Epidemiology and Mortality of Staphylococcus aureus Bacteremia in Australian and New Zealand Children

The effects of delayed appropriate antimicrobial therapy on children with Staphylococcus aureus blood infection

Early appropriate antimicrobial therapy plays a critical role for patients with Staphylococcus aureus bloodstream infection (SAB). We aim to determine the optimal time-window for appropriate antimicrobial therapy and evaluate the effects of delayed therapy on adverse clinical outcomes (in-hospital mortality, sepsis, and septic shock) in children with SAB by propensity score matching (PSM) analysis. Receiver-operating characteristic was used to determine the cut-off point of the time to appropriate therapy (TTAT), the patients were divided into timely and delayed appropriate antimicrobial therapy (delayed therapy) groups accordingly. The PSM was used to balance the characteristics between the two groups, controlling the effects of potential confounders. Kaplan-Meier methods and Cox proportional hazards regression were applied to the matched groups to analyze the association between delayed therapy and clinical outcomes. Inverse probability of treatment weighting and propensity score covariate adjustment were also performed to investigate the sensitivity of the results under different propensity score-based approaches. In total, 247 patients were included in this study. The optimal cut-off point of TTAT was identified as 6.4 h, with 85.0% sensitivity and 69.2% specificity (AUC 0.803, 95% confidence interval 0.702-0.904). Eighty-seven (35.22%) of the 247 patients who received delayed therapy (TTAT ≥ 6.4 h) had higher in-hospital mortality (19.54% vs 1.88%, p < 0.001), higher incidences of sepsis (44.83% vs 15.00%, p < 0.001) and septic shock (32.18% vs 6.25%, p < 0.001) when compared to timely therapy (TTAT < 6.4 h) patients. After PSM analysis, a total of 134 episodes (67 in each of the two matched groups) were further analyzed. No statistically significant difference was observed in in-hospital mortality between delayed and timely -therapy groups (log-rank test, P = 0.157). Patients with delayed therapy had a higher incidence of sepsis or septic shock than those with timely therapy (log-rank test, P = 0.009; P = 0.018, respectively). Compared to the timely-therapy group, the hazard ratio and 95% confidence interval in delayed-therapy group were 2.512 (1.227-5.144, P = 0.012) for sepsis, 3.109 (1.166-8.290, P = 0.023) for septic shock.    Conclusion: Appropriate therapy delayed 6.4 h may increase the incidence of sepsis and septic shock, with similar in-hospital mortality in patients with SAB. What is Known: • Staphylococcus aureus (S. aureus) is a major cause of bloodstream infections in children. Undoubtedly, early antimicrobial application plays a critical role in the treatment of children with Staphylococcus aureus bloodstream infections (SAB). • However, rapid, and aggressive administration of antimicrobials may lead to the overuse of these drugs and the emergence of multidrug-resistant microorganisms. Therefore, it is crucial to determine the optimal time-window for appropriate antimicrobial administration in children with SAB. Unfortunately, the optimal time-window for appropriate antimicrobial administration in children with SAB remains unclear. What is New: • Determining the optimal time-window for appropriate antimicrobial administration in patients with matched data variables is particularly important. The Propensity score matching (PSM) analysis effectively controls for confounding factors to a considerable extent when assessing the impact of treatment, thereby approximating the effects observed in randomized controlled trials. • To our knowledge, this is the first study using PSM method to assess the effects of delayed appropriate antimicrobial therapy on adverse outcomes in children with SAB. In low-risk populations with SAB, a delay of 6.4 h in appropriate therapy might increase the occurrence rate for sepsis and septic shock; however, no correlation has been found between this delay and an increased risk for hospital mortality.

Correlation between the results of cultures and the molecular BIOFIRE® joint infection panel in a cohort of pediatric patients with bone and joint infections in Bogotá, Colombia

Introduction

Bone and Joint Infections (BJI) have high morbidity. Methicillin resistant Staphylococcus aureus (MRSA) has increased. Culture-based diagnosis has difficult to recovering fastidious bacteria and detecting polymicrobial infections, molecular methods offer a promising improvement for the diagnosis of BJI with reduced time to result. The aim of the study was to determine the correlation between culture results and the Biofire joint infection panel (BJIP) in a cohort of pediatric patients with BJI.

Materials and methods

Descriptive study. Patients admitted with probable o confirmed BJI between July 1, 2019 and February 28, 2021 at HOMI. Blood cultures, synovial and bone fluid samples were taken. Samples were kept at -70 °C. On September 2022, the panel was performed.

Results

32 patients were included. The average age was 83m (RIQ: 32-145). 23 (71.8%) patients had a positive culture. The most frequent microorganism were S. aureus 19 (83%), 11/19 (57.9%) Staphylococci isolates were MRSA. 24/32 (75%) were positive by panel, 20 positive detections were concordant with culture, there were 6 additional isolates by panel (2 S. aureus, 2 S. pyogenes, 1 K. kingae and 1 C. albicans), three microorganisms were isolated in culture but not in the panel. (2 S. aureus and 1 S. agalactiae). Two patients with coinfection were detected. All MRSA were detected by culture and panel. In 26 (81.3%) patients the etiology was documented by any method.

Conclusion

These results showed a moderate level of agreement between BJIP and culture (κ = 0.47). The panel allowed the detection of fastidious bacteria including K. kingae and polymicrobial samples. There was a very good level of agreement between the panel and culture for the MRSA detection (κ = 1).

The molecular epidemiology and clinical implication of methicillin-resistant Staphylococcus aureus (MRSA) sequence types in pediatric bacteremia: a restrospective observational study, 2016-2021

BACKGROUND

While there is a high burden of methicillin-resistant Staphylococcus aureus (MRSA) infections among pediatric patients, studies on the molecular epidemiology of MRSA infections in Korean children since the 2010s are lacking. This study aimed to investigate the molecular genotypes and clinical characteristics of MRSA isolates from children with MRSA bacteremia at Asan Medical Center Children's Hospital from 2016 to 2021.

METHODS

Clinical data were retrospectively reviewed, and the molecular types of MRSA were determined using multilocus sequence typing (MLST) and Staphylococcal cassette chromosome mec (SCCmec) typing.

RESULTS

The overall methicillin resistance rate of S. aureus bacteremia was 44.8% (77/172); 49.5% in the period 2016-2018 (period 1) and 37.3% in the period 2019-2021 (period 2) (P = 0.116). Community-acquired infections accounted for only 3.9% of cases. The predominant ST group was ST72 group (67.6%), followed by ST5 group (18.9%) and ST1 group (5.4%). The proportion of ST5 was significantly lower in period 2 compared to period 1 (P = 0.02). Compared to the ST5 and ST1 groups, the ST72 group exhibited lower overall antibiotic resistance and multidrug-resistant (MDR) rates (12.0% [6/50] in ST72 group vs. 100.0% [14/14] in ST5 group vs. 50.0% [2/4] in ST1 group; P < 0.001). In the multivariate analysis, the ST1 group was an independent risk factor for 30-day all-cause mortality (aOR, 44.12; 95% CI, 3.46-562.19).

CONCLUSION

The ST72-MRSA strain remained the most frequently isolated genotype in Korean children, while the ST1 group emerged as an independent risk factor for 30-day all-cause mortality in pediatric MRSA bacteremia. Ongoing efforts to uncover the evolving epidemiology of MRSA are essential for developing effective strategies for prevention and treatment.

Predictive models for sepsis in children with Staphylococcus aureus bloodstream infections: a retrospective cohort study

BACKGROUND

The presence of Staphylococcus aureus in the bloodstream can lead to the development of sepsis; however, the severity and risk factors of the systemic inflammatory response to Staphylococcus aureus bloodstream infections were unclear. This study is aimed to build a model to predict the risk of sepsis in children with Staphylococcus aureus bloodstream infections.

METHODS

A retrospective analysis of hospitalized pediatric patients diagnosed with Staphylococcus aureus bloodstream infections was performed between January 2013 and December 2019. Each patient was assessed using the pediatric version of the Sequential Organ Failure Assessment score (pSOFA) within 24 h of blood culture collection. A nomogram based on logistic regression models was constructed to predict the risk factors for sepsis in children with Staphylococcus aureus bloodstream infections. It was validated using the area under the receiver-operating characteristic curve (AUC).

RESULTS

Of the 94 patients included in the study, 35 cases (37.2%) developed sepsis. The pSOFA scores ranged from 0 to 8, with 35 patients having a pSOFA score of ≥ 2. Six children (6.4%) died within 30 days, who were all from the sepsis group and had different pSOFA scores. The most common organs involved in sepsis in children with staphylococcal bloodstream infections were the neurologic system (68.6%), respiratory system (48.6%), and coagulation system (45.7%). Hospital-acquired infections (adjusted odds ratio [aOR], 3.0; 95% confidence interval [CI], 1.3-7.2), implanted catheters (aOR, 10.4; 95% CI, 3.8-28.4), procalcitonin level ≥ 1.7 ng/mL (aOR, 15.4; 95% CI, 2.7-87.1), and underlying diseases, especially gastrointestinal malformations (aOR, 14.0; 95% CI, 2.9-66.7) were associated with Staphylococcus aureus sepsis. However, methicillin-resistant Staphylococcus aureus infection was not a risk factor for sepsis. The nomogram had high predictive accuracy for the estimation of sepsis risk, with an AUC of 0.85.

CONCLUSIONS

We developed a predictive model for sepsis in children with Staphylococcus aureus infection.

An Update on Pediatric Acute Hematogenous Osteomyelitis in New Zealand - A Decade on

INTRODUCTION

New Zealand (NZ) has high rates of pediatric acute hematogenous osteomyelitis (AHO) with males and children of Pasifika and Māori ethnicity overrepresented.

AIMS

To update the incidence of Pediatric AHO over 10 years, identifying trends in presentation, organisms, treatment, and outcomes.

