Methicillin-resistant Staphylococcus aureus transmission and infections in a neonatal intensive care unit despite active surveillance cultures and decolonization: challenges for infection prevention

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.

A Near Miss of a Retropharyngeal Abscess with MRSA in a 5-Week-Old Boy Due to an Unusual Presentation

A retropharyngeal abscess (RPA) in early childhood is not uncommon due to at-risk lymph nodes in this deep neck space and is typified by fever, odynophagia, and a constellation of respiratory manifestations. However, RPA is exceedingly rare in the neonatal subpopulation and not part of the usual differential diagnosis algorithm in this age range. Herein, we present a unique case of a previously healthy 5-week-old male infant with protracted "congestion" and difficulty in oral feeding, whose clinical course is confounded by intermittent, positional bradycardia and subsequent apnea. He was eventually diagnosed with a methicillin-resistant Staphylococcus aureus (MRSA) RPA, leading to concurrent vascular and airways compromise in the form of baroreceptor-mediated bradycardia from mass-effect carotid body compression. This clinical case is an important reminder that any infant with positional vital sign changes should prompt urgent and thorough investigation for extraordinary and otherwise uncommon pathophysiologic states. The case also highlights the power of multidisciplinary collaboration across multiple specialties and parental advocacy in unifying a diagnosis for rare pediatric illnesses.

SHEA/IDSA/APIC Practice Recommendation: Strategies to prevent methicillin-resistant Staphylococcus aureus transmission and infection in acute-care hospitals: 2022 Update

Previously published guidelines have provided comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute-care hospitals in implementing and prioritizing efforts to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and infection. This document updates the "Strategies to Prevent Methicillin-Resistant Staphylococcus aureus Transmission and Infection in Acute Care Hospitals" published in 2014.1 This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA). It is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the Association for Professionals in Infection Control and Epidemiology (APIC), the American Hospital Association (AHA), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise.

Effect of nasal mupirocin treatment on extranasal carriage of methicillin-resistant Staphylococcus aureus among pediatric patients admitted to the neonatal intensive care unit

Decolonization of MRSA detected in the oral cavity and tracheal aspirates occurred in 85% and 58% of neonates, respectively, with nasal mupirocin treatment. Recurrent MRSA colonization occurred in 45% of neonates whose MRSA was detected in the oral cavity at a mean of 19 days. Recurrent MRSA colonization occurred in 58% of neonates whose MRSA was detected in tracheal aspirates at a mean of 23 days.

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.

Genomic and Epidemiological Features of Two Dominant Methicillin-Susceptible Staphylococcus aureus Clones from a Neonatal Intensive Care Unit Surveillance Effort

Methicillin-susceptible Staphylococcus aureus (MSSA) is a more prevalent neonatal intensive care unit (NICU) pathogen than methicillin-resistant S. aureus (MRSA). However, the introduction and spread of MSSA, the role of systematic decolonization, and optimal infection prevention and control strategies remain incompletely understood. We previously screened infants hospitalized in a university-affiliated level III to IV NICU twice monthly over 18 months for S. aureus colonization and identified several prevalent staphylococcal protein A (spa) types. Here, we performed whole-genome sequencing (WGS) and phylogenetic comparisons of 140 isolates from predominant spa types t279, t1451, and t571 to examine possible transmission routes and identify genomic and epidemiologic features associated with the spread of dominant clones. We identified two major MSSA clones: sequence type 398 (ST398), common in the local community, and ST1898, not previously encountered in the region. ST398 NICU isolates formed distinct clusters with closely related community isolates from previously published data sets, suggesting multiple sources of acquisition, such as family members or staff, including residents of the local community. In contrast, ST1898 isolates were nearly identical, pointing to clonal expansion within the NICU. Almost all ST1898 isolates harbored plasmids encoding mupirocin resistance (mupA), suggesting an association between the proliferation of this clone and decolonization efforts with mupirocin. Comparative genomics indicated genotype-specific pathways of introduction and spread of MSSA via community-associated (ST398) or health care-associated (ST1898) sources and the potential role of mupirocin resistance in dissemination of ST1898. Future surveillance efforts could benefit from routine genotyping to inform clone-specific infection prevention strategies. IMPORTANCE Methicillin-susceptible Staphylococcus aureus (MSSA) is a significant pathogen in neonates. However, surveillance efforts in neonatal intensive care units (NICUs) have focused primarily on methicillin-resistant S. aureus (MRSA), limiting our understanding of colonizing and infectious MSSA clones which are prevalent in the NICU. Here, we identify two dominant colonizing MSSA clones during an 18-month surveillance effort in a level III to IV NICU, ST398 and ST1898. Using genomic surveillance and phylogenetic analysis, coupled with epidemiological investigation, we found that these two sequence types had distinct modes of spread, namely the suggested exchange with community reservoirs for ST398 and the contribution of antibiotic resistance to dissemination of ST1898 in the health care setting. This study highlights the additional benefits of whole-genome surveillance for colonizing pathogens, beyond routine species identification and genotyping, to inform targeted infection prevention strategies.

Reducing Staphylococcus aureus infections in the neonatal intensive care unit

OBJECTIVE

Our neonatal intensive care unit (NICU) saw an increase in Staphylococcus aureus (SA) infections-methicillin-resistant SA (MRSA) infections increased from 2.1/10,000 patient days (PD) to 5.1/10,000 PD, and methicillin-sensitive SA (MSSA) infections from 1.2/10,000 PD to 3.9/10,000 PD. This quality improvement project aimed to decrease the rates of SA infections to less than 2.0/10,000 PD, and to determine the rate of SA decolonization.

METHODS

Infection prevention interventions targeted patient factors (SA surveillance, patient cohorting, decolonization protocol), provider factors (provider cohorting, enhanced hand hygiene) and environmental factors (room structure, equipment optimization).

RESULTS

The rates of MRSA and MSSA infections decreased to 0.6/10,000 PD and 0.7 infections/10,000 PD respectively. Persistent decolonization of SA was successful in 67% of colonized patients.

