Sarah A. Keim of the Center for Biobehavioral Health, The Research Institute at Nationwide Children's Hospital in Columbus and colleagues at The Ohio State University and Cincinnati Children's Hospital Medical Center said websites selling human milk for infant consumption are gaining in popularity among women who want to breast feed but don't produce enough milk.
The researchers quantified microbial contamination of human milk purchased via the Internet. They purchased 102 cross-sectional samples of human milk through a popular U.S. milk-sharing website.
The milk samples were sent to a rented mail box in Ohio, and later compared with samples of unpasteurized, donated milk obtained through a milk bank.
The study, published online ahead of the November print edition of the journal Pediatrics, found 74 percent of the Internet milk samples were colonized with high bacterial counts overall, or had at least some gram-negative bacteria; while 64 percent of the Internet samples tested positive for staphylococcus, compared with 25 percent of the milk bank samples.
Three of the Internet samples were contaminated with Salmonella, the study found.
"The high overall bacterial growth and frequent contamination with disease-causing bacteria in the Internet milk reflected poor collection, storage or shipping practices," the study authors wrote in the study. "Infants consuming human milk purchased via the Internet are at risk for negative outcomes, especially premature infants and those with compromised immune systems."
Keim and colleagues recommended lactation support for mothers who want to provide breast milk to their infants but who have difficulty making enough and women who have extra milk should consider donating to a milk bank.