METHODS

A 10-year retrospective review of children aged 6 weeks to 15 years admitted with Pediatric AHO across two centers from 2008 to 2017. Demographic data, features of presentation, investigations, management, and complications were collected. Incidence was calculated from census data. Data were compared with our osteomyelitis database from the previous decade. (1).

RESULTS

796 cases were identified. The incidence was 18 per 100,000 per annum. The average age was 7.7 years. Pasifika and Māori children are overrepresented (57%). 370 children (51%) came from low socioeconomic areas. Methicillin-sensitive Staphylococcus aureus was the most common pathogen (87%). Methicillin-resistant Staphylococcus aureus (MRSA) rates are low (4.4%). Forty-four (5.5%) children were admitted to the Pediatric Intensive Care Unit (PICU) with 9% mortality. The mean duration of antibiotics was 40 days. 325 children (41%) had surgery. Chronic infection has increased from 1.7% to 5.7%.

CONCLUSIONS

NZ has high rates of AHO, however, the incidence has decreased from the previous decade. Males, those in low socioeconomic areas, Pasifika and Māori have high disease burden. The use of MRI as a diagnostic modality has increased. Future studies should focus on improving treatment via prospective analysis and reporting long-term morbidity to improve outcomes for children with severe disease and reduce rates of chronic infection.

Pediatric Swine Model of Methicillin-Resistant Staphylococcus aureus Sepsis-Induced Coagulopathy, Disseminated Microvascular Thrombosis, and Organ Injuries

Sepsis-induced coagulopathy leading to disseminated microvascular thrombosis is associated with high mortality and has no existing therapy. Despite the high prevalence of Gram-positive bacterial sepsis, especially methicillin-resistant Staphylococcus aureus (MRSA), there is a paucity of published Gram-positive pediatric sepsis models. Large animal models replicating sepsis-induced coagulopathy are needed to test new therapeutics before human clinical trials.

HYPOTHESIS

Our objective is to develop a pediatric sepsis-induced coagulopathy swine model that last 70 hours.

METHODS AND MODELS

Ten 3 weeks old piglets, implanted with telemetry devices for continuous hemodynamic monitoring, were IV injected with MRSA (n = 6) (USA300, Texas Children's Hospital 1516 strain) at 1 × 10⁹ colony forming units/kg or saline (n = 4). Fluid resuscitation was given for heart rate greater than 50% or mean arterial blood pressure less than 30% from baseline. Acetaminophen and dextrose were provided as indicated. Point-of-care complete blood count, prothrombin time (PT), activated thromboplastin time, d-dimer, fibrinogen, and specialized coagulation assays were performed at pre- and post-injection, at 0, 24, 48, 60, and 70 hours. Piglets were euthanized and necropsies performed.

RESULTS

Compared with the saline treated piglets (control), the septic piglets within 24 hours had significantly lower neurologic and respiratory scores. Over time, PT, d-dimer, and fibrinogen increased, while platelet counts and activities of factors V, VII, protein C, antithrombin, and a disintegrin and metalloproteinase with thrombospondin-1 motifs (13th member of the family) (ADAMTS-13) decreased significantly in septic piglets compared with control. Histopathologic examination showed minor focal organ injuries including microvascular thrombi and necrosis in the kidney and liver of septic piglets.

INTERPRETATIONS AND CONCLUSIONS

We established a 70-hour swine model of MRSA sepsis-induced coagulopathy with signs of consumptive coagulopathy, disseminated microvascular thrombosis, and early organ injuries with histological minor focal organ injuries. This model is clinically relevant to pediatric sepsis and can be used to study dysregulated host immune response and coagulopathy to infection, identify potential early biomarkers, and to test new therapeutics.

Twenty-Five Year Trend Change in the Etiology of Pediatric Invasive Bacterial Infections in Korea, 1996-2020

BACKGROUND

The coronavirus disease-2019 (COVID-19) pandemic has contributed to the change in the epidemiology of many infectious diseases. This study aimed to establish the pre-pandemic epidemiology of pediatric invasive bacterial infection (IBI).

METHODS

A retrospective multicenter-based surveillance for pediatric IBIs has been maintained from 1996 to 2020 in Korea. IBIs caused by eight bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus pyogenes, Listeria monocytogenes, and Salmonella species) in immunocompetent children > 3 months of age were collected at 29 centers. The annual trend in the proportion of IBIs by each pathogen was analyzed.

RESULTS

A total of 2,195 episodes were identified during the 25-year period between 1996 and 2020. S. pneumoniae (42.4%), S. aureus (22.1%), and Salmonella species (21.0%) were common in children 3 to 59 months of age. In children ≥ 5 years of age, S. aureus (58.1%), followed by Salmonella species (14.8%) and S. pneumoniae (12.2%) were common. Excluding the year 2020, there was a trend toward a decrease in the relative proportions of S. pneumoniae (r_s = -0.430, P = 0.036), H. influenzae (r_s = -0.922, P < 0.001), while trend toward an increase in the relative proportion of S. aureus (r_s = 0.850, P < 0.001), S. agalactiae (r_s = 0.615, P = 0.001), and S. pyogenes (r_s = 0.554, P = 0.005).

CONCLUSION

In the proportion of IBIs over a 24-year period between 1996 and 2019, we observed a decreasing trend for S. pneumoniae and H. influenzae and an increasing trend for S. aureus, S. agalactiae, and S. pyogenes in children > 3 months of age. These findings can be used as the baseline data to navigate the trend in the epidemiology of pediatric IBI in the post COVID-19 era.

Advanced Imaging for Detection of Foci of Infection in Staphylococcus aureus Bacteremia- Can a Scan Save Lives?

Bloodstream infection or sepsis is a common cause of mortality globally. Staphylococcus aureus (S. aureus) is of particular concern, through its ability to seed metastatic infections in almost any organ after entering the bloodstream (S. aureus bacteraemia), often without localising signs. A positive blood culture for S. aureus bacteria should lead to immediate and urgent identification of the cause. Failure to detect a precise focus of infection is associated with higher mortality, sometimes despite appropriate antibiotics. This is likely due to the limited ability to effectively target therapy in occult lesions. Early detection of foci of metastatic S. aureus infection is therefore key for optimal diagnosis and subsequent therapeutic management. 18F-FDG-PET/CT and MRI offer us invaluable tools in the localisation of foci of S. aureus infection. Crucially, they may identify unexpected foci at previously unsuspected locations in the body, for example vertebral osteomyelitis in the absence of back pain. S. aureus bloodstream infections are further complicated by their microbiological recurrence; 18F-FDG-PET/CT provide a means of localising, thus enabling source control. More evidence is emerging as to the utility of 18F-FDG-PET/CT in this setting, perhaps even to the point of reducing mortality. 18 F-FDG-PET/MRI may have a similar impact. The available evidence demonstrates a need to investigate the impact of 18F-FDG-PET/CT and MRI scanning in clinical management and outcomes of S. aureus infection further in a randomised prospective clinical trial.

Predictive Factors to Guide Empiric Antimicrobial Therapy of Acute Hematogenous Osteomyelitis in Children

BACKGROUND

Acute hematogenous osteomyelitis (AHO) is a serious infection in children. Pediatric Infectious Diseases Society guidelines recommend empiric methicillin-resistant Staphylococcus aureus (MRSA) therapy in regions where MRSA accounts for more than 10-20% of all staphylococcal osteomyelitis. We sought to examine factors present at the time of admission which may predict etiology and guide empiric treatment for pediatric AHO in a region with endemic MRSA.

METHODS

We reviewed admissions with International Classification of Diseases 9/10 codes for AHO from 2011 to 2020 in otherwise healthy children. Medical records were reviewed for clinical and laboratory parameters present on the day of admission. Logistic regression was used to determine clinical variables independently associated with (1) MRSA infection and (2) non-Staphylococcus aureus infection.

RESULTS

A total of 545 cases were included. An organism was identified in 77.1% of cases and S. aureus was the most common (66.2%); 18.9% of all AHO cases were MRSA. Organisms besides S. aureus were identified in 10.8% of cases. CRP >7 mg/dL, subperiosteal abscess, history of any prior skin or soft tissue infection (SSTI) and need for intensive care unit admission were independently associated with MRSA infection. Vancomycin was used as an empiric treatment in 57.6% of cases. If the above criteria were relied upon to predict MRSA AHO, empiric vancomycin use could have been reduced by 25%.

CONCLUSIONS

Critical illness, CRP >7 mg/dL at the time of presentation, subperiosteal abscess and history of SSTI are suggestive of MRSA AHO, and could be considered when planning empiric therapy. Further work is needed to validate these findings before wider implementation.

Therapeutic Options and Outcomes for the Treatment of Children with Gram-Positive Bacteria with Resistances of Concern: A Systematic Review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant coagulase-negative Staphylococci (MR-CoNS), and vancomycin-resistant Enterococci (VRE) are increasing worldwide and represent a threat for the limited treatment options in pediatric patients and neonates compared to adults. Recommendations in pediatrics are mainly extrapolated from adults' studies.

METHODS

A literature search for the treatment of these pathogens in children (<18 years old) was conducted in Embase, MEDLINE, and Cochrane Library. Studies reporting data on single-patient-level outcomes related to a specific antibiotic treatment for multidrug resistant (MDR) Gram-positive bacterial infection in children were included. Studies reporting data from adults and children were included if single-pediatric-level information could be identified (PROSPERO registration: CRD42022383867).

RESULTS

The search identified 11,740 studies (since January 2000), of which 48 fulfilled both the inclusion and the exclusion criteria and were included in the analysis: 29 for MRSA, 20 for VRE, and seven for MR-CoNS. Most studies were retrospective studies. Vancomycin was mainly used as a comparator, while linezolid and daptomycin were the most studied antimicrobials showing good efficacy.