CONCLUSIONS

Specific interventions targeting patient, provider, and environmental factors, including the implementation of a SA decolonization protocol, were successful in decreasing the incidence of SA infections in neonates.

Methicillin-resistant Staphylococcus aureus transmission and hospital-acquired bacteremia in a neonatal intensive care unit in Greece

BACKGROUND

Staphylococcus aureus is a common pathogen causing hospital acquired infections (HAIs) in neonates. In this study, the epidemiology of methicillin-resistant S. aureus (MRSA) colonization and infections in a 30-bed, level III university-affiliated neonatal intensive care unit (NICU) located in a children's hospital was retrospectively investigated for the period 2014-2018.

METHODS

Genes encoding Panton-Valentine Leukocidin (lukS/lukF-PV, PVL), toxic shock syndrome toxin (tst), exfoliative toxins (eta, etb), and the resistance genes mecA, mecC and fusB, were defined in 46 representative strains by PCRs. Relatedness of strains was assessed by MLST.

RESULTS

Of 1538 neonates, 77 (5%) had a positive culture for MRSA (23/77 were NICU-acquired and 54/77 imported cases). Four MRSA bacteremias occurred. Most isolates were multi-resistant. One major clone was identified, ST225, among 40 tested neonatal strains (23/40, 58%). Of these, 14/23 were imported from the same maternity hospital (MH). Another clone, ST217, was predominant (4/6) among health care workers (HCWs), found colonized. Four isolates classified as ST80 were PVL-positive. Additional four strains carried tst (10%), belonging to ST30 and ST225 (two strains each), and two etb. The implicated MH was notified for the problem, decolonization treatment was successfully performed in HCWs and neonates. Strengthening of infection control measures with emphasis on hand hygiene was applied.

CONCLUSIONS

Uncovering reservoirs for on-going MRSA transmission in NICUs has proved challenging. Well known nosocomial MRSA clones are being constantly introduced and transmitted via MHs and HCWs. Effective infection prevention and control requires constant vigilance.

Randomized Placebo-Controlled Trial of Topical Mupirocin to Reduce Staphylococcus aureus Colonization in Infants in the Neonatal Intensive Care Unit

OBJECTIVE

To evaluate the efficacy of topical mupirocin in reducing Staphylococcus aureus colonization in infants in the neonatal intensive care unit (NICU).

STUDY DESIGN

A prospective double-blind randomized controlled trial of mupirocin vs placebo in S aureus-colonized infants was conducted in a tertiary care NICU between October 2016 and December 2019. Weekly universal active surveillance with polymerase chain reaction screening identified colonized infants. Colonized infants received a 5-day course of mupirocin (mupirocin group) or petroleum jelly (control group). Repeat courses were given for additional positive screens.

RESULTS

A total of 216 infants were enrolled; 205 were included in data analyses. Primary decolonization was more successful for mupirocin-treated infants (86 of 104 [83%]) than for controls (20 of 101; 20%) (P < .001). Although recurrent S aureus colonization occurred frequently (59 of 81 [73%] mupirocin-treated and 26 of 33 [79%] controls), subsequent decolonization remained more successful for mupirocin-treated infants than for controls (38 of 49 [78%] vs 2 of 21 [10%]; P < .001). Subgroup analyses of infants of ≤30 weeks' gestational age yielded similar results; decolonization occurred more often in mupirocin-treated infants compared with control infants (63 of 76 [83%] vs 13 of 74 [18%]; P < .001). Bacterial sterile site infections tended to be less frequent in mupirocin-treated infants compared with controls (2 of 104 [2%] vs 8 of 101 [8%]; P = .057). No invasive S aureus infections occurred in mupirocin-treated infants, but 50% of infections in controls were from S aureus, and 1 resulted in death.

CONCLUSIONS

Universal active surveillance and targeted treatment with topical mupirocin is a successful decolonization strategy for NICU infants and may prevent S aureus infection. However, S aureus colonization frequently recurs, necessitating repeat treatment.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02967432.

Infection Prevention in the Neonatal Intensive Care Unit

Although many aspects of infection prevention and control (IPC) mirror institutional efforts, optimization of IPC practices in the neonatal intensive care unit requires careful consideration of its unique population and environment, addressed here for key IPC domains. In addition, innovative mitigation efforts to address challenges specific to limited resource settings are discussed.

Epidemiological typing of methicillin resistant Staphylococcus aureus recovered from patients attending a maternity hospital in Ireland 2014-2019

It has previously been reported that maternity hospitals have lower levels of MRSA compared to other healthcare facilities, due to the patient population - mostly healthy patients with limited healthcare contact. In this epidemiological study, all MRSA isolates recovered from patients attending a maternity hospital from 2014 – 2019 were investigated. 171 isolates from adults (n=120) and babies (n=51) from diagnostic and screening investigations were submitted to the National MRSA Reference Laboratory (NMRSARL). Investigations included: spa typing, antimicrobial susceptibility testing, detection of the mecA/mecC genes and lukS-PV and lukF-PV. All were susceptible to glycopeptides, linezolid, rifampicin and mupirocin, while 29 of 171 (17%) were resistant to β-lactam agents only. Thirteen isolates (8%) were resistant to two classes of antibiotic; one resistant to three. All isolates harboured mecA and 33 of 171 (19%) harboured PV-lukF/S. Among the collection, 21 multilocus sequence types (ST) were inferred from 63 spa types. EARS-NET data shows that ST22-MRSA-IV accounts for approximately 75% of MRSA recovered in Irish hospitals. Here, it accounted for only 25.7%. MLST types associated with community acquired MRSA accounted for the remaining 74.3%. These included ST8, ST30, ST1, ST5 and ST88, suggesting a diverse population, harbouring multiple resistance and virulence genes, some of which have been previously associated with outbreaks in Ireland. This study exposes a reservoir of MRSA in the community which may be imported into hospitals, leading to outbreaks. The diversity of MRSA lineages with enhanced virulence factors highlights the need for regular surveillance to ensure appropriate infection prevention and control interventions are implemented promptly.

