Predictors and Outcomes for Pregnant Women with Vaginal-Rectal Carriage of Community-Associated Methicillin-Resistant Staphylococcus aureus

Abstract

The purpose of this study was to determine the predictors and outcomes of pregnant women with vaginal-rectal carriage of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). We performed an unmatched 1:4 case-control study with two control groups (13 CA-MRSA cases, 52 methicillin-sensitive S. aureus (MSSA) controls, and 52 S. aureus-negative controls) via a retrospective medical record review. We found that CA-MRSA cases were 12.5 times significantly less likely to be colonized with group B streptococci (GBS) compared with MSSA controls in multivariable analyses. When we compared MSSA patients with S. aureus-negative patients, we found that MSSA patients were 4.5 times significantly more likely to be colonized with GBS and 11 times significantly more likely to have a postpartum fever > or = 100.4 degrees F in multivariable analyses. Traditional risk factors for hospital-associated MRSA do not appear to predict vaginal-rectal CA-MRSA carriage in pregnant women. Instead, CA-MRSA carriage is significantly associated with lack of GBS carriage. Additional microbiologic studies and epidemiologic studies are needed to clarify the relationship between S. aureus and GBS, given that these two colonizing organisms have the potential to become pathogens.

Trends in Methicillin-Resistant Staphylococcus aureus Anovaginal Colonization in Pregnant Women in 2005 versus 2009

“…Conversely, MSSA colonization was more frequent in GBS-positive women (8). Of note, the rates of GBS colonization in the control groups were 46 to 50% (8,33), which is higher than the generally reported rates of 10 to 30% (29). In contrast, others have reported that both MSSA and MRSA colonization were significantly more common in GBS-positive women (2).…”

“…Two reports demonstrated a decreased frequency of MRSA colonization in the on May 9, 2018 by guest http://jcm.asm.org/ setting of GBS colonization (8,33). Conversely, MSSA colonization was more frequent in GBS-positive women (8). Of note, the rates of GBS colonization in the control groups were 46 to 50% (8,33), which is higher than the generally reported rates of 10 to 30% (29).…”

“…Two reports demonstrated a decreased frequency of MRSA colonization in the on May 9, 2018 by guest http://jcm.asm.org/ setting of GBS colonization (8,33). Conversely, MSSA colonization was more frequent in GBS-positive women (8).…”

“…More recent studies conducted in other locales have suggested that the prevalence of anovaginal colonization with MRSA is increasing, with reported rates ranging from 3.5 to 10.4% (2,13). The association of MRSA colonization with group B streptococcus (GBS) colonization is less clear; some reports have shown an increased rate of MRSA colonization in GBS-positive women (2), while others have shown a decreased rate (8,32).…”

Intestinal carriage of Staphylococcus aureus: how does its frequency compare with that of nasal carriage and what is its clinical impact?

“…A significant association between S. aureus colonization and Group B streptococcus (GBS) colonization was found. In a subsequent study this association was analyzed in more detail [66] and the significant association between MSSA and GBS was confirmed. Pregnant women with MSSA carriage were significantly more likely to have postpartum fever than those who were S. aureus-negative.…”