CONCLUSIONS

Linezolid showed a safety and efficacy profile in a neonatal setting; daptomycin is increasingly used for MRSA, but the evidence is scarce for VRE.

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.

Changes in Etiology of Invasive Bacterial Infections in Infants Under 3 Months of Age in Korea, 2006-2020

OBJECTIVES

Invasive bacterial infection (IBI) causes a significant burden in infants. In this study, we analyzed changes in epidemiology of IBI among infants in Korea.

METHODS

A retrospective multicenter-based surveillance for IBIs in infants <3 months of age was performed during 2006-2020. Cases were classified as an early-onset disease (EOD) (0-6 days) or late-onset disease (LOD) (7-89 days). The temporal trend change in proportion of pathogens was analyzed.

RESULTS

Among 1545 cases, the median age was 28 days (IQR: 12, 53) and EOD accounted for 17.7%. Among pathogens, S. agalactiae (40.4%), E. coli (38.5%), and S. aureus (17.8%) were the most common and attributed for 96.7%. Among EOD (n = 274), S. agalactiae (45.6%), S. aureus (31.4%), E. coli (17.2%) and L. monocytogenes (2.9%) were most common. Among LOD (n = 1274), E. coli (43.1%), S. agalactiae (39.3%), S. aureus (14.9%) and S. pneumoniae (1.3%) were most common. In the trend analysis, the proportion of S. aureus (r s = -0.850, P < 0.01) decreased significantly, while that of S. agalactiae increased (r s = 0.781, P < 0.01).

CONCLUSION

During 2006-2020, among IBI in infants <3 months of age, S. agalactiae, E. coli, and S. aureus were most common and an increasing trend of S. agalactiae was observed.

Increasing Pediatric Infectious Diseases Consultation Rates for Staphylococcus aureus Bacteremia

Introduction

Staphylococcus aureus bacteremia (SAB) in children is associated with significant mortality and morbidity, including recurrent bacteremia. Infectious disease consultation (IDC) improves SAB outcomes in adult patients. However, increasing IDC and impact for pediatric patients with SAB is not well described.

Methods

This quality improvement project aimed to increase IDC for SAB events at a quaternary pediatric medical center. First, we evaluated the local practices regarding pediatric SAB and engaged stakeholders (July 2018-August 2020). We added an advisory comment supporting IDC for SAB to all blood culture results in September 2020. Using statistical process control charts, we monitored the number of SAB events with IDC before a SAB event without IDC. Finally, we evaluated SAB recurrences before and after initiating the advisory comment.

Results

In the baseline period, 30 of 49 (61%) SAB events received an IDC with a mean of 1.4 SAB events with IDC before a SAB event without IDC. Postintervention, 22 of 23 (96%) SAB events received IDC with a mean of 14 events with IDC before 1 event without IDC. The SAB recurrence rate was 8%, with 6 events in 4 children; none of the index cases resulting in recurrence received an IDC (P = 0.0002), and all occurred before any intervention.

Conclusions

An electronic advisory comment supporting IDC for SAB significantly increased the rate of pediatric IDC with no further SAB recurrence episodes following intervention. This low-resource intervention may be considered in other pediatric centers to optimize SAB management.

Whole genome sequencing and molecular epidemiology of pediatric Staphylococcus aureus bacteremia

BACKGROUND

The role Staphylococcus aureus antimicrobial resistance genes and toxins play in disease severity, management and outcome in childhood is an emerging field requiring further exploration.

METHODS

A prospective multi-site study of Australian and New Zealand children hospitalized with S. aureus bacteremia (SAB), occurred over 24-months (2017-2018). Whole genome sequencing (WGS) data was paired with clinical information from the ISAIAH cohort.

RESULTS

353 SAB isolates were sequenced; 85% methicillin-susceptible S. aureus ([MSSA], 301/353); 15% methicillin-resistant S. aureus ([MRSA], 52/353). There were 92 sequence types (STs), most commonly; ST5 (18%) and ST30 (8%), grouped into 23 clonal complexes (CCs), most frequently CC5 (21%) and CC30 (12%). MSSA comprised the majority of healthcare-associated SAB (87%, 109/125), with principal clones CC15 (48%, 11/21) and CC8 (33%, 7/21). Panton Valentine Leukocidin (PVL)-positive SAB occurred in 22% (76/353); predominantly MSSA (59%, 45/76), community-onset (92%, 70/76) infections. For community-onset SAB, the only microbiological independent predictor of poor outcomes was PVL-positivity (aOR 2.6 [CI 1.0-6.2]).

CONCLUSION

From this WGS pediatric SAB data, we demonstrate the previously under-recognized role MSSA has in harboring genetic virulence and causing healthcare-associated infections. PVL-positivity was the only molecular independent predictor of poor outcomes in children. These findings underscore the need for further research to define the potential implications PVL-producing strains may have on approaches to S. aureus clinical management.

Management and Prevention of Staphylococcus aureus Infections in Children

Staphylococcus aureus is a common skin commensal with the potential to cause severe infections resulting in significant morbidity and mortality. Up to 30% of individuals are colonized with S aureus, though infection typically does not occur without skin barrier disruption. Infection management includes promptly addressing the source of infection, including sites of metastatic infection, and initiation of effective antibiotics, which should be selected based on local antibiotic susceptibility patterns. Given that S aureus colonization is a risk factor for infection, preventive strategies are aimed at optimizing hygiene measures and decolonization regimens for outpatients and critically ill children with prolonged hospitalizations.

Identifying a therapeutic target for vancomycin against staphylococci in young infants

OBJECTIVES

To determine the therapeutic target of vancomycin in young infants with staphylococcal infections.

METHODS

Retrospective data were collected for infants aged 0 to 90 days with CoNS or MRSA bacteraemia over a 4 year period at the Royal Children's Hospital Melbourne, Australia. Vancomycin broth microdilution MICs were determined. A published pharmacokinetic model was externally validated using the study dataset and a time-to-event (TTE) pharmacodynamic model developed to link the AUC of vancomycin with the event being the first negative blood culture. Simulations were performed to determine the trough vancomycin concentration that correlates with a 90% PTA of the target AUC24.

RESULTS

Thirty infants, 28 with CoNS and 2 with MRSA bacteraemia, who had 165 vancomycin concentrations determined were included. The vancomycin broth microdilution MIC was determined for 24 CoNS and 1 MRSA isolate, both with a median MIC of 1 mg/L (CoNS range = 0.5-4.0). An AUC0-24 target of ≥300 mg/L·h or AUC24-48 of ≥424 mg/L·h. increased the chance of bacteriological cure by 7.8- and 7.3-fold, respectively. However, AUC0-24 performed best in the pharmacokinetic-pharmacodynamic model. This correlates with 24 to 48 h trough concentrations of >15-18 mg/L and >10-15 mg/L for 6- and 12-hourly dosing, respectively, and can be used to guide vancomycin therapy in this population.

CONCLUSIONS

An AUC0-24 ≥300 mg/L·h or AUC24-48 ≥424 mg/L·h was associated with an increase in bacteriological cure in young infants with staphylococcal bloodstream infections.

Microbiology and Treatment Outcomes of Community-Acquired Hematogenous Osteoarticular Infections in Infants ≤12 Months of Age

We investigated the microbiology, management, and orthopedic outcomes of osteoarticular infections in infants age ≤1 year at our institution. Among 87 patients, Staphylococcus aureus was the most common pathogen (44.8%), followed by group B Streptococcus. Twenty-nine patients (33%), with a median age of 9.2 months, were transitioned to oral antibiotic therapy after ≤14 days of parenteral therapy; orthopedic outcomes were similar to those with prolonged parenteral therapy.

Differences Between Methicillin-susceptible Versus Methicillin-resistant Staphylococcus aureus Infections in Pediatrics: Multicenter Cohort Study Conducted in Bogotá, Colombia, 2014-2018

BACKGROUND

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) has changed in recent years. The present article is intended to establish differences between clinical, laboratory and imaging findings and outcomes of MSSA and MRSA infections, as well as among subgroups of infection such as skin and soft tissue infection, osteoarticular, bacteremia or pneumonia in a pediatric population from Bogota, Colombia.

METHODS

Retrospective cohort study using clinical records of patients under 18 years of age treated at the participating centers in Bogota, Colombia, between 2014 and 2018. The first positive S. aureus culture was studied. MSSA and MRSA were compared. The χ2 test, Fisher exact test, and Kruskal-Wallis test were calculated, and the statistical significance was presented using the difference and its 95% CI.

RESULTS

Five hundred fifty-one patients were included; 211 (38%) corresponded to MRSA and 340 (62%) to MSSA for a total of 703 cultures. A significantly higher probability of having an MSSA infection than MRSA was found in patients with previous heart disease (3.3% vs. 0.5%), neurologic disease (5.9% vs. 2.5%), recent major surgeries (11% vs. 5%) or who has an implanted device (11% vs. 4%). In contrast, in severe MRSA infections (bacteremia, osteoarticular infections and pneumonia), a higher rate of complications was seen (admission to the pediatric intensive care unit, mechanical ventilation and vasoactive support), and in osteoarticular MRSA, more than 1 surgery per case was seen (89% vs. 61%). Laboratory results and mortality were similar.

CONCLUSIONS

MRSA was associated with a more severe course in bacteremia, osteoarticular infections and pneumonia. Some classical risk factors associated with MRSA infections were found to be related to MSSA. In general, with the exception of skin and soft tissue infection, there was an increased risk of pediatric intensive care unit admission and mechanical and inotropic support with MRSA in a pediatric population.

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.

Surveillance of pediatric parapneumonic effusion/empyema in New Zealand

AIM

The incidence of childhood empyema has been increasing in some developed countries despite the introduction of pneumococcal vaccination. This study aimed to document the incidence, bacterial pathogens, and morbidity/mortality of parapneumonic effusion/empyema in New Zealand.