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.

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.

Decolonization of Staphylococcus aureus

Staphylococcus aureus infections are associated with increased morbidity, mortality, hospital stay, and health care costs. S aureus colonization has been shown to increase risk for invasive and noninvasive infections. Decolonization of S aureus has been evaluated in multiple patient settings as a possible strategy to decrease the risk of S aureus transmission and infection. In this article, we review the recent literature on S aureus decolonization in surgical patients, patients with recurrent skin and soft tissue infections, critically ill patients, hospitalized non-critically ill patients, dialysis patients, and nursing home residents to inform clinical practice.

Effect of Contact Precautions on Staphylococcus aureus and Clinical Outcomes of Colonized Patients in the Neonatal Intensive Care Unit

BACKGROUND

Staphylococcus aureus is a common pathogen in neonatal intensive care units (NICUs), yet little is known about the effect of contact precautions and clinical outcomes of colonized patients.

METHODS

Retrospective cohort study of all neonates from August 2014 to November 2018 colonized with either methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA) and select noncolonized patients at two neonatal intensive care units at the University of California, Los Angeles. Outcomes during two time periods (during and after the use of contact precautions) were assessed.

RESULTS

A total of 234 patients were included in the study: 83 colonized and 151 noncolonized patients. There was a fourfold higher incidence of MSSA colonization versus MRSA (P < 0.001). There was a higher incidence of positive surveillance cultures after contact precautions were discontinued (P = 0.01), but this did not correlate with a higher incidence of invasive cultures (P = 0.475). There were twice as many MSSA invasive cultures than MRSA, but a higher rate of invasion with MRSA (P < 0.05). Colonized patients were more likely to develop an invasive infection than noncolonized (P = 0.003 MRSA; P = 0.004 MSSA). When controlling for gestational age and surgical interventions, colonization was more likely to be associated with skin and soft tissue infections (P < 0.001) and a longer length of stay by a mean of 27.8 days (P < 0.0001).

CONCLUSIONS

Contact precautions resulted in a lower incidence of colonization without a difference in invasive cultures in our NICUs. Those colonized with S. aureus had a higher incidence of skin and soft tissue infections and a longer NICU length of stay.

Neonatal Staphylococcus aureus acquisition at a tertiary intensive care unit

BACKGROUND

In this study, we explored the role of colonization in health care workers (HCWs) in transmission of methicillin-susceptible Staphylococcus aureus (MSSA) to neonates at a level IV neonatal intensive care unit (NICU).

METHODS

All available screening and clinical MSSA isolates, from the period March 2015 through April 2016, isolated from HCWs and neonates at the level IV NICU, were included. MSSA isolates were initially genotyped using spa typing, and for the most prevalent spa types, whole-genome sequencing (WGS) was performed.

RESULTS

From March 2015 through April 2016, 159 neonates and 115 HCWs were found positive for MSSA, and all isolates were typed by means of spa typing. Twenty-three spa types were found in both HCWs and neonates. Within the most prevalent spa types (t002, t015 and t2787), 4 WGS clusters of genetically indistinguishable MSSA isolates were found in which 4 HCWs and 35 neonates were involved. A total of 10 neonates included in the 4 WGS clusters suffered from bacteremia.

CONCLUSIONS

We showed that HCWs carried the same MSSA isolates as those found in neonates, and that HCWs might serve as a reservoir for transmission of MSSA to neonates. Ten neonates suffered from a bacteremia caused by a MSSA previously detected in a HCW.

Colonization profile and duration by multi-resistant organisms in a prospective cohort of newborns after hospital discharge

The aim of this study was to determine the spontaneous decolonization period and characteristics in a prospective cohort of newborns colonized by multidrug-resistant organisms, after their discharge from the neonatal intensive care unit. Multidrug resistance is defined as bacterial non-susceptibility to ≥ 1 agent of ≥ 3 antimicrobial categories. In total, 618 newborns were included in the study, of which 173 (28.0%) presented a positive culture for multidrug-resistant microorganisms, and of these, 52 (30.1%) were followed up in this study. The most frequent intrinsic factors were be born by cesarean section (86.5%), prematurity (84.6%), and very low birth weight (76.9%). The extrinsic factors were having remained hospitalized for an average of 27 days, during which 67.3% were submitted to invasive procedures and 88.5% received antimicrobials. The intrinsic and extrinsic factors of newborns were not associated to a decolonization period longer or shorter than 3 months, which was the average period of decolonization found in the present study. From the totality of colonization cultures sampled at hospital discharge, the Gram-negative Extended Spectrum β-lactamase producing bacteria were the most common, with 28.9% of babies colonized by Klebsiella spp. The median period of decolonization by multidrug-resistant microorganisms in the newborns population after hospital discharge was 3 months, but was highly dependent on the microbial species, and this period was not associated to any intrinsic and extrinsic factors of the newborn.

Effect of Treating Parents Colonized With Staphylococcus aureus on Transmission to Neonates in the Intensive Care Unit: A Randomized Clinical Trial

IMPORTANCE

Staphylococcus aureus is a leading cause of health care-associated infections in the neonatal intensive care unit (NICU). Parents may expose neonates to S aureus colonization, a well-established predisposing factor to invasive S aureus disease.

OBJECTIVE

To test whether treating parents with intranasal mupirocin and topical chlorhexidine compared with placebo would reduce transmission of S aureus from parents to neonates.

DESIGN, SETTING, AND PARTICIPANTS

Double-blinded randomized clinical trial in 2 tertiary NICUs in Baltimore, Maryland. Neonates (n = 236) with S aureus-colonized parent(s) were enrolled. The study period was November 7, 2014, through December 13, 2018.

INTERVENTIONS

Parents were assigned to intranasal mupirocin and 2% chlorhexidine-impregnated cloths (active treatment, n = 117) or petrolatum intranasal ointment and nonmedicated soap cloths (placebo, n = 119) for 5 days.

