Detection of community-acquired methicillin-resistant staphylococcus aureus colonization among pregnant women

Abstract

CUS AUREUS COLONIZATION AMONG PREGNANT WOMEN KATHERINE CHEN, RICHARD HUARD, PHYLLIS DELLA-LATTA, LISA SAIMAN, Columbia University, Obstetrics & Gynecology and Epidemiology, New York, New York, Columbia University, Pathology, New York, New York, Columbia University, Pediatrics and Epidemiology, New York, New York OBJECTIVE: Community-acquired methicillin-resistant S. aureus (MRSA) infection has emerged in postpartum women and neonates. To estimate the extent of community-acquired MRSA colonization among pregnant women, we determined the prevalence of methicillin-susceptible and methicillin-resistant S. aureus from group B streptococcus (GBS) screening cultures obtained from pregnant women. STUDY DESIGN: We conducted a prospective surveillance study for methicillin-susceptible and methicillin-resistant S. aureus on all routine de-identified GBS screening cultures obtained from pregnant women that were submitted to the Clinical Microbiology Laboratory of a large tertiary care referral center with an average of 4,000 live births annually. We analyzed the antibiotic susceptibility patterns of the MRSA isolates to identify isolates with phenotypic characteristics of community-acquired MRSA (isolates that were not multidrug-resistant) and hospital-acquired MRSA (isolates that were multi-drugresistant). RESULTS: From January 2005 to June 2005, 2,118 GBS screening cultures were processed. Five hundred (23.6%) GBS isolates and 364 (17.2%) S. aureus isolates were identified. Colonization with GBS significantly predicted colonization with S. aureus (OR 1.7, 95% CI 1.4, 2.4, p!0.0001). Of the S. aureus isolates, 9 (2.5%) were methicillin-resistant. Of the MRSA isolates, 8 (88.9%) had phenotypic characteristics of community-acquired MRSA whereas one isolate had characteristics of hospital-acquired MRSA. CONCLUSION: We identified a higher than previously reported colonization rate of S. aureus among pregnant women, yet detected a low rate of community-acquired MRSA. Despite the emergence of community-acquired MRSA infections in the postpartum and neonatal populations, we do not advocate routine screening of pregnant women for colonization of community-acquired MRSA at this time. However, the monitoring of community-acquired MRSA infections should continue.