Methicillin-resistant Staphylococcus aureus colonization among women admitted for preterm delivery

Clinical characteristics and antibiotic resistance profile of invasive MRSA infections in newborn inpatients: a retrospective multicenter study from China

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) can cause invasive infections with significant mortality in neonates. This study aimed to analyze the clinical characteristics and antibiotic resistance profiles of invasive MRSA infections and determine risk factors associated with invasive MRSA infections in newborn inpatients.

METHODS

This multicenter retrospective study of inpatients from eleven hospitals in the Infectious Diseases Surveillance of Pediatrics (ISPED) group of China was performed over a two-year period (2018-2019). Statistical significance was calculated by applying the χ2 test or by Fisher's exact test in the case of small sample sizes.

RESULTS

A total 220 patients were included. Among included cases, 67 (30.45%) were invasive MRSA infections, including two deaths (2.99%), while 153 (69.55%) were noninvasive infections. The invasive infections of MRSA occurred at a median age of 8 days on admission, which was significantly younger compared to 19 days in noninvasive cases. Sepsis (86.6%) was the most common invasive infection, followed by pneumonia (7.4%), bone and joint infections (3.0%), central nervous system infection (1.5%), and peritonitis (1.5%). Congenital heart disease, low birth weight infant (<2500 g), but not preterm neonates, and bronchopulmonary dysplasia, were more commonly found in invasive MRSA infections. All these isolates were susceptible to vancomycin and linezolid and were resistant to penicillin. Additionally, 69.37% were resistant to erythromycin, 57.66% to clindamycin, 7.04% to levofloxacin, 4.62% to sulfamethoxazole-trimethoprim, 4.29% to minocycline, 1.33% to gentamicin, and 3.13% were intermediate to rifampin.

CONCLUSION

Low age at admission (≤8 days), congenital heart disease, and low birth weight were associated with invasive MRSA infections in neonates, and no isolates resistant to vancomycin and linezolid were found. Determining these risks in suspected neonates may help identify patients with imminent invasive infections who may require intensive monitoring and therapy.

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.

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.

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.

Risk factors for methicillin-resistant Staphylococcus aureus colonization in the neonatal intensive care unit: A systematic review and meta-analysis

CONTEXT

Methicillin-resistant Staphylococcus aureus (MRSA) causes a significant burden of illness in neonatal intensive care units (NICUs) worldwide. Identifying infants colonized with MRSA has become an important infection control strategy to interrupt nosocomial transmission.

OBJECTIVE

Assess risk factors for MRSA colonization in NICUs via a systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, Web of Science, and The Cochrane Library databases were searched from inception through September 2015.

STUDY SELECTION

Studies reporting risk factors for MRSA colonization using noncolonized controls in subspecialty level III or IV NICUs were included.

DATA EXTRACTION

Two authors independently extracted data on MRSA colonization risk factors, study design, and MRSA screening methodology.

RESULTS

Eleven articles were included in the systematic review, with 10 articles analyzed via meta-analysis. MRSA colonization was associated with gestational age <32 weeks (odds ratio [OR], 2.67; 95% confidence interval [CI], 1.35-5.27; P = .01) and birth weight <1,500 g (OR, 2.63; 95% CI, 1.25-5.55; P = .01). Infant sex (P = .21), race (P = .06), inborn status (P = .09), and delivery type (P = .24) were not significantly associated with colonization.

CONCLUSIONS

Very preterm and very-low birth weight infants were identified as having an increased risk for MRSA colonization on meta-analysis. Multifaceted infection prevention strategies should target these high-risk infants to reduce MRSA colonization rates in NICUs.