MAIN OUTCOMES AND MEASURES

The primary end point was concordant S aureus colonization by 90 days, defined as neonatal acquisition of an S aureus strain that was the same strain as a parental strain at time of screening. Secondary outcomes included neonatal acquisition of any S aureus strain and neonatal S aureus infections.

RESULTS

Among 236 randomized neonates, 208 were included in the analytic sample (55% male; 76% singleton births; mean birth weight, 1985 g [SD, 958 g]; 76% vaginal birth; mean parent age, 31 [SD, 7] years), of whom 18 were lost to follow-up. Among 190 neonates included in the analysis, 74 (38.9%) acquired S aureus colonization by 90 days, of which 42 (56.8%) had a strain concordant with a parental baseline strain. In the intervention and placebo groups, 13 of 89 neonates (14.6%) and 29 of 101 neonates (28.7%), respectively, acquired concordant S aureus colonization (risk difference, -14.1% [95% CI, -30.8% to -3.9%]; hazard ratio [HR], 0.43 [95.2% CI, 0.16 to 0.79]). A total of 28 of 89 neonates (31.4%) in the intervention group and 46 of 101 (45.5%) in the control group acquired any S aureus strain (HR, 0.57 [95% CI, 0.31 to 0.88]), and 1 neonate (1.1%) in the intervention group and 1 neonate (1.0%) in the control group developed an S aureus infection before colonization. Skin reactions in parents were common (4.8% intervention, 6.2% placebo).

CONCLUSIONS AND RELEVANCE

In this preliminary trial of parents colonized with S aureus, treatment with intranasal mupirocin and chlorhexidine-impregnated cloths compared with placebo significantly reduced neonatal colonization with an S aureus strain concordant with a parental baseline strain. However, further research is needed to replicate these findings and to assess their generalizability.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02223520.

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.

A survey of the implementation status of selected infection control strategies in neonatal intensive care units in Japan

BACKGROUND

Infection control strategies are implemented in all neonatal intensive care units (NICUs); however, the details of the strategies seem to differ among institutions. The purpose of this survey was to investigate the current implementation status of infection control strategies in NICUs in Japan and to identify and recommend appropriate strategies for the prevention of outbreaks in neonatal units.

METHODS

This survey documented the current implementation status and methods of selected infection prevention and control measures (active surveillance cultures and standard precaution) in 453 Japanese NICUs/neonatal units registered with the Japan Society of Perinatal and Neonatal Medicine, using questionnaires, in May 2018.

FINDINGS

The response rate was 48.1% (level I institutions, 25.5%; level II, 55.9%; level III, 64.2%). Surveillance cultures were performed every week and targeted all bacteria in most units. The proportion of level III institutions that experienced outbreaks over the previous five years was significantly higher than that of level II institutions (55% vs 27%, P=0.0003). However, wearing a mask was less frequently recommended in level III institutions (55.7%) than in level II institutions (67.9%). Meticillin-resistant Staphylococcus aureus (MRSA) was the most frequently reported bacterial pathogen responsible for NICU outbreaks.

CONCLUSION

Infection prevention and control practices regarding active pathogen surveillance cultures and the use of barrier precautions varied widely in Japanese neonatal units. National guidelines and evidence-based recommendations are needed to rationalize and standardize current infection prevention and control practices in neonatal units in Japan.

MRSA outbreak in a tertiary neonatal intensive care unit in Iceland

Introduction: Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) and understanding the pathophysiology and transmission is essential. This study describes an MRSA outbreak in a neonatal intensive care unit in Reykjavik, Iceland at a time where no screening procedures were active. Materials and methods: After isolating MRSA in the neonatal intensive care unit in 2015, neonates, staff members and parents of positive patients were screened and environmental samples collected. The study period was from 14 April 2015 until 31 August 2015. Antimicrobial susceptibility testing, spa-typing and whole genome sequencing were done on MRSA isolates. Results: During the study period, 96/143 admitted patients were screened for colonization. Non-screened infants had short admissions not including screening days. MRSA was isolated from nine infants and seven parents. All tested staff members were negative. Eight infants and six parents carried MRSA ST30-IVc with spa-type t253 and one infant and its parent carried MRSA CC9-IVa (spa-type t4845) while most environmental samples were MRSA CC9-IVa (spa-type t4845). Whole genome sequencing revealed close relatedness between all ST30-IVc and CC9-IVa isolates, respectively. All colonized infants received decolonization treatment, but 3/9 were still positive when last sampled. Discussion: The main outbreak source was a single MRSA ST30-IVc (spa-type t253), isolated for the first time in Iceland. A new CC9-IVa (spa-type t4845) was also identified, most abundant on environmental surfaces but only in one patient. The reason for the differences in the epidemiology of the two strains is not clear. The study highlights a need for screening procedures in high-risk settings and guidelines for neonatal decolonization.

Impact of MRSA Transmission and Infection in a Neonatal Intensive Care Unit in China: A Bundle Intervention Study during 2014-2017

Objective. To evaluate the efficacy of bundle intervention on healthcare-associated (HA) methicillin-resistant Staphylococcus Aureus (MRSA) infection in the neonatal intensive care unit (NICU). Methods. In this study, 11,277 infants having undergone treatment at the NICU in Xiamen, China, from January 2014 to February 2017 were recruited. We retrospectively reviewed patients' demographic and clinical information. Patients from 2014 to 2015 were treated as the control group and those from 2016 to 2017 were classified as the experimental group. Bundle intervention measures were performed, including screening for MRSA, isolation precautions, training of hand hygiene, cleaning protocols, and decontamination of isolation ward. The HA-MRSA data and compliance of infection control measures between both groups were analyzed. Results. Through bundle interventions, the compliance with the isolation of MRSA raised from 55.88% to 92.86% and hand hygiene compliance increased from 90.07% to 93.23% (P < 0.05). The HA infection decreased from 1.87% to 1.71% (P > 0.05) and HA detection rate of MRSA declined from 2.63‰ to 1.00‰, respectively (P < 0.05). Conclusion. Multifaceted interventions can effectively prevent MRSA infection and transmission; this includes active surveillance, isolation precautions, increased hand hygiene compliance, environmental cleaning, and decontamination.

