of breast-feeding: medication, mother's milk feedings, and the mechanics of breast-feeding.

Acquisition of human cytomegalovirus infection in infants via breast milk: natural immunization or cause for concern?

Since the recognition in the 1960s that human cytomegalovirus (HCMV) infections could be transmitted by breast milk, there has been relatively little attention paid to the potential medical consequences of such infections. Indeed, since HCMV infections acquired by healthy newborn infants appear to be largely asymptomatic in nature, there has been no real incentive to develop or implement strategies to prevent transmission by this route. However, recent studies have identified a significant risk for low-birth weight, premature infants for the development of HCMV disease following acquisition of infection via breast milk. Such infections may cause considerable short-term morbidity and, in some cases, severe, life-threatening illness. There is little consensus amongst neonatologists on the approach to prevention and management of such infections. This review summarises the epidemiology and natural history of HCMV infections acquired via breast milk, and outlines available strategies for prevention and management of such infections, as well as opportunities for future clinical research on this understudied topic.

Cytomegalovirus in human breast milk: risk to the premature infant

Human cytomegalovirus (HCMV) can be transmitted through breast milk to neonates. Although healthy full-term infants rarely develop symptoms of CMV infection; premature or low-birth-weight infants can experience symptomatic infection that is occasionally severe. There is limited information on the long-term effects of postnatal CMV infection in premature infants, suggesting that these infants do not develop cognitive function delays or hearing loss, although those with intrapartum infection do. Readily available methods of treating breast milk to inactivate the CMV either diminish the immunologic and nutritive benefits of breast milk or incompletely inactivate the virus. This review considers the data on measuring CMV in breast milk, the recent clinical studies on CMV transmission via breast milk, reported methods of inactivation of CMV in breast milk, and immunologic factors that may play a role in transmission. CMV-IVIG treatment needs further evaluation but appears promising. Recommendations are made to help address the issue of CMV transmission to premature infants in clinical practice in the neonatal intensive care unit (NICU).