Preventing transfusion-acquired cytomegalovirus infection in infants

Abstract

Dr Gilbert and colleagues (June 3, p 1228) report on the incidence and prevention of transfusion-acquired cytomegalovirus (CMV) infection in infants by blood filtration to remove leucocytes. They record a CMV infection rate of 21 % (9 of 42) amongst very low birthweight (below 1500 g) seronegative infants and they state that this rate is similar to that reported by Yeager et al’ m 1981. However, two 1988 studies found much lower CMV infection rates amongst such babies: 7 of 2222 and 1 of 41.3 In 133 premature infants weighing less than 1500 g admitted over two years to the special nursery unit at this hospital we have found a low CMV acquisition rate (2 of 46) amongst seronegative babies exposed to unscreened blood. The discrepancy may be partly explained by the fact that 3 of the 9 infected babies in Gilbert’s study were diagnosed only by seroconversion 6 months after the last seropositive transfusion. This has to be interpreted with caution. In our study, using similar commercial enzyme immunoassays that can detect very low levels of CMV antibody, we detected passive antibody after seropositive transfusions up to at least 10 weeks in 10 babies. We called these "transient seroconverters" since at a 10-month follow-up visit none remained CMV seropositive except the genuinely infected babies. [Excerpt]