Leukocyte counts in urine reflect the risk of concomitant sepsis in bacteriuric infants: a retrospective cohort study

Infant Escherichia coli urinary tract infection: is it associated with meningitis?

OBJECTIVES

Determine the prevalence of coexisting bacterial meningitis (BM) and sterile cerebrospinal fluid (CSF) with raised white cell count relative to age ('pleocytosis') in the presence of Escherichia coli urinary tract infection (UTI), with the addition of CSF E. coli PCR analysis.

DESIGN

Single-centre, retrospective cohort study.

SETTING

Tertiary paediatric hospital.

PARTICIPANTS

Children aged 8 days to 2 years, with a pure growth of E. coli from urine and a CSF sample taken within 48 hours of a positive urine culture between 1 January 2014 and 30 April 2019.

MAIN OUTCOME MEASURE

Prevalence of coexisting E. coli BM with UTI, defined as a pure growth E. coli from urine and a CSF culture with pure growth E. coli and/or positive E. coli PCR.

RESULTS

1903 patients had an E. coli UTI, of which 314 (16%) had a CSF sample taken within 48 hours. No cases of coexisting E. coli BM were identified. There were 71 (23%) cases of pleocytosis, 57 (80%) of these had PCR analysis, all of which were E. coli PCR not detected. Patients aged 1-6 months accounted for 72% of all lumbar punctures (LPs).

CONCLUSION

The risk of E. coli UTI and coexisting E. coli BM is low. There is potential to reduce the number of routine LPs in infants with a diagnosis of E. coli UTI with the greatest impact in children up to 6 months of age. CSF E. coli PCR can help further reduce post-test probability of BM in the setting of pleocytosis.

Diagnostic value of biomarkers for paediatric urinary tract infections in primary care: systematic review and meta-analysis

Background

Accurate diagnosis of urinary tract infection is essential as children left untreated may suffer permanent renal injury.

Aim

To compare the diagnostic values of biomarkers or clinical prediction rules for urinary tract infections in children presenting to ambulatory care.

Design and setting

Systematic review and meta-analysis of ambulatory care studies.

Methods

Medline, Embase, WOS, CINAHL, Cochrane library, HTA and DARE were searched until 21 May 2021. We included diagnostic studies on urine or blood biomarkers for cystitis or pyelonephritis in children below 18 years of age. We calculated sensitivity, specificity and likelihood ratios. Data were pooled using a bivariate random effects model and a Hierarchical Summary Receiver Operating Characteristic analysis.

Results

Seventy-five moderate to high quality studies were included in this review and 54 articles in the meta-analyses. The area under the receiver-operating-characteristics curve to diagnose cystitis was 0.75 (95%CI 0.62 to 0.83, n = 9) for C-reactive protein, 0.71 (95% CI 0.62 to 0.80, n = 4) for procalcitonin, 0.93 (95% CI 0.91 to 0.96, n = 22) for the dipstick test (nitrite or leukocyte esterase ≥trace), 0.94 (95% CI 0.58 to 0.98, n = 9) for urine white blood cells and 0.98 (95% CI 0.92 to 0.99, n = 12) for Gram-stained bacteria. For pyelonephritis, C-reactive protein < 20 mg/l had LR- of 0.10 (95%CI 0.04–0.30) to 0.22 (95%CI 0.09–0.54) in children with signs suggestive of urinary tract infection.

Conclusions

Clinical prediction rules including the dipstick test biomarkers can support family physicians while awaiting urine culture results. CRP and PCT have low accuracy for cystitis, but might be useful for pyelonephritis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01530-9.

Bacterial meningitis in febrile young infants acutely assessed for presumed urinary tract infection: a systematic review

Urinary tract infections, the most common severe bacterial infections in young infants, may be associated with co-existing meningitis. There is no consensus on when to perform a lumbar puncture in these infants. Our aim was to quantify the frequency of co-existing bacterial meningitis in febrile young infants acutely assessed for presumed urinary tract infections. We systematically reviewed PubMed, EMBASE, and the Cochrane Library for studies including infants ≤ 3 months with suspected/confirmed urinary tract infections, who underwent a lumbar puncture. Two investigators independently reviewed articles for inclusion and extracted relevant data. Our outcomes were culture-confirmed meningitis and identification of low-/high-risk criteria of meningitis. Overall 20/2079 studies, including 4191 infants, met inclusion criteria. A total of 11 infants had bacterial meningitis (frequency between 0 and 2.1% across studies) and were mostly neonates. Of 253 infants meeting the low-risk criteria (well-appearing, age > 21 days, procalcitonin ≤ 0.5 ng/ml, and C reactive protein ≤ 20 mg/L) none developed meningitis, but only 15 underwent lumbar puncture.Conclusion: Co-existing bacterial meningitis in febrile young infants with urinary tract infection is rare. In those meeting low-risk criteria, a lumbar puncture may not be indicated. A case by case assessment should be made in infants not meeting low-risk criteria.Trial registration: CRD42018105339 What is known: • When caring for febrile infants ≤ 3 months with urinary tract infections, clinicians may have uncertainty on whether to perform a lumbar puncture (LP) for possible co-existing meningitis What is new: • An up-to-date systematic review of 20 studies found the frequency of co-existing meningitis in this population to be between 0 and 2.1% • Despite limited data, an LP may not be indicated in infants meeting low-risk criteria (being well-appearing, age > 21 days, procalcitonin ≤ 0.5 ng/ml, C reactive protein ≤ 20 mg/L). Ill-appearance and neonatal age appear to be significant risk factors of co-existing meningitis.

