Breast Milk and Saliva Lactoferrin Levels and Postnatal Cytomegalovirus Infection

Am J Perinatol. 2021 Aug;38(10):1070-1077. doi: 10.1055/s-0040-1701609. Epub 2020 Feb 18.


Objective: Very low birth weight preterm infants are at risk for life-threatening infections in the NICU. Breast milk protects against infections but carries the risk of infection by cytomegalovirus (CMV) shed in mother's milk. Lactoferrin is a breast milk and saliva protein with potent neutralizing activity against CMV.

Study design: VLBW, maternal breast milk fed infants in the NICU and their lactating mothers were enrolled and followed for 3 months/discharge. Breast milk and infant saliva samples were collected biweekly. Maternal CMV status was determined on breast milk. CMV was measured using quantitative polymerase chain reaction and lactoferrin by enzyme-linked immunosorbent assay.

Results: In an in vitro neutralization assay, the IC90 of purified human lactoferrin against CMV was 2.08 ng/mL. Bovine lactoferrins were more potent, IC90s > 10-fold higher. Lactoferrin was detected in all breast milk (median: 3.3 × 106 ng/mL) and saliva (median: 84.4 ng/swab) samples. Median CMV load in breast milk was 893 copies/mL. There was no correlation between breast milk lactoferrin concentration and CMV load. Five infants acquired postnatal CMV. There was no difference in saliva or breast milk lactoferrin concentration for mother-infant pairs and postnatal CMV acquisition.

Conclusion: Lactoferrin neutralizes CMV in vitro, but concentrations in breast milk and saliva are likely too low for effective neutralization in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breast Feeding / adverse effects*
  • Cytomegalovirus
  • Cytomegalovirus Infections / transmission*
  • DNA, Viral / analysis
  • Female
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Infant, Very Low Birth Weight
  • Infectious Disease Transmission, Vertical
  • Lactoferrin / analysis*
  • Male
  • Milk, Human / chemistry*
  • Milk, Human / virology
  • Pregnancy
  • Pregnancy Complications, Infectious / virology
  • Prospective Studies
  • Saliva / chemistry*


  • DNA, Viral
  • Lactoferrin