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

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

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

The pneumococcal conjugate vaccine had a sustained effect on Swedish children 8 years after its introduction

AIM

The pneumococcal conjugate vaccine, which covered seven serotypes of Streptococcus pneumoniae (PCV7), was introduced in Stockholm, Sweden, in 2007. It was replaced by a 13-valent vaccine (PCV13) in 2011. We previously reported a decreased incidence of pneumonia and sinusitis among young children 4 years after the introduction of the PCV7. This study followed the incidence of pneumonia, sinusitis, mastoiditis and meningitis for four more years.

METHODS

We studied validated hospital registry data covering children up to 17 years of age, who were hospitalised in the Stockholm region from 2003 to 2016, when the child population peaked at 485 687. All 11 115 cases diagnosed with pneumonia, coded as bacterial pneumonia, sinusitis, mastoiditis, bacterial meningitis or empyema, were identified. The controls had viral pneumonia or pyelonephritis.

RESULTS

The incidence rates for children under 2 years of age hospitalised for sinusitis, mastoiditis and meningitis decreased significantly by 61%-79% during the eight-year post-vaccination period. Hospitalisations for bacterial pneumonia decreased by 19%-25% in the same age group. These changes were probably due to both the vaccines and changes in diagnosis routines.

CONCLUSION

The effect of vaccination on children under 2 years of age was sustained 8 years after the introduction of the pneumococcal conjugate vaccines.

Contemporary Trends in Global Mortality of Sepsis Among Young Infants Less Than 90 Days: A Systematic Review and Meta-Analysis

Objective

Current knowledge on the global burden of infant sepsis is limited to population-level data. We aimed to summarize global case fatality rates (CFRs) of young infants with sepsis, stratified by gross national income (GNI) status and patient-level risk factors.

Methods

We performed a systematic review and meta-analysis on CFRs among young infants < 90 days with sepsis. We searched PubMed, Cochrane Central, Embase, and Web of Science for studies published between January 2010 and September 2019. We obtained pooled CFRs estimates using the random effects model. We performed a univariate analysis at patient-level and a meta-regression to study the associations of gestational age, birth weight, onset of sepsis, GNI, age group and culture-proven sepsis with CFRs.

Results

The search yielded 6314 publications, of which 240 studies (N = 437,796 patients) from 77 countries were included. Of 240 studies, 99 were conducted in high-income countries, 44 in upper-middle-income countries, 82 in lower-middle-income countries, 6 in low-income countries and 9 in multiple income-level countries. Overall pooled CFR was 18% (95% CI, 17-19%). The CFR was highest for low-income countries [25% (95% CI, 7-43%)], followed by lower-middle [25% (95% CI, 7-43%)], upper-middle [21% (95% CI, 18-24%)] and lowest for high-income countries [12% (95% CI, 11-13%)]. Factors associated with high CFRs included prematurity, low birth weight, age less than 28 days, early onset sepsis, hospital acquired infections and sepsis in middle- and low-income countries. Study setting in middle-income countries was an independent predictor of high CFRs. We found a widening disparity in CFRs between countries of different GNI over time.

Conclusion

Young infant sepsis remains a major global health challenge. The widening disparity in young infant sepsis CFRs between GNI groups underscore the need to channel greater resources especially to the lower income regions.

Systematic Review Registration

[www.crd.york.ac.uk/prospero], identifier [CRD42020164321].

A high percentage of hospital-acquired neonatal bacteraemia but rare resistance to standard antibiotic regimens

AIM

We examined community and hospital-acquired bacteraemia, namely bloodstream infections or meningitis, and looked at the clinical features and outcomes of cases.

METHODS

The study comprised infants under 3 months of age, who were admitted to a tertiary referral centre in northern Israel with bacteraemia from 2010-2019. Causative pathogens, antibiotic susceptibility and mortality were retrospectively recorded.

