A 7-year study of bloodstream infections in an English children's hospital

Shifting focus toward healthcare-associated bloodstream infections: The need for neonatal intensive care unit-specific NHSN definitions

OBJECTIVE

Healthcare-associated bloodstream infections (HABSIs) are a significant cause of mortality and morbidity in the neonatal intensive care unit (NICU) population. Our objectives were to review the epidemiology of HABSIs in our NICU and to examine the applicability of National Healthcare Safety Network (NHSN) definitions to the NICU population.

METHODS

We performed a retrospective review of all neonates admitted to the 54-bed, level IV NICU at Yale-New Haven Children's Hospital with a HABSI between January 1, 2013, and December 31, 2018. Clinical definitions per NICU team and NHSN site-specific definitions used for source identification were compared using the McNemar χ2 test.

RESULTS

We identified 86 HABSIs with an incidence rate of 0.80 per 1,000 patient days. Only 13% of these were CLABSIs. Both CLABSIs and non-catheter-related bloodstream infections occurred primarily in preterm neonates, but the latter were associated with a significantly higher incidence of comorbidities and the need for respiratory support. The NHSN definitions were less likely to identify a source compared to the clinical definitions agreed upon by our NICU treating team (P < .001). Furthermore, 50% of patients without an identified source of infection by NHSN definitions were bacteremic with a mucosal barrier injury organism, likely from gut translocation.

CONCLUSIONS

HABSIs occur primarily in premature infants with comorbidities, and CLABSIs account for a small proportion of these infections. With the increasing focus on HABSI prevention, there is a need for better NHSN site-specific definitions for the NICU population to prevent misclassification and direct prevention efforts.

Impact of rapid diagnostics with antimicrobial stewardship support for children with positive blood cultures: A quasi-experimental study with time trend analysis

OBJECTIVE

Evaluate the clinical impact of the implementation of VERIGENE gram-positive blood culture testing (BC-GP) coupled with antimicrobial stewardship result notification for children with positive blood cultures.

DESIGN

Quasi-experimental study.

SETTING

Quaternary children's hospital.

PATIENTS

Hospitalized children aged 0-21 years with positive blood culture events 1 year before and 1 year after implementation of BC-GP testing.

METHODS

The primary outcome was time to optimal antibiotic therapy for positive blood cultures, defined as receiving definitive therapy without unnecessary antibiotics (pathogens) or no antibiotics (contaminants). Secondary outcomes were time to effective therapy, time to definitive therapy, and time to stopping vancomycin, length of stay, and 30-day mortality. Time-to-therapy outcomes before and after the intervention were compared using Cox regression models and interrupted time series analyses, adjusting for patient characteristics and trends over time. Gram-negative events were included as a nonequivalent dependent variable.

RESULTS

We included 264 preintervention events (191 gram-positive, 73 gram-negative) and 257 postintervention events (168 gram-positive, 89 gram-negative). The median age was 2.9 years (interquartile range, 0.3-10.1), and 418 pediatric patients (80.2%) had ≥1 complex chronic condition. For gram-positive isolates, implementation of BC-GP testing was associated with an immediate reduction in time to optimal therapy and time to stopping vancomycin for both analyses. BC-GP testing was associated with decreased time to definitive therapy in interrupted time series analysis but not Cox modeling. No such changes were observed for gram-negative isolates. No changes in time to effective therapy, length of stay, or mortality were associated with BC-GP.

CONCLUSIONS

The implementation of BC-GP testing coupled with antimicrobial stewardship result notification was associated with decreased time to optimal therapy and time to stopping vancomycin for hospitalized children with gram-positive blood culture isolates.

Pediatric Blood Cultures and Antibiotic Resistance: An Overview

Bloodstream infections (BSI) due to multidrug-resistant organisms, especially from pediatric intensive care units (PICU), are being increasingly reported across the world. Since BSI is associated with high mortality, it is essential to treat these infections early with appropriate antibiotics. Surveillance of etiology and emerging antimicrobial resistance (AMR) is considered an important step in the formulation of antibiotic policy for early treatment and judicious use of antibiotics. In this review on etiology and its antibiogram in community acquired BSI, S. typhi followed by S. paratyphi A were the major bacterial isolates. Quinolone resistance of more than 90% in Salmonella is now reported from all over India. Ceftriaxone remains the drug of choice for enteric fever due to its 100% susceptibility. In PICU there is an emergence of candidemia due to non-albicans candida which are now predominant isolates at few centers. BSI due to gram-negative bacteria, mostly by Klebseilla pneumoniae and gram-positive cocci (S. aureus) are the other major pathogens commonly observed in BSI from PICU. There is a high prevalence of antimicrobial resistance to commonly used antibiotics like ampicillin (94.9%-90.7%), cefotaxime (92.4%-71.4%), piperacillin-tazobactum (31.2%-27.5%) and levofloxacin (42.4%-39.8%). Resistance to carbapenems, primarily due to bla_NDM is seen in all the centers and the rate varies between 1%- 79% with K. pneumoniae and A. baumannii showing the maximum resistance. This review highlights the magnitude of the AMR in the pediatric population and calls for the urgent implementation of antimicrobial stewardship programs to save the remaining antimicrobials.

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.

Supraclavicular catheterization of the brachiocephalic vein: a way to prevent or reduce catheter maintenance-related complications in children

Placement of a central venous catheter (CVC) in the brachiocephalic vein (BCV) via the ultrasound (US)-guided supraclavicular approach was recently described in children. We aimed to determine the CVC maintenance-related complications at this site compared to the others (i.e., the femoral, the subclavian, and the jugular). We performed a retrospective data collection of prospectively registered data on CVC in young children hospitalized in a pediatric intensive care unit (PICU) during a 4-year period (May 2011 to May 2015). The primary outcome was a composite of central line-associated bloodstream infection (CLABSI) and deep-vein thrombosis (CLAT) according to the CVC site. Two hundred and twenty-five children, with respective age and weight of 7.1 (1.3-40.1) months and 7.7 (3.6-16) kg, required 257 CVCs, including 147 (57.2%) inserted in the BCV. The risk of the primary outcome was lower in the BCV than in the other sites (5.4 vs 16.4%; OR: 0.29; 95% CI: 0.12-0.70; p = 0.006). CLABSI incidence density rate (2.8 vs 8.96 per 1000 catheter days, p < 0.001) and CLAT incidence rate (2.7 vs 10%, p = 0.016) were also lower at this site.

