Methicillin-resistant Staphylococcus aureus in the neonatal intensive care unit

Optimization of Vancomycin Initial Dosing Regimen in Neonates Using an Externally Evaluated Population Pharmacokinetic Model

BACKGROUND

Vancomycin therapeutic monitoring guidelines were revised in March 2020, and a population pharmacokinetics-guided Bayesian approach to estimate the 24-hour area under the concentration-time curve to the minimum inhibitory concentration ratio has since been recommended instead of trough concentrations. To comply with these latest guidelines, we evaluated published population pharmacokinetic models of vancomycin using an external dataset of neonatal patients and selected the most predictive model to develop a new initial dosing regimen.

METHODS

The models were identified from the literature and tested using a retrospective dataset of Canadian neonates. Their predictive performance was assessed using prediction- and simulation-based diagnostics. Monte Carlo simulations were performed to develop the initial dosing regimen with the highest probability of therapeutic target attainment.

RESULTS

A total of 144 vancomycin concentrations were derived from 63 neonates in the external population. Five of the 28 models retained for evaluation were found predictive with a bias of 15% and an imprecision of 30%. Overall, the Grimsley and Thomson model performed best, with a bias of -0.8% and an imprecision of 20.9%; therefore, it was applied in the simulations. A novel initial dosing regimen of 15 mg/kg, followed by 11 mg/kg every 8 hours should favor therapeutic target attainment.

CONCLUSIONS

A predictive population pharmacokinetic model of vancomycin was identified after an external evaluation and used to recommend a novel initial dosing regimen. The implementation of these model-based tools may guide physicians in selecting the most appropriate initial vancomycin dose, leading to improved clinical outcomes.

Impact of active surveillance and decolonization strategies for methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit

OBJECTIVE

To assess the impact of active surveillance and decolonization strategies on methicillin-resistant Staphylococcus aureus (MRSA) infection rates in a NICU.

STUDY DESIGN

MRSA infection rates were compared before (2014-2016) and during (2017-2022) an active surveillance program. Eligible infants were decolonized with chlorohexidine gluconate (CHG) bathing and/or topical mupirocin. Successful decolonization and rates of recolonization were assessed.

RESULTS

Fifty-two (0.57%) of 9 100 hospitalized infants had invasive MRSA infections from 2014 to 2022; infection rates declined non-significantly. During the 6-year surveillance program, the risk of infection was 16.9-times [CI95 8.4, 34.1] higher in colonized infants than uncolonized infants. Those colonized with mupirocin-susceptible MRSA were more likely successfully decolonized (aOR 9.7 [CI95 4.2, 22.5]). Of 57 infants successfully decolonized who remained hospitalized, 34 (60%) became recolonized.

CONCLUSIONS

MRSA infection rates did not significantly decline in association with an active surveillance and decolonization program. Alternatives to mupirocin and CHG are needed to facilitate decolonization.

Effects of Discontinuation of Weekly Surveillance Testing on Methicillin-Resistant Staphylococcus aureus in the NICU

OBJECTIVE

 Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major cause of serious morbidity and mortality in the neonatal intensive care unit (NICU). There is no clear consensus on infection control measures. Some approaches to MRSA colonization management may be burdensome with unclear benefits. The objective of this study was to determine if stopping weekly MRSA surveillance with active detection and contact isolation (ADI) was associated with a change in infection rate.

STUDY DESIGN

 This is a retrospective cohort study of infants admitted to two affiliated NICUs. The ADI cohort infants received weekly nasal MRSA cultures and were placed in contact isolation if MRSA colonized for the duration of their hospitalization. The No Surveillance cohort infants were only placed in isolation if there was active MRSA infection or if MRSA colonization was identified incidentally. The rates of infection were determined between the cohorts.

RESULTS

 There were 8,406 neonates representing 193,684 NICU days in the comparison period. In the ADI cohort, MRSA colonization occurred in 3.4% of infants and infection occurred in 29 infants (0.4%). There were no differences between cohorts in the percent of infants with a MRSA infection at any site (0.5 vs. 0.5%, p = 0.89), rate of MRSA infections per 1,000 patient-days (0.197 vs. 0.201, p = 0.92), rate of bloodstream infections (0.12 vs. 0.26%, p = 0.18), or in the overall mortality rate (3.7 vs. 3.0% p = 0.13). ADI represented an annual cost of $590,000.

CONCLUSION

 The rates of MRSA infection did not change when weekly ADI was discontinued and was associated with a decrease in cost and resource utilization.

KEY POINTS

· Placing MRSA-colonized infants in contact isolation is a common practice.. · Data are limited with respect to efficacy in the NICU.. · This study provides evidence that active detection and contact isolation for MRSA colonization may not be beneficial..

Methicillin-resistant Staphylococcus aureus (MRSA) clusters in neonatal intensive care units (NICUs) and other neonatal units in New York State (NYS), 2001 to 2017

BACKGROUND

New York State (NYS) mandates reporting of all hospital-associated communicable disease outbreaks. We describe trends in NYS surveillance for neonatal unit methicillin-resistant Staphylococcus aureus (MRSA) outbreaks, the evolution of national MRSA infection prevention and control (IPC) recommendations, and IPC measures taken by NYS neonatal units.

METHODS

We evaluated trends of reported neonatal unit MRSA outbreaks by etiology from 2001 to 2017. We reviewed all reports and the use of IPC recommendations over time.

RESULTS

From 2001 to 2017, 124 MRSA outbreaks were reported in 47 hospital neonatal units, with a total of 1,055 laboratory-confirmed infant cases, 18 infant deaths, and 52 laboratory-confirmed staff cases. The number of outbreaks increased with the level of care. During the study period, a higher proportion of hospitals reported implementing IPC measures, including reinforcing hand hygiene compliance (increased from 79.2% to 95.1%) and enhancing environmental cleaning and disinfection (increased from 4.2% to 78.0%) as well as performing active surveillance testing (AST) on exposed neonates (increased from 4.2% to 51.2%) and molecular testing on MRSA-positive isolates (increased from 5.3% to 18.9%).

CONCLUSIONS

From 2001 to 2017, IPC measures in neonatal units increased in parallel with expanded national IPC recommendations. However, MRSA outbreaks in neonatal units continued to be frequent occurrences in NYS.

Healthcare worker perceptions surrounding Staphylococcus aureus transmission and prevention practices in the neonatal intensive care unit

OBJECTIVE

To understand healthcare worker (HCW) perceptions surrounding Staphylococcus aureus transmission and prevention in the neonatal intensive care unit (NICU).

DESIGN

Qualitative case study with focus groups.

SETTING

A level IV, 150-bed NICU at a Midwestern academic medical center that conducts active surveillance and decolonization of S. aureus-positive patients.

PARTICIPANTS

NICU HCWs, including bedside nurses, nurse managers, therapy services personnel, pediatric nurse practitioners, clinical fellows, and attending neonatologists.

METHODS

Semistructured focus group interviews, assembled by occupation, were conducted by 2 study team members. Interviews were video recorded and transcribed. Deductive coding and thematic analyses were performed using NVivo software.

RESULTS

In total, 38 HCWs participated in 10 focus groups (1-12 participants each), lasting 40-90 minutes. Four main themes emerged: (1) Methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) are inconsistently described as high risk. (2) Infection prevention interventions are burdensome. (3) Multiple sources of transmission are recognized. (4) opportunities exist to advance infection prevention. HCWs perceived MSSA to be less clinically relevant than MRSA. Participants expressed a desire to see published data supporting infection prevention interventions, including contact precautions, environmental cleaning, and patient decolonization. These practices were identified to be considerable burdens. HCWs perceived families to be the main source of S. aureus in the NICU, and they suggested opportunities for families to play a larger role in infection prevention.

