Transfusion acquired cytomegalovirus (CMV) can cause serious complications and even death in very low birth weight infants. Because of this risk, transfusion services provide CMV negative blood components for fetal and intrauterine transfusions and for very low birth weight premature infants. When infants become infected with CMV, neonatologists often suspect that transfusion is the source of the infection. A donor with a recent CMV infection can harbor virus in their plasma or white blood cells even though they test negative for antibodies. The window period for CMV infection is estimated to be 6 to 8 weeks.
A prospective multicenter study sought to determine the source of postnatal CMV infection during the first 90 days after birth in 539 very low birth weight infants. Postnatal CMV infection was detected in 29 infants by both serological and nucleic acid tests. More than half of these infants had been transfused with cellular blood components that were CMV seronegative and leukocyte reduced. Testing of donors revealed that non of the infections were associated with transfusion. Instead, all of the infections were transmitted by CMV positive breast milk.
The findings of this study suggest that the risk of CMV transmission by blood transfusion is negligible when CMV seronegative and leukocyte reduced blood components are transfused. However, CMV transmission by breast milk from CMV-positive donors remains a serious risk.
Josephson CD, Caliendo AM, Easley KA, Knezevic A, Shenvi N, Hinkes MT, Patel RM, Hillyer CD, Roback JD. Blood Transfusion and Breast Milk Transmission of Cytomegalovirus in Very Low-Birth-Weight Infants: A Prospective Cohort Study. JAMA Pediatr 2014;168(11):1054-62.