Methicillin-resistant Staphylococcus aureus (MRSA) isolation in breast abscesses in a Public Maternity

Mastitis and breast abscess in lactating women are risk factors for early breastfeeding cessation. This pathology is included in the group of skin and soft tissue infections. A descriptive study was performed with an advanced outlook. As of January 2007 through December 2011 a total of 137 breast abscesses were treated in our institution. We analyzed incidence, parity, postpartum days, risk factors, microbiological isolation and the adequacy of initial antibiotic treatment. In that period we observed a steady and significant increase in breast abscesses. Incidence from 0.19 to 0.84% in lactating women 2007 vs. 2011 p = 0.0001 IC 95% (-0.009; 0.003), 70.6% of them primiparous and a mean interval from delivery to breast abscess of 41.9 +/- 35.8 days. The most frequent risk factors were sore nipples and breast engorgement. Staphylococcus aureus was isolated in 82.3 to 95.0%. Methicillin resistance was higher than 60%. These strains were susceptible to erythromycin, clindamycin, gentamicin, rifampicin, ciprofloxacin and trimethoprim-sulfamethoxazol. All the cases were surgically drained; the initial empirical treatment was inadequate in 60% of them, 90% of patients could maintain breast feeding after the procedure. In conclusion: these data emphasize the need to prevent risk factors associated to breast abscesses: sore nipples and breast engorgement. In order to determine the adequate antibiotic treatment, bacteriological studies are required at every collection because SAMR prevalence varies according to diverse populations and geographic location.