RESULTS

We identified 314 infants, 325 episodes of bacteraemia and 344 pathogens. Meningitis was identified in 22 (7.0%) infants. Hospital-acquired bacteraemia accounted for 84.8% of the 325 episodes. Coagulase-negative staphylococci (33.9%) was the most prevalent pathogen in the hospital-acquired cases, while Escherichia coli (37.2%) dominated the community-acquired cases. The susceptibility of Gram-negative early-onset sepsis cases to ampicillin-gentamicin or ampicillin-cefotaxime was 96% and 94.7% for hospital-acquired cases and 91.7% and 88% for community-acquired cases, respectively. Susceptibility to piperacillin-tazobactam or amikacin in late-onset sepsis were 92.8% and 98%, respectively, in hospital-acquired cases. The 30-day mortality was 5.7% in infants with hospital-acquired cases. Risk factors were Arab ethnicity (p < 0.028), haemodynamic instability (<0.001) and Gram-negative sepsis (0.043).

CONCLUSION

Most cases of bacteraemia were acquired during hospitalisation and these accounted for the majority of the deaths. Resistance to standard antibiotic regimens was rare.

Cephalosporin Resistance in Escherichia coli Isolated from Children with Septicemia in Mainland China from 2007 to 2017: A Systematic Review and Meta-Analysis

Background: Septicemia in children in mainland China has recently become a public health concern. Methods: A meta-analysis was performed on studies investigating the prevalence of cephalosporin-resistant Escherichia coli isolated from children with septicemia in mainland China from 2007 to 2017 following a search of relevant databases. Results: A total of 43 articles reporting 11 cephalosporins were included in the review. The results of the meta-analysis revealed that for the first-generation cephalosporins, the pooled summarized prevalence of resistance to cefazolin was 74.96% (95% confidence interval [CI]: 64.79-83.91) and cephalothin resistance was 62.28% (95% CI: 36.45-100). Regarding the second-generation cephalosporins, cefoxitin-resistant E. coli comprised 23.85% (95% CI: 10.60-40.40) and cefuroxime resistance was 60.32% (95% CI: 51.25-68.73). For the third-generation cephalosporins, the pooled summarized prevalence of resistance was 51.34% for cefotaxime (95% CI: 40.08-62.54), 40.43% for ceftazidime (95% CI: 31.07-50.15), 45.51% for cefoperazone (95% CI: 20.41-70.61), 12.10% for cefoperazone/sulbactam (95% CI: 6.55-18.76), 62.99% for ceftriaxone (95% CI: 55.00-70.98), and 0% for cefotetan. Among the fourth-generation cephalosporins, resistance to cefepime was 34.08% (95% CI: 25.91-43.31). Conclusions: Most third-generation cephalosporins (e.g., cefotaxime and ceftriaxone) retained high resistance rates throughout the 11-year study period without significant changes. The new fourth-generation cephalosporin, cefepime, is rapidly gaining resistance. Interestingly, ceftazidime, cefepime, and cefoperazone/sulbactam showed a recent decreasing trend of drug resistance. These situations may present a risk for treating children with septicemia and should be closely monitored and treated.

Clinical Characteristics of Nosocomial Bloodstream Infections in Neonates in Two Hospitals, China

BACKGROUND

The improvement of medical condition requires prolonged hospital stays, which increase the risk of nosocomial bloodstream infections (BSIs).

METHODS

All nosocomial BSI newborns in two hospitals were included, and the demographic and clinical characteristics of bacteremia patients were obtained from the information systems. Isolates were identified by biochemical assays. Antimicrobial susceptibility was determined using disk diffusion method.

RESULTS

Except for three same risk factors, intubation with mechanical ventilation was a risk factor in Chongqing, while low birth weight was a risk factor in Henan. Klebsiella pneumoniae was the predominant strain in Chongqing, and Escherichia coli was the most prevalent strain in Henan. The resistance rate of gram-negative bacteria in Henan was higher than that of strains in Chongqing.

CONCLUSIONS

The risk factors and resistance rate of pathogens were different in different areas. Therefore, treatment protocols should be established based on the trends of drug resistance and bacterial spectrum.