CONCLUSIONS

These data highlight opportunities for HCW and parental education, research, and reevaluating interventions aimed at improving infection prevention efforts to reduce the burden of S. aureus in NICU settings.

Risk factors for methicillin-resistant Staphylococcus aureus colonization in a level-IV neonatal intensive care unit: a retrospective study

Objective

To identify risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) colonization in neonatal patients during an MRSA outbreak to minimize future outbreaks.

Design

Retrospective case-control study.

Setting

Level-IV neonatal intensive care unit (NICU) at Copenhagen University Hospital, Rigshospitalet, Denmark.

Patients

Neonates with either MRSA or methicillin-susceptible Staphylococcus aureus (MSSA).

Methods

Methicillin-resistant Staphylococcus aureus-positive neonates were matched with those colonized or infected with MSSA in a 1:1 ratio. The control group was selected from clinical samples, whereas MRSA-positive neonates were identified from clinical samples or from screening. A total of 140 characteristics were investigated to identify risk factors associated with MRSA acquisition. The characteristics were categorized into three categories: patient, unit, and microbiological characteristics.

Results

Out of 1,102 neonates screened for MRSA, between December 2019 and January 2022, 33 were MRSA positive. They were all colonized with an MRSA outbreak clone (spa type t127) and were included in this study. Four patients (12%) had severe infection. Admission due to respiratory diseases, need for intubation, need for peripheral venous catheters, admission to shared rooms with shared toilets and bath facilities in the aisles, and need for readmission were all correlated with later MRSA colonization (P < 0.05).

Conclusion

We identified clinically relevant diseases, procedures, and facilities that predispose patients to potentially life-threatening MRSA infections. A specific MRSA reservoir remains unidentified; however, these findings have contributed to crucial changes in our NICU to reduce the number of MRSA infections and future outbreaks.

Methicillin-Resistant Staphylococcus aureus Colonization in Intensive Care and Burn Units: A Narrative Review

Methicillin-resistant Staphylococcus aureus (MRSA) is a common hospital-acquired pathogen and can cause a wide spectrum of infections. In recent years, MRSA has emerged as a significant public health concern, particularly in hospitals. Intensive care units (ICUs) and burn units are high-risk areas for hospital-acquired MRSA infections, which can lead to increased morbidity, mortality, and healthcare costs. MRSA exhibits resistance to multiple antibiotics and can cause serious infections, including but not limited to pneumonia, endocarditis, and cutaneous infections, particularly in patients with burn injuries. The prevention and effective management of MRSA infections in both burn patients and those in ICUs is crucial, with strategies like isolation, regular disinfection, and prophylactic intranasal mupirocin. Early diagnosis of MRSA infection and isolation of patients is vital to prevent the spread of MRSA. Implementation of prevention strategies faces many challenges, such as cost, and the most successful infection management practices are still debated. This review has highlighted the substantial concern of MRSA colonization in intensive care and burn units. MRSA poses a significant risk to vulnerable patients, influenced by factors such as compromised immunity and invasive procedures. The prevalence of MRSA colonization varies, influenced by regional factors and infection control practices. Combating MRSA requires a multifaceted approach, including stringent infection control measures and education for healthcare workers and patients. As we move forward, continued research and cooperation are essential to reduce the burden of MRSA in these critical care settings.

Septic Arthritis of the Elbow in a Premature Neonate: An Uncommon Disease in an Uncommon Location

Septic arthritis (SA) is an infrequent diagnosis in the neonate. This case illustrates the presentation of SA within the elbow, an atypical location for neonatal SA. SA should be considered in any neonate with joint swelling, as symptoms are often subtle. Constitutional symptoms of infection, including fever, may not be present in the neonate. Staphylococcus aureus is the most common etiologic organism, and neonatal SA is often caused by hematogenous spread partially due to unique neonatal intraosseous anatomy. Joint aspiration can provide a definitive diagnosis and aid in targeted antimicrobial therapy. Other laboratory tests, including C-reactive protein and erythrocyte sedimentation rate, can aid in diagnosis. Ultrasound and magnetic resonance imaging can demonstrate joint effusion along with osteomyelitis, which is often seen concurrently with neonatal SA. There are no definitive guidelines for the treatment of neonatal SA. Conservative therapy with antimicrobials along with surgical intervention are the mainstays of treatment. Prompt diagnosis and treatment are crucial to decrease permanent joint damage. [Pediatr Ann. 2023;52(8):e292-e296.].

Next Steps for Health Care-Associated Infections in the Neonatal Intensive Care Unit

We discuss the burden of health care-associated infections (HAIs) in the neonatal ICU and the role of quality improvement (QI) in infection prevention and control. We examine specific QI opportunities and approaches to prevent HAIs caused by Staphylococcus aureus , multidrug-resistant gram-negative pathogens, Candida species, and respiratory viruses, and to prevent central line-associated bloodstream infections (CLABSIs) and surgical site infections. We explore the emerging recognition that many hospital-onset bacteremia episodes are not CLABSIs. Finally, we describe the core tenets of QI, including engagement with multidisciplinary teams and families, data transparency, accountability, and the impact of larger collaborative efforts to reduce HAIs.

Prospective Genomic Surveillance Reveals Cryptic MRSA Outbreaks with Local to International Origins among NICU Patients

Methicillin-resistant Staphylococcus aureus (MRSA) infections cause substantive morbidity and mortality in neonates. Using publicly available resources from the National Center of Biotechnology Information (NCBI) and Food and Drug Administration's (FDA) GalaxyTrakr pipeline, we illustrate the dynamics of MRSA colonization and infection in neonates. Over 217 days of prospective surveillance, analyses revealed concurrent MRSA transmission chains affecting 11 of 17 MRSA-colonized patients (65%), with two clusters that demonstrated intervals of more than a month among the appearance of isolates. All MRSA infected neonates (n = 3) showed previous colonization with the infecting strain. GalaxyTrakr clustering of the NICU strains, in the context of 21,521 international isolates deposited in NCBI's Pathogen Detection Resource, revealed NICU isolates to be distinct from adult MRSA strains seen locally and internationally. Clustering of the NICU strains within an international context enhanced the resolution of strain clusters and supported the rule-out of suspected, local transmission events within the NICU. Analyses also identified sequence type 1535 isolates, emergent in the Middle East, carrying a unique SCCmec with fusC and aac(6')-Ie/aph(2'')-1a that provided a multidrug-resistant phenotype. NICU genomic pathogen surveillance, leveraging public repositories and outbreak detection tools, supports rapid identification of cryptic MRSA clusters, and can inform infection prevention interventions for this vulnerable patient population. Results demonstrate that sporadic infections in the NICU may be indicative of hidden chains of asymptomatic transmission best identified with sequenced-based approaches.

Reducing MRSA Infection in a New NICU During the COVID-19 Pandemic

BACKGROUND AND OBJECTIVES

Methicillin-resistant Staphylococcus aureus (MRSA) is prevalent in most NICUs, with a high rate of skin colonization and subsequent invasive infections among hospitalized neonates. The effectiveness of interventions designed to reduce MRSA infection in the NICU during the coronavirus disease 2019 (COVID-19) pandemic has not been characterized.

METHODS

Using the Institute for Healthcare Improvement's Model for Improvement, we implemented several process-based infection prevention strategies to reduce invasive MRSA infections at our level IV NICU over 24 months. The outcome measure of invasive MRSA infections was tracked monthly utilizing control charts. Process measures focused on environmental disinfection and hospital personnel hygiene were also tracked monthly. The COVID-19 pandemic was an unexpected variable during the implementation of our project. The pandemic led to restricted visitation and heightened staff awareness of the importance of hand hygiene and proper use of personal protective equipment, as well as supply chain shortages, which may have influenced our outcome measure.

