Pediatric blood cultures-turning up the volume: a before and after intervention study.

The major determinant of blood culture (BC) diagnostic performance is blood volume, and pediatric sample volumes are frequently low. We aimed to assess BC volumes in our institution, design an intervention to increase volumes, and assess its impact. All pediatric BCs submitted over a 7-month period to the microbiology laboratory in a university hospital (including emergency department, pediatric ward, and neonatal unit) were included. A pre-intervention period assessed current practice. A multi-faceted intervention (education, guideline introduction, active feedback strategies) was collaboratively designed by all stakeholders. Impact was assessed in a post-intervention period. The main outcome measures included the percentage of samples adequately filled using three measures of sample adequacy (1) manufacturer-recommended minimum validated volume-> 0.5 ml, (2) manufacturer-recommended optimal minimum volume-> 1.0 ml, (3) newly introduced age-specific recommendations. Three hundred ninety-eight pre-intervention and 388 post-intervention samples were included. Initial volumes were low but increased significantly post-intervention (median 0.77 ml vs. 1.52 ml), with multivariable regression analysis estimating volumes increased 89% post-intervention. There were significant increases in all measures of volume adequacy, including an increase in age-appropriate filling (20.4-53.1%), with less improvement in those aged > 3 years. Overall, 68.4% of pathogens were from adequately filled cultures, while 76% of contaminants were from inadequately filled cultures. A pathogen was detected in a higher proportion of adequately filled than inadequately filled cultures (9.4% vs. 2.2%, p < 0.001).  Conclusion: Blood volume impacts BC sensitivity, with lower volumes yielding fewer pathogens and more contaminants. Focused intervention can significantly improve volumes to improve diagnostic performance. What is Known: • Blood volume is the major determinant of blood culture positivity, and yet pediatric blood culture volumes are frequently low, resulting in missed pathogens and increased contamination. What is New: • Adequately filled (for age) blood cultures have a pathogen detection rate three times higher than inadequately filled blood cultures. • This interventional study shows that collaboratively designed multi-modal interventions including focus on accurate volume measurement can lead to significant increases in blood volumes and improve blood culture diagnostic performance.

Paediatric Escherichia coli urinary tract infection: susceptibility trends and clinical management-a retrospective analysis of a 10-year period.

BACKGROUND: Escherichia coli is the predominant urinary pathogen in children. Irish and international studies have demonstrated increasing antimicrobial resistance (AMR) to antibiotics such as co-amoxiclav. AIMS: We aimed to (1) examine the AMR patterns of paediatric urinary E. coli isolates, from both hospital and community sources, over a 10-year period; (2) assess the effectiveness of Children's Health Ireland (CHI) antimicrobial guidance given local susceptibility data; and (3) review the clinical management of an admitted patient sub-set over a 6-year period. METHODS: Pure growth of urinary E. coli from patients aged ≤ 14 from 2012 to 2021 were analysed for AMR. Differences in susceptibility rates were assessed. A retrospective chart review conducted on inpatients aged ≥ 2 months to ≤ 14 years, 2016-2021. RESULTS: E. coli accounted for 70.8% of likely significant positive pure growth cultures (9314 isolates). Susceptibility to co-amoxiclav significantly increased over time, from 66.7% to 80.4% (2016-2021, p < 0.001). Nitrofurantoin and cefalexin had significantly higher susceptibility rates than trimethoprim (< 70% annually). 85.1% of isolates were susceptible to the combination of co-amoxiclav and gentamicin, recommended for those > 2months and systemically unwell. The additional gain in empiric susceptibility provided by gentamicin above that provided by co-amoxiclav alone has fallen from 16.4% to 6.7% (2016-2021). The 222 clinical cases reviewed showed improved antimicrobial guideline compliance over time. CONCLUSIONS: This study provides important regional AMR data. Co-amoxiclav susceptibility increased significantly over time, contrasting with previous studies. This was temporally associated with stewardship measures reducing co-amoxiclav prescribing. Decreasing utility of gentamicin supports recent CHI guideline updates reducing gentamicin use.

