Contamination in expressed breast milk following breast cleansing

Abstract

The purpose of this study was to determine if preexpression breast cleansing reduced the bacterial count in expressed breast milk. The study involved the collection of 178 breast milk samples (89 matched samples); 38 matched samples were from mothers of term infants and 51 matched samples were from mothers of preterm infants. One half of the samples were collected following breast cleansing with Phisoderm and tap water. The other half were collected following breast cleansing with tap water only. Hand and equipment washing with Phisoderm and tap water preceded all sample collections. Storage containers were sterile. Samples were cultured for pathogenic and nonpathogenic bacteria and examined at 24 and 48 hours. Data were analyzed by Wilcoxon Matched-Pairs sign test and Chi square. Breast cleansing with Phisoderm and water was not more effective than water alone at reducing nonpathogenic bacteria or eliminating pathogenic bacteria. Mothers of preterm infants had higher levels of both nonpathogenic and pathogenic bacteria than mothers of full-term infants. The most common form of bacterial contamination was coagulase-negative Staphylococcus epidermidis. This particular bacteria is found in higher levels in the stools of breast fed infants than formula fed infants and it also the most common contaminant found in the blood of preterm infants who develop sepsis. The findings of this study reveal that chemical interventions may not be effective at rendering breast milk free from pathogenic bacteria. More research is needed to determine the optimal cleansing protocol to achieve bacterial decontamination of breast milk or to determine the clinically acceptable level of contamination based on the effects on infants.