Community-acquired, healthcare-associated and hospital-acquired bloodstream infection definitions in children: a systematic review demonstrating inconsistent criteria

Carbapenemase-producing Klebsiella pneumoniae in community settings: a cross-sectional study in Belgrade, Serbia

Aim: The types of carbapenemases and clonal relatedness among community isolates of carbapenemase-producing Klebsiella pneumoniae in Belgrade, Serbia, were determined. Materials & methods: During the period 2016-2020, K. pneumoniae community isolates were screened for carbapenemases, and carbapenemase production was confirmed by multiplex PCR. Clonality was determined based on genetic profiles obtained by enterobacterial repetitive intergenic consensus PCR. Results: Carbapenemase genes were detected in 114 of 4800 isolates (2.4%). The most frequent gene was blaOXA-48-like. Most isolates (70.5%) were grouped in ten clusters. Cluster 11 contained 16.4% of all blaOXA-48-like-positive isolates, and all blaKPC-positive isolates were grouped in one cluster. Conclusion: Laboratory-based detection and surveillance are highly recommended in order to control the spread of resistance in community settings.

The limited value of triage vital signs in predicting influenza infection in children aged 5 years and under in the emergency department: A single-center retrospective cross-sectional study

Diagnosing influenza in children aged 5 years and under can be challenging because of their difficulty in verbalizing symptoms. This study aimed to explore the value of the triage heart rate (HR), respiratory rate (RR), and temperature, either alone or when combined with individual symptoms and signs, in predicting influenza infection in this age group.This was a retrospective study covering 4 influenza seasons from 2017 to 2019 in an emergency department (ED) in Hong Kong. We recruited patients ≤5 years of age who had an reverse transcription polymerase chain reaction influenza test within 48 hours of ED presentation. The diagnostic performance of the triage HR, RR, and temperature was evaluated as dichotomized or categorized values with diagnostic odds ratios (DORs) calculated based on different age-appropriate thresholds. Linear discriminant analysis was performed to assess the combined discriminatory effect of age, HR, RR, and temperature as continuous variables.Of 322 patients (median age 26 months), 99 had influenza A and 13 had influenza B infection. For HR and RR dichotomized based on age-appropriate thresholds, the DORs ranged from 1.16 to 1.54 and 0.78 to 1.53, respectively. A triage temperature ≥39.0 °C had the highest DOR (3.32) among different degrees of elevation of temperature. The diagnostic criteria that were based on the presence of fever and cough and/or rhinitis symptoms had a higher DOR compared with the Centers for Disease Control and Prevention influenza-like illness criteria (4.42 vs 2.41). However, combining HR, RR, or temperature with such diagnostic criteria added very little to the diagnostic performance. The linear discriminant analysis model had a high specificity of 92.5%, but the sensitivity (18.3%) was too low for clinical use.Triage HR, RR, and temperature had limited value in the diagnosis of influenza in children ≤5 years of age in the ED. Fever and cough and/or rhinitis symptoms had a better diagnostic performance than the Centers for Disease Control and Prevention influenza-like illness criteria in predicting influenza in this age group.

The role of co-infections and secondary infections in patients with COVID-19

BACKGROUND

It has been recognised for a considerable time-period, that viral respiratory infections predispose patients to bacterial infections, and that these co-infections have a worse outcome than either infection on its own. However, it is still unclear what exact roles co-infections and/or superinfections play in patients with COVID-19 infection.

MAIN BODY

This was an extensive review of the current literature regarding co-infections and superinfections in patients with SARS-CoV-2 infection. The definitions used were those of the Centers for Disease Control and Prevention (US), which defines coinfection as one occurring concurrently with the initial infection, while superinfections are those infections that follow on a previous infection, especially when caused by microorganisms that are resistant, or have become resistant, to the antibiotics used earlier. Some researchers have envisioned three potential scenarios of bacterial/SARS-CoV-2 co-infection; namely, secondary SARS-CoV-2 infection following bacterial infection or colonisation, combined viral/bacterial pneumonia, or secondary bacterial superinfection following SARS-CoV-2. There are a myriad of published articles ranging from letters to the editor to systematic reviews and meta-analyses describing varying ranges of co-infection and/or superinfection in patients with COVID-19. The concomitant infections described included other respiratory viruses, bacteria, including mycobacteria, fungi, as well as other, more unusual, pathogens. However, as will be seen in this review, there is often not a clear distinction made in the literature as to what the authors are referring to, whether true concomitant/co-infections or superinfections. In addition, possible mechanisms of the interactions between viral infections, including SARS-CoV-2, and other infections, particularly bacterial infections are discussed further. Lastly, the impact of these co-infections and superinfections in the severity of COVID-19 infections and their outcome is also described.