CONCLUSION

BCV catheterization via the US-guided supraclavicular approach may decrease CVC maintenance-related complications in children hospitalized in a PICU. What is Known: • Placement of a central venous catheter (CVC) in children is associated with mechanical risks during insertion, and with infectious and thrombotic complications during its maintenance. • Ultrasound (US)-guided supraclavicular catheterization of the brachiocephalic vein (BCV) is feasible in infants and children. What is New: • This observational study suggested that BCV catheterization via the US-guided supraclavicular approach was associated with a lower risk of CVC insertion and maintenance-related complications, compared with the other catheterization sites.

Staphylococcus aureus bacteraemia and endocarditis - epidemiology and outcome: a review

PURPOSE

To review the epidemiology of Staphylococcus aureus bacteraemia (SAB) and endocarditis (SAE), and discuss the short- and long-term outcome.  Materials and methods: A literature review of the epidemiology of SAB and SAE.

RESULTS

The reported incidence of SAB in Western countries is 16-41/100,000 person-years. Increasing incidence has been observed in many regions, in Iceland by 27% during 1995-2008. The increase is believed to depend on changes in population risk factors and possibly better and more frequent utilization of diagnostic procedures. S. aureus is now the leading causes of infective endocarditis (IE) in many regions of the world. It accounts for 15-40% of all IE cases, and the majority of cases in people who inject drugs (PWID). Recently, the incidence of SAE in PWID in Stockholm, Sweden, was found to be 2.5/1000 person-years, with an in-hospital mortality of 2.5% in PWID as compared to 15% in non-drug users. The 30-day mortality associated with SAB amounts to 15-25% among adults in Western countries, but is lower in children (0-9%). Mortality associated with SAE is high (generally 20-30% in-hospital mortality), and symptomatic cerebral embolizations are common (12-35%). The 1-year mortality reported after SAB and SAE is 19-62% and reflects deaths from underlying diseases and complications caused by the infection. In a subset of SAE cases, valvular heart surgery is needed (15-45%), but active intravenous drug use seems to be a reason to refrain from surgery. Despite its importance, there are insufficient data on the optimal management of SAB and SAE, especially on the required duration of antibiotic therapy.  Conclusions: The epidemiology of SAB and SAE has been changing in the past decades. They still carry a substantial morbidity and mortality. Intensified studies on treatment are warranted for improving patient outcome.

Impact of healthcare-associated sepsis on mortality in critically ill infants

Healthcare-associated sepsis (HAS) is a life-threatening complication in neonatal intensive care. Research into the impact of HAS on mortality adjusted for comorbidities is however limited. We conducted a historical cohort study to evaluate impact of HAS on mortality stratified by birth weight and risk factors for mortality in the HAS cohort. HAS was defined according to the National Institute of Child Health and Human Development criteria. Logistic regression was used to calculate adjusted odds of mortality. Of 5134 admissions, 342 infants developed HAS (6.7 %). Mortality in the total and HAS cohort was 5.6 and 10.5 %, respectively. The majority of HAS was caused by commensals (HAS-COM, 59.4 %) and 40.6 % by recognized pathogens (HAS-REC). Adjusted for comorbidities, "HAS-REC" is only a risk factor for mortality in newborns >1500 g (adjusted odds ratio [aOR] 2.3, confidence interval [CI] 1.1-4.9). Post-hoc analysis identified HAS-REC as an independent risk factor for mortality in infants with gastrointestinal disease (aOR 4.8, CI 2.1-10.8). "Renal insufficiency," "focal intestinal perforation," and "necrotizing enterocolitis" are independent risk factors for mortality in the HAS cohort (aOR 13.5, CI 4.9-36.6; aOR 7.7, CI 1.5-39.2; aOR 2.1, CI 1.0-4.7, respectively).

CONCLUSION

For very low birth weight infants (≤1500 g), several comorbidities overrule the impact of HAS on mortality. After adjustment for comorbidities, HAS-REC independently predicts in-hospital mortality in heavier infants and in those with gastrointestinal disease.

WHAT IS KNOWN

• The relationship between healthcare-associated sepsis and mortality is influenced by the causative pathogen and is confounded by comorbidities. • Research on impact of healthcare-associated sepsis on mortality adjusted for comorbidities is limited as well as research on independent risk factors for mortality in neonates with sepsis. What is New: • We included a large list of comorbidities and stratified risk by birth weight in order to assess the true effect of healthcare-associated sepsis on mortality. • Risk for mortality was calculated for commensal flora and for recognized pathogens as causative micro-organisms.

Assessment of anaerobic blood cultures in pediatric oncology patients

INTRODUCTION

The routine use of a single aerobic bottle for blood culture in pediatric patients has become commonplace, as anaerobic bacteria are not frequently involved in clinically significant infections. The aim of this study was to assess the usefulness of routinely performing anaerobic blood cultures in pediatric oncology patients.

METHODS

Prospective study was conducted on pediatric (<18 years) patients affected with febrile syndrome after receiving chemotherapy for hematological or solid malignancies. Samples were inoculated into pediatric aerobic and standard anaerobic bottles (BacT/Alert automatic system). Strains were considered clinically significant, or deemed as contaminants, depending on isolation circumstances and clinical criteria.