Risk of Meningitis in Infants Aged 29 to 90 Days with Urinary Tract Infection: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine the risk of bacterial meningitis in infants aged 29-90 days with evidence of urinary tract infection (UTI).

METHODS

PubMed (MEDLINE), Embase, and the Cochrane Library were systematically searched for studies reporting rates of meningitis in infants aged 29-90 days with abnormal urinalysis or urine culture. Observational studies in infants with evidence of UTI who underwent lumbar puncture (LP) reporting age-specific event rates of bacterial meningitis and sterile cerebrospinal fluid pleocytosis were included. Prevalence estimates for bacterial meningitis in infants with UTI were pooled in a random effects meta-analysis.

RESULTS

Three prospective and 17 retrospective cohort studies were included in the meta-analysis. The pooled prevalence of concomitant bacterial meningitis in infants with UTI was 0.25% (95% CI, 0.09%-0.70%). Rates of sterile pleocytosis ranged from 0% to 29%. Variation in study methods precluded calculation of a pooled estimate for sterile pleocytosis. In most studies, the decision to perform a LP was up to the provider, introducing selection bias into the prevalence estimate.

CONCLUSIONS

The risk of bacterial meningitis in infants aged 29-90 days with evidence of UTI is low. A selective approach to LP in infants identified as low risk for meningitis by other clinical criteria may be indicated.

Epidemiology of Bacteremia in Previously Healthy Febrile Infants: A Follow-up Study

OBJECTIVE

Describe the etiology of bacteremia among a geographically diverse sample of previously well infants with fever admitted for general pediatric care and to characterize demographic and clinical characteristics of infants with bacteremia according to bacterial etiology. We hypothesized that the epidemiology of bacteremia in febrile infants from a geographically diverse cohort would show similar results to smaller or single-center cohorts previously reported.

METHODS

This was a retrospective review of positive, pathogenic blood cultures in previously healthy, febrile infants≤90 days old admitted to a general unit. In total, there were 17 participating sites from diverse geographic regions of the United States. Cultures were included if the results were positive for bacteria, obtained from an infant 90 days old or younger with a temperature≥38.0°C, analyzed using an automated detection system, and treated as pathogenic.

RESULTS

Escherichia coli was the most prevalent species, followed by group B Streptococcus, Streptococcus viridans, and Staphylococcus aureus. Among the most prevalent bacteria, there was no association between gender and species (Ps>.05). Age at presentation was associated only with Streptococcus pneumoniae. There were no cases of Listeria monocytogenes.

CONCLUSIONS

Our study confirms the data from smaller or single-center studies and suggests that the management of febrile well-appearing infants should change to reflect the current epidemiology of bacteremia. Further research is needed into the role of lumbar puncture, as well as the role of Listeria and Enterococcus species in infantile bacteremia.

The age-related risk of co-existing meningitis in children with urinary tract infection

Objective

The primary aim of this study was to determine age-stratified rates of co-existing bacterial meningitis in children with urinary tract infection (UTI). The secondary aims of this study were to determine the causative pathogens of UTI, and the clinical features and outcome of children with co-existing meningitis.

Methods

Analysis of data collected over a nine-year period at a tertiary pediatric hospital in Australia. Study population: children below 16 years of age with culture-confirmed UTI and a paired CSF sample.

Results

A total of 748 episodes in 735 cases were included in the final analysis. The commonest pathogens causing UTI were Escherichia coli (67.4%), Enterococcus faecalis (8.4%), Klebsiella oxytoca (3.5%) and Klebsiella pneumoniae (3.5%). Only two (1.2%; 95% CI: 0.15–4.36%) of 163 neonates (between 0 and 28 days of age) with UTI had co-existing meningitis. Both presented with pyrexia, irritability and lethargy, and recovered uneventfully with antibiotic treatment. There were no cases of co-existing meningitis among 499 infants (between 29 days and 12 months of age) with UTI (95% CI: 0.00–0.74%), or any of the 86 children aged 12 months or over (95% CI: 0.00–4.20%).

Conclusions

These findings indicate that clinicians should have a low threshold to perform a lumbar puncture in neonates with UTI, as the risk of co-existing meningitis is not insignificant in this age group. In contrast, beyond the neonatal period, the risk is small and a more selective approach is warranted.