METHODS

A prospective study of 102 children <15 years of age requiring hospitalization with parapneumonic effusion/empyema between May 1, 2014 and May 31, 2016 notified via the New Zealand Paediatric Surveillance Unit. Parapneumonic effusion/empyema was defined as pneumonia and pleural effusion persisting ≥7 days, and/or any pneumonia, and pleural effusion necessitating drainage. Notifying pediatricians completed standardized questionnaires.

RESULTS

Annual pediatric parapneumonic effusion/empyema incidence was 5.6/100,000 (95% confidence interval [CI]: 4.7-6.9). Most children (80%) required surgical intervention and 31% required intensive care. A causative organism was identified in 71/102 (70%) cases. Although Staphylococcus aureus (25%) and Streptococcus pneumoniae (25%) infection rates were equal, prolonged hospitalization and intensive care admission were more common in children with S. aureus PPE/E. Māori and Pasifika children were over-represented at 2.2 and 3.5 times, their representation in the New Zealand pediatric population. Pneumococcal vaccination was incomplete, with only 61% fully immunized and 30% unimmunized. Haemophilus influenzae type b vaccine uptake was near complete at 89/94 (95%), with influenza immunization only 3/78 (4%).

CONCLUSIONS

New Zealand has a high incidence of pediatric complicated parapneumonic effusion/empyema with significant morbidity. S. aureus was a significant cause of severe empyema in New Zealand, particularly for Māori and Pasifika children. Improvements in vaccine coverage are needed along with strategies to reduce S. aureus disease morbidity.

Infección metastásica por Staphylococcus aureus en neonatos: a propósito de un caso

Metastatic infection as an infrequent complication of Staphylococcus aureus bacteremia in neonates is challenging due to the limited literature. To report the clinical case of a premature neonate who developed a metastatic infection as a complication of S. aureus bacteremia. We present the case of a premature neonate admitted to the Neonatal Intensive Care Unit, diagnosed with bacterial sepsis, neonatal respiratory distress syndrome, and involvement by premature rupture of the membrane. A patch catheter was inserted, and he was successfully treated for E. coli bacteremia. He was re-admitted for late sepsis due to infection with multi-sensitive S. aureus in a patch catheter. An abscess appears on the front of the chest due to S. aureus, confirming metastatic infection. The abscess was drained with a favorable resolution of the clinical picture. In neonates submitted to invasive procedures, it is essential to monitor the clinical evolution and early identification of metastatic infection after Staphylococcus aureus bacteremia and provide early treatment to avoid sequelae.

Infective Endocarditis in Children in Queensland, Australia: Epidemiology, Clinical Features and Outcome

BACKGROUND

Infective endocarditis (IE) is a rare entity in children associated with significant morbidity and mortality. To optimize management, it is important to understand local epidemiology, risk factors, clinical features and outcome. These are investigated in this retrospective 10-year study of endocarditis in children in Queensland.

METHODS

Children <18 years with IE were identified from the state-wide pediatric cardiology center (Mater Children's Hospital, 2009-2014; Queensland Children's Hospital, 2014-2018) through International Classification of Diseases codes and local cardiology database. Clinical records were assessed by a clinician and echocardiograms by a cardiologist. Incidence was calculated using Australian Bureau of Statistics Queensland Estimated Resident Population data, 2019.

RESULTS

Fifty-one children were identified, with an overall estimated incidence of 0.84 per 100,000 per year; 0.69 per 100,000 in 2009-2013 and 0.99 per 100,000 in 2014-2018, respectively. Twenty-four (47.1%) children were male and 10 (19.6%) were identified as Aboriginal or Torres Strait Islander peoples. Underlying cardiac conditions were present in 29 (56.9%): 25 congenital heart disease, 3 rheumatic heart disease and 1 cardiomyopathy. A causative pathogen was identified in 46 (90.2%) children with Staphylococcus aureus most common. Thirty-six (70.6%) met criteria for "Definite IE" as per modified Duke criteria, with the remainder "Possible IE." Surgery was required in 26 (51%). Median duration of antibiotics was 42 (interquartile range = 32-51) days and hospitalization 49 (interquartile range = 34-75) days. One child died due to IE.

CONCLUSIONS

IE in children in Queensland is increasing in incidence and is higher than the reported incidence in New Zealand and the United States. Congenital heart disease is the most common risk factor and S. aureus is the commonest responsible organism. Aboriginal or Torres Strait Islander children are over-represented. Mortality remains low.

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.

Comparison of a new predictive model with other critical scores for predicting in-hospital mortality among children with pneumonia-related bacteremia

Prediction of mortality in children with pneumonia-related bacteremia is necessary for providing timely care and treatment. This study aims to develop and validate a nomogram and compare it with Pediatric Risk of Mortality III (PRISM III), Brighton Pediatric Early Warning Score (Brighton PEWS) and Pediatric Critical Illness Score (PCIS), which are widely used in predicting in-hospital mortality in children with pneumonia-related bacteremia. This retrospective study collected clinical data of hospitalized children with pneumonia-related bacteremia in Chongqing, China (January 2013-May 2019). The nomogram was built using multivariate logistic regression analysis. The nomogram was compared with PRISM III, PEWS and PCIS in accuracy and clinical benefits in predicting in-hospital mortality in children with pneumonia-related bacteremia. A total of 242 children were included. The nomogram including time to first positivity of blood cultures (TTFP), serum albumin (ALB) and lactate dehydrogenase (LDH) was established. The area under the receiver operating characteristic curve of the nomogram was 0.84 (95% CI 0.77 to 0.91) in the training set and 0.82 (95% CI 0.71 to 0.93) in the validating set. Good consistency was observed between the predictions and the actual observations, and the decision curve analysis showed that the nomogram was clinically useful. The results showed that the nomogram significantly performed better than the three critical scores. In conclusion, a nomogram-illustrated model incorporating TTFP, ALB and LDH for predicting in-hospital mortality in children with pneumonia-related bacteremia at the early stage was established and validated. It performed better than PRISM III, PEWS and PCIS.

Impact of Infectious Diseases Consultation on Management and Outcome of Staphylococcus aureus Bacteremia in Children

BACKGROUND

To examine the impact of infectious diseases consultation (IDC) on the management and outcome of Staphylococcus aureus bacteremia (SAB) in children.

METHODS

A retrospective cohort study of children with SAB at a teritary pediatric hospital (January 2009-June 2015) identified by medical record review as to whether they received an IDC for SAB at the discretion of the admitting physician or surgeon was conducted. Differences in management and outcomes for those with and without IDC were evaluated, and multivariate regression analysis was used to determine factors associated with cure.

RESULTS

There were 100 patients included in the analysis. Fifty-five patients received IDC and 45 had no IDC (NIDC). Appropriate directed therapy within 24 hours (54/55 = 98.2% vs 34/45 = 75.6%, P < .01), choice (54/55 = 98.2% vs 37/45 = 82.2%, P < .01), dose (54/55 = 98.2% vs 36/45 = 80%, P < .01), and duration (52/55 = 94.5% vs 24/45 = 53.3%, P < .01) of directed antibiotic therapy were appropriate in more IDC group patients. Achievement of source control in indicated cases was also more common in the IDC group (28/32 = 87.5% vs 5/26 = 19.1%, P < .01). Appropriate investigation with repeat blood cultures and echocardiograms was not significantly different. All 55 patients in the IDC group had a complete response (cure) compared with 40 of the 45 (88.9%) patients in the NIDC group: 2 patients died and 3 patients had a relapse of infection with subsequent cure. In multivariate regression analysis, methicillin-susceptible SAB and IDC were factors independently associated with cure.

CONCLUSIONS

Children who received IDC for SAB in a tertiary pediatric setting were more likely to have appropriate investigations and management and had improved outcomes.

Epidemiology and Antimicrobial Susceptibility of Invasive Bacterial Infections in Children-A Population-Based Study From Norway

OBJECTIVE

To describe epidemiology and antimicrobial susceptibility testing (AST) data of bacteria causing invasive infections in Norwegian children (0-18 years).

METHODS

Population-based observational study using prospectively collected AST data from the Norwegian Surveillance System of Antimicrobial Resistance from 2013 to 2017. We included all clinically relevant bacterial isolates (blood and cerebrospinal fluid), and compared incidence of invasive infections and AST data in isolates from children and adults.

RESULTS

We included 1173 isolates from children and 44,561 isolates from adults. Staphylococcus aureus accounted for 220/477 (46.2%, 95% CI: 41.6-50.7) of all isolates in schoolchildren (6-18 years). Compared with Streptococcus pneumonia isolates from adults (N = 2674), we observed higher nonsusceptibility rates to penicillin in isolates from children (N = 151), 11.9% versus 5.8%, P < 0.01; also higher resistance rates to erythromycin (11.3% vs. 4.9%, P < 0.01), clindamycin (9.3% vs. 3.6%, P < 0.001), and trimethoprim/sulfamethoxazole (17.9% vs. 6.4%, P < 0.001). Compared with Escherichia coli isolates in adults (N = 9073), we found lower rates of ESBL in isolates from children (N = 212), 2.4% versus 6.4%, P < 0.05.

CONCLUSION

The study indicates the importance of microbiologic surveillance strategies in children and highlights the need for pediatric AST data. The high rates of nonsusceptibility to commonly used antibiotics among S. pneumoniae in children and the high burden of invasive S. aureus infections in schoolchildren calls for modifications of Norwegian guidelines.

Impact of a Best Practice Advisory for Pediatric Patients With Staphylococcus aureus Bacteremia

BACKGROUND

Infectious diseases (ID) consultation and optimal antibiotic therapy improve outcomes in Staphylococcus aureus bacteremia (SAB). Data on strategies to improve adherence to these practices in children are limited.