RESULTS

A total of 876 blood cultures from 228 patients were processed during the 21-month study period (January 2014 to September 2015). Baseline diagnosis included 143 solid tumors and 67/18 cases of leukemia/lymphoma. Bacterial growth was detected in 90 (10.2%) blood cultures for 95 different isolates, of which 62 (7.1%)/63 isolates were considered clinically significant. Among the latter, 38 (60.3%) microorganisms grew in both aerobic and anaerobic bottles, 18 (28.6%) only in aerobic bottles, and 7 (11.1%) only in anaerobic bottles. Gram-negative bacilli (33; 52.4%), mainly from the Enterobacteriaceae family, were the most frequently isolated microorganisms. Overall, only 3 out of 90 isolates (3.3%) were strict anaerobes (Propionibacterium acnes), and all of them were deemed contaminants.

CONCLUSION

Strict anaerobes did not cause significant infections in febrile pediatric oncology patients, and anaerobic blood culture bottles offered no additional advantages over aerobic media. Our results suggest that routine blood cultures should be solely processed in aerobic media in this group of patients.

Survival Benefit of Empirical Therapy for Staphylococcus aureus Bloodstream Infections in Infants

BACKGROUND

The impact of early adequate empirical antibiotic therapy on outcomes of infants in the neonatal intensive care unit (NICU) who develop Staphylococcus aureus bloodstream infections (BSI) is unknown.

METHODS

Infants with S. aureus BSI discharged in 1997-2012 from 348 NICUs managed by the Pediatrix Medical Group were identified. Early adequate empirical antibiotic therapy was defined as exposure to ≥1 antibiotic with anti-staphylococcal activity on the day the first positive blood culture was obtained. All other cases were defined as inadequate empirical antibiotic therapy. We evaluated the association between inadequate empirical antibiotic therapy on outcomes controlling for gestational age, small for gestational age status, gender, discharge year, mechanical ventilation, inotropic support and use of supplemental oxygen. The primary outcome was 30-day mortality. Secondary outcomes were 7-day mortality, death before hospital discharge and length of bacteremia.

RESULTS

Of the 3339 infants with S. aureus BSI, 2492 (75%) had methicillin-susceptible S. aureus (MSSA) BSI and 847 (25%) had methicillin-resistant S. aureus (MRSA) BSI. Inadequate empirical antibiotic therapy was administered in 725 (22%) cases. Inadequate empirical antibiotic therapy was associated with increased 30-day mortality (odds ratio: 2.03; 95% confidence interval: 1.08-3.82) among infants with MRSA BSI. Inadequate empirical antibiotic therapy was not associated with increases in mortality among infants with MSSA BSI.

CONCLUSIONS

After controlling for confounders, inadequate empirical antibiotic therapy was associated with a modestly increased mortality at 30 days for infants with MRSA BSI.

Risk Factors for Health Care-Associated Sepsis in Critically Ill Neonates Stratified by Birth Weight

BACKGROUND

Health care-associated bloodstream infection (HABSI) is a frequent complication in neonatal intensive care. Research on risk factors stratified by birth weight and adjusted for severity of illness and comorbidities is limited. Our objective is to describe independent risk factors for HABSI in critically ill neonates with emphasis on risk variation between birth weight groups.

METHODS

We performed a single-center historical cohort study in a tertiary referral center. A neonatal intensive care-audit system was used to identify eligible neonates admitted for ≥72 hours (2002-2011). HABSI is defined according to National Institute of Child Health and Human Development criteria. Risk factors for HABSI were assessed by univariate and logistic regression analysis for the total cohort and for birth weight subgroups, that is, neonates ≤1500 g and >1500 g.

RESULTS

A total of 342 neonates developed HABSI in 5134 admissions of ≥72 hours (6.7%). Very low birth weight, total parenteral nutrition (TPN), mechanical ventilation, gastrointestinal disease, surgery (cardiac and other type), and renal insufficiency are independent risk factors for the total cohort. Gastrointestinal disease and cardiac surgery are independent risk factors in both birth weight groups; mechanical ventilation (odds ratio [OR]: 2.6; confidence interval [CI]: 1.6-4.0) and other type of surgery (OR: 4.3; CI: 2.1-8.8) are solely independent risk factors in the ≤1500-g cohort; TPN is exclusively an independent risk factor (OR: 7.9; CI: 3.9-16.2) in the >1500-g cohort.

CONCLUSIONS

In our neonatal intensive care unit, risk stratification by birth weight revealed some difference. Special attention concerning infection control practices is for neonates receiving TPN, mechanical ventilation, cardiac surgery, and with a gastrointestinal disease.

Targeted empiric antibiotic therapy for children with non-oncological comorbidities and community-onset invasive bacterial infections

OBJECTIVES

To describe the aetiology, risk factors, treatment and outcome of children with community-onset invasive bacterial infections (IBI) and determine the appropriateness of the nationally recommended empiric antibiotic therapy in children with non-oncological comorbidities.

METHOD

The CABIN network prospectively collected clinical information for all positive blood and cerebrospinal fluid cultures in children aged 1 month to 15 years in southwest London over three years.

RESULTS

During 2009-11, 119 healthy children each had a single IBI episode and 61 children with non-oncological comorbidities had 83 IBI episodes. The pathogens causing IBI in children with comorbidities and no central venous catheter (CVC) were similar to those causing IBI in healthy children. However, those with a CVC had multiple IBI episodes, often with pathogens usually associated with nosocomial infection. In particular, gastro-intestinal commensals were frequently responsible for IBI in TPN-dependent children with gastro-intestinal disease (16/43 episodes) and those with liver disease (8/43). Nationally recommended antibiotics were commenced empirically in 93%, with additional or alternate antibiotics more likely to be prescribed in children with comorbidities or those requiring intensive care. Fifteen children died (11 healthy, 4 with comorbidity), including 12 who died before arrival or in the Emergency Department.

CONCLUSION

Increasing care of children with comorbidities in the community has resulted in a significant proportion of community-onset IBI occurring in this group. Children with a CVC in situ - particularly those with gastro-intestinal and liver disease - were infected with a wider range of potentially more virulent pathogens. They might benefit from more broad-spectrum antimicrobial cover.