Antibiotic use during infectious episodes in the first 6 months of anticancer treatment-A Swedish cohort study of children aged 7-16 years

BACKGROUND

Children undergoing cancer therapy are at risk for infectious complications that require hospitalization and antimicrobial therapy. Host factors such as age and underlying disease may predict the risk of severe infections in these children. To describe the increased morbidity due to infections in children with cancer, we characterized the antibiotic use during the infectious complications in a national cohort of children 7-16 years of age with cancer.

PROCEDURE

Data on infectious complications were prospectively collected from the medical records of all newly diagnosed children with cancer, aged 7-16 years, in Sweden between 2004 and 2006. An episode of infection was defined as a period of time when oral or intravenous antimicrobial treatment was prescribed because of symptoms of infection.

RESULTS

A total of 230 infectious episodes occurred in 80 of the 101 patients. Pathogens were isolated in 15% of the blood cultures that showed a predominance of Gram-positive bacteria. Intravenous broad-spectrum antibiotics with cephalosporins and carbapenems were mostly used as single drugs but also in combination with aminoglycosides and glycopeptide. The median treatment length varied between 6 and 11 days depending on cancer diagnosis.

CONCLUSION

Our data demonstrate that infectious complications contribute significantly to morbidity in children with cancer aged 7-16 years. At the time of this survey, antibiotic prescription patterns varied and cephalosporins and carbapenems were mostly used. With increasing antibiotic resistance, a more stringent antibiotic stewardship with less use of cephalosporins and carbapenems should be encouraged for children with cancer. Data on prescription patterns should be incorporated as a quality measurement in pediatric cancer care.

Clonal Structure and Characterization of Staphylococcus aureus Strains from Invasive Infections in Paediatric Patients from South Poland: Association between Age, spa Types, Clonal Complexes, and Genetic Markers

The aim of current study was to examine clonal structure and genetic profile of invasive Staphylococcus aureus isolates recovered from infants and children treated at the Jagiellonian University Children’s Hospital of Krakow, Poland. The 107 invasive S. aureus isolates, collected between February 2012 and August 2014, were analysed retrospectively. Antimicrobial susceptibility testing, spa typing and DNA microarray analysis were performed to determine clonal distribution, diversity and gene content in regard to patients characteristics. In total, 107 isolates were recovered from 88 patients with clinical symptoms of invasive bacterial infection. The final set of 92 non-duplicate samples included 38 MRSA isolates. Additionally, a set of 54 S. aureus isolates collected during epidemiological screening was genotyped and analysed. There were 72 healthcare-associated (HCA) and 20 community-onset (CO) infection events caused by 33 and 5 MRSA isolates, respectively. The majority of isolates were affiliated with the major European clonal complexes CC5 (t003, spa-CC 002), CC45 (spa-CC 015), CC7 or CC15 (t084, t091, spa-CC 084). Two epidemic clones (CC5-MRSA-II or CC45-MRSA-IV) dominated among MRSA isolates, while MSSA population contained 15 different CCs. The epidemiological screening isolates belonged to similar genetic lineages as those collected from invasive infection cases. The HCA infection events, spa types t003, t2642 or CC5 were significantly associated with infections occurring in neonates and children under 5 years of age. Moreover, carriage of several genetic markers, including erm(A), sea (N315), egc-cluster, chp was significantly higher in isolates obtained from children in this age group. The spa types t091 and t008 were underrepresented among patients aged 5 years or younger, whereas spa type t008, CC8 and presence of splE was associated with infection in children aged 10 years or older. The HCA-MRSA strains were most frequently found in children under 5 years, although the majority of invasive infections was associated with MSSA strains. Moreover, an association between age group of children from the study population and a specific strain genotype (spa type, clonal complex or genetic content) was observed among the patients.

The aetiology of paediatric bloodstream infections changes after pneumococcal vaccination and group B streptococcus prophylaxis

AIM

This study explored the incidence and aetiology of bloodstream infections after patients received the pneumococcal conjugate vaccination and a risk-based intrapartum antibiotic prophylaxis against early onset sepsis caused by group B streptococcus. We also monitored clinically relevant antimicrobial resistance.

