Impact of breast milk-acquired cytomegalovirus infection in premature infants: Pathogenesis, prevention, and clinical consequences?

Maternal–fetal transmission of cytomegalovirus (CMV) represents the most common infectious cause of long-term neurodevelopmental disability in children. Congenital CMV (cCMV) infection is associated with microcephaly, seizure disorders, cognitive disability, developmental delay, and sensorineural hearing loss (SNHL). Of these disabilities, SNHL is the most common, affecting approximately 10% of infants with cCMV. Although the sequelae of cCMV are well recognized, it is much less clear what long-term morbidities may occur in neonates that acquire post-natal CMV infection. Post-natal CMV (pCMV) infection is most commonly transmitted by breast-feeding, and in full-term infants is of little consequence. However, in preterm, very-low birthweight (VLBW) infants (<1500 g), pCMV can result in a severe sepsis-like syndrome, with wide-ranging end-organ disease manifestations. Although such short-term complications are well recognized among clinicians caring for premature infants, the long-term risks with respect to adverse neurodevelopmental outcomes remain controversial. In this review, we provide an overview of the clinical manifestations of breast milk-acquired pCMV infection. In particular, we summarize studies that have examined—sometimes with conflicting conclusions—the risks of long-term adverse neurodevelopmental outcome in VLBW infants that acquire pCMV from breast milk. We highlight proposed preventive strategies and antiviral interventions, and offer recommendations for high-priority areas for future basic science and clinical research.