Prediction models for neonatal health care-associated sepsis: a meta-analysis

BACKGROUND AND OBJECTIVES

Blood culture is the gold standard to diagnose bloodstream infection but is usually time-consuming. Prediction models aim to facilitate early preliminary diagnosis and treatment. We systematically reviewed prediction models for health care-associated bloodstream infection (HABSI) in neonates, identified superior models, and pooled clinical predictors.

DATA SOURCES

LibHub, PubMed, and Web of Science.

METHODS

The studies included designed prediction models for laboratory-confirmed HABSI or sepsis. The target population was a consecutive series of neonates with suspicion of sepsis hospitalized for ≥ 48 hours. Clinical predictors had to be recorded at time of or before culturing. Methodologic quality of the studies was assessed. Data extracted included population characteristics, total suspected and laboratory-confirmed episodes and definition, clinical parameter definitions and odds ratios, and diagnostic accuracy parameters.

RESULTS

The systematic search revealed 9 articles with 12 prediction models representing 1295 suspected and 434 laboratory-confirmed sepsis episodes. Models exhibit moderate-good methodologic quality, large pretest probability range, and insufficient diagnostic accuracy. Random effects meta-analysis showed that lethargy, pallor/mottling, total parenteral nutrition, lipid infusion, and postnatal corticosteroids were predictive for HABSI. Post hoc analysis with low-gestational-age neonates demonstrated that apnea/bradycardia, lethargy, pallor/mottling, and poor peripheral perfusion were predictive for HABSI. Limitations include clinical and statistical heterogeneity.

CONCLUSIONS

Prediction models should be considered as guidance rather than an absolute indicator because they all have limited diagnostic accuracy. Lethargy and pallor and/or mottling for all neonates as well as apnea and/or bradycardia and poor peripheral perfusion for very low birth weight neonates are the most powerful clinical signs. However, the clinical context of the neonate should always be considered.

Paediatric bacteraemias in tropical Australia

AIM

Bacteraemias in children are an important cause of morbidity and mortality. Knowledge of local epidemiology and trends is important to inform practitioners of likely pathogens in the sick child. This study aimed to determine trends over time in pathogenic organisms causing paediatric bacteraemia in North Queensland and to audit a hospital's blood culture results with respect to contamination rate.

METHODS

This was a retrospective review of 8385 blood cultures collected from children attending a tertiary centre in North Queensland over a 10-year period (2001-2010).

RESULTS

There were 696 positive blood cultures (8.3%) with 70 different bacterial species detected. Gram-positive and Gram-negative bacteria accounted for 48.6% and 51.4% of isolates, respectively. Overall, bacteraemia accounted for 4.7 per 1000 admissions. The rate of contamination was 60.6% among positive blood cultures and 5.0% for all blood cultures sampled. These results were compared with previous published reports. Notable differences were seen in the frequencies of Salmonella and group A Streptococcus bacteraemias in North Queensland when compared with other reports. There was also a decline in vaccine-preventable infections such as S. pneumoniae and an increasing trend of community-acquired MRSA bacteraemia.

CONCLUSION

This study has demonstrated the unique profile of causative pathogens of paediatric bacteraemias in tropical Australia. In light of the increasing prevalence of MRSA, empiric treatment for sepsis for children in this region needs to be reconsidered.

Low mortality of Staphylococcus aureus bacteremia in Icelandic children: nationwide study on incidence and outcome

BACKGROUND

Staphylococcus aureus is a major cause of blood stream infections, but population-based studies on pediatric S. aureus bacteremia (SAB) are sparse. The objective of the study was to evaluate the incidence and mortality of SAB in Icelandic children over time, and to assess the proportions of nosocomial and health-care-associated infections.

METHODS

Children <18 years with positive blood cultures for S. aureus from January 1995 through December 2011 were identified retrospectively at the clinical microbiology laboratories performing blood cultures in Iceland. Clinical data were collected from medical records.

RESULTS

In total, 140 children had 146 distinct episodes of SAB. Bacteremia-related mortality was 0.7% (1/146), all-cause 30-day mortality, 1.4% (2/146), and 1-year mortality, 3.6% (5/140). The annual incidence of SAB was 10.9/100,000 children, decreasing by 36% from 13.1/100,000 in 1995-2003 to 8.4/100,000 in 2004-2011 (P < 0.001). At the same time the annual number of blood cultures analyzed at the main study site decreased from 1529 to 1143 (25%). SAB incidence was highest in infants (<1 year), 58.8/100,000. Of 146 episodes 50 (34%) were nosocomial, 21 (14%) health-care associated and 75 (51%) community acquired. No methicillin-resistant S. aureus isolate was identified.

CONCLUSIONS

In this nationwide study on pediatric SAB, the case fatality ratio was very low. A decreasing incidence was seen, possibly related to fewer blood cultures being collected. Nosocomial and health-care-associated infections accounted for 50% of the cases. The findings provide useful information on the epidemiology and outcome of SAB in children.

Timing of positive blood samples does not differentiate pathogens causing healthcare-associated from community-acquired bloodstream infections in children in England: a linked retrospective cohort study

Paediatricians recognize that using the time-dependent community-acquired vs. hospital-acquired bloodstream infection (BSI) dichotomy to guide empirical treatment no longer distinguishes between causative pathogens due to the emergence of healthcare-associated BSIs. However, paediatric epidemiological evidence of the aetiology of BSIs in relation to hospital admission in England is lacking. For 12 common BSI-causing pathogens in England, timing of laboratory reports of positive paediatric (3 months to 5 years) bacterial blood isolates were linked to in-patient hospital data and plotted in relation to hospital admission. The majority (88·6%) of linked pathogens were isolated <2 days after hospital admission, including pathogens widely regarded as hospital acquired: Enterococcus spp. (67·2%) and Klebsiella spp. (88·9%). Neisseria meningitidis, Streptococcus pneumoniae, group A streptococcus and Salmonella spp. were unlikely to cause hospital-acquired BSI. Pathogens commonly associated with hospital-acquired BSI are being isolated <2 days after hospital admission alongside pathogens commonly associated with community-acquired BSI. We confirm that timing of blood samples alone does not differentiate between bacterial pathogens. Additional factors including clinical patient characteristics and healthcare contact should be considered to help predict the causative pathogen and guide empirical antibiotic therapy.