CONCLUSION

The current review describes varying rates of co-infections and/or superinfections in patients with COVID-19 infections, although often a clear distinction between the two is not clear in the literature. When they occur, these infections appear to be associated with both severity of COVID-19 as well as poorer outcomes.

Optimizing the Use of Antibiotic Agents in the Pediatric Intensive Care Unit: A Narrative Review

Antibiotics are one of the most prescribed drug classes in the pediatric intensive care unit, yet the incidence of inappropriate antibiotic prescribing remains high in critically ill children. Optimizing the use of antibiotics in this population is imperative to guarantee adequate treatment, avoid toxicity and the occurrence of antibiotic resistance, both on a patient level and on a population level. Antibiotic stewardship encompasses all initiatives to promote responsible antibiotic usage and the PICU represents a major target environment for antibiotic stewardship programs. This narrative review provides a summary of the available knowledge on the optimal selection, duration, dosage, and route of administration of antibiotic treatment in critically ill children. Overall, more scientific evidence on how to optimize antibiotic treatment is warranted in this population. We also give our personal expert opinion on research priorities.

Trends of Pediatric Bloodstream Infections in Stockholm, Sweden: A 20-year Retrospective Study

BACKGROUND

The etiology of bloodstream infections (BSIs) changes over time due to updated immunization programs, new antibiotic-use strategies, changes in patient mix and travel. Continuous surveillance can guide empiric therapy and identify targets for prevention.

METHOD

We conducted a descriptive retrospective analysis among children <18 years of age who were detected with BSI between July 1998 and June 2018 for changes in the incidence, risk factors, and etiology of BSI in a Swedish tertiary hospital (Karolinska University Hospital).

RESULTS

We evaluated 2079 episodes of BSI. During the study period, the incidence of BSI in children 0-17 years of age decreased (τ = -0.45, P = 0.016), which was most evident among children 3 months to 2 years of age (τ = -0.59, P = 0.0006) and in early neonatal period (0-7 days; τ = -0.44, P = 0.0069). These were explained by the reduced occurrence of Streptococcus pneumoniae in children 3 months to 2 years of age and Streptococcus agalactiae and Candida spp. in neonates. Staphylococcus aureus was the commonest pathogen, accounting for 31.6% of episodes. The proportion of hospital-acquired infection was higher in patients with underlying risk factors (47.6% vs. 2.6%). The etiology of hospital-acquired infection BSI was more diverse than that of community-acquired infections and was related to underlying risk factors. The crude mortality rate was 5.7%. For children admitted to the neonatal ward, the mortality was 17.6%, but declined (τ = -0.469, P = 0.004) over the study period.

CONCLUSIONS

There was a decreasing trend of pediatric BSI and mortality over last 20 years, which was associated with pneumococcal immunization and antimicrobial prophylaxis for high-risk patients.

Inhibitory mechanism of BAC-IB17 against β-lactamase mediated resistance in methicillin-resistant Staphylococcus aureus and application as an oncolytic agent