Risk Factors for Staphylococcus aureus Acquisition in the Neonatal Intensive Care Unit: A Matched Case-Case-Control Study

OBJECTIVE To determine risk factors independent of length of stay (LOS) for Staphylococcus aureus acquisition in infants admitted to the neonatal intensive care unit (NICU). DESIGN Retrospective matched case-case-control study. SETTING Quaternary-care referral NICU at a large academic children's hospital. METHODS Infants admitted between January 2014 and March 2016 at a level IV NICU who acquired methicillin resistant (MRSA) or susceptible (MSSA) S. aureus were matched with controls by duration of exposure to determine risk factors for acquisition. A secondary post hoc analysis was performed on the entire cohort of at-risk infants for risk factors identified in the primary analysis to further quantify risk. RESULTS In total, 1,751 infants were admitted during the study period with 199 infants identified as having S. aureus prevalent on admission. There were 246 incident S. aureus acquisitions in the remaining at-risk infant cohort. On matched analysis, infants housed in a single-bed unit were associated with a significantly decreased risk of both MRSA (P=.03) and MSSA (P=.01) acquisition compared with infants housed in multibed pods. Across the entire cohort, pooled S. aureus acquisition was significantly lower in infants housed in single-bed units (hazard ratio,=0.46; confidence interval, 0.34-0.62). CONCLUSIONS NICU bed design is significantly associated with S. aureus acquisition in hospitalized infants independent of LOS. Infect Control Hosp Epidemiol 2018;39:46-52.

A Snapshot on MRSA Epidemiology in a Neonatal Intensive Care Unit Network, Palermo, Italy

Objectives: We performed a 1-year prospective surveillance study on MRSA colonization within the five NICUs of the metropolitan area of Palermo, Italy. The purpose of the study was to assess epidemiology of MRSA in NICU from a network perspective.

Methods: Transfer of patients between NICUs during 2014 was traced based on the annual hospital discharge records. In the period February 2014–January 2015, in the NICU B, at the University teaching hospital, nasal swabs from all infants were collected weekly, whereas in the other four NICUs (A, C, D, E) at 4 week-intervals of time. MRSA isolates were submitted to antibiotic susceptibility testing, SCCmec typing, PCR to detect lukS-PV and lukF-PV (lukS/F-PV) genes and the gene encoding the toxic shock syndrome toxin (TSST-1), multilocus variable number tandem repeat fingerprinting (MLVF), and multilocus sequence typing (MLST).

Results: In the period under study, 587 nasal swabs were obtained from NICU B, whereas 218, 180, 157, and 95 from NICUs A, C, D, and E, respectively. Two groups of NICUs at high prevalence and low prevalence of MRSA colonization were recognized. Overall, 113 isolates of MRSA were identified from 102 infants. Six MLVF types (A–F) were detected, with type C being subdivided into five subtypes. Five sequence types (STs) were found with ST22-IVa being the most frequent type in all NICUs. All the MRSA molecular subtypes, except for ST1-IVa, were identified in NICU B.

Conclusions: Our findings support the need to approach surveillance and infection control in NICU in a network perspective, prioritizing referral healthcare facilities.

Neonatal host defense against Staphylococcal infections

Preterm infants are especially susceptible to late-onset sepsis that is often due to Gram-positive bacterial infections resulting in substantial morbidity and mortality. Herein, we will describe neonatal innate immunity to Staphylococcus spp. comparing differences between preterm and full-term newborns with adults. Newborn innate immunity is distinct demonstrating diminished skin integrity, impaired Th1-polarizing responses, low complement levels, and diminished expression of plasma antimicrobial proteins and peptides, especially in preterm newborns. Characterization of distinct aspects of the neonatal immune response is defining novel approaches to enhance host defense to prevent and/or treat staphylococcal infection in this vulnerable population.

Update on Epidemiology and Treatment of MRSA Infections in Children

In 2000-10 the epidemiology of pediatric MRSA infections in the United States was transformed with an epidemic of CA-MRSA infections. We review the epidemiology of MRSA in the community and in the health care setting, including intensive care units, among infants and CF patients, and in households as well as the impact that the CA-MRSA epidemic has had on hospitalization with MRSA infections. Risk factors for carriage, transmission, and initial and recurrent infection with MRSA are discussed. New studies on the treatment of pediatric MRSA infections and on the efficacy of MRSA decolonization are reviewed.