Invasive Staphylococcus aureus Infections in Children in Tropical Northern Australia

BACKGROUND

Despite a high burden of staphylococcal skin disease in children and high incidence of Staphylococcus aureus bacteremia in adult Indigenous populations in northern Australia, there are few studies describing incidence or clinical information of invasive S aureus (ISA) infections in children.

METHODS

We conducted a retrospective review for all cases of S aureus bacteremia and sterile site infections, for children under 15 years, in northern Australia over a 4-year period (2007-2010). Cases were categorized as neonatal (<28 days) and pediatric (≥28 days).

RESULTS

Forty-four cases (9 neonatal, 35 pediatric) were identified. The annual incidence of ISA was 27.9 cases per 100 000 population. Among pediatric cases, the annual incidence was significantly higher in the Indigenous (46.6) compared with the non-Indigenous (4.4) population (IRR: 10.6 [95% confidence interval, 3.8-41.4]). Pediatric infections were predominantly community-associated (86%). Clinical infection sites included osteoarticular (66%), pleuropulmonary (29%), and endocarditis (9%), and multifocal disease was common (20%). Eighty-three percent of pediatric cases presented with sepsis; 34% resulted in intensive care admission. Neonatal cases were all born prematurely; 89% were late-onset infections. Overall, 27% of infections were due to methicillin-resistant S aureus (MRSA). Compared with methicillin-sensitive S aureus (MSSA), there was no difference in severity or presentation in pediatric MRSA cases, but a higher proportion of MRSA cases were readmitted.

CONCLUSIONS

The annual incidence of ISA infection in this study is among the highest described, largely due to a disproportionate burden in Indigenous children. Infections are frequently severe and infection with MRSA is common. Children presenting with suspected ISA in this region should be treated empirically for MRSA.

Healthcare-associated bloodstream infections in a neonatal intensive care unit over a 20-year period (1992-2011): trends in incidence, pathogens, and mortality

OBJECTIVE

To analyze trends in the incidence and pathogen distribution of healthcare-associated bloodstream infections (HABSIs) over a 20-year period (1992-2011).

DESIGN

Historical cohort study.

SETTING

Thirty-two-bed neonatal intensive care unit (NICU) in a tertiary referral hospital.

PATIENTS

Neonates with HABSIs defined according to the criteria of the National Institute of Child Health and Development (NICHD).

METHODS

A hospital-based ongoing surveillance program was used to identify HABSI cases in neonates. A distinction between definite or possible HABSI was made according to the NICHD criteria. Incidence, incidence densities (HABSIs per 1,000 hospital-days and HABSIs per 1,000 total parenteral nutrition-days), and case fatality rate were calculated. Logistic regression analysis was used to find time trends. Four periods of 5 years were considered when executing variance analysis.

RESULTS

In total, 682 episodes of HABSIs occurred on 9,934 admissions (6.9%). The median total incidence density rate was 3.1 (interquartile range, 2.2-3.9). A significant increasing time trend in incidence density was observed for the period 1995-2011 (P < .003). A significant decrease in the case fatality rate was found in the last 5-year period (P < .001). No neonate died following possible HABSIs, whereas the case fatality rate among neonates with definite HABSIs was 9.7%. Most HABSIs were caused by coagulase-negative staphylococci (n = 414 [60.7%]). A significant increase in Staphylococcus aureus HABSI was observed in the last 10-year period (P < .001).

CONCLUSIONS

An increase in incidence density rate occurred, while the case fatality rate dropped. Better perinatal care could be responsible for the latter. A decrease in days before infection and a high incidence of coagulase-negative Staphylococcus HABSIs indicate the need for vigorous application of evidence-based prevention initiatives, in particular for catheter care.

Age and risk factors influence the microbial aetiology of bloodstream infection in children

AIM

To study the aetiology of bloodstream infections (BSI) in children 0-17 years, the influence of age and underlying co-morbidity on BSI rate, distribution of pathogens and outcome; and to provide data on antimicrobial susceptibility patterns.

METHODS

A retrospective population-based study. Data on blood cultures were collected at yearly intervals during 1998-2008. Information about risk factors, focal infection and outcome was retrieved from the patient charts.

RESULTS

We identified 1097 BSI. The incidence of BSI was 0.4/1000. The age-specific incidence was 2.3/1000 in neonates (0-28 days old) and 0.2/1000 in the age group 6-17 years. Staphylococcus aureus was the most common pathogen. The number of species causing BSI in previously healthy children was lower compared with children with co-morbidity. Most children requiring intensive care had a serious underlying illness. Antimicrobial resistance was rare and did not influence outcome. The case-fatality rate was 14.4% in neonates, 5.4% in children with co-morbidity and 1.7% in previously healthy children.

CONCLUSION

Mortality from BSI is low, and a limited spectrum of pathogens is isolated from previously healthy children compared with children with co-morbidity. When choosing empirical therapy for suspected BSI, age and presence of risk factors should be taken into account.

Exploring the Epidemiology of Hospital-Acquired Bloodstream Infections in Children in England (January 2009-March 2010) by Linkage of National Hospital Admissions and Microbiological Databases

BACKGROUND

Hospital-acquired bloodstream infection (HA-BSI) requires immediate effective antibiotic treatment. However, there are no published national data for England that describe the pathogen profile and antibiotic resistance rates of HA-BSI in children.

METHODS

Probabilistic matching methods were used to link national data on microbiologically confirmed BSI to hospital in-patient admissions data for the period of January 2009-March 2010. HA-BSI was defined as a positive blood culture drawn from a child aged 1 month-18 years 2 or more days after admission (and before discharge).