METHOD

We studied 3986 positive blood cultures from children up to 17 years of age at a paediatric hospital in Stockholm, Sweden, using data from medical records before and after the initiatives, to reduce early onset sepsis, were introduced in 2007 and 2008.

RESULTS

Bloodstream infections caused by Streptococcus pneumoniae declined by 42% overall (5.6 to 3.2/100 000) and by 62% in previously healthy children under 36 months of age (24.2 to 9.2/100 000). Early onset sepsis caused by group B streptococcus declined by 60% (0.5 to 0.2/1000 live born children). Bacterial meningitis caused by these bacteria decreased by 70%. Staphylococcus aureus and various Gram-negative bacteria became the dominant pathogens, in both previously healthy children and those with underlying disease. Overall, antimicrobial resistance remained low between the two 5-year study periods.

CONCLUSION

Pneumococcal conjugate vaccination and risk-based intrapartum antibiotic prophylaxis against group B streptococcus effectively decreased the incidence of bloodstream infections. Empirical antibiotic therapy should target Staphylococcus aureus in both community and hospital-acquired invasive bacterial infections.

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.

Impact of the lab-score on antibiotic prescription rate in children with fever without source: a randomized controlled trial

Background

The Lab-score, based on the combined determination of procalcitonin, C-reactive protein and urinary dipstick results, has been shown accurate in detecting serious bacterial infections (SBI) in children with fever without source (FWS) on retrospective cohorts. We aimed to prospectively assess the utility of the Lab-score in safely decreasing antibiotic prescriptions in children with FWS and to determine its diagnostic characteristics compared to common SBI biomarkers.

Methods

Randomized controlled trial in children 7 days to 36 months old with FWS, allocated either to the Lab-score group (Lab-score reported, blinded WBC count) or to the control group (WBC, bands and C-reactive protein determined, blinded procalcitonin and Lab-score), followed up until recovery. Demographic data, antibiotic prescription rate, admission rate and diagnostic properties of the Lab-score were analyzed.

Results

271 children were analyzed. No statistically significant difference concerning antibiotic prescription rate was observed: 41.2% (54 of 131) in the Lab-score group and 42.1% (59 of 140) in the control group (p = 1.000). If recommendations based on the Lab-score had been strictly applied, a hypothetical 30.6% treatment rate would have been encountered, compared to the overall 41.7% observed rate (p = 0.0095). A Lab-score ≥3 showed the following characteristics: sensitivity 85.1% (95% CI: 76.5–93.6%), specificity 87.3% (95% CI: 82.7–91.8%), positive predictive value 68.7% (95% CI: 58.7–78.7%), negative predictive value 94.1% (95% CI: 91.5–97.9%), positive and negative likelihood ratios: 6.68 and 0.17 respectively. Area under the receiver operating characteristic curve was best for the Lab-score (0.911, 95% CI: 0.871–0.950).

Discussion

No difference regarding antibiotic treatment rate was observed when using the Lab-score, due to lack of adherence to the related recommendations. However, if strictly followed, a significant 26.5% reduction of antibiotic prescriptions would have been encountered. Medical education needs to be reinforced in order to observe rather than treat low-risk well-appearing children with FWS.

Trial Registration

ClinicalTrials.gov NCT02179398

Species determination within Staphylococcus genus by extended PCR-restriction fragment length polymorphism of saoC gene

Genetic methods based on PCR-restriction fragment length polymorphism (RFLP) are widely used for microbial species determination. In this study, we present the application of saoC gene as an effective tool for species determination and within-species diversity analysis for Staphylococcus genus. The unique sequence diversity of saoC allows us to apply four restriction enzymes to obtain RFLP patterns, which appear highly distinctive even among closely related species as well as atypical isolates of environmental origin. Such patterns were successfully obtained for 26 species belonging to Staphylococcus genus. What is more, tracing polymorphisms detected by different restriction enzymes allowed for basic phylogeny analysis for Staphylococcus aureus, which is potentially applicable for other staphylococcal species.