RESULTS

Invasive MRSA infections were reduced from 0.131 to 0 per 1000 patient days during the initiative. This positive shift was sustained for 30 months, along with a delayed decrease in MRSA colonization rates. Several policy and practice changes regarding personnel hygiene and environmental cleaning likely contributed to this reduction.

CONCLUSIONS

Implementation of a multidisciplinary quality improvement initiative aimed at infection prevention strategies led to a significant decrease in invasive MRSA infections in the setting of the COVID-19 pandemic.

The Impact of COVID-19 on Laboratory Test Utilization at a Pediatric Medical Center

Background

The epidemiology and clinical manifestation of coronavirus disease 2019 (COVID-19) in the pediatric population is different from the adult population. The purpose of this study is to identify effects of the COVID-19 pandemic on laboratory test utilization in a pediatric hospital.

Methods

We performed retrospective analysis on test utilization data from Ann & Robert H. Lurie Children’s Hospital of Chicago, an academic pediatric medical center. Data between two 100-day periods prior to (prepandemic) and during the pandemic (mid-pandemic) were analyzed to evaluate changes in test volume, lab utilization, and test positivity rate. We also evaluated these metrics based on in- vs outpatient testing and performed modeling to determine what variables significantly impact the test positivity rate.

Results

During the pandemic period, there was an expected surge in COVID-19 testing, while over 84% of lab tests studied decreased in ordering volume. The average number of tests ordered per patient was not significantly different during the pandemic for any of the laboratories (adjusted P value &gt; 0.05). Thirty-three studied tests showed significant change in positivity rate during the pandemic. Linear modeling revealed test volume and inpatient status as the key variables associated with change in test positivity rate.

Conclusions

Excluding severe acute respiratory syndrome coronavirus 2 tests, the COVID-19 pandemic has generally led to decreased test ordering volume and laboratory utilization. However, at this pediatric hospital, the average number of tests performed per patient and test positivity rates were comparable between pre- and mid-pandemic periods. These results suggest that, overall, clinical test utilization at this site remained consistent during the pandemic.

External Validation of a Vancomycin Population Pharmacokinetic Model and Developing a New Dosage Regimen in Neonates

BACKGROUND AND OBJECTIVE

Vancomycin is the drug of choice in the treatment of MRSA infections. In a published vancomycin population pharmacokinetic study on neonates in Singapore healthcare institutions, it was found that vancomycin clearance was predicted by weight, postmenstrual age, and serum creatinine. The aim of this study was to externally validate the vancomycin population pharmacokinetic model to develop a new dosage regimen in neonates, and to compare this regimen with the existing institutional and NeoFax^® dosage regimens.

METHODS

A retrospective chart review of neonates who received vancomycin therapy and therapeutic drug monitoring was conducted. The median prediction error percentage was calculated to assess bias, while the median absolute prediction error percentage and the root mean squared error percentage were calculated to assess precision. The new dosage regimen was developed using Monte Carlo simulation.

RESULTS

A total of 20 neonates were included in the external validation dataset. Eighteen of them were premature, with a median gestational age of 27.7 (25.9-31.5) weeks and postmenstrual age of 30.5 (27.3-34.3) weeks at the point of vancomycin initiation. No apparent systematic bias was found in the predictions of the model. The external validation performed in the current study found the model to be generally unbiased. Our new vancomycin dosage regimen was able to achieve target trough concentrations and area under the curve (AUC₂₄) at a greater proportion as compared to existing institutional and NeoFax^® dosage regimens.

CONCLUSION

The pharmacokinetic model built in the previous study can be used to conduct reliable population simulations of our Asian neonatal population in Singapore. The new dosage regimen was able to achieve target trough concentrations and AUC₂₄ better than existing institutional and NeoFax^® dosage regimens.

Infection prevention for extremely low birth weight infants in the NICU

Extremely preterm infants are particularly vulnerable to systemic infections secondary to their immature immune defenses, prolonged hospitalizations, delays in enteral feeding, early antibiotic exposure, and need for life-sustaining invasive interventions. There have been several evidence-based practices for infection prevention in this population, such as human milk feedings, utilization of "bundle checklists" and decolonization of pathogenic organisms. Other practices, such as the use of probiotics, human milk-derived fortifiers, and antifungal prophylaxis are more controversial and require further investigation regarding the risks and benefits of such interventions. This chapter examines the susceptibility of the preterm newborn infant to invasive infections and describes several strategies for infection prevention, along with the associated limitations of such practices. It also addresses the various gaps in our understanding of preventing infections in this population, and the need for additional large multi-center randomized controlled trials. Additionally, the role of the SARs-CoV-2 global pandemic and associated strategies for infection prevention in the NICU are discussed.

Rapid Point-of-Care Genotyping to Avoid Aminoglycoside-Induced Ototoxicity in Neonatal Intensive Care

Importance

Aminoglycosides are commonly prescribed antibiotics used for the treatment of neonatal sepsis. The MT-RNR1 m.1555A>G variant predisposes to profound aminoglycoside-induced ototoxicity (AIO). Current genotyping approaches take several days, which is unfeasible in acute settings.

Objective

To develop a rapid point-of-care test (POCT) for the m.1555A>G variant before implementation of this technology in the acute neonatal setting to guide antibiotic prescribing and avoid AIO.

Design, Setting, and Participants

This pragmatic prospective implementation trial recruited neonates admitted to 2 large neonatal intensive care units between January 6, 2020, and November 30, 2020, in the UK.

Interventions

Neonates were tested for the m.1555A>G variant via the rapid POCT on admission to the neonatal intensive care unit.

Main Outcomes and Measures

The primary outcome assessed the proportion of neonates successfully tested for the variant of all infants prescribed antibiotics. Secondary outcomes measured whether implementation was negatively associated with routine clinical practice and the performance of the system. The study was statistically powered to detect a significant difference between time to antibiotic administration before and after implementation of the MT-RNR1 POCT.

Results

A total of 751 neonates were recruited and had a median (range) age of 2.5 (0-198) days. The MT-RNR1 POCT was able to genotype the m.1555A>G variant in 26 minutes. Preclinical validation demonstrated a 100% sensitivity (95% CI, 93.9%-100.0%) and specificity (95% CI, 98.5%-100.0%). Three participants with the m.1555A>G variant were identified, all of whom avoided aminoglycoside antibiotics. Overall, 424 infants (80.6%) receiving antibiotics were successfully tested for the variant, and the mean time to antibiotics was equivalent to previous practice.

Conclusions and Relevance

The MT-RNR1 POCT was integrated without disrupting normal clinical practice, and genotype was used to guide antibiotic prescription and avoid AIO. This approach identified the m.1555A>G variant in a practice-changing time frame, and wide adoption could significantly reduce the burden of AIO.

Vancomycin Use in Children and Neonates across Three Decades: A Bibliometric Analysis of the Top-Cited Articles

Vancomycin is frequently prescribed in pediatrics, especially in intensive care unit settings, to treat Gram-positive bacterial infections. This work aims to collect the top-cited articles of pediatric and infectious diseases areas to gather the current evidence and gaps of knowledge on the use of vancomycin in these populations. The most relevant journals reported in the "pediatrics" and "infectious diseases" categories of the 2019 edition of Journal Citation Reports were browsed. Articles with more than 30 citations and published over the last three decades were collected. A bibliometric analysis was performed and 115 articles were retrieved. They were published in 21 journals, with a median impact factor of 4.6 (IQR 2.9-5.4). Sixty-eight of them (59.1%) belonged to "infectious diseases" journals. The most relevant topic was "bloodstream/complicated/invasive infections", followed by "antibiotic resistance/MRSA treatment". As for population distribution, 27 articles were on children only and 27 on neonates, most of which were from intensive care unit (ICU) settings. The current literature mainly deals with vancomycin as a treatment for severe infections and antibiotic resistance, especially in neonatal ICU settings. Lately, attention to new dosing strategies in the neonatal and pediatric population has become a sensible topic.