METHODS

This was a quasi-experimental study evaluating the impact of an electronic medical record (EMR)-based best practice advisory (BPA) for SAB, recommending ID consult and optimal antibiotic therapy based on rapid mecA gene detection. Inpatients < 21 years old with SAB before (January 2015-July 2017) and after (August 2017-December 2018) BPA implementation were included. Primary outcome was receipt of ID consult. Secondary outcomes included receipt of optimal therapy, time to ID consult and optimal therapy, recurrent SAB, and 30-day all-cause mortality. ID consultation rates pre- and postimplementation were compared using interrupted time series (ITS) analysis. Hazard ratios (HRs) and 95% confidence intervals (CIs) for time to optimal therapy were calculated using Cox regression.

RESULTS

We included 99 SAB episodes (70 preintervention, 29 postintervention). Preintervention, 48 (68.6%) patients received an ID consult compared to 27 (93.1%) postintervention, but this was not statistically significant on ITS analysis due to a preexisting trend of increasing consultation. Median hours to optimal therapy decreased from 26.1 to 5.5 (P = .03), most notably in patients with methicillin-sensitive S. aureus (MSSA) (42.2 to 10.8; P < .01). On Cox regression, BPA implementation was associated with faster time to optimal therapy (HR, 3.22 [95% CI, 1.04-10.01]).

CONCLUSIONS

Implementation of an EMR-based BPA for SAB resulted in faster time to optimal antibiotic therapy, particularly for patients with MSSA. ID consultation increased throughout the study period and was not significantly impacted by the BPA.

Relationship between death and admission of pediatric patients to intensive care due to Staphylococcus aureus bacteremia acquired in the community, 2014-2017

Introducción

La bacteriemia por Staphylococcus aureus adquirida en la comunidad (SA-AC) es una condición frecuente en pediatría que, además, constituye un problema de salud pública por las altas tasas de morbimortalidad y de resistencia bacteriana.

Objetivos

Analizar los factores relacionados con la muerte y el ingreso a cuidados intensivos de pacientes menores de 18 años con bacteriemia por SA-AC que ingresaron al Hospital Infantil Los Ángeles de Pasto, Colombia, entre el 2014 y el 2017.

Materiales y métodos

Se hizo un estudio observacional descriptivo y transversal. Se analizaron 86 pacientes con bacteriemia por SA-AC que cumplían los criterios de inclusión en el estudio utilizando un modelo multivariado de regresión logística.

Resultados

El 25,6% de los 86 pacientes falleció y el 40,7% ingresó a la unidad de cuidados intensivos. La resistencia a la meticilina fue de 52,3%. Los focos principales de infección fueron los tejidos blandos, el sistema osteoarticular y el respiratorio. El 32,6% de los pacientes provenía de la zona del Pacífico de Nariño. Las etnias predominantes fueron la mestiza y la indígena. Entre los indígenas hubo mayor mortalidad que entre mestizos y afrocolombianos. En el análisis multivariado de la variable de muerte, se registró significación de la endocarditis (odds ratio, OR ajustado=20; IC_95%1,5-254; p=0,02); no se registró significación estadística en cuanto al ingreso en la unidad de cuidados intensivos.

Conclusiones

La bacteriemia por SA-AC determinó altas tasas de mortalidad e ingreso a la unidad de cuidados intensivos. Las cepas resistentes representaron el 52,3%, y la resistencia a la meticilina desembocó en una mayor mortalidad, aunque la mortalidad con cepas sensibles también fue considerable. La endocarditis fue responsable de una mortalidad bastante elevada. Se debe ajustar el tratamiento empírico cuando se sospeche bacteriemia por SA-AC.

The epidemiology of Staphylococcus aureus bacteraemia in Israeli children: Community- vs hospital-acquired or healthcare related infections

AIM

Incidences of Staphylococcus aureus bacteraemia (SAB) in Israeli children are unknown. The characteristics of SAB in children have not been evaluated.

METHODS

SAB from children aged ≤18 years old, admitted to a tertiary hospital in Israel during 2002-2015, were included. The proportional rate of SAB was calculated per 1000 admissions. SAB were classified as community acquired (CA), hospital acquired (HA) and healthcare related (HCR). Patients' characteristics, antibiotic susceptibility and outcomes were assessed in each group.

RESULTS

The rate of SAB was stable, 1.48 per 1000 admissions. HA, CA and HCR-SAB comprised 53%, 25% and 22%, respectively. Only 27/185 (14.6%) were caused by methicillin-resistant S aureus (MRSA): 22%, 6% and 5% of HA, CA and HCR-SAB, respectively. Central venous catheter, recent surgery, immunodeficiency and age <6 years were the main risk factors for HA and HCR-SAB (adjusted OR: 68.9, 7.5, 5.8 and 5.5, respectively). Treatment duration for CA was >21 days: and for HA and HCR, 14-20 days. All-cause in-hospital mortality and 30-day mortality were documented in 10 (5%) and 3 (2%) episodes, respectively.

CONCLUSION

The rate of SAB; the proportions of CA, HA and HCR-SAB; and the proportion of MRSA was stable over the years. MRSA was mainly in HA-SAB. Thirty-day mortality was rare.

Surviving sepsis campaign international guidelines for the management of septic shock and sepsis-associated organ dysfunction in children

Objectives

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

Design

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

Methods

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, “in our practice” statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

Results

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 49 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, “in our practice” statements were provided. In addition, 52 research priorities were identified.

Conclusions

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Association Between Culture-Negative Versus Culture-Positive Sepsis and Outcomes of Patients Admitted to the Pediatric Intensive Care Unit

Background

Sepsis remains a major cause of death, with high mortality and morbidity rates in children. The cause of mortality may be associated with several factors, including differences in cultures and the type of organism. This study was aimed at evaluating the characteristics and outcomes of negative bacterial blood culture compared to those of positive bacterial blood culture in children with severe sepsis/septic shock.

Methods

A retrospective cohort study was conducted at a pediatric intensive care unit (PICU) of a tertiary care medical center. All pediatric patients, from newborn to 14 years of age, admitted between April 2015 and January 2018 were included in the study if they fulfilled the criteria for severe sepsis/septic shock.

Results

Of the 209 patients, 30 (14.3%) had a positive bacterial blood culture whereas 179 (86.6%) had a negative bacterial blood culture. Mortality was more in positive bacterial blood culture 13 (43%) vs 35 (20%) in negative bacterial blood culture (P = 0.004). Respiratory tract infections were extremely common, present in 108 of 179 (60%) patients, and tended to result in a negative culture. The rate of organ dysfunction was higher in the positive bacterial blood culture group at admission (P = 0.01). However, the results did not reveal a significant finding related to multiorgan dysfunction syndrome (MODS) progression over three days of PICU admission (P = 0.06).

Conclusion

The negative bacterial blood culture constitutes a substantial proportion of pediatric patients with severe sepsis/septic shock. Furthermore, these pediatric patients have a lower mortality rate compared to positive bacterial blood cultures. The culture-negative sepsis group also had less organ dysfunction.

Cefazolin Inoculum Effect and Methicillin-Susceptible Staphylococcus aureus Osteoarticular Infections in Children

Select methicillin-susceptible Staphylococcus aureus (MSSA) strains may produce β-lactamases with affinity for first-generation cephalosporins (1GCs). In the setting of a high inoculum, these β-lactamases may promote the cleavage of 1GCs, a phenomenon known as the cefazolin inoculum effect (CzIE). We evaluated the prevalence and impact of CzIE on clinical outcomes among MSSA acute hematogenous osteomyelitis (AHO) cases. MSSA AHO isolates obtained from two children's hospitals between January 2011 and December 2018 were procured through ongoing surveillance studies. Isolates were tested for CzIE via a broth macrodilution assay using an inoculum of 10⁷ CFU/ml; CzIE was defined as a cefazolin MIC of ≥16 μg/ml. Isolates were characterized by accessory gene regulator group (agr). The progression from acute to chronic osteomyelitis was considered an important outcome. A total of 250 cases with viable isolates were included. Notably, 14.4% of isolates exhibited CzIE with no observed temporal trend; and 4% and 76% of patients received a 1GC as an empirical and definitive therapy, respectively. CzIE isolates were more often resistant to clindamycin, belonged to agrIII, and associated with the development of chronic osteomyelitis. In multivariable analyses, agrIII, multiple surgical debridements, delayed source control, and CzIE were independently associated with progression to chronic osteomyelitis. A higher rate of chronic osteomyelitis was observed with CzIE isolates regardless of definitive antibiotic choice. CzIE is exhibited by 14.4% of MSSA AHO isolates in children. CzIE is independently associated with progression to chronic osteomyelitis in cases of AHO irrespective of final antibiotic choice. These data suggest that negative outcomes reported with CzIE may more accurately reflect strain-dependent virulence factors rather than true antibiotic failure.

Vancomycin Therapeutic Drug Monitoring in Children: New Recommendations, Similar Challenges

The American Society of Health-System Pharmacists, the Infectious Diseases Society of America, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists have recently published revised guidelines for the therapeutic monitoring of vancomycin. Previous iterations of the guideline largely focused on targeting vancomycin trough concentrations (VTCs) in the range of 15 to 20 mg/L for therapeutic efficacy. The revised guidelines shift the focus of therapeutic monitoring directly to AUC/MIC-based therapeutic monitoring for children, with a suggestion of a goal AUC/MIC 400 to 800. The primary hesitation in applying these recommendations to children stems from the absence of pediatric clinical data demonstrating correlations with clinical outcomes and either VTC or AUC and no benefit in other secondary outcomes (e.g., recurrence, duration of bacteremia). One can glean indirectly from this that such aggressive dosing and monitoring strategies are unnecessary to achieve therapeutic success in the majority of children with serious methicillin-resistant Staphylococcus aureus infections. Providers should carefully weigh the potential unknown benefits of targeting vancomycin AUC 400 to 800 mg*hr/L in children with the known risks of acute kidney injury associated with increasing the dose of vancomycin as well as the substantial time, effort, and costs of this process.