Combination of Nasal and Expanded Skin Swabs Enhances the Detection Rate of Staphylococcus aureus Colonization in Premature Infants

Nasal cultures are commonly used to detect carriers of Staphylococcus aureus (SA) in infants. Combination of nasal and skin swabs has been shown to enhance the detection rate of SA colonization in adult hospitalized patients. Combining nasal swabs with expanded body skin swabs enhanced detection of SA colonization in premature infants in a tertiary care neonatal department.

The Role of the Environment and Colonization in Healthcare-Associated Infections

Healthcare-associated infections (HAIs) can be caused by endogenous host microbial flora or by exogenous microbes, including those found in the hospital environment. Efforts to decrease endogenous pathogens via decolonization and skin antisepsis may decrease the risk of infection in some settings. Controlling the spread of potential pathogens from the environment requires meticulous attention to cleaning and disinfection practices. In addition to selection of the appropriate cleaning agent, use of tools that assess the adequacy of cleaning and addition of no-touch cleaning technology may decrease environmental contamination. Hand hygiene is also a critical component of preventing transmission of pathogens from the environment to patients via healthcare worker hands.

The impact of chlorhexidine gluconate bathing on skin bacterial burden of neonates admitted to the Neonatal Intensive Care Unit

OBJECTIVE

To assess the impact of chlorhexidine gluconate (CHG) bathing on skin bacterial burden in neonates.

STUDY DESIGN

In this prospective observational study, arm and groin skin bacterial growth was measured in 40 CHG-exposed and nonexposed neonates admitted to the NICU. Exposed neonates received 2% CHG baths per protocol for central line-associated bloodstream infection (CLABSI) prevention or Staphylococcus aureus decolonization.

RESULTS

Forty neonates were enrolled, 18 of whom were CHG-exposed. Mean baseline Gram-positive (GP) bacterial burden was 2.19 log CFU/ml on the arm and 1.81 log CFU/ml on the groin. Bacterial burden decreased after the first bath, but returned to baseline by 72 h. Residual skin CHG concentration declined over time, with a corresponding increase in GP bacterial burden.

CONCLUSIONS

CHG bathing reduces skin bacterial burden, but burden returns to baseline after 72 h. Twice weekly CHG bathing may be inadequate to suppress skin bacterial growth in hospitalized neonates.

Mupirocin for Staphylococcus aureus Decolonization of Infants in Neonatal Intensive Care Units

: media-1vid110.1542/5849573989001PEDS-VA_2018-1565Video Abstract BACKGROUND AND OBJECTIVES: Staphylococcus aureus (SA) is the second leading cause of late-onset sepsis among infants in the NICU. Because colonization of nasal mucosa and/or skin frequently precedes invasive infection, decolonization strategies, such as mupirocin application, have been attempted to prevent clinical infection, but data supporting this approach in infants are limited. We conducted a phase 2 multicenter, open-label, randomized trial to assess the safety and efficacy of intranasal plus topical mupirocin in eradicating SA colonization in critically ill infants.

METHODS

Between April 2014 and May 2016, infants <24 months old in the NICU at 8 study centers underwent serial screening for nasal SA. Colonized infants who met eligibility criteria were randomly assigned to receive 5 days of mupirocin versus no mupirocin to the intranasal, periumbilical, and perianal areas. Mupirocin effects on primary (day 8) and persistent (day 22) decolonization at all three body sites were assessed.

RESULTS

A total of 155 infants were randomly assigned. Mupirocin was generally well tolerated, but rashes (usually mild and perianal) occurred significantly more often in treated versus untreated infants. Primary decolonization occurred in 62 of 66 (93.9%) treated infants and 3 of 64 (4.7%) control infants (P < .001). Twenty-one of 46 (45.7%) treated infants were persistently decolonized compared with 1 of 48 (2.1%) controls (P < .001).

CONCLUSIONS

Application of mupirocin to multiple body sites was safe and efficacious in eradicating SA carriage among infants in the NICU; however, after 2 to 3 weeks, many infants who remained hospitalized became recolonized.

First report on USA300 outbreak in a neonatal intensive care unit detected by polymerase chain reaction-based open reading frame typing in Japan

Outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) in the neonatal intensive care unit (NICU) have been reported worldwide. Some outbreaks were caused by USA300, which is a community-associated MRSA clone. In 2011, polymerase chain reaction-based open reading frame typing (POT) for the initial MRSA isolates from all inpatients was started at the Tokyo Metropolitan Children's Medical Center. From March 2014 to April 2015, a total of 131 MRSA strains were isolated, 104 of which were analyzed as healthcare-associated MRSA. Thirteen stains (12.5%) had a POT number of 106-9-93, which strongly suggested USA300; these included 6 from nasal swabs, 6 from blood cultures and 1 from subcutaneous pus. All the MRSA strains were isolated from patients in the NICU; were typed as sequence type 8, spa type t008, and staphylococcal cassette chromosome type mec IVa; and possessed the lukS-lukF and arginine catabolic mobile element-arcA gene. Pulsed-field gel electrophoresis of all the strains, with USA300-0114 as a reference, showed indistinguishable banding pattern. Based on these results, POT was useful in recognizing this first MRSA outbreak of USA300 in a Japanese NICU and was advantageous in terms of swiftness, less cost and monitoring change of the epidemic MRSA lineage.

Whole-genome sequencing for methicillin-resistant Staphylococcus aureus (MRSA) outbreak investigation in a neonatal intensive care unit

OBJECTIVE

To evaluate whole-genome sequencing (WGS) as a molecular typing tool for MRSA outbreak investigation.

DESIGN

Investigation of MRSA colonization/infection in a neonatal intensive care unit (NICU) over 3 years (2014-2017).

SETTING

Single-center level IV NICU.PatientsNICU infants and healthcare workers (HCWs).