Pediatric Staphylococcus aureus bacteremia: clinical spectrum and predictors of poor outcome

BACKGROUND

Staphylococcus aureus is a common cause of bacteremia, yet the epidemiology, and predictors of poor outcome remain inadequately defined in childhood.

METHODS

ISAIAH is a prospective, cross-sectional study of S. aureus bacteremia (SAB), in children hospitalized in Australia and New Zealand, over 24-months (2017-2018).

RESULTS

Overall, 552 SABs were identified, (incidence 4.4/100,000/yr [95% confidence interval (CI) 2.2-8.8]), with methicillin-susceptible (84%), community onset (78%) infection predominating. Indigenous children (8.1/100,000/yr [CI 4.8-14.4]), those from lower-socioeconomic areas (5.5/100,000/yr [CI 2.8-10.2]) and neonates (6.6/100,000/yr (CI 3.4-11.7) were over-represented. Although 90-day mortality was infrequent, one-third experienced the composite of: length of stay >30 days (26%), ICU admission (20%), relapse (4%), or death (3%).Predictors of mortality included prematurity (aOR 16.8 [CI 1.6-296.9]), multifocal infection (aOR 22.6 [CI 1.4-498.5]), necrotizing pneumonia (aOR 38.9 [CI 1.7 - 1754.6]), multiorgan dysfunction (aOR 26.5 [CI 4.1-268.8]) and empiric-vancomycin (aOR 15.7 [CI 1.6-434.4]); whilst Infectious Diseases (ID) consultation (aOR 0.07 [CI 0.004-0.9]) was protective. Neither MRSA nor vancomycin trough-targets impacted survival; however, empiric-vancomycin was associated with significant nephrotoxicity (OR 3.1 [CI 1.3-8.1]).

CONCLUSIONS

High SAB incidence was demonstrated, with at-risk populations identified for future prioritized care. For the first time in a pediatric setting, necrotizing pneumonia and multifocal infection were predictors of mortality, whilst ID consultation was protective. The need to re-evaluate pediatric vancomycin trough-targets and limit unnecessary empiric-vancomycin exposure, to reduce poor outcomes and nephrotoxicity is highlighted. One in three children experienced considerable SAB morbidity, therefore pediatric inclusion in future SAB comparator trials is paramount to improve outcomes.

Methicillin-resistant Staphylococcus aureus (MRSA) submandibular abscess in a neonate

Neonatal suppurative submandibular sialadenitis and abscess formation is an exceedingly rare entity. This report describes a complex case of a male neonate with a methicillin-resistant Staphylococcus aureus (MRSA) submandibular abscess, requiring emergency intubation due to acute airway compromise. The patient was admitted to the paediatric intensive care unit, received appropriate antibiotic treatment and underwent urgent surgical drainage of the abscess. He made a full recovery and remains well 18 months later. No comorbidities or common risk factors for the disease were identified. Although extremely uncommon, neonatal submandibular abscesses can lead to significant morbidity. Neonates tend to present insidiously, and sudden clinical deterioration with airway compromise is possible. MRSA has been increasingly implicated in these infections, even in the absence of relevant risk factors. As such, continued clinical vigilance is essential for prompt diagnosis and prevention of life-threatening complications. Multidisciplinary input is paramount for appropriate management of these complex infections.

MRSA colonisation rates on a neonatal and paediatric intensive care unit

Methicillin-resistant Staphylococcus aureus (MRSA) colonisation is a challenge in healthcare institutions worldwide. In this retrospective nation-wide study, the rates of MRSA colonisation and infection from 2012 to 2015, on the only neonatal and paediatric intensive care unit (NPICU) in the country, were determined. Mean local rates were compared to rates of MRSA colonisation reported in units in North America, Asia and Europe between 2001 and 2010. The average rate of MRSA colonisation on admission to NPICU from 2012 to 2015 was 3.71% (95% confidence interval [CI] 2.17-5.25), while the mean rate of acquired colonisation was 14.60% (95% CI 6.16-23.04). Both were significantly higher than in units abroad: 1.9% and 4.1%, respectively (P = 0.04 and P < 0.001). There were no cases of invasive MRSA infection, while the mean rate of non-invasive infection was 0.77% (95% CI 0.54-1.01). Improved adherence to infection control measures and newer molecular diagnostic techniques are needed to further decrease the acquisition of MRSA.

Mupirocin and Chlorhexidine Genotypic Resistance Found in Staphylococcus aureus Isolated From Young Infants Below 90 Days Old: A Genetic Basis for Eradication Failure

OBJECTIVES

To investigate the genetic characteristics associated with eradication failure of Staphylococcus aureus in infants below 90 days old.

METHODS

S. aureus isolated from clinical specimen cultures (blood, surgical tissue, or drainage, pus, etc.) and routine screening cultures in the neonatal intensive care unit (nasal and axillary skin swab) from patients below 90 days old were collected prospectively for 1 year, from August 2017 to July 2018. The isolates underwent typing and screening for genes associated with chlorhexidine (qacA/B), quaternary ammonium (smr), and mupirocin resistance (iles mutation, mupA, mupB), as well as Panton-Valentine leukocidin (PVL) toxin.

RESULTS

During the study period, 40 nonduplicate isolates were included for analyses, of which 70.0% were methicillin-resistant S. aureus (MRSA). Mupirocin resistance was found in 25% of the total isolates; 17.4% of the colonizers; and 35.3% of the pathogens (P = 0.196). Chlorhexidine resistance gene was found in 3 MRSA isolates colonized in the nares of preterm infants. All isolates harbored the disinfectant quaternary ammonium compound (QAC) resistance gene. PVL toxin gene was found in 57.5%, and the presence of PVL gene among colonizers and pathogens was similar (69.6% vs. 41.2%, P = 0.072).

CONCLUSIONS

Mupirocin, chlorhexidine, and QAC-resistant MRSAs harboring the PVL toxin gene were found in the nasal carriages of preterm infants. In this highly vulnerable patient population, one-fourth of the isolates harbored mupirocin-resistant genes, and all were resistant to QAC disinfectants. These strains are associated with persistence in both carriage and environmental reservoirs within the hospitals.

Factors associated with progression to infection in methicillin-resistant Staphylococcus aureus-colonized, critically ill neonates

OBJECTIVE

To identify factors associated with development of symptomatic infection in infants colonized with methicillin-resistant Staphylococcus aureus (MRSA) in the Neonatal Intensive Care Unit (NICU).

STUDY DESIGN

This case-control study was performed at St. Louis Children's Hospital NICU from 2009 to 2019. The MRSA-colonized infants who developed symptomatic MRSA infection (cases) were matched 1:3 with MRSA-colonized infants who did not develop infection (controls). Demographics and characteristics of NICU course were compared between groups. Longitudinal information from subsequent hospitalizations was also obtained.

RESULTS

Forty-two infected cases were compared with 126 colonized-only controls. Cases became colonized earlier in their NICU stay, were less likely to have received mupirocin for decolonization, and had a longer course of mechanical ventilation than controls. Longitudinally, cases had a more protracted NICU course and were more likely to require hospital readmission.

CONCLUSION

Progression from MRSA colonization to symptomatic infection is associated with increased morbidity and may be mitigated through decolonization.

Methicillin Resistant Staphylococcus aureus and public fomites: a review

Staphylococcus genus is a Gram-positive coccus normally associated with skin and mucous membranes of warm-blooded animals. It is part of the commensal human microflora, or found in animals, or contaminating surfaces in the community and hospital settings. Staphylococcus aureus is the most pathogenic species belonging to this genus, as it possesses a collection of virulence factors that are expressed solely to evade the immune system. The increase in the misuse of antimicrobial agents predisposed S. aureus to develop antibiotic resistance, including the resistance to methicillin which led to the emergence of Methicillin-Resistant S. aureus (MRSA). MRSA is considered one of the most dangerous nosocomial pathogens causing many hard to treat infections in hospitals and was named as Hospital Associated MRSA (HA-MRSA). Over the past 20-25 years, MRSA was isolated from community settings and thus Community Associated MRSA (CA-MRSA) has emerged. Inside hospitals, MRSA has been isolated from fomites in contact with patients, as well as staff's protective and personal items. This review highlights the worldwide prevalence of MRSA on fomites within the contexts of hospital and community settings.