RESULTS

A total of 8718 episodes of BSI was reported during the study period. Linkage allowed 82% of records to be matched, of which 23% (1734) were HA-BSI, giving a rate of 4.74 per 1000 admissions. The median age of infection was 1 year, and 54% of infections were in males. Methicillin resistance was seen in 83% and 17% of coagulase-negative staphylococci and Staphylococcus aureus, respectively. Penicillin resistance was rare in pyogenic streptococci but more common in viridans streptococci (39%). Among Gram-positive organisms, only 3% were vancomycin-resistant. The overall proportion of Gram-negative bacteria resistant to recommended empirical antibiotics (meropenem or piperacillin/tazobactam) was 5% and 16%, respectively, but <4% of isolates were resistant when either of these drugs were combined with gentamicin.

CONCLUSIONS

This study provides the first national estimates of the proportion of pediatric BSI that is hospital-acquired and describes the antimicrobial resistance of organisms causing infection. Pediatric HA-BSI remains unacceptably high; interventions must focus on identifying effective means of preventing HA-BSI, fostering antibiotic stewardship, and improving surveillance.

Bloodstream Bacterial Pathogens and their Antibiotic Resistance Pattern in Dhahira Region, Oman

OBJECTIVES

To describe the epidemiological, clinical, microbiological characteristics and antimicrobial resistance pattern of Bloodstream infections in Dhahira region, Oman.

METHODS

Clinical data was collected from all patients with positive blood cultures for two years period. Standard laboratory methods were used for blood culture. Antibiotic sensitivity was tested using Kirby-Bauer disc diffusion method.

RESULTS

Of the 360 bacterial pathogens isolated from 348 patients, 57.8% were gram-positive and 42.2% were gram-negative. The common isolates were: Streptococcus species 76 (21.1%), coagulase-negative Staphylococci 75 (20.8%), Escherichia coli 43 (11.9%), Staphylococcus aureus 41 (11.4%). Overall, mortality was 21.3% (74/348). Staphylococcus species (Staphylococcus aureus and CoNS) were more commonly resistant to Trimethoprim/ Sulphamethoxazole (35.3%) and Penicillin (25.9%). Streptococcus species were resistant to Trimethoprim/Sulphamethoxazole (39.1%) and Erythromycin (19.6%).

CONCLUSION

Bloodstream infections are important causes of morbidity and mortality in our patients, especially among chronically ill elderly adult males. Prescription of proven resistant antibiotics to suspected bacteremic patients needs attention in Dhahira region.

[Incidence of central line-associated bloodstream infection in an intensive care unit]

BACKGROUND

Central line-associated bloodstream infection (CLABSI) is one of the most common nosocomial infections. The incidence is higher in paediatric patients than in adults, especially in those admitted to Intensive Care Units (ICU). CLABSI-related morbidity makes it a major health problem; therefore it is necessary to develop prevention strategies against it.

PATIENTS AND METHODS

An intervention study in a paediatric ICU (PICU) was performed, in order to assess the impact of the introduction of the program «Bacteraemia zero» in December 2007. This program aims to prevent CLABSI. Demographic data and variables related to hospitalisation and infection were collected from January to December 2007 (before the intervention) and from January to December 2008 (after the intervention), and were compared. In the first period, 497 patients were studied, and 495 in the second.

RESULTS

A reduction of 30.4% in the incidence of CLABSI (P=0.49) in the second year was observed (5.5 to 3.8 episodes per 1000 catheter-days). The CVC use ratio was 0.59 and 0.64, respectively. The most frequently isolated organism was coagulase-negative Staphylococcus spp.

CONCLUSIONS

The implementation of a «no bacteraemia» program, involving all staff in the PICU as well as the professionals in infection control, reduces the incidence of CLABSI.

The changing aetiology of paediatric bacteraemia in England and Wales, 1998–2007

Bacteraemia in children is a potentially life-threatening condition. The objective of this study was to determine trends in the aetiology of bacteraemia in children aged 1 month–15 years in England and Wales by collecting data voluntarily reported by National Health Service hospital microbiology laboratories. Over the 10-year period 1998–2007, a total of 51 788 bacteraemia cases involving 105 genera/species of bacteria were reported. Total annual reports of bacteraemia increased from 4125 to 6916, with a mean increase of 6.5 % per year (95 % CI: 1.3–12.1 %). In 2007, just over half the cases were accounted for by four groups of organisms: coagulase-negative staphylococci (28 %), Staphylococcus aureus (10 %), non-pyogenic streptococci (9 %) and Streptococcus pneumoniae (7 %). These organisms along with a further 13 species/genera accounted for 90 % of the cases. The commonest Gram-negative organisms were Neisseria meningitidis and Escherichia coli, which each accounted for 5 % of total bacteraemia reports in 2007. There was a significant decrease in reports of bacteraemia due to the three vaccine-preventable pathogens Haemophilus influenzae, N. meningitidis and Strep. pneumoniae, following the introduction of each vaccine programme or catch-up campaign. This study identified the commonest causes of bacteraemia in children in England and Wales, and highlighted the shifts in trends observed over time.

Pediatric and neonatal Staphylococcus aureus bacteremia: epidemiology, risk factors, and outcome

OBJECTIVE

To evaluate the impact of methicillin-resistant Staphylococcus aureus on the prevalence of S. aureus bloodstream infection among children.

METHODS

Retrospective analysis of demographic data, risk factors for infection, and clinical outcomes for children (age, less than 18 years) with S. aureus bacteremia hospitalized at a children's hospital during 2001-2006.

RESULTS

We identified 164 episodes of S. aureus bacteremia among 151 children. The prevalence of bacteremia due to methicillin-susceptible S. aureus during 2001-2003 was approximately the same as that during 2004-2006 (29 and 30 cases, respectively, per 10,000 hospitalized children [hereafter, "per 10,000 hospitalizations"]), but the prevalence of bacteremia due to methicillin-resistant S. aureus increased from 4 to 11 cases, respectively, per 10,000 hospitalizations (P=.015). A total of 48% of infections involved children who had S. aureus-positive blood cultures less than 3 days after hospital admission. Seventy-four percent of these children had a preexisting comorbidity. When the prevalence of S. aureus bacteremia was stratified by race, sex, or age, neonates hospitalized at birth and Hispanic children had significantly reduced risks of infection. Children younger than 1 year of age (excluding neonates hospitalized at birth) had an increased prevalence of hospital-onset S. aureus bacteremia. There was a disproportionate increase in the risk of S. aureus bacteremia for each additional week of hospitalization among children with hospital-onset S. aureus bacteremia. Children with methicillin-resistant S. aureus bacteremia had a longer hospital stay, were transferred to another facility at a greater rate than they were discharged home, and had a greater mortality rate, compared with children with methicillin-susceptible S. aureus bacteremia.

