Methicillin-resistant Staphylococcus aureus (MRSA)

Staphylococcus aureus (staph), is a type of bacteria found on people’s skin. Staph bacteria can be carried by individuals and not cause any symptoms, but can also cause serious infections that can lead to sepsis or death. Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph bacteria that is resistant to several antibiotics.

These bacterial pathogens can be associated with mastitis (a breast infection) and breast abscesses in breastfeeding mothers, and require prompt medical attention. In most cases, mothers with a staph or MRSA infection can continue to breastfeed their infant.

If a mother has a MRSA infection, can she continue to breastfeed?

Usually, yes. Continued breastfeeding is appropriate and recommended for most healthy infants. Breastfeeding promotes drainage and helps to resolve the infection, if it involves the breast. Staph bacteria, including MRSA, are not transmissible via human milk; however, these bacteria can be transferred through direct contact with infected tissue, such as an open lesion on the breast, or through expressed milk that has come in contact with infected tissue. Breastfeeding can continue on the affected breast (even if a drain is present in the case of an abscess) as long as the infant’s mouth does not come in contact with purulent drainage or open infected tissue. All open infectious tissue should be completely covered with clean, dry bandages while breastfeeding or expressing milk. Continued breastfeeding is also recommended for most healthy infants when their mother is colonized, but does not have a MRSA infection.

If it is not possible to avoid contact with infectious tissue while breastfeeding or expressing milk, the mother can express milk from the affected breast and discard it until she is no longer infectious on that side (undergone 24-48 hours of antibiotic therapy).  Expressing milk is important for maintaining milk production while not directly breastfeeding from the affected breast. Mothers should be vigilant about practicing appropriate hand hygiene and cleaning breast pump parts thoroughly.

What is the best treatment for breastfeeding mothers diagnosed with MRSA?

There are several medications used to treat MRSA that are compatible with breastfeeding. For additional information on medications and lactation, please refer to the Drugs and Lactation Database (LactMed®) – NCBI Bookshelf (nih.gov). If the mother requires abscess drainage, outpatient treatment using needle or catheter aspiration will allow the infant to remain with the mother and continue breastfeeding. Furthermore, breastfeeding promotes abscess drainage and helps resolve the infection. If a drain needs to be left in the abscess to allow for healing, the infant can continue to breastfeed or receive expressed milk from that breast as long as the infant’s mouth or the pump’s flange does not come in contact with the insertion of the drain.

Are there special precautions for a mother-infant dyad infected with MRSA if the infant is in the Neonatal Intensive Care Unit (NICU)?

Yes. Infants in the NICU, or who are premature or small-for-gestational-age, are more susceptible to morbidity and mortality due to MRSA. Infants in the NICU are at higher risk, so a facility might recommend special precautions, like using gowns and gloves when caring for infants whose mothers are carrying or are infected with MRSA, or placing mother and infant in their own room. If the MRSA infection is in the breast (e.g., mastitis) it might be prudent to minimize the infant’s exposure to infected tissue or contaminated milk. One approach might be to culture breast milk expressed by a mother with a MRSA infection to confirm the breast milk does not contain staph bacteria before feeding it to the infant. Alternatively, expressed milk could be discarded and if appropriate, pasteurized donor human milk could be provided to the infant until the mother’s milk is culture-negative for MRSA or until the signs of active infection have resolved. It is important for the mother to receive lactation support and continue to express her milk to maintain her milk supply during this time while she receives treatment.