Paediatric sepsis

PURPOSE OF REVIEW

Sepsis remains among the leading causes of childhood mortality worldwide. This review serves to highlight key areas of knowledge gain and ongoing controversies pertinent to sepsis in children.

RECENT FINDINGS

Several recent publications describe the epidemiology of paediatric sepsis, demonstrating the impact on child health in terms of mortality and morbidity, and the shortcomings of current paediatric sepsis definitions. Although emerging data support the importance of organ dysfunction as a hallmark of paediatric sepsis, the understanding of host susceptibility to sepsis and to sepsis severity remains very limited. Next-generation sequencing and host transcriptomics have the potential to provide new insights into the pathogenesis of sepsis and may enable personalized medicine approaches. Despite good observational data indicating benefit of sepsis recognition and treatment bundles, the evidence for the individual bundle components remains scarce, implying an urgent need for large trials.

SUMMARY

Recent studies have demonstrated distinct epidemiological patterns pertinent to age groups, healthcare settings, and comorbidities in the era post meningococcal epidemics. Although sepsis quality improvement initiatives have led to substantial outcome improvements, there is urgency for innovative trials to reduce uncertainty around the optimal approach for the recognition and treatment of sepsis in children.

Culture-proven Bloodstream Infections at a Specialist Pediatric Hospital

BACKGROUND

Bloodstream infection (BSI) is one of the leading causes of morbidity and mortality in children. This study was done to assess the local epidemiology and outcome of BSIs managed at a large specialist pediatric hospital with a focus on community-onset BSI.

METHODS

We retrospectively reviewed laboratory-confirmed BSI in children (0-18 years) at The Children's Hospital at Westmead over a 3-year period (2014-2016). Laboratory data and patient medical records were used to determine BSI rates, blood culture contamination rates, patient demographics, isolate profile, antimicrobial resistance and mortality rate in this cohort.

RESULTS

In total, 47,368 blood cultures were collected; 1027 (2.2%) grew probable contaminants and 991 (2.1%) grew clinically significant isolates. Clinically significant bacteremia accounted for 4.8 per 1000 admissions, with 391 children managed for 465 culture-proven BSI episodes. One hundred thirty-one (28.2%) episodes were community-onset community-associated, and 334 (71.8%) were either community-onset healthcare-associated (HCA) (187; 40.2 %) or hospital-onset (147; 31.6%). Of the significant isolates, 243 (52.3%) were Gram-positive bacteria, 198 (42.6%) were Gram-negative bacteria, 6 (1.3%) were polymicrobial infections and 18 (3.9%) were yeast. Staphylococcus aureus (115; 24.7%) and Escherichia coli (54; 11.6%) were the most common organisms identified. Osteoarticular infection (44; 33.6%) and urosepsis (23; 17.6%) were the most frequent sites of infection associated with non-HCA BSI. Mortality at 30 days was reported in 15 (3.3%) children, all whom had preexisting comorbidities.

CONCLUSIONS

The majority of BSI episodes managed in our hospital were either community-onset HCA or hospital-onset infections. This highlights the considerable importance of infection control and central venous catheter device care initiatives. Among community-associated BSI, S. aureus in association with osteoarticular infection was predominant.

Applicability of an in-house saponin-based extraction method in Bruker Biotyper matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for identifying bacterial and fungal species in positively flagged pediatric VersaTREK blood cultures

BACKGROUND/PURPOSE

Early identification of pathogens causing bloodstream infection (BSI) is critical for prompt administration of appropriate antimicrobial therapy.

METHODS

We used an in-house saponin-based extraction method to evaluate the performance of Bruker Biotyper MALDI-TOF MS system (MALDI Biotyper) for bacterial and fungal identification in 2013 positively-flagged VersaTREK blood culture bottles.

RESULTS

A total of 180 monomicrobial and 23 polymicrobial positive blood cultures were investigated. Among monomicrobial positive blood cultures, the MALDI Biotyper recognized 90.6% and 81.7% of organisms directly from the flagged blood culture bottles to the genus and species levels, respectively. The MALDI Biotyper also correctly characterized one of the polymicrobial organisms to the species level in 20 (87%) bottles and to the genus level in 21 (91.3%) bottles. The overall identification rate using our protocol was 90.6% (184/203) and 82.3% (167/203) for genus and species levels, respectively. Identification accuracy was higher for Gram-positive than Gram-negative organisms and was the lowest for yeasts. Score values of identification were ≥1.500 for 200 (98.5%) bottles, ≥1.700 for 195 (96.1%) bottles and ≥2.000 for 182 (89.7%) bottles. Moreover, 83.5% and 92% of the isolates were identified precisely to species and genus level with the lower cutoff score of 1.500. Using our protocol also helped identifying BSI pathogens 18-24 h earlier compared to the sub-cultured colonies.

CONCLUSION

Using Bruker MALDI Biotyper for identification of isolates directly from positive VersaTREK blood culture bottles, our in-house saponin-based protocol provided a more rapid turn-around time for correct identification of BSI pathogens than the conventional methods.

Community-acquired invasive Staphylococcus aureus: Uncovering disparities and the burden of disease in Auckland children

AIM

Staphylococcus aureus (SA) causes serious invasive disease in children. Large studies have measured the incidence of SA bacteraemia, but there is less information on the total burden of community-acquired invasive SA (iSA) in children.

METHODS

A retrospective, cross-sectional analysis of Auckland resident children aged 0-14 years who were hospitalised with iSA between 2011 and 2015 was performed. Laboratory databases and SA-related international classification of diseases 10 discharge codes were searched to identify community-onset cases with SA isolated from a normally sterile site. Clinical records and coroner's reports were reviewed to determine clinical syndromes and exclude nosocomial infections.

RESULTS

A total of 295 children with iSA were identified. The average annual incidence of iSA was 18.6 per 100 000 - for Pacific populations 44.3 per 100 000, Māori 24.3 per 100 000 and New Zealand European and other 8.8 per 100 000; 68% had bacteraemia. The incidence of iSA for Pacific infants was 10 times greater than non-Māori/non-Pacific (113.4/100 000 population vs. 11.8/100 000). Multivariate analysis found a higher risk of admission in Pacific children, males and those living in areas of high deprivation. Thirty-two patients (10.8%) were admitted to the intensive care unit; risk was higher in infants, Pacific children and those with respiratory infection (Relative Risk (RR) 12.2, 95% confidence interval (CI) 5.7-26.4) and multifocal (RR 6.9, 95% CI 3.4-13.8) and endovascular disease (RR 8.9, 95% CI 3.9-20.6). All deaths (n = 7) had respiratory infections, and four were patients <1 year of age.

CONCLUSIONS

Studies investigating SA bacteraemia alone significantly underestimate the total burden of iSA disease. There are marked ethnic and socio-economic disparities in iSA disease among Auckland children. Pacific infants are at the highest risk.

Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children

OBJECTIVES

To develop evidence-based recommendations for clinicians caring for children (including infants, school-aged children, and adolescents) with septic shock and other sepsis-associated organ dysfunction.

DESIGN

A panel of 49 international experts, representing 12 international organizations, as well as three methodologists and three public members was convened. Panel members assembled at key international meetings (for those panel members attending the conference), and a stand-alone meeting was held for all panel members in November 2018. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. Teleconferences and electronic-based discussion among the chairs, co-chairs, methodologists, and group heads, as well as within subgroups, served as an integral part of the guideline development process.

METHODS

The panel consisted of six subgroups: recognition and management of infection, hemodynamics and resuscitation, ventilation, endocrine and metabolic therapies, adjunctive therapies, and research priorities. We conducted a systematic review for each Population, Intervention, Control, and Outcomes question to identify the best available evidence, statistically summarized the evidence, and then assessed the quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. We used the evidence-to-decision framework to formulate recommendations as strong or weak, or as a best practice statement. In addition, "in our practice" statements were included when evidence was inconclusive to issue a recommendation, but the panel felt that some guidance based on practice patterns may be appropriate.

RESULTS

The panel provided 77 statements on the management and resuscitation of children with septic shock and other sepsis-associated organ dysfunction. Overall, six were strong recommendations, 52 were weak recommendations, and nine were best-practice statements. For 13 questions, no recommendations could be made; but, for 10 of these, "in our practice" statements were provided. In addition, 49 research priorities were identified.

CONCLUSIONS

A large cohort of international experts was able to achieve consensus regarding many recommendations for the best care of children with sepsis, acknowledging that most aspects of care had relatively low quality of evidence resulting in the frequent issuance of weak recommendations. Despite this challenge, these recommendations regarding the management of children with septic shock and other sepsis-associated organ dysfunction provide a foundation for consistent care to improve outcomes and inform future research.

Rare complications of Staphylococcus aureus infection in children: Case reports

Disseminated staphylococcal disease comprises a set of clinical manifestations secondary to multiple organ invasion that may range from cellulitis to sepsis. In pediatrics, the most common complications are osteoarticular and cutaneous infection; however, this article presents rare manifestations such as glomerulonephritis and thrombotic phenomena. This is the report of two cases of previously healthy adolescents: one presented with osteomyelitis and kidney injury, and the other, with lower limb cellulitis and respiratory deterioration with septic pulmonary embolism. The diagnostic process and additional management are described, highlighting the role of oxacillin in therapy. This article aims to highlight the importance of considering the rare manifestations of S. aureus infection, when the clinical evolution is abnormal, in order to initiate a timely treatment and get a better prognosis.

Perinatal risk factors associated with skin infection hospitalisation in Western Australian Aboriginal and Non-Aboriginal children

BACKGROUND

Hospitalisation with skin infection in Western Australian (WA) Aboriginal children is common, with the highest rates in infants and children from remote WA.