A persistent recurring cluster of meticillin-resistant Staphylococcus aureus (MRSA) colonizations in a special care baby unit: a matched case-control study

BACKGROUND

Between August 2016 and November 2019, a cluster of babies colonized with meticillin-resistant Staphylococcus aureus (MRSA) was reported in a special care baby unit in northern England.

AIM

A case-control study was performed to identify the source and prevent further cases.

METHODS

Cases were admitted neonates colonized or infected with MRSA (spa type t316). A retrospective case-control study was performed with two matched controls per case. Exposures were determined by medical record review. Cases were compared with controls using conditional logistic regression. Environmental investigations and staff screening were undertaken.

FINDINGS

Thirty-one colonized cases were identified across the 3-year period, with no infections reported. Thirteen of the 31 cases were sequenced and were within a cluster of 25 single nucleotide polymorphisms, consistent with exposure to a common source over a prolonged period. Most MRSA cases had a prior negative screen (N=22, 71%). Environmental sampling and staff screening were performed on several occasions. In the analytical study, 31 cases were compared with 62 controls. One ward location and one healthcare worker were identified as significant exposures in the multi-variable analysis.

CONCLUSIONS

Due to the sporadic nature of the colonizations, it was hypothesized that MRSA was being introduced intermittently, likely by a colonized healthcare worker, with possible transmission between infants also occurring within each temporal cluster. It is recommended that transiently colonized healthcare workers should be considered as a source of MRSA during outbreaks. This study highlights the importance of analytic epidemiological studies in persistent outbreaks of MRSA.

Development, Evaluation, and Pharmacokinetic Assessment of Polymeric Microarray Patches for Transdermal Delivery of Vancomycin Hydrochloride

Methicillin-resistant Staphylococcus aureus (MRSA) can cause harmful and potentially deadly infections. Vancomycin remains the first-line antibiotic treatment for MRSA-derived infections. Nevertheless, as a peptide drug, it is poorly absorbed when administered orally because of its high molecular weight and low permeability in the gastrointestinal tract and is therefore administered intravenously for the treatment of systemic diseases. In order to circumvent some of the many drawbacks associated with intravenous injection, other routes of drug delivery should be investigated. One of the strategies which has been employed to enhance transdermal drug delivery is based on microarray patches (MAPs). This work, for the first time, describes successful transdermal delivery of vancomycin hydrochloride (VCL) using dissolving MAPs (DMAPs) and hydrogel-forming MAPs (HFMAPs). VCL was formulated into DMAPs and reservoirs [film dosage forms, lyophilized wafers, and compressed tablets (CSTs)] using excipients such as poly(vinyl pyrrolidone), poly(vinyl alcohol), sodium hyaluronate, d-sorbitol, and glycerol. In this study, HFMAPs were manufactured using aqueous blends containing poly(methylvinyl ether-co-maleic acid) cross-linked by esterification with poly(ethylene glycol). The VCL-loaded CSTs (60% w/w VCL) were the most promising reservoirs to be integrated with HFMAPs based on the physicochemical evaluations performed. Both HFMAPs and DMAPs successfully delivered VCL in ex vivo studies with the percentage of drug that permeated across the neonatal porcine skin recorded at 46.39 ± 8.04 and 7.99 ± 0.98%, respectively. In in vivo studies, the area under the plasma concentration time curve from time zero to infinity (AUC_0-∞) values of 162.04 ± 61.84 and 61.01 ± 28.50 μg h/mL were achieved following the application of HFMAPs and DMAPs, respectively. In comparison, the AUC_0-∞ of HFMAPs was significantly greater than that of the oral administration control group, which showed an AUC_0-∞ of 30.50 ± 9.18 μg h/mL (p < 0.05). This work demonstrates that transdermal delivery of VCL is feasible using DMAPs and HFMAPs and could prove effective in the treatment of infectious diseases caused by MRSA, such as skin and soft tissue infections, lymphatic-related infections, and neonatal sepsis.

Eliminating MRSA transmission in a tertiary neonatal unit-A quality improvement initiative

BACKGROUND

Health care facility-onset methicillin-resistant Staphylococcus aureus (HO-MRSA) colonization or infection is a major cause of health care-associated infection (HAI) worldwide. HAIs are preventable and considered a health care quality outcome indicator. A quality improvement project to eliminate HO-MRSA transmission was conducted in a tertiary care neonatal unit over a 9-month period, and sustainability data were monitored. The primary aim of this project was to achieve zero transmission of MRSA among all neonatal unit admissions, and secondary aims were to improve hand hygiene (HH) and environmental hygiene compliance to 100%.

METHODS

Existing inpatient admission processes, staff HH, and environmental hygiene practices were critically analyzed. Sequential interventions were implemented, including reinforcing staff awareness on infection control practices through regular education and updates, providing "just in time" feedback, ensuring easy availability of cleaning equipment, individualizing items for all patients, keeping personal belongings away from clinical areas, and revising admission work flow for ex-utero transferred babies from other hospitals.

RESULTS

The neonatal unit achieved zero MRSA transmission to previously noninfected and noncolonized patients over the 9-month period, and HH and environmental hygiene compliance improved from a preintervention median of 87.1% and 82.2%, respectively, to 100%, which has been sustained to date.

CONCLUSIONS

Intensive reinforcement of infection control practices, strict cohorting of ex-utero transfers, universal surveillance on admission, and improvement in HH and environmental hygiene compliance were key to infection prevention and control measures, resulting in elimination of MRSA transmission in our neonatal unit.

Prevalence and clinical impact of methicillin-resistant Staphylococcus aureus colonization among infants at a level III neonatal intensive care unit

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a well-known nosocomial pathogen in neonatal intensive care unit (NICU) patients. Studies on the impact of MRSA colonization on neonatal morbidities are scarce.

METHODS

We conducted a 1:3 matched cohort study among infants with and without MRSA colonization, born between January 2010 and June 2014, in a tertiary NICU to review their demographic characteristics and outcomes.

RESULTS

During the study period, rates of MRSA colonization and bacteremia were found to be 0.68% and 0.10%, respectively. No differences in demographic characteristics, mortality, and major morbidities were identified among infants with and without MRSA colonization.

CONCLUSIONS

We reported a low rate of MRSA colonization in infants admitted to our NICU, without impact on mortality and inhospital morbidity. Further large-scale studies are needed to understand the implications and cost-effectiveness of active MRSA surveillance.

Surface colonization and subsequent development of infections with multi drug resistant organisms in a neonatal intensive care unit

BACKGROUND

This study analyzes colonization of the neonates in a NICU and incidence of these colonized infants developing infections due to the colonizers.

METHODS

Over a 12 month period, samples (surface swabs and rectal swabs) were obtained from all the infants admitted to NICU. The samples were cultured and examined for the presence of colonizers and especially for multi-drug resistant organisms.

RESULTS

From the total 533 patients, 473 (89%) neonates acquired colonizers and 60 (11%) did not. Of the 473 (89%) colonized infants, 57 (12%) developed infections of whom 33 (58%) were infected from the same organism as the colonizer and 24 (42%) neonates developed an infection that was different from the colonizer. 416 (88%) infants did not develop any infection inspite of being colonized.