METHODS

Infants were screened for MRSA using a swab of the anterior nares, axilla, and groin, initially by targeted (ring) screening, and later by universal weekly screening. Clinical cultures were collected as indicated. HCWs were screened once using swabs of the anterior nares. MRSA isolates were typed using WGS with core-genome multilocus sequence typing (cgMLST) analysis and by pulsed-field gel electrophoresis (PFGE). Colonized and infected infants and HCWs were decolonized. Control strategies included reinforcement of hand hygiene, use of contact precautions, cohorting, enhanced environmental cleaning, and remodeling of the NICU.

RESULTS

We identified 64 MRSA-positive infants: 53 (83%) by screening and 11 (17%) by clinical cultures. Of 85 screened HCWs, 5 (6%) were MRSA positive. WGS of MRSA isolates identified 2 large clusters (WGS groups 1 and 2), 1 small cluster (WGS group 3), and 8 unrelated isolates. PFGE failed to distinguish WGS group 2 and 3 isolates. WGS groups 1 and 2 were codistributed over time. HCW MRSA isolates were primarily in WGS group 1. New infant MRSA cases declined after implementation of the control interventions.

CONCLUSION

We identified 2 contemporaneous MRSA outbreaks alongside sporadic cases in a NICU. WGS was used to determine strain relatedness at a higher resolution than PFGE and was useful in guiding efforts to control MRSA transmission.

Epidemiology and risk factors for recurrent Staphylococcus aureus colonization following active surveillance and decolonization in the NICU

OBJECTIVES

To examine neonatal risk factors associated with recurrent Staphylococcus aureus colonization and to determine the genetic relatedness of S. aureus strains cultured from neonates before and after decolonization.Study designSingle-center retrospective cohort study of neonates admitted to the neonatal intensive care unit (NICU) from April 2013 to December 2015, during which weekly nasal cultures from hospitalized NICU patients were routinely obtained for S. aureus surveillance.

SETTING

Johns Hopkins Hospital's 45-bed level IV NICU in Baltimore, Maryland.

METHODS

Demographics and clinical data were collected on all neonates admitted to the NICU with S. aureus nasal colonization who underwent mupirocin-based decolonization during the study period. A decolonized neonate was defined as a neonate with ≥1 negative culture after intranasal mupirocin treatment. Pulsed-field gel electrophoresis was used for strain typing.

RESULTS

Of 2,060 infants screened for S. aureus, 271 (13%) were colonized, and 203 of these 271 (75%) received intranasal mupirocin. Of those treated, 162 (80%) had follow-up surveillance cultures, and 63 of these 162 infants (39%) developed recurrent colonization after treatment. The S. aureus strains were often genetically similar before and after decolonization. The presence of an endotracheal tube or nasal cannula/mask was associated with an increased risk of recurrent S. aureus colonization (hazard ratio [HR], 2.65; 95% confidence interval [CI], 1.19-5.90; and HR, 2.21; 95% CI, 1.02-4.75, respectively).

CONCLUSION

Strains identified before and after decolonization were often genetically similar, and the presence of invasive respiratory devices increased the risk of recurrent S. aureus nasal colonization in neonates. To improve decolonization efficacy, alternative strategies may be needed.

Evaluating a neonatal intensive care unit MRSA surveillance programme using agent-based network modelling

BACKGROUND

Surveillance for meticillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs) is a commonplace infection prevention strategy, yet the optimal frequency with which to monitor the unit is unknown.

AIM

To compare various surveillance frequencies using simulation modelling.

METHODS

One hundred NICU networks of 52 infants were simulated over a six-month period to assess MRSA transmission. Unit-wide surveillance occurred every N weeks where N={1,2,3,4}, and was compared with the current NICU policy of dynamic surveillance (i.e. weekly when at least one positive screen, otherwise every three weeks). For each surveillance period, colonized infants received a decolonization regimen (56% effective) and were moved to isolation rooms, if available.

FINDINGS

As the surveillance frequency increased, the mean number of MRSA-colonized infants decreased, from a high of 2.9 (four-weekly monitoring) to a low of 0.6 (weekly monitoring) detected per episode. The mean duration of colonization decreased from 307 h (four-weekly monitoring) to 61 h (weekly monitoring). Meanwhile, the availability of isolation rooms followed an inverse relationship: as surveillance frequency increased, the availability of isolation rooms decreased (61% isolation success rate for four-weekly monitoring vs 49% success rate for weekly monitoring). The dynamic policy performed similar to a biweekly programme.

CONCLUSIONS

An effective MRSA surveillance programme needs to balance resource availability with potential for harm due to longer colonization periods and opportunity for development of invasive disease. While more frequent monitoring led to greater use of a decolonization regimen, it also reduced the likelihood of isolation rooms being available.

Spatial and environmental correlates of organism colonization and infection in the neonatal intensive care unit

OBJECTIVE

To examine organism colonization and infection in the neonatal intensive care unit as a result of environmental and spatial factors.

STUDY DESIGN

A retrospective cohort of infants admitted between 2006 and 2015 (n = 11 428), to assess the relationship between location and four outcomes: methicillin-resistant Staphylococcus aureus (MRSA) colonization; culture-confirmed late-onset sepsis; and, if intubated, endotracheal tube colonization with Pseudomonas aeruginosa or Klebsiella pneumonia. Independent risk factors were identified with mixed-effects logistic regression models and Moran's I for spatial autocorrelation.

RESULT

All four outcomes statistically clustered by location; neighboring colonization also influenced risk of MRSA (p < 0.05). For P. aeruginosa, being in a location with space for more medical equipment was associated with 2.61 times the odds of colonization (95% CrI: 1.19, 5.78).

CONCLUSION

Extrinsic factors partially explained risk for neonatal colonization and infection. For P. aeruginosa, infection prevention efforts at locations with space for more equipment may lower future colonization.

