Breast Milk Bought Online May Contain Harmful Germs
Nearly three-quarters of samples from an Internet milk-sharing site contained microbes that could make a baby sick
"That tells me that the person who pumped that milk used very bad hygiene. Essentially, they didn't wash their hands after using the toilet," said Marinelli, who was not involved in the study.
None of the samples tested positive for HIV (the AIDS virus), which can be passed through breast milk. But one in five tested positive for another virus called cytomegalovirus, or CMV.
CMV is common -- somewhere between 50 percent and 80 percent of people have had CMV by the time they're 40, according to the U.S. Centers for Disease Control and Prevention.
In healthy babies, CMV causes a mild flu-like illness that's rarely serious, Marinelli said. But for premature infants and those with compromised immune function, the virus can be very dangerous.
"If preemies get milk with CMV in it, they can get everything from a systemic illness that can put them back on a ventilator and make them really, really sick, to death, so you don't want them to get milk with CMV in it," said Marinelli, who is also a neonatologist at Connecticut Children's Medical Center, in Hartford.
Intriguingly, when the researchers compared the contamination in the purchased breast milk to unpasteurized samples that had been donated to a local breast milk bank, they found the donated samples were less likely to contain harmful germs.
Researchers say there may be a couple of reasons for the differences. The first is that milk banks carefully educate donors about safe collection and handling of breast milk. Some websites also post safe-sharing guidelines, but buyers have no way to know whether sellers are actually following them.
And previous studies have found that almost one in three mothers never cleans her breast pump.
"What this experience has taught us is that when you open the box of milk that you've bought, there's really nothing that can reassure you that the milk is safe," said study researcher Sarah Keim, principal investigator in the Center for Biobehavioral Health at Nationwide Children's Hospital in Columbus, Ohio.
Keim said the researchers logged all sorts of information about the milk they got to find patterns of problems that might signal contamination. Some of the milk was shipped with gel packs or dry ice to keep it cold, but that didn't seem to matter. The temperature of the milk when it reached the researchers didn't make a difference. The kind of container and its condition also didn't seem to play a role, nor did promises of healthy, fresh, or organic milk in ads placed by sellers.