Cancer remains a foremost cause of deaths worldwide, despite several advances in the medical science. The conventional chemotherapeutic methods are not only harmful for normal body cells but also become inactive due to the development of resistance by cancer cells. Therefore, the demand of safe anticancer agents is increasing and enforced the bottomless research on the bacteriocins. Several studies have reported the selective anticancer property of bacteriocins. Current research is the contribution to explore the exact mechanism of action and in vitro application of bacteriocin (BAC-IB17) as an oncolytic agent. In this study, β-lactamase mediated resistance of methicillin resistant Staphylococcus aureus (MRSA) was studied and inhibitory mechanism of MRSA by BAC-IB17 was investigated. Cytotoxic studies were conducted to analyze the anticancerous potential of BAC-IB17. Results revealed that BAC-IB17 inhibited the β-lactamase and produced profound effect on the membrane integrity of MRSA confirmed by scanning electron microscope (SEM). FTIR spectroscopic analysis revealed the changes in the functional groups of bacterial cells before and after treatment with BAC-IB17. BAC-IB17 also found anticancer in nature as it kills HeLa cell lines with the IC₅₀ value of 12.5 μg mL^-1 with no cytotoxic effect on normal cells at this concentration. This specific anticancer property of BAC-IB17 will make it a promising candidate for the treatment of cancer after further clinical trials. Moreover, BAC-IB17 may control MDR bacteria responsible for the secondary complications in cancer patients.

A Systematic Review and Meta-analysis of the Prevalence of Community-Onset Bloodstream Infections among Hospitalized Patients in Africa and Asia

Community-onset bloodstream infections (CO-BSI) are major causes of severe febrile illness and death worldwide. In light of new data and the growing problem of antimicrobial resistance (AMR) among pathogens causing BSI, we undertook a systematic review of hospital-based studies of CO-BSI among patients hospitalized with fever.

Community-onset bloodstream infections (CO-BSI) are major causes of severe febrile illness and death worldwide. In light of new data and the growing problem of antimicrobial resistance (AMR) among pathogens causing BSI, we undertook a systematic review of hospital-based studies of CO-BSI among patients hospitalized with fever. Without restriction to language or country, we searched PubMed, Web of Science, and Scopus for prospective hospital-based studies of culture-confirmed CO-BSI among febrile inpatients. We determined by study the prevalence of BSI among participants, the pathogens responsible for BSI, and the antimicrobial susceptibility patterns of pathogens causing BSI, according to place and time. Thirty-four (77.3%) of 44 eligible studies recruited 29,022 participants in Africa and Asia combined. Among participants in these two regions, the median prevalence of BSI was 12.5% (range, 2.0 to 48.4%); of 3,220 pathogens isolated, 1,119 (34.8%) were Salmonella enterica, 425 (13.2%) Streptococcus pneumoniae, and 282 (8.8%) Escherichia coli. Antimicrobial susceptibility testing was reported in 16 (36.4%) studies. When isolates collected prior to 2008 were compared to those collected in the period of 2008 through 2018, the proportions of typhoidal Salmonella and Staphylococcus aureus isolates resistant to several clinically relevant antimicrobials increased over time, while S. pneumoniae susceptibility was stable. CO-BSI remain a major cause of severe febrile illness among hospitalized patients in Africa and Asia, with S. enterica, S. pneumoniae, and E. coli predominating. There is a concerning increase in AMR among serious infections caused by community-onset pathogens. Ongoing surveillance is needed to inform empirical management and strategies to control AMR.

Implementation of an empirical antimicrobial protocol in a critical care setting: A single-center retrospective observational cohort study in bacteremic patients

In the treatment of severe infections in critical care settings, the selection of initial empirical antimicrobials affects patient outcomes and antimicrobial overuse. The application of a comprehensive treatment guidance might facilitate appropriate antimicrobial selection. Therefore, we developed such an antimicrobial guidance for use in emergency and critical care center and verified its efficacy. We retrospectively analyzed the data of 195 patients (96 patients before guidance introduction [control group] and 99 after guidance introduction [intervention group]) who were ultimately diagnosed with bacteremia to assess the effects of the guidance (the intervention). The appropriateness of the empirical therapy was greater in the intervention than in the control group (96% vs. 90%, respectively; P = 0.10). Moreover, the rate of carbapenem use was significantly lower in the intervention than in the control group (6% vs. 20%, respectively; P < 0.01). The control and intervention groups had similar 28-day survival rates of 81% and 85%, respectively; P = 0.50). These findings imply that introducing an empirical antimicrobial guidance in emergency outpatient and emergency intensive care settings could improve antimicrobial stewardship without affecting patient mortality. The data of this study can be used as a reference for establishing the study design of a large-scale prospective trial, aimed at verifying guidance efficacy.