CONCLUSIONS

The total numbers of babies contracting infection were more in the colonized group than the non-colonized. Other factors like gestational age and preterm may have played a role in development of infection in addition to colonization in these babies. Screening for the presence of MDRO colonization may be of limited use in predicting infections in the colonized individual. However, knowledge of their presence results in implementation of strict infection control practices. This along with judicious uses of antimicrobials effectively reduces infections from colonized bacteria and more importantly prevent their spread.

Methicillin-Resistant Staphylococcus aureus: Molecular Characterization, Evolution, and Epidemiology

Staphylococcus aureus, a major human pathogen, has a collection of virulence factors and the ability to acquire resistance to most antibiotics. This ability is further augmented by constant emergence of new clones, making S. aureus a "superbug." Clinical use of methicillin has led to the appearance of methicillin-resistant S. aureus (MRSA). The past few decades have witnessed the existence of new MRSA clones. Unlike traditional MRSA residing in hospitals, the new clones can invade community settings and infect people without predisposing risk factors. This evolution continues with the buildup of the MRSA reservoir in companion and food animals. This review focuses on imparting a better understanding of MRSA evolution and its molecular characterization and epidemiology. We first describe the origin of MRSA, with emphasis on the diverse nature of staphylococcal cassette chromosome mec (SCCmec). mecA and its new homologues (mecB, mecC, and mecD), SCCmec types (13 SCCmec types have been discovered to date), and their classification criteria are discussed. The review then describes various typing methods applied to study the molecular epidemiology and evolutionary nature of MRSA. Starting with the historical methods and continuing to the advanced whole-genome approaches, typing of collections of MRSA has shed light on the origin, spread, and evolutionary pathways of MRSA clones.

Successful termination of sustained transmission of resident MRSA following extensive NICU refurbishment: an intervention study

BACKGROUND

Neonatal sepsis is a leading cause of morbidity and mortality in neonatal units worldwide. Meticillin-resistant Staphylococcus aureus (MRSA) has become a leading causative pathogen. Many neonatal units experience endemic colonization and infection of their infants, which is often very challenging to successfully eradicate.

AIM

To assess the impact of neonatal unit refurbishment and redesign on endemic MRSA colonization and infection.

METHODS

A retrospective review was carried out over an eight-year period in a 14-cot, level 2-3 neonatal unit in University Hospital Galway, a large university teaching hospital in the West of Ireland. Surveillance, colonization, and infection data for a four-year period pre and four-year period post neonatal unit refurbishment are described. Clinical and microbiological data were collected on all MRSA-colonized and -infected infants between 2008 and 2015. Molecular typing data are available for MRSA isolates. An interrupted time-series design was used, with unit refurbishment as the intervention.

FINDINGS

Our neonatal unit had a pattern of sustained transmission of endemic resident MRSA strains which we could not eradicate despite repeated standard infection control interventions. Complete unit refurbishment led to successful termination of sustained transmission of these strains. Colonization decreased and no infants were actively infected post refurbishment of the unit.

CONCLUSION

We report successful termination of sustained transmission of endemic strains of MRSA from our neonatal unit following complete unit redesign and refurbishment.

Evaluating the Relationship between Vancomycin Trough Concentration and 24-Hour Area under the Concentration-Time Curve in Neonates

Bacterial sepsis is a major cause of morbidity and mortality in neonates, especially those involving methicillin-resistant Staphylococcus aureus (MRSA). Guidelines by the Infectious Diseases Society of America recommend the vancomycin 24-h area under the concentration-time curve to MIC ratio (AUC₂₄/MIC) of >400 as the best predictor of successful treatment against MRSA infections when the MIC is ≤1 mg/liter. The relationship between steady-state vancomycin trough concentrations and AUC₂₄ values (mg·h/liter) has not been studied in an Asian neonatal population. We conducted a retrospective chart review in Singapore hospitals and collected patient characteristics and therapeutic drug monitoring data from neonates on vancomycin therapy over a 5-year period. A one-compartment population pharmacokinetic model was built from the collected data, internally validated, and then used to assess the relationship between steady-state trough concentrations and AUC₂₄ A Monte Carlo simulation sensitivity analysis was also conducted. A total of 76 neonates with 429 vancomycin concentrations were included for analysis. Median (interquartile range) was 30 weeks (28 to 36 weeks) for postmenstrual age (PMA) and 1,043 g (811 to 1,919 g) for weight at the initiation of treatment. Vancomycin clearance was predicted by weight, PMA, and serum creatinine. For MRSA isolates with a vancomycin MIC of ≤1, our major finding was that the minimum steady-state trough concentration range predictive of achieving an AUC₂₄/MIC of >400 was 8 to 8.9 mg/liter. Steady-state troughs within 15 to 20 mg/liter are unlikely to be necessary to achieve an AUC₂₄/MIC of >400, whereas troughs within 10 to 14.9 mg/liter may be more appropriate.

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.

Hospital-associated methicillin-resistant Staphylococcus aureus: A cross-sectional analysis of risk factors in South African tertiary public hospitals

Introduction

Hospital-associated methicillin-resistant S. aureus (HA-MRSA) remains a significant cause of morbidity and mortality worldwide. We conducted a study to determine risk factors for HA-MRSA in order to inform control strategies in South Africa.

Methods

We used surveillance data collected from five tertiary hospitals in Gauteng and Western Cape provinces during 2014 for analysis. A case of HA-MRSA was defined as isolation of MRSA from a blood culture 48 hours after admission and/or if the patient was hospitalised in the six months prior to the current culture. Multivariable logistic regression modelling was used to determine risk factors for HA-MRSA.

Results

Of the 9971 patients with positive blood cultures, 7.7% (772) had S. aureus bacteraemia (SAB). The overall prevalence of MRSA among those with SAB was 30.9% (231/747; 95% confidence interval [CI] 27.6%– 34.3%). HA-MRSA infections accounted for 28.3% of patients with SAB (207/731; 95% CI 25.1%– 31.7%). Burns (adjusted odds ratio [aOR] 12.7; 95% CI 4.7–34.4), age ≤1 month (aOR 8.7; 95% CI 3.0–24.6), residency at a long-term care facility (aOR 5.2; 95% CI, 1.5–17.4), antibiotic use within two months of the current SAB episode (aOR 5.1; 95% CI 2.8–9.1), hospital stay of 13 days or more (aOR 2.8; 95% CI 1.3–5.6) and mechanical ventilation (aOR 2.2; 95% CI 1.07–4.6), were independent risk factors for HA-MRSA infection.

Conclusion

The prevalence of MRSA remains high in South African tertiary public hospitals. Several identified risk factors of HA-MRSA infections should be considered when instituting infection and prevention strategies in public-sector hospitals, including intensifying the implementation of antimicrobial stewardship programmes. There is an urgent need to strengthen infection prevention and control in burn wards, neonatal wards, and intensive care units which house mechanically ventilated patients.

Infant Colonization With Methicillin-Resistant Staphylococcus aureus or Vancomycin-Resistant Enterococci Preceding Neonatal Intensive Care Unit Discharge

Rates of colonization with methicillin-resistant Staphylococcus aureus (MRSA) and/or vancomycin-resistant enterococci (VRE) were determined for 1320 infants within 7 days of neonatal intensive care unit discharge. Overall, 4% and 1% of the infants were colonized with MRSA or VRE, respectively. Predictors identified in fixed-effects models were surgery during hospitalization (for MRSA colonization) and prolonged antimicrobial treatment (for VRE colonization).