CONCLUSION

This study documents the prevalence of S. aureus bacteremia among children with a high risk for acquiring this infection, and it describes populations of children who are at higher risk for bacteremia due to either methicillin-susceptible or methicillin-resistant S. aureus. Methods to improve prevention of S. aureus bacteremia are needed for children with healthcare-associated risk factors for S. aureus bacteremia.

Incidencia estimada y análisis de la sepsis en un área de Valencia

OBJECTIVES

To study the incidence of sepsis in an area of Valencia, as well as its characteristics, and to evaluate short-term outcomes.

PATIENTS AND METHODS

An active surveillance program was carried out to determine the incidence and characteristics of sepsis. All patients attending the Hospital de La Ribera from January 1999 to December 2004 were included. Incidence rates were calculated and logistic regression analysis was performed.

RESULTS

The incidence rate was 60.9 per 100,000 person-years. The incidence was highest among children younger than 1 year (1,138 per 100,000 person-years). A total of 14.4 % of cases were nosocomial infections. The most common microorganisms found were Escherichia coli, Streptococcus pneumoniae and Neisseria meningitidis. Microbiologically undocumented sepsis accounted for 32 % of the cases. The case-fatality rate was 1.3 %. Seventeen patients (11.1 %) were transferred to an intensive care unit (ICU). The risk of being transferred to an ICU was 14 times higher in patients with meningitis than in those with other sources of infection, independently of age and microbiological characteristics (OR 13.9, 95 % CI 2.6-75.3, P = 0.002).

CONCLUSIONS

The incidence rate of sepsis is high in the pediatric age group. Clinical sepsis represented an important percentage of pediatric sepsis in our center. The main factor associated with patient transfer to the ICU was the central nervous system as the source of sepsis.

Healthcare-associated infections in neonatal units: lessons from contrasting worlds

Neonatal intensive care units are vulnerable to outbreaks and sporadic incidents of healthcare-associated infections (HAIs). The incidence and outcome of these infections are determined by the degree of immaturity of the neonatal immune system, invasive procedures involved, the aetiological agent and its antimicrobial susceptibility pattern and, above all, infection control policies practised by the unit. It is important to raise awareness of infection control practices in resource-limited settings, since overdependence upon antimicrobial agents and co-existing lack of awareness of infection control is encouraging the emergence of multi-drug-resistant nosocomial pathogens. We reviewed 125 articles regarding HAIs from both advanced and resource-limited neonatal units in order to study risk factors, aetiological agents, antimicrobial susceptibility patterns and reported successes in infection control interventions. The articles include surveillance studies, outbreaks and sporadic incidents. Gram-positive cocci, viruses and fungi predominate in reports from the advanced units, while Gram-negative enteric rods, non-fermenters and fungi are commonly reported from resource-limited settings. Antimicrobial susceptibility patterns from surveillance studies determined the empirical therapy used in each neonatal unit. Most outbreaks, irrespective of the technical facilities available, were traced to specific lack of infection control practices. We discuss infection control interventions, with special emphasis on their applicability in resource-limited settings. Cost-effective measures for implementing these interventions, with particular reference to the recognition of the role of the microbiologist, the infection control team and antibiotic policies are presented.

Arterielle und zentralvenöse Katheter bei Neugeborenen und Säuglingen

In neonates and infants, arterial and central venous catheters are of vital importance to optimize perioperative surveillance during surgery as well as postoperative care in the intensive care unit. The insertion of umbilical venous (UVC) and umbilical arterial catheters (UAC) in neonates in the first days of life is relatively simple and associated with a low procedure-related risk. As with other centrally placed catheters, correct positioning must be verified and the catheters should not be used for more than 5-7 days. Peripherally inserted central catheters (PICC) are commonly used in neonates and can be an alternative to conventional central venous lines in older infants. In order to minimize the risk associated with catheter malposition, correct position must always be verified by appropriate imaging studies or ECG guidance. Surgically placed Broviac catheters are mainly used in patients with a long-term need for central venous access. Finally, it has been shown that adherence to strict guidelines for insertion and handling can significantly reduce catheter-associated infections.

[Epidemiology of nosocomial bacterial infections in a neonatal and pediatric Tunisian intensive care unit]

OBJECTIVE

The authors had for aim to describe the epidemiology of nosocomial bacterial infections in the neonatal and pediatric intensive care unit of the Tunis children's hospital.

DESIGN

A prospective surveillance study was made from January 2004 to December 2004. All patients remaining in the intensive care unit for more than 48 h were included. CDC criteria were applied for the diagnosis of nosocomial infections.

RESULTS

340 patients including 249 (73%) neonates were included. 22 patients presented with 22 nosocomial bacterial infections. The incidence and the density incidence rates of nosocomial bacterial infections were 6.5% and 7.8 per 1,000 patient-days, respectively. Two types of infection were found: bloodstream infections (68.2%) and pneumonias (22.7%). Bloodstream infections had an incidence and a density incidence rate of 4.4% and 15.3 per 1,000 catheter-days, respectively. Pneumonia had an incidence and a density incidence rate of 2% and 4.4 per 1,000 mechanical ventilation-days, respectively. The most frequently isolated pathogens were Gram-negative bacteria (68%) with Klebsiella pneumoniae isolates accounting for 22.7%. The most common isolate in bloodstream infections was K. Pneumoniae (26.7%), which was multiple drug-resistant in 85% of the cases, followed by Staphylococcus aureus (20%). Pseudomonas aeruginosa was the most common isolate in pneumonia (28.6%). Associated factors of nosocomial infection were invasive devices and colonization with multiple drug-resistant Gram-negative bacteria.