Bacteriological profile of community-acquired musculoskeletal infections: a study from Queensland

BACKGROUND

The purpose of this study was to determine bacteriology of community-acquired musculoskeletal infections requiring hospitalization and to compare this with published national and international data. This will help treating physicians select the appropriate antibiotic.

METHODS

All patients who underwent surgical procedures for community-acquired musculoskeletal infections over a period of 22 months were included in the study. Hospital acquired infections, post-operative infections and infections involving prosthetic joints were excluded. Patient characteristics, treatment details, cultured organisms and their antibiotic sensitivity were recorded.

RESULTS

Forty-five patients with 46 cases met the inclusion criteria. Ten patients were from paediatric age group. Soft tissue infections were the most common diagnosis and accounted for 20 cases. The remainder were septic arthritis (n = 17) and osteomyelitis (n = 9). Thirteen patients (28.3%) had negative cultures from the operative samples. Staphylococcus aureus was the most common isolated organism overall accounting for 23 cases (69.7%). Methicillin-resistant S. aureus (MRSA) sensitive to vancomycin was cultured in four adult cases (12.1%), of which three were hand infections (50%). For the entire cohort, 67.7% and 61.3% isolates that were tested were sensitive to cefazolin and flucloxacillin, respectively.

CONCLUSION

The bacteriological profile in this study is consistent with European and Australian data. While the overall MRSA infection rate was low, it was much higher among hand infections and is comparable to reports from the USA. Flucloxacillin and cefazolin should be considered as the first line of antibiotic therapy for all cases. Vancomycin should be considered when MRSA is suspected.

Blood Cultures Drawn From Arterial Catheters Are Reliable for the Detection of Bloodstream Infection in Critically Ill Children

OBJECTIVES

Arterial catheters may serve as an additional source for blood cultures in children when peripheral venipuncture is challenging. The aim of the study was to evaluate the accuracy of cultures obtained through indwelling arterial catheters for the diagnosis of bloodstream infections in critically ill pediatric patients.

DESIGN

Observational and comparative.

SETTING

General and cardiac ICUs of a tertiary, university-affiliated pediatric medical center.

PATIENTS

The study group consisted of 138 patients admitted to the general or cardiac PICU in 2014-2015 who met the following criteria: presence of an indwelling arterial catheter and indication for blood culture.

INTERVENTIONS

Blood was drawn by peripheral venipuncture and through the arterial catheter for each patient and sent for culture (total 276 culture pairs).

MEASUREMENTS AND MAIN RESULTS

Two specialists blinded to the blood source evaluated each positive culture to determine if the result represented true bloodstream infection or contamination. The sensitivity, specificity, and positive and negative predictive values of the arterial catheter and peripheral cultures for the diagnosis of bloodstream infection were calculated. Of the 56 positive cultures, 41 (15% of total samples) were considered diagnostic of true bloodstream infection. In the other 15 (5%), the results were attributed to contamination. The rate of false-positive results was higher for arterial catheter than for peripheral venipuncture cultures (4% vs 1.5%) but did not lead to prolonged unnecessary antibiotic treatment. On statistical analysis, arterial catheter blood cultures had high sensitivity (85%) and specificity (95%) for the diagnosis of true bloodstream infection, with comparable performance to peripheral blood cultures.

CONCLUSION

Cultures of arterial catheter-drawn blood are reliable for the detection of bloodstream infection in PICUs.

The Impact of the Staphylococcus aureus Virulome on Infection in a Developing Country: A Cohort Study

We performed a cohort study to analyze the virulome of Staphylococcus aureus from the Democratic Republic of the Congo using whole genome sequencing and to assess its impact on the course of S. aureus infections. Community-associated S. aureus from nasal colonization (n = 100) and infection (n = 86) were prospectively collected. Phenotypic susceptibility testing and WGS was done for each isolate. WGS data were used to screen for 79 different virulence factors and for genotyping purposes (spa typing, multilocus sequence typing). The majority of the 79 virulence factors were equally distributed among isolates from colonization and infection. Panton-Valentine leukocidin (PVL) and the non-truncated hemolysin β were associated with skin and soft tissue infection (SSTI) and recurrence of disease but did not influence the course of infection (i.e., mortality, surgical intervention). For the first time, we show that not only PVL but also hemolysin β could contribute to the development of SSTI in PVL-endemic areas such as Africa.