OBJECTIVE

We aimed to quantify infant, maternal, and sociodemographic risk factors for skin infection hospitalisation in WA children, focussing on Aboriginal children aged <17 years.

METHODS

We conducted a retrospective population-based cohort study with linked perinatal and hospitalisation data on WA-born children (1996-2012), of whom 31 348 (6.7%) were Aboriginal. We used Cox regression to calculate adjusted hazard ratios and associated population attributable fractions (PAFs) for perinatal factors attributed to first hospitalisation with skin infection. To identify specific risk factors for early-onset infection, we further restricted the cohort to infants aged <1 year.

RESULTS

Overall, 5439 (17.4%) Aboriginal and 6750 (1.5%) non-Aboriginal children were hospitalised at least once with a skin infection. Aboriginal infants aged <1 year had the highest skin infection hospitalisation rate (63.2 per 1000 child-years). The strongest risk factors in Aboriginal children aged <17 years were socio-economic disadvantage, very remote location at birth, and multi-parity (≥3 previous pregnancies) accounting for 24%, 23%, and 15% of skin infection hospitalisations, respectively. Other risk factors included maternal age <20 years, maternal smoking during pregnancy, and low birthweight.

CONCLUSIONS

We have quantified the relative influence of perinatal risk factors associated with skin infection hospitalisations in WA children, providing measures indicating which factors have the potential to reduce the most hospitalisations. Our evidence not only supports existing calls for substantial government investment in addressing underlying social and environmental barriers to healthy skin in WA Aboriginal children but also identifies potential areas to target health promotion messaging at individuals/families on maternal smoking during pregnancy and skin hygiene for families.

CASSETTE-clindamycin adjunctive therapy for severe Staphylococcus aureus treatment evaluation: study protocol for a randomised controlled trial

BACKGROUND

Exotoxins are important virulence factors in Staphylococcus aureus. Clindamycin, a protein synthesis inhibitor antibiotic, is thought to limit exotoxin production and improve outcomes in severe S. aureus infections. However, randomised prospective data to support this are lacking.

METHODS

An open-label, multicentre, randomised controlled trial (RCT) will compare outcome differences in severe S. aureus infection between standard treatment (flucloxacillin/cefazolin in methicillin-susceptible S. aureus; and vancomycin/daptomycin in methicillin-resistant S. aureus) and standard treatment plus an additional clindamycin given for 7 days. We will include a minimum of 60 participants (both adult and children) in the pilot study. Participants will be enrolled within 72 h of an index culture. Severe infections will include septic shock, necrotising pneumonia, or multifocal and non-contiguous skin and soft tissue/osteoarticular infections. Individuals who are immunosuppressed, moribund, with current severe diarrhoea or Clostridiodes difficile infection, pregnant, and those with anaphylaxis to β-lactams or lincosamides will be excluded. The primary outcomes measure is the number of days alive and free (1 or 0) of systemic inflammatory response syndrome (SIRS) within the first 14 days post randomisation. The secondary outcomes measure will include all-cause mortality at 14, 42, and 90 days, time to resolution of SIRS, proportion with microbiological treatment failure, and rate of change of C-reactive protein over time. Impacts of inducible clindamycin resistance, strain types, methicillin susceptibility, and presence of various exotoxins will also be analysed.

DISCUSSION

This study will assess the effect of adjunctive clindamycin on patient-centred outcomes in severe, toxin-mediated S. aureus infections. The pilot study will provide feasibility for a much larger RCT.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12617001416381p . Registered on 6 October 2017.

Staphylococcus aureus Bacteremia in Children: Antibiotic Resistance and Mortality

BACKGROUND

Staphylococcus aureus (SA) is a major cause of bacteremia in children. Methicillin-resistant SA (MRSA) is considered a public health threat; however, the differences in the prognosis of children with methicillin-susceptible SA (MSSA) versus MRSA bacteremia are not well defined.

METHODS

Data from all SA bacteremia events in children (0-16 years) from 2002 to 2016 in a single Israeli tertiary center were collected. Positive cultures within 48 hours of hospitalization were considered community associated (CA). Those obtained afterward or from children hospitalized within the previous year were considered health-care associated (HA).

RESULTS

We recorded 427 events, 284 (66%) were HA, 64 (15%) were MRSA and 9 (2%) were CA-MRSA. There was no increase in MRSA during the study period. In-hospital, 30-day and 1-year mortality were 3% (12 cases), 3.5% (16 cases), and 12% (50 cases), respectively. A multivariable analysis controlling for demographics, admitting department and prior morbidity showed an increased 1-year mortality in children with HA bacteremia (hazard ratio [HR] 4.1; 95% confidence interval [CI]: 1.3-12) and prior chronic disease (HR 3.4; 95% CI 1.2 to 9.0). MRSA was not independently associated with increased one-year mortality compared with MSSA: HR (95% CI: 1.4 [0.6-3.1]).

CONCLUSIONS

Short-term pediatric mortality after SA bacteremia is low. HA-SA bacteremia has an increased long-term risk for mortality, particularly in children with chronic diseases. Our data suggest mortality was not increased for MRSA compared with MSSA bacteremia. The very low rate of CA-MRSA bacteremia justifies the current practice not to include glycopeptides in the empiric treatment of CA bacteremia in Israel.

Risk Factors for Complications in Children with Staphylococcus aureus Bacteremia

OBJECTIVES

To determine risk factors for complications in children with Staphylococcus aureus (S aureus) bacteremia, including methicillin resistance.

STUDY DESIGN

Single center, retrospective cohort study of children ≤18 years of age hospitalized with S aureus bacteremia. We compared clinical characteristics and outcomes between those with methicillin-sensitive S aureus (MSSA) and methicillin-resistant S aureus (MRSA) bacteremia. Multivariate regression models identified risk factors associated with developing complications and with longer duration of bacteremia.

RESULTS

We identified 394 episodes of S aureus bacteremia, 279 (70.8%) with MSSA, and 115 (29.2%) with MRSA. Primary site of infection was catheter-related in 34%, musculoskeletal in 30%, skin/soft tissue in 10.2%, pneumonia in 6.4%, and endovascular in 6.6%. Eight children (2.0%) died within 30 days because of S aureus bacteremia, 15 (3.5%) had recurrence within 30 days, and 38 (9.6%) had complications including septic emboli or a metastatic focus of infection. Methicillin resistance was associated with development of a complication (aOR 3.31; 95% CI 1.60-6.85), and catheter-related infections were less likely to be associated with a complication (aOR 0.40; 95% CI 0.15-1.03). In a Poisson regression analysis on duration of bacteremia, methicillin resistance, musculoskeletal infection, endovascular infection, black race, and delayed intervention for source control were significantly associated with longer duration of bacteremia.

CONCLUSIONS

In this cohort of children with S aureus bacteremia, MRSA infections ere associated with longer duration of bacteremia and a higher likelihood of complications.

Aetiology and risks factors associated with the fatal outcomes of childhood pneumonia among hospitalised children in the Philippines from 2008 to 2016: a case series study

OBJECTIVE

Pneumonia remains the leading cause of hospitalisations and deaths among children aged <5 years. Diverse respiratory pathogens cause acute respiratory infections, including pneumonia. Here, we analysed viral and bacterial pathogens and risk factors associated with death of hospitalised children.

DESIGN

A 9-year case series study.

SETTING

Two secondary-care hospitals, one tertiary-care hospital and one research centre in the Philippines.

PARTICIPANTS

5054 children aged <5 years hospitalised with severe pneumonia.

METHODS

Nasopharyngeal swabs for virus identification, and venous blood samples for bacterial culture were collected. Demographic, clinical data and laboratory findings were collected at admission time. Logistic regression analyses were performed to identify the factors associated with death.

RESULTS

Of the enrolled patients, 57% (2876/5054) were males. The case fatality rate was 4.7% (238/5054), showing a decreasing trend during the study period (p<0.001). 55.0% of the patients who died were either moderately or severely underweight. Viruses were detected in 61.0% of the patients, with respiratory syncytial virus (27.0%) and rhinovirus (23.0%) being the most commonly detected viruses. In children aged 2-59 months, the risk factors significantly associated with death included age of 2-5 months, sensorial changes, severe malnutrition, grunting, central cyanosis, decreased breath sounds, tachypnoea, fever (≥38.5°C), saturation of peripheral oxygen <90%, infiltration, consolidation and pleural effusion on chest radiograph.Among the pathogens, adenovirus type 7, seasonal influenza A (H1N1) and positive blood culture for bacteria were significantly associated with death. Similar patterns were observed between the death cases and the aforementioned factors in children aged <2 months.

CONCLUSION

Malnutrition was the most common factor associated with death and addressing this issue may decrease the case fatality rate. In addition, chest radiographic examination and oxygen saturation measurement should be promoted in all hospitalised patients with pneumonia as well as bacteria detection to identify patients who are at risk of death.

Treatment, prevention and public health management of impetigo, scabies, crusted scabies and fungal skin infections in endemic populations: a systematic review

We conducted a systematic review of the treatment, prevention and public health control of skin infections including impetigo, scabies, crusted scabies and tinea in resource‐limited settings where skin infections are endemic. The aim is to inform strategies, guidelines and research to improve skin health in populations that are inequitably affected by infections of the skin and the downstream consequences of these. The systematic review is reported according to the PRISMA statement. From 1759 titles identified, 81 full text studies were reviewed and key findings outlined for impetigo, scabies, crusted scabies and tinea. Improvements in primary care and public health management of skin infections will have broad and lasting impacts on overall quality of life including reductions in morbidity and mortality from sepsis, skeletal infections, kidney and heart disease.

