Salmonella from breast milk!

Via the New York Times, a story to add to the list of things that have led to Salmonella outbreaks recently. A study published this week in the journal Pediatrics details a growing problem with breast milk sold or donated via websites that has been found to be contaminated with high levels of potentially pathogenic microorganisms. Researchers obtained 101 samples from a popular Internet milk-sharing website, as well as 20 samples of unpasteurized breast milk which had been donated to a more traditional local milk bank.  Most of the Internet samples (74%) were contaminated with Gram negative bacteria, whereas 35% of the banked milk were contaminated. Additionally, contaminated Internet samples had at least 10-fold higher levels of bacteria in comparison to the banked samples.  Internet samples were also contaminated with cytomegalovirus 20% of the time.

The authors conclude that the high level of contamination reflects the overall poor attention to “collection, storage, and shipping practices” with very fundamental lapses in aseptic technique. Although the websites typically prominently display collection criteria, because there is no oversight in the process, it is unclear what level of compliance is actually followed. Local milk bank resources on the other hand have strict guidelines, and the milk is pasteurized prior to distribution. Some advocates of the websites maintain that pasteurization itself diminishes the benefits of expressed breast milk relative to infant formula, however there doesn’t appear to be any concrete evidence that such benefits exist to use unpasteurized milk when pasteurization is easily accomplished. Comments in the Times article from Kim Updegrove, president of the milk-bank association, further underscore issues with these unregulated Internet sites, including the possibility that recipients might be getting cow’s milk or formula from an unknown Internet source.


About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on October 21, 2013, in The more you know, Yikes!. Bookmark the permalink. 8 Comments.

  1. In this case, due to the Internet sites selling breast milk without much regulation or oversight, showed to have higher contamination than banked breast milk. This is because it might not be only breast milk, it might be milk from a cow or formula. So the breast milk might not be the cause of Salmonella, it might be from the cow milk, or how it is packaged and shipped. Getting banked breast milk is safer than buying milk on the internet! And, milk bought online is a bigger threat to babies that are born prematurely or that have prior medical issues, for they might get very serious health problems. I think that for the safety of the babies there should be stricter guidelines for selling milk online to prevent babies from ingesting breast milk that is contaminated!

  2. I had no idea you could buy breast milk offline. You would think that when buying things for infants parents and retailers of breast milk would take extra precautions to make sure that the breast milk is nothing but safe for this time in a child’s life is crucial for development physically and mentally. When looking up more info about micro organisms in breast milk I came across this

    • I was speaking to another Bio faculty member yesterday–Dr. Hagerty, who teaches Biostatistics–and she noted one significant flaw with the conclusions of this study. The researchers reported that there was a large number of Internet contacts, who when asked to provide expressed milk, either refused to do so for unknown reasons, or outright ignored the request. It may be better to conclude “we don’t know how much of a problem this is” as opposed to “there is a really big problem.”

      Your link is interesting as well, and nicely illustrates that for an infant it is actually important to have bacteria in breast milk, as this is the main mechanism by which that baby develops their normal microbial flora.

  3. Martin Nedyalkov

    Although, breast milk form the mother is the best source of essential nutrients for the baby, formulas are now improving and deliver just as much nutrients. One really disturbing fact about this article is that there have been confirmed cases of cytomegalovirus. After looking up the virus, I found out it was a type of a herpes virus. This is an alarming statistic, that needs to be further investigated by the FDA. With the amount of safety regulations in place for children safety, suppliers of breast milk need to be held responsible for supplying unsafe products to mothers and babies.

    Companies that refuse to supply samples need to be sanctioned by the FDA or a regulatory committee of some sort. It all comes to keeping the children safe and preventing the spread of disease.

    • According to the CDC, cytomegalovirus (CMV) infections are extremely common, and in many cases are pretty much asymptomatic, however because of the prevalence there are complications and these mainly occur in the immunocompromised and in infants. It is estimated that about 1 in 150 infants are born with CMV acquired from their mother (or congenital CMV infection), and about 1 in 5 of those infants show some kind of permanent problem ranging from hearing loss to developmental problems. If you consider how many live births there are annually in the US, these “problem cases” produces a really big number!

  4. Wow! This is bad! Just the lack of aseptic technique could be adding the Salmonella to the milk without it even being noticed. Maybe more regulation of how the milk is shipped, stored and transported could decrease this number itself. This really goes to show how important aseptic technique is, we think it is just something we do in lab right now, but it is more serious and a more universal action than we think. If better aseptic technique was put in place for the internet breast milk sellers, most likely the trend of such bacteria rates could decrease.

  5. This is seriously disgusting. I don’t understand why anyone would even want to buy breast milk off line! If it is impossible for the mother to produce milk herself for whatever reason or she just chooses not to then she should totally feed her child formula or, if it comes down to it, go to the breast milk bank. I think the idea of parents feeding breast milk from God knows where to their babies is more disgusting and disturbing than the fact that there is bacteria in the milk. I feel like buying anything that is going to be consumed orally off the internet is a huge risk to take and just shouldn’t be done. That is all just my opinion though, factually there should be much more restrictions and monitoring of this sort of thing and as a buyer of the milk, the parents should be sure to test it themselves.

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