A Prospective Cohort Pilot Study of the Clinical and Molecular Epidemiology of Staphylococcus Aureus in Pregnant Women at the Time of Group B Streptococcal Screening in a Large Urban Medical Center in Chicago, IL USA

Background: Community acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen of the 21st century whose incidence as a cause of local and invasive infections has significantly increased, especially in previously healthy term and near term newborns. The etiology of the increasing incidence of infection in previously healthy term and near-term newborns remains unclear. Hypothesis: 1. The incidence of previously healthy newborns infected with CA-MRSA skin \& soft tissue (SSTI) and invasive infections is higher in those born to mothers colonized with CA-MRSA. 2. Pregnant women colonized with CA-MRSA are at higher risk for post-partum infection with this organism. Specific Aims: 1. To determine the incidence of nasal and vaginal colonization with CA-MRSA in pregnant women and determine the genetic similarities of these strains. 2. To study CA-MRSA transmission dynamics and evaluate the incidence of SSTI and invasive infections in newborns born to S. aureus colonized mothers. 3. To study the efficacy of attempted decolonization in CA-MRSA colonized mothers in decreasing the incidence of transmission and development of SSTI and invasive infections in their infants during the first month of life. Potential Impact: Understanding the epidemiology of the transmission dynamics of CA-MRSA in previously healthy newborns will provide important information to support the development of strategies aimed at the interruption of transmission and prevention of infection caused by CA-MRSA in newborns, as well as in pregnant women. This will also allow for the development of infection control strategies to prevent the spread of this organism among post-partum units and nurseries.