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.