Sporadic (nonepidemic) acute puerperal mastitis was diagnosed 65 times over a period of 26 months in 2.5% of mothers who elected to nurse their infants. Staphylococcus aureus was cultured from the milk of 23 of 48 infected breasts, but from only one breast of 19 normal mothers. Forty-one women with mastitis continued to nurse without difficulty for an average of 13 weeks, although mastitis recurred in four women. Three breast abscesses resulted from the 65 infections (4.6%).
(JAMA 233:1377-1379, 1975)
Marshall BR, Hepper JK, Zirbel CC. Sporadic Puerperal MastitisAn Infection That Need Not Interrupt Lactation. JAMA. 1975;233(13):1377-1379. doi:10.1001/jama.1975.03260130035019