New Threats from an Old Foe: Methicillin-Resistant Staphylococcus aureus Infections in Neonates

Methicillin-resistant Staphylococcus aureus (MRSA) is a ubiquitous human inhabitant and one of the important pathogens of neonatal infections. MRSA is associated with significant mortality and morbidity, especially in very immature preterm neonates. Moreover, MRSA may be implicated in adverse long-term neonatal outcomes, posing a substantial disease burden. Recent advances in molecular microbiology have shed light on the evolution of MRSA population structure and virulence factors, which may contribute to MRSA epidemic waves worldwide. Equipped with remarkable genetic flexibility, MRSA has successfully developed resistance to an extensive range of antibiotics including vancomycin, as well as antiseptics. In the face of these new challenges from MRSA, our armamentarium of anti-infective strategies is very limited and largely dependent on prevention measures. Active surveillance cultures followed by decolonization may be a promising approach to control MRSA infections, with its efficacy and safety in the specific population of neonates yet to be addressed by large multicenter studies.

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.

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.

A Network Model of Hand Hygiene: How Good Is Good Enough to Stop the Spread of MRSA?

BACKGROUND Simulation models have been used to investigate the impact of hand hygiene on methicillin-resistant Staphylococcus aureus (MRSA) transmission within the healthcare setting, but they have been limited by their ability to accurately model complex patient-provider interactions. METHODS Using a network-based modeling approach, we created a simulated neonatal intensive care unit (NICU) representing the potential for per-hour infant-infant MRSA transmission via the healthcare worker resulting in subsequent colonization. The starting prevalence of MRSA colonized infants varied from 2% to 8%. Hand hygiene ranged from 0% (none) to 100% (theoretical maximum), with an expected effectiveness of 88% inferred from literature. RESULTS Based on empiric care provided within a 1-hour period, the mean number of infant-infant MRSA transmissible opportunities per hour was 1.3. Compared to no hand hygiene and averaged across all initial colonization states, colonization was reduced by approximately 29%, 51%, 67%, 80%, and 86% for the respective levels of hygiene: 24%, 48%, 68%, 88%, and 100%. Preterm infants had a 61% increase in MRSA colonization, and mechanically ventilated infants had a 27% increase. CONCLUSIONS Even under optimal hygiene conditions, horizontal transmission of MRSA is possible. Additional prevention paradigms should focus on the most acute patients because they are at greatest risk. Infect Control Hosp Epidemiol 2017;38:945-952.

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.

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.

Active Surveillance Cultures and Targeted Decolonization Are Associated with Reduced Methicillin-Susceptible Staphylococcus aureus Infections in VLBW Infants

BACKGROUND

Methicillin-susceptible Staphylococcus aureus (MSSA) is a major contributor to infectious episodes of very low birth weight infants (VLBWI), resulting in significant morbidity and mortality.

OBJECTIVE

To examine the efficacy and safety of surveillance cultures and the decolonization of MSSA-colonized VLBWI.

METHODS

VLBWI admitted to our neonatal wards in 2011-2016 were retrospectively analyzed. Rates of MSSA-attributable infections were compared before and after the implementation of active surveillance cultures and the decolonization of MSSA-colonized patients. The mupirocin susceptibility of isolated MSSA strains was routinely tested.

RESULTS

A total of 1,056 VLBWI were included in the study, 552 in the pre-intervention period and 504 in the post-intervention period. The implementation of surveillance cultures and decolonization of colonized patients resulted in a 50% reduction of incidence rates per 1,000 patient-days of MSSA-attributable infections (1.63 [95% CI 1.12-2.31] vs. 0.83 [95% CI 0.47-1.35], p = 0.024). No adverse effects were observed from application of the decolonization protocol with mupirocin and octenidin. No mupirocin-resistant MSSA strains were detected during the study period.

CONCLUSION

Implementation of an active surveillance and decolonization protocol resulted in a reduction of MSSA-attributable infections in VLBWI.

Regional Epidemiology of Methicillin-Resistant Staphylococcus aureus Among Critically Ill Children in a State With Mandated Active Surveillance

BACKGROUND

In theory, active surveillance of methicillin-resistant Staphylococcus aureus (MRSA) reduces MRSA spread by identifying all MRSA-colonized patients and placing them under contact precautions. In October 2007, Illinois mandated active MRSA surveillance in all intensive care units, including neonatal intensive care units (NICUs) and pediatric intensive care units (PICUs). We evaluated MRSA trends in a large metropolitan region in the wake of this law.

METHODS

Chicago hospitals with a NICU or PICU were recruited for 8 single-day point prevalence surveys that occurred twice-yearly between June 2008 and July 2011 and then yearly in 2012 to 2013. Samples from all patients were cultured for MRSA (nose and umbilicus for neonates, nose and groin for pediatric patients). Hospital-reported admission MRSA-screening results also were obtained. Point prevalence cultures were screened for MRSA by using broth enrichment, chromogenic agar, and standard confirmatory methods.

RESULTS

All eligible hospitals (N = 10) participated (10 NICUs, 6 PICUs). Hospital-reported adherence to state-mandated MRSA screening at admission was high (95% for NICUs, 94% for PICUs). From serial point prevalence surveys, overall MRSA prevalences in the NICUs and PICUs were 4.2% (89 of 2101) and 5.7% (36 of 632), respectively. MRSA colonization prevalences were unchanged in the NICUs (year-over-year risk ratio [RR], 0.93 [95% confidence interval (CI), 0.78-1.12]; P = .45) and trended toward an increase in the PICUs (RR, 1.25 [95% CI, 0.72-2.12]; P = .053). We estimated that 81% and 40% of MRSA-positive patients in the NICUs and PICUs, respectively, had newly acquired MRSA.

CONCLUSIONS

In a region with mandated active MRSA surveillance, we found ongoing unchanged rates of MRSA colonization and acquisition among NICU and PICU patients.

Meticillin-resistant Staphylococcus aureus (MRSA) acquisition risk in an endemic neonatal intensive care unit with an active surveillance culture and decolonization programme

BACKGROUND

Meticillin-resistant Staphylococcus aureus (MRSA) is a leading cause of healthcare-associated infection in the neonatal intensive care unit (NICU). Decolonization may eliminate bacterial reservoirs that drive MRSA transmission.

