Salmonellosis is a common gastrointestinal illness caused by Salmonella bacteria, frequently contracted through contaminated food or water. When breastfeeding parents contract this infection, they often worry about passing the bacteria to their infant, especially since newborns are vulnerable. This article provides evidence-based information on whether Salmonella can pass through breast milk and outlines necessary safety precautions.
How Salmonella Bacteria Interacts with Breast Milk
In most Salmonella infections, the bacteria remain localized within the mother’s gastrointestinal tract, causing symptoms like diarrhea and fever. Since the bacteria does not usually enter the bloodstream, it is extremely unlikely to pass into the breast milk. Documented cases where Salmonella has been isolated from breast milk usually involve the mother having a systemic infection (septicemia) or mastitis caused by the bacteria.
The body’s response to the infection provides a powerful protective mechanism for the infant. As the mother fights the illness, she produces specific antibodies, primarily secretory Immunoglobulin A (IgA), which are transferred directly into her breast milk. These IgA antibodies are tailored to the exact strain of Salmonella that caused the maternal illness, providing the nursing infant with passive immunity.
When the infant consumes this milk, the antibodies line the baby’s intestinal tract. This action effectively blocks the Salmonella bacteria from attaching to the gut wall and causing infection. The transfer of these protective IgA antibodies is a primary reason why medical guidance recommends continuing to breastfeed during a maternal gastrointestinal illness.
Preventing Transmission Through Contact and Environment
While direct passage of Salmonella into breast milk is uncommon, the primary risk of transmission is through the fecal-oral route. Salmonella is shed in the mother’s stool, and cross-contamination from unwashed hands to surfaces or the infant’s mouth is the most likely transmission route.
Parents must practice rigorous hand hygiene, especially after using the restroom or changing a diaper, and immediately before handling the infant or expressing milk. Hands should be washed thoroughly with soap and water for at least 20 seconds.
It is also important to sanitize high-touch surfaces in the home, such as doorknobs, light switches, and bathroom fixtures, to reduce the environmental spread of the bacteria. If using a breast pump, all parts that contact milk must be cleaned and sterilized after every use to prevent external contamination. Parents should also avoid practices that could transfer bacteria directly, such as kissing the infant on the mouth or face while symptomatic.
Medical Guidance for Breastfeeding While Infected
In most mild to moderate cases of Salmonellosis, the mother should continue breastfeeding. Breastfeeding should proceed as normal unless the mother is too unwell or severely dehydrated to safely hold and nurse the infant. If the mother is feeling too ill, she should express her milk to maintain her supply and allow a caregiver to feed the baby using a clean cup or bottle.
Immediate medical consultation is necessary if the mother experiences severe symptoms, such as a fever above 102°F, severe dehydration, or bloody diarrhea. This helps rule out a rare systemic infection that could pose a greater risk to the infant.
If a physician prescribes antibiotics, the mother must inform them that she is breastfeeding to ensure a compatible medication is chosen. Resources like the LactMed database can verify the safety of specific drugs for the nursing infant. The decision to temporarily pause or discontinue breastfeeding should only be made in consultation with a healthcare provider.