Methicillin-resistant Staphylococcus aureus colonization in a pediatric intensive care unit: risk factors

Pediatric Clinical Outcomes of Nasal Methicillin-resistant Staphylococcus aureus Polymerase Chain Reaction Utilization

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinical challenge in selecting empiric antimicrobials for pediatric infections. We implemented nasal MRSA polymerase chain reaction (nMRSA PCR) screening as a diagnostic tool and evaluated its impact on empiric antibiotic use and clinical outcomes.

METHODS

A retrospective single-center study of patients hospitalized with infections who were empirically prescribed anti-MRSA antibiotics was conducted prior to and following the initiation of nMRSA PCR screening. Electronic medical records, pharmacy data and bacterial cultures results were reviewed. Predictive values of nMRSA PCR testing were calculated and the duration of anti-MRSA empiric therapy and clinical outcomes preimplementation and postimplementation were compared.

RESULTS

During the preimplementation period, there were 382 distinct episodes (294 unique patients) that met the inclusion criteria and during post-nMRSA PCR implementation, 394 episodes (360 unique patients) were identified. The median time to discontinuation of anti-MRSA antibiotics and proportion of patients prescribed anti-MRSA antibiotics at discharge were significantly lower in postimplementation compared with preimplementation period; 48 versus 56 hours, P < 0.001 and 20.1% versus 40.3%, P < 0.001, respectively. The negative and positive predictive values of nMRSA PCR compared to clinical culture results were 95.6% and 51.2%, respectively. Predefined adverse outcomes were documented in 11 patients who had early anti-MRSA discontinuation with negative nMRSA PCR results but only 3 were restarted on anti-MRSA treatment and none grew MRSA in clinical cultures.

CONCLUSIONS

Shortened anti-MRSA antibiotic duration, high negative predictive value and low adverse events provide promising evidence that nMRSA PCR is an effective, rapid antimicrobial stewardship tool for hospitalized children.

Prevalence and molecular characterizations of Staphylococcus aureus nasal colonization among patients in pediatric intensive care units in Taiwan

Background

Nasal colonization of Staphylococcus aureus is a risk factor for the pathogen transmission and the development of infections. Limited information is available on the prevalence and molecular characteristics of S. aureus colonization in pediatric intensive care unit (ICU) patients.

Methods

A cross-sectional, island-wide study was conducted in 2011. Nasal swabs were collected from pediatric ICU patients at six tertiary hospitals in Taiwan.

Results

Of 114 patients enrolled in total, nasal colonization of S. arueus was detected in 30 (26.3%) of them, among whom 20 (17.5%) with methicillin-resistant S. arueus (MRSA). The ST59/SCCmec IV and V clones were most common and accounted for 45% of MRSA isolates, followed by ST239/SCCmec III (25%) and ST45/SCCmec IV (20%) clones. Three ST59 MRSA isolates carried the Panton-Valentine Leukocidin genes.

Conclusions

The results indicated a high prevalence of S. arueus and MRSA nasal colonization among pediatric ICU patients in Taiwan. Identification of epidemic clones warrants the implement of infection control measures to reduce colonization and prevent the dissemination of MRSA in hospitals.

Methicillin-resistant Staphylococcus aureus Swab Results Did Not Change Treatment or Outcome in Pediatric Spinal Fusion Patients

INTRODUCTION

The aim of this study was to investigate whether preoperative methicillin-resistant Staphylococcus aureus (MRSA) swab results were predictive of surgical site infections (SSIs) in pediatric patients who have undergone spinal fusion.

METHODS

We conducted a retrospective chart review of patients who underwent posterior spinal fusion between 2004 and 2014 to determine preoperative MRSA colonization status and SSI rates and organisms. Before October 1, 2012, we administered vancomycin to the patients for infection prophylaxis; beginning October 1, 2012, patients received ceftazidime and Ancef (cefazolin for injection; GlaxoSmithKline). We added powdered vancomycin to all bone grafts.

RESULTS

A total of 1,200 patients met inclusion criteria. Of the patients, 2.3% (n = 28 of 1,200) were positive for MRSA, and an SSI developed in 3.1% (n = 37 of 1,200). No significant difference in infection rates was found between patients whose MRSA swab was positive and negative (positive swab = 1 SSI, negative swab = 36 SSIs; P = 0.88). Three SSIs were caused by MRSA.

CONCLUSION

The results of a preoperative MRSA nasal swab had no correlation with SSI rates.

LEVEL OF EVIDENCE

Level III.

Utility of nasal swab and age in detecting methicillin-resistant Staphylococcus aureus in pediatric head and neck abscesses

OBJECTIVE

To identify risk factors associated with the presence of methicillin-resistant Staphylococcus aureus (MRSA) in surgical cultures taken from incision and drainage (I&D) of head and neck abscesses in the pediatric population.

STUDY DESIGN

Retrospective case series.

METHODS

All patients under 18 years of age with a head and neck abscess requiring I&D from 2009 to 2015 were reviewed. MRSA nasal swab cultures were taken from all patients upon hospitalization. Surgical cultures were obtained from all patients and correlated with MRSA nasal swab results. Univariate and multivariate logistic regression was performed, and odds ratios (ORs) along with descriptive statistics were analyzed.

RESULTS

Of a total of 272 patients, there were 68 (25%) MRSA-positive abscesses. The majority (86.8%) of these abscesses were in children under 2 years of age. Overall, 12 (4.4%) presented with positive admission MRSA nasal swabs. Of these, 91.7% had MRSA-positive abscess cultures. Decreasing age in years showed an OR of 1.650 (P < 0.001) for MRSA-positive abscess, with children less than 1 year old having the highest OR of 10.74 (P < 0.001).

