Incidence of Methicillin-Resistant Staphylococcus aureus in Postpartum Breast Abscesses

Objective: The study objective is to determine the incidence of methicillin-resistant Staphylococcus aureus (MRSA) in postpartum breast abscesses in two Houston, TX, area hospitals. Study Design and Methods: This is a retrospective chart review of women hospitalized for postpartum breast abscesses at Woman's Hospital of Texas and Memorial Hermann Hospital between January 1, 2000 and December 31, 2006. Patients were identified by searching admission records for ICD-9 codes related to breast abscesses. Demographic characteristics, medical history, culture results, and pertinent procedures were recorded. Statistical analyses included the Fisher exact test for categorical data and Student's test for continuous variables. Results: Thirty-three postpartum abscesses were identified: 19 from Memorial Hermann Hospital and 14 from Woman's Hospital. MRSA and S. aureus were the only causative bacteria identified. Twelve of the 19 abscesses from Hermann Hospital were MRSA positive (63%), and nine of the 14 from Woman's Hospital were MRSA positive (64%). There were no statistically significant differences among women with MRSA abscesses versus those with S. aureus abscesses in terms of ethnicity, age, time to presentation, parity, insurance, or mode of delivery. Susceptibility patterns were consistent with community-acquired MRSA. Conclusions: MRSA is a significant pathogen in postpartum breast abscesses in our population, and a high level of suspicion is warranted. Local susceptibility patterns should guide treatment. Empirical treatment of breast abscesses without first obtaining cultures should be discouraged.