Emergence and characterization of tigecycline resistance in multidrug-resistant Klebsiella pneumoniae isolates from blood samples of patients in intensive care units in northern China

Serious infections in intensive care unit patients caused by multidrug-resistant (MDR) Klebsiella pneumoniae represent a major threat worldwide owing to increased mortality and limited treatment options. With the application of tigecycline for MDR pathogens, tigecycline-non-susceptible K. pneumoniae isolates have recently emerged in China. To identify the susceptibility profile of MDR K. pneumoniae to tigecycline and evaluate the molecular characterization of tigecycline resistance, 214 MDR K. pneumoniae isolates were collected from blood samples of patients in intensive care units. MICs and clonal relatedness were determined by standard broth microdilution and multilocus sequence typing, respectively. Expression levels of efflux pumps and their global regulators were examined using real-time PCR. Mutations of local repressor were identified by PCR and sequencing. Our results show that the tigecycline resistance rate of 214 MDR K. pneumoniae isolates was 6.07 %. ST11 was the predominant clone type of tigecycline-non-susceptible K. pneumoniae isolates. Expression of efflux pump AcrB and global regulator RamA correlated with tigecycline MICs (AcrB: x2=8.91, P=0.03; RamA: x2=13.91, P<0.01), and mean expression levels of AcrB for the MICs ≥4 mg l-1 were significantly higher than MICs ≤2 mg l-1 (t=2.48, P=0.029). In addition, one tigecycline-resistant isolate harboured a deletion mutation in the ramR gene. These data indicated a linear correlative trend for overexpression of the AcrB and the tigecycline MICs resulting from the upregulation of RamA. The emergence of molecular type ST11 of MDR K. pneumoniae isolates should be monitored to identify factors that contribute to tigecycline resistance in intensive care units.

Seasonal Variation of Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae Bacteremia According to Acquisition and Patient Characteristics: A Population-Based Study

OBJECTIVE Seasonal variation is a characteristic of many infectious diseases, but relatively little is known about determinants thereof. We studied the impact of place of acquisition and patient characteristics on seasonal variation of bacteremia caused by the 3 most common pathogens. DESIGN Seasonal variation analysis. METHODS In 3 Danish health regions (2.3 million total inhabitants), patients with bacteremia were identified from 2000 through 2011 using information from laboratory information systems. Analyses were confined to Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Additional data were obtained from the Danish National Hospital Registry for the construction of admission histories and calculation of the Charlson comorbidity index (CCI). Bacteremias were categorized as community acquired, healthcare associated (HCA), and hospital acquired. We defined multiple subgroups by combining the following characteristics: species, acquisition, age group, gender, CCI level, and location of infection. Assuming a sinusoidal model, seasonal variation was assessed by the peak-to-trough (PTT) ratio with a 95% confidence interval (CI). RESULTS In total, we included 16,006 E. coli, 6,924 S. aureus, and 4,884 S. pneumoniae bacteremia cases. For E. coli, the seasonal variation was highest for community-acquired cases (PTT ratio, 1.24; 95% CI, 1.17-1.32), was diminished for HCA (PTT ratio, 1.14; 95% CI, 1.04-1.25), and was missing for hospital-acquired cases. No seasonal variation was observed for S. aureus. S. pneumoniae showed high seasonal variation, which did not differ according to acquisition (overall PTT ratio, 3.42; 95% CI, 3.10-3.83). CONCLUSIONS Seasonal variation was mainly related to the species although the place of acquisition was important for E. coli. Infect Control Hosp Epidemiol 2016;37:946-953.

Ciprofloxacin resistance in community- and hospital-acquired Escherichia coli urinary tract infections: a systematic review and meta-analysis of observational studies

Background

During the last decade the resistance rate of urinary Escherichia coli (E. coli) to fluoroquinolones such as ciprofloxacin has increased. Systematic reviews of studies investigating ciprofloxacin resistance in community- and hospital-acquired E. coli urinary tract infections (UTI) are absent. This study systematically reviewed the literature and where appropriate, meta-analysed studies investigating ciprofloxacin resistance in community- and hospital-acquired E. coli UTIs.

