Nearly 75% of breast milk samples purchased online contained illness-causing bacteria and often showed signs of poor collection, storage or shipping practices, according to a recent study.
The study, conducted by researchers at the Nationwide Children’s Hospital in Columbus, Ohio, is described as the first to examine the safety of selling breast milk to others through the Internet, a trend that has grown during the past several years. It is unknown exactly how common purchasing breast milk online is, but an earlier study cited 13,000 postings on U.S. milk sharing websites in 2011.
The team from the Center for Biobehavioral Health at The Research Institute at Nationwide Children’s purchased breast milk listed for sale on public websites and analyzed it in the lab. Researchers from the Cincinnati Children’s Hospital Medical Center and The Ohio State University, Columbus, collaborated on the project. Their findings were published Oct. 21 on the website of the journal Pediatrics.
We were surprised so many samples had such high bacterial counts and even fecal contamination in the milk, most likely from poor hand hygiene, Sarah A. Keim, PhD, principal investigator in the Center for Biobehavioral Health, said in a news release, adding the team also found salmonella in a few samples. Other harmful bacteria may have come from the use of either unclean containers or unsanitary breast milk pump parts.
To purchase breast milk samples, the researchers responded to online classified ads describing the breast milk they wanted to sell. They chose ads from sellers who did not ask about the infant receiving the milk and did not require a phone call before making a transaction.
The team analyzed 101 samples bought online and compared them with 20 samples from a milk bank. In the U.S., 12 nonprofit milk banks follow the Human Milk Banking Association of North America guidelines and provide pasteurized milk from carefully screened donors to fragile and sick infants. Even before pasteurization, the milk bank samples were less likely to contain several types of bacteria and had less bacterial growth in many instances.
They found 74% of the online milk samples contained significant amounts of Gram-negative bacteria. The online milk samples also contained higher average total counts of aerobic bacteria, total Gram-negative bacteria, coliform and Staphylococcus than the milk bank samples, according to their findings. They also found 21% of the online samples tested positive for cytomegalovirus DNA.
Shipping practices were related to the levels of bacteria in the milk purchased online. A longer shipping time was positively associated with more milk contamination. Dry ice or other cooling methods was not used by 19% of sellers, and the milk temperature was outside of recommended storage range.
Researchers found particularly high levels of one or more types of bacteria in 17% of the online samples.
The study also showed information in the classified ads did not have any direct relationship with the safety of the breast milk.
It is difficult to determine whether a particular infant would be sickened by consuming any given bottle of milk, according to Keim, but bacteria in the online samples included some that cause illnesses known to be linked to contaminated breast milk.
Milk banks are a safer alternative for breast milk for sick babies because donors receive proper instructions and the milk is pasteurized, Keim said. Human breast milk can help strengthen the immune system and has been shown to protect against illnesses such as necrotizing enterocolitis. The researchers suggest women who have extra milk consider donating it to a milk bank, so it will be handled properly and go to a baby who needs it.
Our research results may not apply to situations where milk is shared among friends or relatives or donated rather than sold the potential risks of those situations are less well understood, Keim said in the release.