Systematic review of host genomic biomarkers of invasive bacterial disease: Distinguishing bacterial from non-bacterial causes of acute febrile illness.

BACKGROUND: Infectious diseases play a significant role in the global burden of disease. The gold standard for the diagnosis of bacterial infection, bacterial culture, can lead to diagnostic delays and inappropriate antibiotic use. The advent of high- throughput technologies has led to the discovery of host-based genomic biomarkers of infection, capable of differentiating bacterial from other causes of infection, but few have achieved validation for use in a clinical setting. METHODS: A systematic review was performed. PubMed/Ovid Medline, Ovid Embase and Scopus databases were searched for relevant studies from inception up to 30/03/2022 with forward and backward citation searching of key references. Studies assessing the diagnostic performance of human host genomic biomarkers of bacterial infection were included. Study selection and assessment of quality were conducted by two independent reviewers. A meta-analysis was undertaken using a diagnostic random-effects model. The review was registered with PROSPERO (ID: CRD42021208462). FINDINGS: Seventy-two studies evaluating the performance of 116 biomarkers in 16,216 patients were included. Forty-six studies examined TB-specific biomarker performance and twenty-four studies assessed biomarker performance in a paediatric population. The results of pooled sensitivity, specificity, negative and positive likelihood ratio, and diagnostic odds ratio of genomic biomarkers of bacterial infection were 0.80 (95% CI 0.78 to 0.82), 0.86 (95% CI 0.84 to 0.88), 0.18 (95% CI 0.16 to 0.21), 5.5 (95% CI 4.9 to 6.3), 30.1 (95% CI 24 to 37), respectively. Significant between-study heterogeneity (I2 77%) was present. INTERPRETATION: Host derived genomic biomarkers show significant potential for clinical use as diagnostic tests of bacterial infection however, further validation and attention to test platform is warranted before clinical implementation can be achieved. FUNDING: No funding received.

Vaccine hesitancy and reported non-vaccination in an Irish pediatric outpatient population.

Vaccine hesitancy is defined as a delay in acceptance, or refusal, of vaccines, despite availability. It is a complex and context specific phenomenon and identified as a global health priority. The "Parent Attitudes about Childhood Vaccines" (PACV) questionnaire is a validated tool for identifying vaccine hesitancy. Our aim was to use the PACV to assess vaccine hesitancy and its relationship with reported non-vaccination in an Irish population, for the first time. Our participants were parents or caregivers of children attending general pediatric clinics in a tertiary pediatric hospital in Dublin, Ireland, between September and December 2018. In total, 436 participants completed the questionnaire. 5.5% of our population reported non-vaccination. Human papilloma virus and measles, mumps, rubella vaccines were the most commonly cited vaccines of concern (11.5% and 6.7%, respectively), and autism spectrum disorder was the most commonly side effect of concern (4.3%). Mean PACV score was 26.9 (SD 19.1), with a significant difference between non-vaccinators and vaccinators (53.2 vs 25.3, p<0.001). Safety and efficacy concerns were the major contributor to non-vaccination. 14.4% of our population were vaccine-hesitant using the conventional cut-off score, which increased to 22% when using an optimal cut-off which maximized sensitivity and specificity. The accuracy of the PACV score to identify non-vaccination was good (area under the ROC curve = 0.827), and the optimal cut-off had a high negative predictive value (98.5%).Conclusion: PACV identified reported non-vaccination with high accuracy in our population. It may be useful to screen vaccine-hesitant parents who could benefit from interventions to improve uptake. What is Known: • Vaccine hesitancy is a leading threat to global health, with falls in vaccine uptake associated with disease outbreaks worldwide. • The Parent Attitudes about Childhood Vaccines (PACV) questionnaire is a validated measure of vaccine hesitancy and correlates with non-vaccination in many populations. What is New: • This large study in a pediatric outpatient clinic setting represents the first use of the PACV in a Western European population to assess vaccination hesitancy. • The PACV may be an effective way of screening a pediatric clinic population to identify vaccine-hesitant parents or caregivers for targeted vaccine promotion.