CONCLUSIONS

The major type of nosocomial bacterial infections in our unit was bloodstream infection and the majority of infections resulted from Gram-negative bacteria. Factors associated with nosocomial bacterial infections were identified in our unit.

Enterococcal Infection in Children

From relative obscurity, enterococci have become a leading cause of nosocomial infection. This has been attributed, in part, to the growth in susceptible host populations, increased use of intravascular devices, prolonged hospital stay, and widespread antibiotics use. Furthermore, the facility with which enterococci acquire resistance characteristics coupled with their capacity to survive in the environment renders them uniquely suited as nosocomial opportunists and have resulted in global dissemination of resistant strains. Debate continues as to whether most serious infections arise from a person's indigenous flora or dissemination of virulent clones. Enterococci are normal inhabitants of the human gastrointestinal tract. Classically associated with endocarditis and wound and urinary tract infections, increasingly they are a cause of nosocomial bacteremia. The rise in incidence of serious enterococcal infection has been particularly evident in neonatal, paediatric intensive care, and haematology/oncology units. Spread of resistant phenotypes has posed a difficult therapeutic challenge. We have been rescued, albeit perhaps only temporarily, by the addition of newer agents, such as linezolid, to the therapeutic armamentarium. However, there is no room for complacency. Linezolid resistance already has been reported. Efforts must continue to focus on prevention of the emergence and dissemination of resistance through policies of rational antibiotic use, infection control and education.

MRSA at an English children's hospital from 1998 to 2003

AIMS

To investigate the epidemiological and clinical aspects of MRSA among inpatients and outpatients presenting to hospital.

METHODS

Analysis of demographic, epidemiological, and clinical data collected on 385 children first identified as having MRSA between January 1998 and December 2003 in a 250 bed English children's hospital.

RESULTS

There were 267 inpatients and 118 outpatients. The number of new cases of MRSA declined from 72 in 1998 to 52 in 2003, whereas hospital activity increased. Ninety nine (37.1%) inpatients acquired MRSA outside the hospital; a further 90 occurred among 31 clusters of cases. One hundred and seventy eight (66.7%) inpatients were aged <2 years; cardiac services and paediatric & neonatal surgery accounted for 59.6% of cases. Dermatology and A&E accounted for 51.7% of outpatients; 73.8% of outpatients had recently previously attended the hospital. A total of 13.9% of inpatients with MRSA developed bacteraemia; MRSA accounted for 15% of Staphylococcus aureus bacteraemias. The risk of MRSA bacteraemia in colonised patients, and the proportion of S aureus bacteraemias that were MRSA, varied between specialties. Intravascular devices were the most common source of MRSA bacteraemia (63.4% of cases). The mortality rate was 7.3%.

CONCLUSIONS

Enhanced surveillance of MRSA can identify at-risk patient groups, thus facilitating targeting of control measures. The absence of a link between numbers of cases of acquisition of MRSA and bacteraemia suggests that the rise in MRSA bacteraemia may not solely reflect an increase in MRSA prevalence in children in the UK. The need for larger epidemiological studies is emphasised.

Gram-negative bacilli associated with catheter-associated and non-catheter-associated bloodstream infections and hand carriage by healthcare workers in neonatal intensive care units

OBJECTIVE

Bloodstream infections caused by Gram-negative bacilli are a substantial cause of morbidity and mortality in infants in neonatal intensive care units. This study describes the species of Gram-negative bacilli causing bloodstream infections in two neonatal intensive care units, compares characteristics of catheter-related and non-catheter-related bloodstream infections, and compares species and antibiotic resistance patterns of these organisms with those isolated from the hands of nurses working in the same neonatal intensive care units.

DESIGN

Interventional study.

SETTING

Two high-risk neonatal intensive care units.

PATIENTS

Neonates hospitalized for >or =24 hrs.

INTERVENTIONS

Prospective surveillance for bloodstream infections was performed in two neonatal intensive care units from March 2001 to January 2003. Hand cultures were obtained quarterly from participating nurses immediately after they performed hand hygiene.

MEASUREMENTS AND MAIN RESULTS

There were 298 episodes of bloodstream infections among 2,935 admissions (5.75 episodes per 1,000 patient-days); 77 of 298 (26%) episodes were caused by Gram-negative bacilli. Among these, 47 (61.0%) were catheter-related bloodstream infections (2.61 episodes per 1,000 catheter-days). Eleven and 24 Gram-negative bacilli species were isolated from neonates and nurses, respectively. The most common Gram-negative bacilli causing bloodstream infections were Klebsiella pneumoniae (38.7%), Escherichia coli (21.2%), Enterobacter cloacae (11.2%), and Serratia marcescens (11.2%). In contrast, Acinetobacter lwoffi (18.1%), K. pneumoniae (11.7%), E. cloacae (10.6%), K. oxytoca (10.6%), and Pseudomonas spp. (7.4%) were most commonly isolated from hands of nurses. E. coli, P. aeruginosa, E. cloacae, and E. aerogenes were significantly more likely to cause bloodstream infections than to be isolated from nurses' hands (all p < .001). Although 39% of bloodstream infections were non-catheter-related, there were no significant differences in types of organisms or antimicrobial resistance patterns between catheter-related bloodstream infections and non-catheter-related bloodstream infections (all p > or = .35). Resistance patterns were similar between Gram-negative bacilli isolates from neonates and nurses' hands except for a significantly higher proportion of resistance to cefotaxime and gentamicin among neonatal isolates of K. pneumoniae (p < .05).

CONCLUSIONS

Gram-negative bacilli species isolated from neonatal bloodstream infections and nurses' hands varied significantly. Clean hands of providers are an unlikely source of endemic Gram-negative bacilli, suggesting that prevention strategies should focus more on control of endogenous neonatal flora or environmental sources.