Incidence and clinical outcome of cytomegalovirus transmission via breast milk in preterm infants ≤31 weeks

Abstract

To evaluate incidence, timing and clinical relevance of acquired human cytomegalovirus (HCMV) infection in preterm infants. The prospective longitudinal study included preterm infants </=31 weeks. Congenital HCMV infection was excluded by negative HCMV culture from urine or by HCMV-PCR-negative umbilical cord blood. Infants from HCMV-IgG-positive mothers received thawed frozen breast milk until 33 weeks. Urine samples were obtained weekly for HCMV culture. Data were collected regarding clinical course and milk-intake. Twenty-nine mothers (29/48, 60%) of 35 infants were HCMV-IgG-positive. Five of 35 infants (14%) excreted HCMV in urine. Three of five children remained asymptomatic. One child developed a respirator-dependent HCMV pneumonia, the other child an upper airway infection and a transient thrombocytopenia. HCMV infected children had a significant longer hospital stay (median 96 vs. 73 days, p = 0.025) and received more formula milk (89 vs. 44 mL/kg/day, p = 0.04). Mothers of infected children had significantly higher HCMV-IgG levels than those of non-infected children (mean 1557 vs. 921 AU/mL, p = 0.048). Nineteen of 48 mothers (40%) with 23 infants were HCMV-IgG-negative. These children remained HCMV negative. Feeding preterm infants </=31 weeks of HCMV-IgG-positive mothers with thawed frozen breast milk until 33 completed weeks does not prevent symptomatic HCMV infection in all cases. These infections can be associated with a prolonged hospital stay.