CONCLUSION

Younger age and MRSA nasal colonization were two statistically significant risk factors for developing an MRSA abscess of the head and neck. This study demonstrates a high positive predictive value for MRSA-positive neck abscesses when nasal swab screenings were MRSA-positive (91.7%). Children under 2 years of age-especially those under 1 year of age-or those with MRSA nasal colonization can be considered a high-risk population that may benefit from empiric antibiotics against MRSA for head and neck abscesses.

LEVEL OF EVIDENCE

4. Laryngoscope, 127:2407-2412, 2017.

Prevalence of ESBL-producing Enterobacteriaceae in paediatric urinary tract infections: A systematic review and meta-analysis

OBJECTIVES

We aimed to evaluate the prevalence of paediatric urinary tract infections (UTIs) caused by extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE), identify predisposing factors and examine their effect on the length of hospital stay (LOS).

METHODS

For this systematic review and meta-analysis, we searched the PubMed and EMBASE databases for studies that provide data on the rate of ESBL-PE among paediatric UTIs.

RESULTS

Out of 1828 non-duplicate citations, 16 studies reporting a total of 7374 cases of UTI were included. The prevalence of ESBL-PE was 14% [(95%CI 8, 21)]. Vesicoureteral reflux (VUR) [OR = 2.79, (95%CI 1.39, 5.58)], history of UTI [OR = 2.89 (95%CI 1.78, 4.68)] and recent antibiotic use [OR = 3.92, (95%CI 1.76, 8.7)] were identified as risk factors. The LOS was significantly longer among children infected with ESBL-PE, compared to those infected with other uropathogens. [SMD = 0.88, (95%CI 0.40, 1.35)].

CONCLUSIONS

In the paediatric population, 1 out of 7 UTIs are caused by ESBL-PE. Patients with VUR, previous UTI or recent antibiotic use constitute a high risk group and these pathogens are associated with increased LOS. The significant incidence of ESBL-PE in this population should be taken into consideration in the development of empiric treatment protocols and antibiotic stewardship programmes, especially in high-prevalence areas.

Differences in epidemiological and molecular characteristics of nasal colonization with Staphylococcus aureus (MSSA-MRSA) in children from a university hospital and day care centers

Background

Clinical significance of Staphylococcus aureus colonization has been demonstrated in hospital settings; however, studies in the community have shown contrasting results regarding the relevance of colonization in infection by community-associated MRSA (CA-MRSA). In Colombia there are few studies on S. aureus colonization. The aim of this study was to determine the molecular and epidemiological characteristics of nasal colonization by S. aureus (MSSA-MRSA) in children from a university hospital and day care centers (DCCs) of Medellin, Colombia.

Methods

An observational cross-sectional study was conducted in 400 children (200 in each setting), aged 0 months to 5 years, during 2011. Samples were collected from each nostril and epidemiological information was obtained from the parents. Genotypic analysis included spa typing, PFGE, MLST, SCCmec typing, detection of genes for virulence factors and agr groups.

Results

Frequency of S. aureus colonization was 39.8% (n = 159) (hospital 44.5% and DCCs 35.0%) and by MRSA, 5.3% (n = 21) (hospital 7.0% and DCCs 3.5%). Most S. aureus colonized children were older than two years (p = 0.005), the majority of them boys (59.1%), shared a bedroom with a large number of people (p = 0.028), with history of β-Lactamase inhibitors usage (p = 0.020). MSSA strains presented the greatest genotypic diversity with 15 clonal complexes (CC). MRSA isolates presented 6 CC, most of them (47.6%) belonged to CC8-SCCmec IVc and were genetically related to previously reported infectious MRSA strains.

Conclusion

Differences in epidemiological and molecular characteristics between populations may be useful for the understanding of S. aureus nasal colonization dynamics and for the design of strategies to prevent S. aureus infection and dissemination. The finding of colonizing MRSA with similar molecular characteristics of those causing infection demonstrates the dissemination capacity of S. aureus and the risk of infection among the child population.

MRSA colonization and risk of infection in the neonatal and pediatric ICU: a meta-analysis

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of morbidity and mortality in NICUs and PICUs. Our objective was to assess the burden of MRSA colonization on admission, study the time trends, and examine the significance of MRSA colonization in this population.

METHODS

PubMed and Embase databases were consulted. Studies that reported prevalence of MRSA colonization on ICU admission were selected. Two authors independently extracted data on MRSA colonization and infection.

RESULTS

We identified 18 suitable articles and found an overall prevalence of MRSA colonization of 1.9% (95% confidence interval [CI] 1.3%-2.6%) on admission to the NICU or PICU, with a stable trend over the past 12 years. Interestingly, 5.8% (95% CI 1.9%-11.4%) of outborn neonates were colonized with MRSA on admission to NICU, compared with just 0.2% (95% CI 0.0%-0.9%) of inborn neonates (P = .01). The pooled acquisition rate of MRSA colonization was 4.1% (95% CI 1.2%-8.6%) during the NICU and PICU stay and was as high as 6.1% (95% CI 2.8%-10.6%) when the NICU population was studied alone. There was a relative risk of 24.2 (95% CI 8.9-66.0) for colonized patients to develop a MRSA infection during hospitalization.

CONCLUSIONS

In the NICU and PICU, there are carriers of MRSA on admission, and MRSA colonization in the NICU is almost exclusively associated with outborn neonates. Importantly, despite infection control measures, the acquisition rate is high, and patients colonized with MRSA on admission are more likely to suffer a MRSA infection during hospitalization.