Hospital and provider patient volumes, cesarean section rates, and early postpartum invasive methicillin-resistant Staphylococcus aureus infection

Worldwide prevalence of maternal methicillin-resistant Staphylococcus aureus colonization: A systematic review and meta-analysis

Methicillin-resistant Staphylococcus aureus (MRSA) infection during pregnancy can adversely influence the well-being of pregnant women, fetuses, and neonates. To our knowledge, there is no global data on the maternal prevalence of MRSA colonization. We conducted a systematic review and meta-analysis to estimate the global and regional prevalence rates of MRSA colonization among pregnant women. We searched international databases (i.e., MEDLINE/PubMed, EMBASE, Scopus, Web of Science collection, and SciELO) for studies published from inception to March 10, 2022. Observational population-based studies reporting MRSA colonization among pregnant women were eligible to be included. We utilized the random-effects meta-analyses to compute the pooled prevalence estimates of maternal colonization across studies at 95% confidence intervals (CIs). The heterogeneity was assessed by I² statistic and the Cochran's Q test. Subgroup and meta-regression analyses were used to adjust for potential sources of heterogeneity. The data source regarding maternal MRSA colonization included 55 studies from 24 countries and 110,654 pregnant women. The worldwide pooled prevalence for maternal MRSA colonization was 3.23% (95% CI, 2.40-4.17%), with the highest and lowest colonization rates for Africa (9.13%, 4.36-15.34%) and Europe (0.79%, 0.28-1.51%), respectively. We estimated that nearly 4.5 million pregnant women are colonized with MRSA worldwide. MRSA colonization rates were higher among black ethnicity, multiparous women, pregnant women with prior MRSA infection, women with lower personal hygiene, and those living in lower-income and human development indices countries or regions. MRSA colonizes substantial numbers of pregnant women worldwide, with varying prevalence rates in different regions; however, further investigations are needed to recognize regional differences. Our findings emphasized the need for prevention efforts against MRSA to reduce the health risks among women and newborns.

Vertical transmission of methicillin-resistant Staphylococcus aureus at delivery and its clinical impact: An observational, prospective cohort study

INTRODUCTION

Methicillin-resistant Staphylococcus aureus (MRSA) infection has a significant clinical impact on both pregnant women and neonates. The aim of this study was to assess accurately the vertical transmission rate of MRSA and its clinical impacts on both pregnant mothers and neonates.

MATERIAL AND METHODS

We conducted a prospective observational cohort study of 898 pregnant women who were admitted to our department and 905 neonates from August 2016 to December 2017. MRSA was cultured from nasal and vaginal samples taken from the mothers at enrollment and from nasal and umbilical surface swabs taken from neonates at the time of delivery. We examined the vertical transmission rate of MRSA in mother-neonate pairs. We used multivariable logistic regression to identify risk factors for maternal MRSA colonization and maternal/neonatal adverse outcomes associated with maternal MRSA colonization.

RESULTS

The prevalence of maternal MRSA colonization was 6.1% (55 of 898) at enrollment. The independent risk factors were multiparity and occupation (healthcare provider) (odds ratio [OR] 2.35, 95% confidence interval [CI] 1.25-4.42 and OR 2.58, 95% CI 1.39-4.79, respectively). The prevalence of neonatal MRSA colonization at birth was 12.7% (7 of 55 mother-neonate pairs) in the maternal MRSA-positive group, whereas it was only 0.12% (one of 843 pairs) in the maternal MRSA-negative group (OR 121, 95% CI 14.6-1000). When maternal vaginal samples were MRSA-positive, vertical transmission was observed in four of nine cases (44.4%) in this study. Skin and soft tissue infections developed more frequently in neonates in the maternal MRSA-positive group than in the MRSA-negative group (OR 7.47, 95% CI 2.50-22.3).

CONCLUSIONS

The prevalence of MRSA in pregnant women was approximately 6%. Vertical transmission caused by maternal vaginal MRSA colonization was observed in four of nine cases (44.4%). Although our study includes a limited number of maternal MRSA positive cases, the vertical transmission of MRSA may occur in up to 44% of neonates of mothers with vaginal MRSA colonization. Maternal MRSA colonization may be associated with increased development of skin and soft tissue infections in neonates via vertical transmission.

Antibiotics for the Treatment of Staphylococcal Infections in the Obstetric Patient

This review addresses current epidemiology and treatment of obstetric staphylococcal infections. It also examines current prophylaxis methods and the efficacy of universal screening.

Limitations of Vaginal Birth After Cesarean Success Prediction

The Society for Maternal-Fetal Medicine endorses an algorithm for estimating the probability of successful vaginal birth for women undergoing trial of labor after cesarean (TOLAC). The algorithm is available online in the form of an easy-to-use calculator. This calculator has significant limitations that are easily overlooked by women and providers alike. The calculator has much greater positive than negative predictive power, and it cannot predict unsuccessful TOLAC or uterine rupture. Furthermore, the calculator cannot predict rare catastrophes, such as unplanned hysterectomy, permanent injury, or death. Predictions are heavily influenced by race and ethnicity, which are social and not biological constructs. Relevant variables, such as provider attitudes and institutional differences, are not accounted for. Providers should be mindful and transparent about calculator limitations when counseling women, particularly Latina and African American women. It may be appropriate to use the calculator to inform but not restrict women's options.

Risk Factors for Methicillin-Resistant Staphylococcus aureus (MRSA) Colonization Among Patients Admitted to Obstetrical Units: A Nested Case-Control Study

OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) among obstetrical patients can increase birth complications for both mothers and infants, but little is known about the risk factors for MRSA in this population. The objective of this study was to determine the prevalence of MRSA among obstetrical patients and identify risk factors associated with MRSA colonization.

METHODS

This nested case-control study used obstetrical patients with MRSA colonization identified through a universal screening program at The Ottawa Hospital (February 2008-January 2010). Cases and three matched controls were compared using chi-square tests for categorical variables, median and interquartile range (IQR), and Wilcoxon rank-sum tests for continuous variables. Conditional logistic regression using ORs and 95% CIs was used to identify risk factors. Standard microbiologic techniques and pulsed-field gel electrophoresis of the MRSA isolates from case patients were performed.

RESULTS

Out of 11 478 obstetrical patients, 39 (0.34%) were MRSA colonized; 117 patients were selected as matched controls. The median age was 30 (IQR 27.5-35.00) and median length of stay was 2.55 days (IQR 1.95-3.24). Only MRSA cases had a previous MRSA infection (4 vs. 0). MRSA cases had significantly higher parity (median 3; IQR 2-5) compared with controls (median 2; IQR 1-3) (OR 1.52; 95% CI 1.22-1.90) CONCLUSION: This study identified a low prevalence of MRSA among obstetrical patients. Risk factors associated with MRSA colonization were previous MRSA infection and multiparity. Obstetrical patients who previously tested positive for MRSA should be placed on contact precautions at the time of hospital admission because this is a risk factor for future colonization.