Bacterial Infections in Neonates Following Mupirocin-Based MRSA Decolonization: A Multicenter Cohort Study

OBJECTIVE To characterize the risk of infection after MRSA decolonization with intranasal mupirocin. DESIGN Multicenter, retrospective cohort study. SETTING Tertiary care neonatal intensive care units (NICUs) from 3 urban hospitals in the United States ranging in size from 45 to 100 beds. METHODS MRSA-colonized neonates were identified from NICU admissions occurring from January 2007 to December 2014, during which a targeted decolonization strategy was used for MRSA control. In 2 time-to-event analyses, MRSA-colonized neonates were observed from the date of the first MRSA-positive surveillance screen until (1) the first occurrence of novel gram-positive cocci in sterile culture or discharge or (2) the first occurrence of novel gram-negative bacilli in sterile culture or discharge. Mupirocin exposure was treated as time varying. RESULTS A total of 522 MRSA-colonized neonates were identified from 16,144 neonates admitted to site NICUs. Of the MRSA-colonized neonates, 384 (74%) received mupirocin. Average time from positive culture to mupirocin treatment was 3.5 days (standard deviation, 7.2 days). The adjusted hazard of gram-positive cocci infection was 64% lower among mupirocin-exposed versus mupirocin-unexposed neonates (hazard ratio, 0.36; 95% confidence interval [CI], 0.17-0.76), whereas the adjusted hazard ratio of gram-negative bacilli infection comparing mupirocin-exposed and -unexposed neonates was 1.05 (95% CI, 0.42-2.62). CONCLUSIONS In this multicentered cohort of MRSA-colonized neonates, mupirocin-based decolonization treatment appeared to decrease the risk of infection with select gram-positive organisms as intended, and the treatment was not significantly associated with risk of subsequent infections with organisms not covered by mupirocin's spectrum of activity. Infect Control Hosp Epidemiol 2017;38:930-936.

Evaluation of sampling locations in pregnant women and newborns for the detection of colonisation with antibiotic-resistant bacteria

Up to now, little has been known about the prevalence and clinical relevance of colonisation of asymptomatic pregnant women with methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) or extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. In this two-centre cross-sectional study, we evaluated the performance and importance of screening at different times and different locations for colonisation in pregnant women and newborns. Between October 2013 and December 2015, four samples were collected from pregnant women, two from newborns at birth and three from 3-day-old newborns. Samples were screened on culturing media and were confirmed with molecular methods. MSSA was used as a surrogate for MRSA, as the two share most microbiologic characteristics and colonisation patterns. Of 763 pregnant women, 14.5% (111) were colonised with MSSA, 0.4% (3) with MRSA and 2.6% (20) with ESBL-producing E. coli. Of 658 newborns, 0.9% (10) were colonised with MSSA at birth and 13.1% (70) at 3 days old, 0.5% (3) were colonised with MRSA and 2.6% (17) with ESBL-producing E. coli. Nasal sampling identified 91.0% of MSSA-colonised pregnant women and 60.0% of newborns. In newborns, nasal and umbilical sampling at 3 days after birth discovered 84.0% of colonised cases. For ESBL-producing E. coli, the perianal region was positive in all colonised pregnant women and in 88.2% of colonised newborns. Combining nasal and perianal swabs is optimal when screening for antibiotic-resistant bacteria in pregnant women. Nasal, perianal and umbilical sample collection from 3-day-old newborns significantly increased the sensitivity compared to screening immediately after birth.

Prevention and treatment of neonatal nosocomial infections

Nosocomial or hospital acquired infections threaten the survival and neurodevelopmental outcomes of infants admitted to the neonatal intensive care unit, and increase cost of care. Premature infants are particularly vulnerable since they often undergo invasive procedures and are dependent on central catheters to deliver nutrition and on ventilators for respiratory support. Prevention of nosocomial infection is a critical patient safety imperative, and invariably requires a multidisciplinary approach. There are no short cuts. Hand hygiene before and after patient contact is the most important measure, and yet, compliance with this simple measure can be unsatisfactory. Alcohol based hand sanitizer is effective against many microorganisms and is efficient, compared to plain or antiseptic containing soaps. The use of maternal breast milk is another inexpensive and simple measure to reduce infection rates. Efforts to replicate the anti-infectious properties of maternal breast milk by the use of probiotics, prebiotics, and synbiotics have met with variable success, and there are ongoing trials of lactoferrin, an iron binding whey protein present in large quantities in colostrum. Attempts to boost the immunoglobulin levels of preterm infants with exogenous immunoglobulins have not been shown to reduce nosocomial infections significantly. Over the last decade, improvements in the incidence of catheter-related infections have been achieved, with meticulous attention to every detail from insertion to maintenance, with some centers reporting zero rates for such infections. Other nosocomial infections like ventilator acquired pneumonia and staphylococcus aureus infection remain problematic, and outbreaks with multidrug resistant organisms continue to have disastrous consequences. Management of infections is based on the profile of microorganisms in the neonatal unit and community and targeted therapy is required to control the disease without leading to the development of more resistant strains.

Surveillance and Isolation of Methicillin-Resistant Staphylococcus aureus Colonization in the Neonatal Intensive Care Unit

BACKGROUND

Neonatal sepsis causes 1.4 million (36%) neonatal deaths annually. Staphylococcus aureus (SA), a common skin pathogen, remains the second leading cause of late-onset sepsis in the neonatal intensive care unit (NICU). Methicillin-resistant Staphylococcus aureus (MRSA), a resistant strain of SA, has created a significant global communicable health risk, especially in the NICU.

PURPOSE

To examine evidence related to NICU infection control practices surrounding MRSA surveillance, identification, and isolation in response to the clinical question, "What strategies should be universally implemented in the NICU to identify and prevent the spread of MRSA?"

METHODS/SEARCH STRATEGY

Databases were examined for articles on the topical area of MRSA in the neonate. Key terms were used to streamline the search, resulting in 20 primary works and 3 guideline/consensus statements considered imperative in response to the clinical questions.

FINDINGS/RESULTS

Hand hygiene remains the cornerstone to sound infection control practice. Colonization often leads to systemic infection, with smaller neonates at greatest risk. Hospital infection control compliance has improved outcomes. MRSA surveillance has reduced horizontal spread. No universal, specific recommendations exist to guide surveillance and management of MRSA in the NICU.

IMPLICATIONS FOR PRACTICE

Standardized guidelines with procedures for hand hygiene, patient surveillance and isolation, and patient cohorting with recommended staffing patterns should guide practice in the NICU. Both MRSA culture and polymerase chain reaction effectively identify positive patients. Decolonization practices are not yet clear.

IMPLICATIONS FOR RESEARCH

Evaluation of standard isolation practices versus outbreak response and approaches to neonatal decolonization should be evaluated for efficacy, safety, and resistance.

Characteristics and risk factors of hospital acquired - Methicillin-resistant Staphylococcus aureus (HA-MRSA) infection of pediatric patients in a tertiary care hospital in Riyadh, Saudi Arabia

Background and objectives

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infections has been steadily increasing. These infections are considered to be either hospital-acquired MRSA (HA-MRSA) or community-acquired MRSA (CA-MRSA). Children are at higher risk of infection than adults. HA-MRSA has been reported to have more serious outcomes than CA-MRSA. However, there are not enough studies in Saudi Arabia to study the characteristics of HA-MRSA in children. We aim to describe the characteristics of HA-MRSA infection, including risk factors, culture site, clinical manifestations, complications, and outcomes among pediatric patients in a tertiary care hospital in Riyadh, Saudi Arabia.

Design and settings

This is a retrospective chart review study. It was conducted in King Abdulaziz medical city in Riyadh.

Patients and methods

The study included all patients 14 years of age or younger who were culture-positive from any site in the body during the period from January 1, 2009 to December 31, 2011. The time of culture compared to admission time was used to differentiate between CA-MRSA (within 72 h of admission) and HA-MRSA (more than 72 h after admission). The final sample size was 39 patients.

Results

We found HA-MRSA to be more common in males and those with risk factors such as previous surgery and previous hospitalization. Patients had a high Pediatric intensive care unit (PICU) admission rate and were commonly septic with positive blood cultures. Seventy-four percent of patients fully recovered, 10% recovered with complications and 15% died.