AIM

To measure the association between colonization pressure from decolonized and non-decolonized neonates and MRSA acquisition to inform use of this strategy for control of endemic MRSA.

METHODS

An eight-year retrospective cohort study was conducted in a level-4 NICU that used active surveillance cultures and decolonization for MRSA control. Weekly colonization pressure exposures were defined as the number of patient-days of concurrent admission with treated (decolonized) and untreated (non-decolonized) MRSA carriers in the preceding seven days. Poisson regression was used to estimate risk of incident MRSA colonization associated with colonization pressure exposures. The population-attributable fraction was calculated to assess the proportion of overall unit MRSA incidence attributable to treated or untreated patients in this setting.

FINDINGS

Every person-day increase in exposure to an untreated MRSA carrier was associated with a 6% increase in MRSA acquisition risk [relative risk (RR): 1.06; 95% confidence interval (CI): 1.01-1.11]. Risk of acquisition was not influenced by exposure to treated, isolated MRSA carriers (RR: 1.01; 95% CI: 0.98-1.04). In the context of this MRSA control programme, 22% (95% CI: 4.0-37) of MRSA acquisition could be attributed to exposures to untreated MRSA carriers.

CONCLUSION

Untreated MRSA carriers were an important reservoir for transmission. Decolonized patients on contact isolation posed no detectable transmission threat, supporting the hypothesis that decolonization may reduce patient-to-patient transmission. Non-patient reservoirs may contribute to unit MRSA acquisition and require further investigation.

Genomic Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit

Despite infection prevention efforts, neonatal intensive care unit (NICU) patients remain at risk of Methicillin-resistant Staphylococcus aureus (MRSA) infection. Modes of transmission for healthcare-associated (HA) and community-associated (CA) MRSA remain poorly understood and may vary by genotype, hindering the development of effective prevention and control strategies. From 2008–2010, all patients admitted to a level III NICU were screened for MRSA colonization, and all available isolates were spa-typed. Spa-type t008, the most prevalent CA- genotype in the United States, spa-type t045, a HA- related genotype, and a convenience sample of strains isolated from 2003–2011, underwent whole-genome sequencing and phylodynamic analysis. Patient risk factors were compared between colonized and noncolonized infants, and virulence and resistance genes compared between spa-type t008 and non-t008 strains. Epidemiological and genomic data were used to estimate MRSA importations and acquisitions through transmission reconstruction. MRSA colonization was identified in 9.1% (177/1940) of hospitalized infants and associated with low gestational age and birth weight. Among colonized infants, low gestational age was more common among those colonized with t008 strains. Our data suggest that approximately 70% of colonizations were the result of transmission events within the NICU, with the remainder likely to reflect importations of “outside” strains. While risk of transmission within the NICU was not affected by spa-type, patterns of acquisition and importation differed between t008 and t045 strains. Phylodynamic analysis showed the effective population size of spa-type t008 has been exponentially increasing in both community and hospital, with spa-type t008 strains possessed virulence genes not found among t045 strains; t045 strains, in contrast, appeared to be of more recent origin, with a possible hospital source. Our data highlight the importance of both intra-NICU transmission and recurrent introductions in maintenance of MRSA colonization within the NICU environment, as well as spa-type-specific differences in epidemiology.

Characteristics of late-onset sepsis in the NICU: does occupancy impact risk of infection?

OBJECTIVE

Infants in neonatal intensive care units (NICUs) are vulnerable to a variety of infections, and occupancy in the unit may correlate with risk of infection.

STUDY DESIGN

A retrospective cohort of infants admitted to the NICUs between 1997 and 2014. Survival analysis was used to model the relative hazard of sepsis infection in relation to two measures of occupancy: 1) the average census and 2) proportion of infants <32 weeks gestation in the unit.

RESULT

There were 446 (2.3%) lab-confirmed cases of bacterial or fungal sepsis, which steadily declined over time. For each additional percentage of infants <32 weeks gestation, there was an increased hazard of 2% (hazard ratio 1.02, 95% confidence interval: 1.00, 1.03) over their NICU hospitalization. Census was not associated with risk for infection.

CONCLUSION

During times of a greater proportion of infants <32 weeks gestation in the NICU, enhanced infection-control interventions may be beneficial to further reduce the incidence of infections.

Fighting MRSA Infections in Hospital Care: How Organizational Factors Matter

OBJECTIVE

To identify factors associated with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections at the level of the hospital organization.

DATA SOURCES

Data from all 173 acute trusts in the English National Health Service (NHS).

STUDY DESIGN

A longitudinal study based on trust-level panel data for the 5-year period from April 2004 to March 2009. Fixed effects negative binominal and system generalized method of moment models were used to examine the effect of (i) patient mix characteristics, (ii) resource endowments, and (iii) infection control practices on yearly MRSA counts.

DATA COLLECTION

Archival and staff survey data from multiple sources, including Public Health England, the English Department of Health, and the Healthcare Commission, were merged to form a balanced panel dataset.

PRINCIPAL FINDINGS

MRSA infections decrease with increases in general cleaning (-3.52 MRSA incidents per 1 standard deviation increase; 95 percent confidence interval: -6.61 to -0.44), infection control training (-3.29; -5.22 to -1.36), hand hygiene (-2.72; -4.76 to -0.68), and error reporting climate (-2.06; -4.09 to -0.04).

CONCLUSIONS

Intensified general cleaning, improved hand hygiene, additional infection control training, and a climate conducive to error reporting emerged as the factors most closely associated with trust-level reductions in MRSA infections over time.

Airborne transmission from a neonate with Netherton syndrome during an outbreak of MRSA

We encountered a 4 month outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection that was difficult to control despite implementation of standard prevention methods. A neonate with Netherton syndrome had accelerated scaling of the skin and continued positive results for MRSA from clinical samples. The results of air sampling suggested the possibility of airborne transmission. The MRSA outbreak stopped after the patient was transferred to an isolation room, suggesting that airborne MRSA can play a role in MRSA colonization. Isolation rooms should be considered in specific circumstances, as described in the present study.

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.