Methods

Observational studies published between 2004 and 2014 were identified through Medline, PubMed, Embase, Cochrane, Scopus and Cinahl searches. Overall and sub-group pooled estimates of ciprofloxacin resistance were evaluated using DerSimonian-Laird random-effects models. The I² statistic was calculated to demonstrate the degree of heterogeneity. Risk of bias among included studies was also investigated.

Results

Of the identified 1134 papers, 53 were eligible for inclusion, providing 54 studies for analysis with one paper presenting both community and hospital studies. Compared to the community setting, resistance to ciprofloxacin was significantly higher in the hospital setting (pooled resistance 0.38, 95 % CI 0.36-0.41 versus 0.27, 95 % CI 0.24-0.31 in community-acquired UTIs, P < 0.001). Resistance significantly varied by region and country with the highest resistance observed in developing countries. Similarly, a significant rise in resistance over time was seen in studies reporting on community-acquired E. coli UTI.

Conclusions

Ciprofloxacin resistance in E. coli UTI is increasing and the use of this antimicrobial agent as empirical therapy for UTI should be reconsidered. Policy restrictions on ciprofloxacin use should be enhanced especially in developing countries without current regulations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1282-4) contains supplementary material, which is available to authorized users.

Representações sociais da infecção comunitária por profissionais da atenção primária

Resumo Objetivo Apreender as representações sociais elaboradas pelos profissionais da Atenção Primária sobre infecção comunitária e analisar como tais representações influenciam no controle da infecção e na qualidade da assistência. Métodos Pesquisa exploratória, qualitativa, realizada com 16 profissionais da saúde, selecionados por amostragem simples. Para coleta dos dados, utilizou-se formulário semiestruturado. Os dados foram processados e analisados pela Classificação Hierárquica Descendente. Resultados Foram obtidas quatro classes: Atenção Primária em saúde na gestão das infecções comunitárias; O papel da educação em saúde na prevenção e no controle das infecções; O conceito de infecção comunitária e fatores de risco; Medidas de prevenção e controle das infecções comunitárias. Conclusão As representações sociais sobre a infecção comunitária se organizam a partir da prática profissional, na qual os participantes reconhecem as dificuldades em conceituar o termo, elencar fatores de riscos e medidas de prevenção e controle, refletindo na qualidade da assistência prestada.

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.

Etiology of childhood bacteremia and timely antibiotics administration in the emergency department

BACKGROUND

Bacteremia is now an uncommon presentation to the children's emergency department (ED) but is associated with significant morbidity and mortality. Its evolving etiology may affect the ability of clinicians to initiate timely, appropriate antimicrobial therapy.

METHODS

A retrospective time series analysis of bacteremia was conducted in the Alder Hey Children's Hospital ED between 2001 and 2011. Data on significant comorbidities, time to empirical therapy, and antibiotic susceptibility were recorded.

RESULTS

A total of 575 clinical episodes were identified, and Streptococcus pneumoniae (n = 109), Neisseria meningitidis (n = 96), and Staphylococcus aureus (n = 89) were commonly isolated. The rate of bacteremia was 1.42 per 1000 ED attendances (95% confidence interval: 1.31-1.53). There was an annual reduction of 10.6% (6.6%-14.5%) in vaccine-preventable infections, and an annual increase of 6.7% (1.2%-12.5%) in Gram-negative infections. The pneumococcal conjugate vaccine was associated with a 49% (32%-74%) reduction in pneumococcal bacteremia. The rate of health care-associated bacteremia increased from 0.17 to 0.43 per 1000 ED attendances (P = .002). Susceptibility to empirical antibiotics was reduced (96.3%-82.6%; P < .001). Health care-associated bacteremia was associated with an increased length of stay of 3.9 days (95% confidence interval: 2.3-5.8). Median time to antibiotics was 184 minutes (interquartile range: 63-331) and 57 (interquartile range: 27-97) minutes longer in Gram-negative bacteremia than in vaccine-preventable bacteremia.

