Investigators from Birmingham, Alabama, investigated the prevalence of genital tract methicillin-resistant Staphylococcus aureus (MRSA) colonization among pregnant women and its association with early-onset neonatal MRSA infection.
Data on 5,732 pregnant women who were screened for S aureus and group B streptococcus (GBS) between 35 and <37 weeks of gestation from July 2003 through June 2006 and their 5,804 infants (70 twin and 1 triplet sets) were reviewed. The maternal culture results were compared with a database of all neonates with a positive MRSA culture who were delivered to the mothers during the study interval.
Overall, maternal cultures were positive for GBS in 1,312 mothers (22.9%) and for S aureus in 833 (14.5%). Of the 833 positive S aureus cultures, 202 (24.3%) were MRSA, yielding a prevalence of MRSA in this population of 3.5%. Compared with MRSA-negative women, MRSA-positive women were more likely to be black, unmarried, have lower education levels, have government-funded medical care, and a history of drug abuse. However, in a multivariate model only black race was a significant risk factor for MRSA genital colonization (OR 7.1; 95% CI, 3.7–13.6). GBS-positive women were significantly more likely than GBS-negative women to be colonized with S aureus (20.7% vs 12.7%) and MRSA (6% vs 2.8%).
No cases of invasive early-onset MRSA infections occurred in neonates. The authors conclude that screening pregnant women for MRSA is not necessary at this time because of the lack of definitive evidence of an increased risk of invasive MRSA infection in infants born to mothers with anogenital MRSA colonization.
Dr. Rathore has disclosed no financial relationship relevant to this commentary. This commentary does not contain a discussion of an unapproved/investigative use of a commercial product/device.
Over the past decade, MRSA has become increasingly important, as both a hospital- and community-acquired (CA) pathogen. CA-MRSA is now the major etiologic agent of skin and soft tissue infections.1,–3 (See AAP Grand Rounds, July 2006;16:77–782 and February 2000;3:14–15.3) There is concern, as well, that health care providers, parents, and hospital visitors may transmit MRSA to children. This is of special import in intensive care units (ICUs).
The neonatal ICU (NICU) presents a particular challenge because of the risk of newborn colonization with MRSA following exposure to this organism in the birth canal. This risk has been clearly demonstrated with other pathogens such as GBS and herpes simplex virus. NICU outbreaks of MRSA have been reported; however, enhanced infection control procedures have resulted in blunting the spread of MRSA and infections in the NICU.4
The results of this study indicate that maternal-to-child transmission of MRSA is unlikely to cause serious infections in the neonatal period. While the authors conclude that there is not sufficient evidence at the present time to recommend a widespread maternal screening strategy for MRSA similar to that for GBS,...