Cytomegalovirus transmission to extremely low-birthweight infants through breast milk

Aim: To determine the incidence, timing and clinical significance of acquired postnatal cytomegalovirus (CMV) in extremely low-birthweight (ELBW) infants. Methods: Prospective, longitudinal surveillance study. ELBW infants were recruited in the first week of life. Maternal blood was tested for CMV-specific I-G antibodies. Weekly urine samples were obtained from infants for CMV culture and rapid antigen testing. Data were collected regarding clinical course and breast milk intake. Results: Of 181 eligible infants, 119 infants, born to 10 1 mothers, were enrolled. Eighty of the 10 1 mothers had their serum checked for CMV status. Seventy percent of those tested were seropositive for CMV. Of the 65 infants born to seropositive mothers, 94% received breast milk during their hospital stay. Complete urine collection was obtained in 92 infants. CMV was cultured from the urine of only four infants, all of whom were born to seropositive mothers. Only one of these four infants was symptomatic. The range at which CMV was first detected was between 48 and 72 postnatal days of age. Conclusions: Despite a very high CMV seropositivity rate in mothers of ELBW infants, and the previously, reported high rate of CMV excretion into breast milk, the incidence of postnatal CMV transmission was extremely low in our study.