Infectious Diseases Clinician's Variation in the Management of Pediatric Staphylococcus aureus Bacteraemia and Equipoise for Clinical Trials

Background: Pediatric Staphylococcus aureus bacteraemia is one of the leading causes of community-acquired blood-stream infection in the developed world; however, our understanding of management practices by treating clinicians is limited. Methods: The authors designed a web-based clinician survey with support from the Australian and New Zealand Pediatric Infectious Diseases group, of the Australasian Society of Infectious Diseases. Clinicians were presented with three pediatric cases of varying severity. Antibiotic choice, durations of intravenous and oral therapy and research priorities for pediatric S. aureus bacteraemia trials were gauged. Results and Conclusion: Large variation in antibiotic prescribing amongst clinicians is demonstrated and increased, corresponding with escalating case complexity and persisting MRSA bacteraemia. Most clinicians chose defining optimal duration of therapy for S. aureus bacteraemia as their top clinical trial priority. These findings highlight the importance of prioritizing pediatric S. aureus bacteraemia clinical trials, to inform guidelines and best practice management.

Staphylococcus aureus Bacteremia in Children Aged 5-18 Years-Risk Factors in the New Millennium

OBJECTIVES

To assess the association between comorbidities and Staphylococcus aureus bacteremia in children aged 5-18 years, thus, in children with a matured immune system. Further, we aimed to identify presumably healthy children acquiring bacteremia.

STUDY DESIGN

By cross-linking nationwide registries, we consecutively included all children born from 1995 onward at their 5-year birthday or date of immigration during 2000-2015. We examined incidence rate ratios (IRR) between preselected exposures and microbiologically verified S aureus bacteremia (reference = children without exposure) using Poisson regression models.

RESULTS

We followed 1 109 169 children in 2000-2015 during which 307 children (incidence rate: 3.7 per 100 000 person-years) acquired S aureus bacteremia (methicillin-resistant S aureus = 8; 2.6%). Children without known comorbidities or recent contact with the healthcare system comprised 37.1% of infected children. The highest IRRs were observed in children undergoing dialysis or plasmapheresis (IRR = 367.2 [95% CI) = 188.5-715.3]), children with organ transplantation (IRR = 149.5 [95% CI = 73.9-302.2]), and children with cancer (IRR = 102.9 [95% CI = 74.4-142.2]). Positive associations also were observed in children with chromosomal anomalies (IRR = 7.16 [95% CI = 2.96-17.34]), atopic dermatitis (IRR = 4.89 [95% CI = 3.11-7.69]), congenital heart disease (IRR = 3.14 [95% CI = 1.92-5.11]), and in children undergoing surgery (IRR = 3.34 [95% CI = 2.59-4.28]). Neither premature birth nor parental socioeconomic status was associated with increased disease rates.

CONCLUSIONS

S aureus bacteremia is uncommon in children between 5 and 18 years of age. Risk factors known from the adult population, such as dialysis, plasmapheresis, organ transplantation, and cancer, were associated with the highest relative rates. However, prematurity and parental socioeconomic status were not associated with increased rates. Approximately one-third of infected children were presumably healthy.

Amoxicillin-clavulanate versus azithromycin for respiratory exacerbations in children with bronchiectasis (BEST-2): a multicentre, double-blind, non-inferiority, randomised controlled trial

BACKGROUND

Although amoxicillin-clavulanate is the recommended first-line empirical oral antibiotic treatment for non-severe exacerbations in children with bronchiectasis, azithromycin is also often prescribed for its convenient once-daily dosing. No randomised controlled trials involving acute exacerbations in children with bronchiectasis have been published to our knowledge. We hypothesised that azithromycin is non-inferior to amoxicillin-clavulanate for resolving exacerbations in children with bronchiectasis.

METHODS

We did this parallel-group, double-dummy, double-blind, non-inferiority randomised controlled trial in three Australian and one New Zealand hospital between April, 2012, and August, 2016. We enrolled children aged 1-19 years with radiographically proven bronchiectasis unrelated to cystic fibrosis. At the start of an exacerbation, children were randomly assigned to oral suspensions of either amoxicillin-clavulanate (22·5 mg/kg, twice daily) and placebo or azithromycin (5 mg/kg per day) and placebo for 21 days. We used permuted block randomisation (stratified by age, site, and cause) with concealed allocation. The primary outcome was resolution of exacerbation (defined as a return to baseline) by 21 days in the per-protocol population, with a non-inferiority margin of -20%. We assessed several secondary outcomes including duration of exacerbation, time to next exacerbation, laboratory, respiratory, and quality-of-life measurements, and microbiology. This trial was registered with the Australian/New Zealand Registry (ACTRN12612000010897).

FINDINGS

We screened 604 children and enrolled 236. 179 children had an exacerbation and were assigned to treatment: 97 to amoxicillin-clavulanate, 82 to azithromycin). By day 21, 61 (84%) of 73 exacerbations had resolved in the azithromycin group versus 73 (84%) of 87 in the amoxicillin-clavulanate group. The risk difference showed non-inferiority (-0·3%, 95% CI -11·8 to 11·1). Exacerbations were significantly shorter in the amoxicillin-clavulanate group than in the azithromycin group (median 10 days [IQR 6-15] vs 14 days [8-16]; p=0·014). Adverse events were attributed to the trial medication in 17 (21%) of 82 children in the azithromycin group versus 23 (24%) of 97 in the amoxicillin-clavulanate group (relative risk 0·9, 95% CI 0·5 to 1·5).

INTERPRETATION

By 21 days of treatment, azithromycin is non-inferior to amoxicillin-clavulanate for resolving exacerbations in children with non-severe bronchiectasis. In some patients, such as those with penicillin hypersensitivity or those likely to have poor adherence, azithromycin provides another option for treating exacerbations, but must be balanced with risk of treatment failure (within a 20% margin), longer exacerbation duration, and the risk of inducing macrolide resistance.

FUNDING

Australian National Health and Medical Research Council.

Infection characteristics and treatment of Staphylococcus aureus bacteraemia at a tertiary children's hospital

BACKGROUND

Staphylococcus aureus bacteraemia (SAB) causes considerable morbidity and mortality in children. Despite this, its epidemiology and risk factors are poorly understood, with minimal paediatric clinical trial data available to guide clinicians in management. We conducted a pilot study to characterise SAB and validate a severity classification for use in future clinical trials.

METHODS

Patients with SAB were prospectively identified at Princess Margaret Hospital for Children (Perth, Western Australia) from May 2011 to December 2013. Retrospective data were collected from clinical and laboratory records. Cases were classified based on a priori defined criteria as simple (single or contiguous, peripheral site focus) or complex (multi-site, deep tissue, no focus or sepsis) and tested against risk factors and markers of severity of infection.

RESULTS

There were 49 cases of SAB (median age 7.7 years), with classification as simple (n = 30, 61%) and complex (n = 19, 39%) respectively. There were no deaths or relapses in our cohort. Only 10% of isolates were methicillin resistant S. aureus (MRSA), and none of these were healthcare-associated. Age, gender, Indigenous status, MRSA and healthcare-associated infections were not predictive of complex infection. Pre-existing malignancy was a risk factor for complex infection (p = 0.02). Complex infections were associated with a higher median maximum C reactive protein (216 mg/L vs 50 mg/L, p = < 0.001), longer median length of stay (42 vs 10 days, p = < 0.001) and longer duration of antibiotic therapy (43 vs 34 days, p = 0.03).

DISCUSSION

This is the first attempt to categorise paediatric SAB as simple versus complex, to guide clinicians in decision making.

CONCLUSIONS

There is a wide spectrum of disease severity in paediatric SAB, with maximum CRP, length of stay, and duration of therapy greater in those with complex disease. Distinct cohorts with simple and complex courses which may be a target for future clinical trials have been described.

Molecular Characteristics of Community-Associated Staphylococcus aureus Isolates From Pediatric Patients With Bloodstream Infections Between 2012 and 2017 in Shanghai, China

Staphylococcus aureus is known as an invasive human pathogen, resulting in significant morbidity and mortality worldwide; however, information on community-associated S. aureus (CA-SA) from bloodstream infections (BSI) in children in China remains scarce. This study aimed to investigate the molecular characteristics of 78 CA-SA isolates recovered from pediatric patients with BSI between 2012 and 2017 in Shanghai. All isolates including 51 (65.4%) methicillin-susceptible S. aureus (MSSA) and 27 (34.6%) methicillin-resistant S. aureus (MRSA) isolates were characterized based on antimicrobial resistance, virulence genes, multilocus sequence typing (MLST), spa, and SCCmec typing. A total of 18 distinct sequence types (STs) and 44 spa types were identified. ST188 and ST7 were the predominant MSSA clones and ST59-MRSA-SCCmecIV/V was the most common MRSA clone. Spa t189 (9.0%, 7/78) was the most common spa type. SCCmec types IV and V were observed at frequencies of 59.3 and 40.7%, respectively. Notably, 40 (51.3%) S. aureus BSI strains were multidrug resistant (MDR), and these were mostly resistant to penicillin, erythromycin, and clindamycin. MRSA strains were associated with substantially higher rates of resistance to multiple antibiotics than MSSA strains. Fifty (64.1%, 50/78) isolates, including 19 (70.3%) MRSA isolates, harbored ≥ 10 tested virulence genes, as evaluated in this study. Ten (37.0%) MRSA isolates and four (7.8%) MSSA isolates harbored the gene encoding Panton-Valentine leukocidin (PVL). Virulence genes analysis showed diversity in different clones; the seb-sek-seq genes were present in all ST59 strains, whereas the seg-sei-sem-sen-seo genes were present in different clones including ST5, ST20, ST22, ST25, ST26, ST30, ST121, and ST487 strains. In conclusion, this study revealed that community-associated S. aureus strains from BSI in children demonstrated considerable genetic diversity, and identified major genotypes of CA-MRSA and CA-MSSA, with a high prevalence of CA-MRSA. Furthermore, major genotypes were frequently associated with specific antimicrobial resistance and toxin gene profiles. Understanding the molecular characteristics of those strains might provide further insights regarding the spread of BSI S. aureus among children between communities in China.