Conclusion

HA-MRSA is an infection that can cause serious complications and a high rate of PICU admissions. Clinical manifestations such as shock are associated with higher mortality and morbidity rates. Special care should be given to those admitted to PICU, as they have high rates of mortality and morbidity.

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.

Emergence of community-associated methicillin-resistant Staphylococcus aureus strains in the neonatal intensive care unit: an infection prevention and patient safety challenge

Methicillin-resistant Staphylococcus aureus (MRSA) infections cause significant morbidity and mortality in neonatal intensive care units (NICUs). We characterized the clinical and molecular epidemiology of MRSA strains colonizing NICU patients. Nasal MRSA isolates (n = 250, from 96 NICU patients) recovered through active surveillance from 2009 to 2014 were characterized with staphylococcal cassette chromosome mec (SCCmec) typing and detection of mupA (marker of high-level mupirocin resistance) and qacA/B (marker associated with chlorhexidine resistance). Factors associated with community-associated (CA-) or healthcare-associated (HA-) MRSA were evaluated. The overall prevalence of MRSA nasal colonization was 3.9%. Of 96 neonates in our retrospective cohort, 60 (63%) were colonized with CA-MRSA strains and 35 (36%) were colonized with HA-MRSA strains. Patients colonized with HA-MRSA were more likely to develop MRSA infections than patients colonized with CA-MRSA (13/35, 37% versus 8/60, 13%; p 0.007), although the interval from colonization to infection was shorter in CA-MRSA-colonized infants (median 0 days, range -1 to 4 versus HA-MRSA-colonized infants, 7 days, -1 to 43; p 0.005). Maternal peripartum antibiotics were associated with CA-MRSA colonization (adjusted odds ratio (aOR) 8.7; 95% CI 1.7-45.0); intubation and surgical procedures were associated with HA-MRSA colonization (aOR 7.8; 95% CI 1.3-47.6 and aOR 6.0; 95% CI 1.4-24.4, respectively). Mupirocin- and chlorhexidine-resistant MRSA was isolated from four and eight patients, respectively; carriage of a mupirocin-resistant strain precluded decolonization. CA-MRSA strains are prominent in the NICU and associated with distinct risk factors. Given community reservoirs for MRSA acquisition and transmission, novel infection prevention strategies are needed.

Staphylococcus Infections in Pregnancy: Maternal and Neonatal Risks

Staphylococcus aureus is carried by up to one third of the general population; about 2% are carriers for methicillin-resistant S. aureus (MRSA). Infections caused by the antibiotic-resistant form include skin and soft tissue infections, as well as pneumonia, sepsis, and wound infections. Although the risks of hospital-associated systemic infections have decreased with attention to infection control procedures, serious obstetric illness remains a concern. This article describes the range of MRSA infection in the setting of pregnancy and discusses risks to both mother and newborn associated with active MRSA infection during pregnancy and childbirth. Methicillin-resistant S. aureus remains a risk to mothers and newborns, requiring prompt identification and appropriate management.

Clinical and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit in the Decade following Implementation of an Active Detection and Isolation Program

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent source of infection in the neonatal intensive care unit (NICU), often associated with significant morbidity. Active detection and isolation (ADI) programs aim to reduce transmission. We describe a comprehensive analysis of the clinical and molecular epidemiology of MRSA in an NICU between 2003 and 2013, in the decade following the implementation of an MRSA ADI program. Molecular analyses included strain typing by pulsed-field gel electrophoresis, mec and accessory gene regulator group genotyping by multiplex PCR, and identification of toxin and potential virulence factor genes via PCR-based assays. Of 8,387 neonates, 115 (1.4%) had MRSA colonization and/or infection. The MRSA colonization rate declined significantly during the study period from 2.2 to 0.5/1,000 patient days (linear time, P = 0.0003; quadratic time, P = 0.006). There were 19 cases of MRSA infection (16.5%). Few epidemiologic or clinical differences were identified between MRSA-colonized and MRSA-infected infants. Thirty-one different strains of MRSA were identified with a shift from hospital-associated to combined hospital- and community-associated strains over time. Panton-Valentine leukocidin-positive USA300 strains caused 5 of the last 11 infections. Staphylococcal cassette chromosome mec (SCCmec) types II and IVa and agr groups 1 and 2 were most predominant. One isolate possessed the gene for toxic shock syndrome toxin; none had genes for exfoliative toxin A or B. These results highlight recent trends in MRSA colonization and infection and the corresponding changes in molecular epidemiology. Continued vigilance for this invasive pathogen remains critical, and specific attention to the unique host, the neonate, and the distinct environment, the NICU, is imperative.

Neonatal infections due to multi-resistant strains: Epidemiology, current treatment, emerging therapeutic approaches and prevention

Severe infections represent the main cause of neonatal mortality accounting for more than one million neonatal deaths worldwide every year. Antibiotics are the most commonly prescribed medications in neonatal intensive care units. The benefits of antibiotic therapy when indicated are clearly enormous, but the continued and widespread use of antibiotics has generated over the years a strong selective pressure on microorganisms, favoring the emergence of resistant strains. Health agencies worldwide are galvanizing attention toward antibiotic resistance in gram-positive and gram-negative bacteria. Infections in neonatal units due to multidrug and extensively multidrug resistant bacteria are rising and are already seriously challenging antibiotic treatment options. While there is a growing choice of agents against multi-resistant gram-positive bacteria, new options for multi-resistant gram-negative bacteria in the clinical practice have decreased significantly in the last 20 years making the treatment of infections caused by multidrug-resistant pathogens challenging mostly in neonates. Treatment options are currently limited and will be some years before any new treatment for neonates become available for clinical use, if ever. The aim of the review is to highlight the current knowledge on antibiotic resistance in the neonatal population, the possible therapeutic choices, and the prevention strategies to adopt in order to reduce the emergency and spread of resistant strains.

Cationic antimicrobial peptides as potential new therapeutic agents in neonates and children: a review

PURPOSE OF REVIEW

Antimicrobial resistance towards conventional antibiotics is a serious problem for modern medicine and for our society. Multidrug-resistant bacteria are very difficult to treat and treatment options have begun to run out. Here, we summarize the newest studies of drug development using cationic antimicrobial peptides as lead molecules for novel antimicrobial drugs.

RECENT FINDINGS

A new development is the use of antimicrobial peptides not only as direct antimicrobial lead structures but also using their ability to influence the immune system. Such approaches can be used to develop drugs that influence the immune system in a unique way, supporting specific branches of immune cells in order to clear infection. Applying such an 'immune boost' would also minimize the danger of new resistance emerging in bacteria. In addition, searching for and testing substances that trigger the production of host antimicrobial peptides is still ongoing and opens up a totally new avenue for the use of antimicrobial peptides against infections. Currently, more than 10 clinical trials, phase 2 or 3, using antimicrobial peptides are in progress or have been recently completed.

SUMMARY

Multidrug resistance is an urgent problem for modern medicine and novel antimicrobials are needed. Despite some drawbacks, antimicrobial peptides seem now to appear more numerous in clinical trials, indicating the success in developing peptides into novel therapeutics. This can be critical especially for neonates and children, as treatment options for infections with Gram-negatives in neonatal ICUs are becoming rare.

[Update on outbreaks reported from neonatal intensive care units (2010-203): Staphylococcus aureus]

In terms of the unique risk profile of the patients and the morbidity associated with S. aureus infections in this vulnerable patient population, the literature on outbreaks of S. aureus (including MRSA) in neonatal intensive care units (NICUs) needs to be analyzed separately from reports derived from other intensive care units. With the objective of updating important information for those involved in outbreak management and fostering preventive efforts, this article summarizes the results of a systematic literature analysis, referring to an earlier publication by Gastmeier et al. It focuses on NICU outbreaks caused by S. aureus (including MRSA) and on controlling them.