CONCLUSIONS

Changes in the etiology of pediatric bacteremia have implications for prompt, appropriate empirical treatment. Increasingly, pediatric bacteremia in the ED is health care associated, which increases length of inpatient stay. Prompt, effective antimicrobial administration requires new tools to improve recognition, in addition to continued etiological surveillance.

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.

No specific time window distinguishes between community-, healthcare-, and hospital-acquired bacteremia, but they are prognostically robust

OBJECTIVE

We examined whether specific time windows after hospital admission reflected a sharp transition between community and hospital acquisition of bacteremia. We further examined whether different time windows to distinguish between community acquisition, healthcare association (HCA), and hospital acquisition influenced the results of prognostic models.

DESIGN

Population-based cohort study.

SETTING

Hospitals in 3 areas of Denmark (2.3 million inhabitants) during 2000-2011.

METHODS

We computed graphs depicting proportions of males, absence of comorbidity, microorganisms, and 30-day mortality pertaining to bacteremia 0, 1, 2, …, 30, and 31 days and later after admission. Next, we assessed whether different admission (0-1, 0-2, 0-3, 0-7 days) and HCA (30, 90 days) time windows were associated with changes in odds ratio (OR) and area under the receiver operating characteristic (ROC) curve for 30-day mortality, adjusting for sex, age, comorbidity, and microorganisms.

RESULTS

For 56,606 bacteremic episodes, no sharp transitions were detected on a specific day after admission. Among the 8 combined time windows, ORs for 30-day mortality varied from 1.30 (95% confidence interval [CI], 1.23-1.37) to 1.99 (95% CI, 1.48-2.67) for HCA and from 1.36 (95% CI, 1.24-1.50) to 2.53 (95% CI, 2.01-3.20) for hospital acquisition compared with community acquisition. Area under the ROC curve changed marginally from 0.684 (95% CI, 0.679-0.689) to 0.700 (95% CI, 0.695-0.705).

CONCLUSIONS

No time transitions unanimously distinguished between community and hospital acquisition with regard to sex, comorbidity, or microorganisms, and no difference in 30-day mortality was seen for HCA patients in relation to a 30- or 90-day time window. ORs decreased consistently in the order of hospital acquisition, HCA, and community acquisition, regardless of time window combination, and differences in area under the ROC curve were immaterial.

Genome sequencing and genomic characterization of a tigecycline-resistant Klebsiella pneumoniae strain isolated from the bile samples of a cholangiocarcinoma patient

Background

The relationship between Klebsiella pneumoniae and nosocomial and community-acquired infections is well known, and K. pneumoniae resistance to most antibiotics is increasing worldwide. In contrast, tigecycline remains active against many bacterial strains, and serves as a last resort for treating multi-drug resistant bacterial infections. That tigecycline nonsusceptibility among K. pneumoniae isolates has been reported worldwide is worrying. However, the mechanisms of tigecycline resistance in K. pneumoniae are less well known. We report the genome sequence and genomic characterization of tigecycline-resistant K. pneumoniae strain 5422 isolated from the bile samples of a patient with cholangiocarcinoma.

Results

We sequenced the K. pneumoniae strain 5422 genome using next-generation sequencing technologies. Sequence data assembly revealed a 5,432,440-bp draft genome and 57.1% G + C content, which contained 5397 coding sequences. The genome has extensive similarity to other sequenced K. pneumoniae genomes, but also has several resistance-nodulation-cell division (RND) efflux pump genes that may be related to tigecycline resistance.

Conclusions

K. pneumoniae strain 5422 is resistant to multiple antibiotics. The genome sequence of the isolate and comparative analysis with other K. pneumoniae strains presented in this paper are important for better understanding of K. pneumoniae multi-drug resistance. The RND efflux pump genes identified in the genome indicate the presence of an antibiotic resistance mechanism prior to antibiotics overuse. The availability of the genome sequence forms the basis for further comparative analyses and studies addressing the evolution of the K. pneumoniae drug resistance mechanism and the K. pneumoniae transcriptome.