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

Abstract

IntroductionMethicillin‐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 methodsWe 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.ResultsThe 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).ConclusionsThe 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.

The Potential Threat of Vertical Transmission in Methicillin-Resistant Staphylococcus Aureus Infection: A Systematic Review 2022

“…A Japanese study from 2021 (n=898) concluded that a group of 55 mothers had MRSA colonization and delivered babies, of which 12.7% of neonates had MRSA isolates recovered from them at birth [ 6 ]. From the remainder population of 843 mothers without MRSA colonization, only one baby had an MRSA isolate recovered, thereby indicating that maternal colonization does play a significant role in the neonatal outcome.…”

“…Those in perinatal care are even more likely to be compromised hosts of the bug, in particular premature babies, and those being admitted to the neonatal intensive care unit (NICU); thus, the mother-child relationship in terms of MRSA infections has significant importance in the field of obstetrics [6]. Some risk factors associated with neonatal MRSA infection are low birth weight, early gestational age at birth, indwelling catheters, duration of antibiotic administration, or the number of days on a ventilator [7].…”

“…Pregnant mothers are susceptible to a variety of infections, and as this study focuses on staphylococcal infections, colonization with these bugs is found to be high in prevalence in peripartum mothers due to high estrogen levels and blood glucose levels [ 5 ], and MRSA infection is a cause of severe diseases in pregnant women [ 6 ].…”

“…Those in perinatal care are even more likely to be compromised hosts of the bug, in particular premature babies, and those being admitted to the neonatal intensive care unit (NICU); thus, the mother-child relationship in terms of MRSA infections has significant importance in the field of obstetrics [ 6 ].…”

Walking the walk to include pregnant participants in non-obstetric clinical trials: Insights from the SNAP Trial

“…6 Colonization with S. aureus in peripartum patients is common and has been associated with invasive infections-such as skin and soft tissue infections, mastitis, pneumonia, and sepsis-as well as vertical transmission, and adverse neonatal outcomes. [7][8][9][10] Moreover, a prolonged course of intravenous antibiotics is often needed for patients with S. aureus bloodstream infections, including through peripherally inserted central lines, which are at increased risk of infectious and thromboembolic complications during pregnancy. 11 S. aureus infections in pregnancy have also been linked to significant healthcare utilization and subsequent economic burden.…”