Short-term Pasteurization of Breast Milk to Prevent Postnatal Cytomegalovirus Transmission in Very Preterm Infants

Abstract

Background: Postnatally acquired cytomegalovirus (pCMV) infection through breast milk (BM) may cause severe illness and even death, yet BM is advantageous for preterm infants. Therefore, effective methods to prevent CMV transmission are needed.

Methods: To assess the effectiveness of short-term pasteurization (62°C for 5 seconds) in preventing CMV transmission via BM in preterm infants. Design: Prospective interventional bicentric cohort study with infant enrollment between 6/2010 and 1/2012. A cohort from the Tuebingen neonatal intensive care unit (NICU) from 1995-1998 served as historical controls. Differences in CMV transmission were compared with reference to the cumulative time at risk for CMV transmission. Setting: Two German level-3 NICUs. Eighty-seven preterm infants of 69 CMV immunoglobulin G-positive mothers with birth weight <1500 g or gestational age <32 weeks and 83 historical controls were included. Intervention: BM samples were short-term pasteurized from postnatal day 4 to discharge. Primary endpoint: CMV status at discharge, evaluated by polymerase chain reaction and short-term microculture from urine.

Results: Two of 87 (2.3%) study infants had a pCMV transmission. This compared to 17 of 83 (20.5%) controls. Total time under risk for infection was 9.6 years vs 10.0 years in controls, yielding an incidence of 0.21/year (95% confidence interval [CI], 0.03 to 0.75/year) vs 1.70/year (95% CI, 0.99 to 2.72/year), respectively. The risk ratio controls vs study infants was 8.3 (95% CI, 2.4 to 52.4) according to Cox proportional hazard model (P = .0003).

Conclusions: Short-term pasteurization significantly reduces the incidence of pCMV infection through BM in the NICU.

Clinical trials registration: NCT01178905.

Keywords: breast milk; postnatal CMV infection; prevention; short-term pasteurization; very preterm infants.