Prevalence and predictors of bacterial meningitis in young infants with fever without a source

Scoping review of clinical decision aids in the assessment and management of febrile infants under 90 days of age

BACKGROUND

Clinical decision aids (CDA) play an important role in the management of young febrile infants (under 90 days of age) who are at risk of serious or invasive bacterial infections (SBI/IBI). Since 2010, a number of tailored CDAs have been developed that allow for lower-risk infants to be managed safely while undergoing fewer investigations and not receiving parenteral antibiotics. We aimed to map the CDAs developed since 2010, their derivation methodology, and their variable components.

METHODS

A scoping review based on the Joana Briggs Institute framework was conducted for studies published between 2010 and 2025. A database search was conducted using Medline, Embase, Scopus, Web of Science, Google Scholar, and the Cochrane library. Studies evaluating the derivation, validation, and application of CDAs for the assessment of febrile infants were eligible for inclusion. Two reviewers independently screened, analysed, and extracted data from the literature.

RESULTS

A total of 32 studies met the inclusion criteria. The majority of studies were conducted in North America and Canada (56%), followed by Europe (28%), and Asia (16%). Of the 32 studies, 14 were retrospective, 9 prospective and 9 secondary analysis of an available dataset. There were 32 CDAs that were either derived or validated across 32 studies. The derivation methodology was classified into four themes: (i) expert consensus and evidence synthesis; (ii) regression analysis; (iii) recursive partitioning; and (iv) machine learning. CDAs typically either identified a low-risk cohort through sequential assessment (n = 12) or predicted the risk of IBI/SBI using prediction models (n = 20). CDA sensitivity and specificity ranged from 46 - 100% and 9 - 95% respectively for SBI/IBI. The majority (n = 18) of the more complex CDA prediction models have been published in the last five years. The most common variables included within the CDAs were age, urinalysis, height of fever, C-reactive protein, and absolute neutrophil count.

CONCLUSION

This scoping review highlights a wide range of CDAs with a trend towards prediction modelling rather than sequential assessment in the last five years. There is still variability in CDA properties, applicability, and diagnostic performance, necessitating further validation of common CDA and prediction models.

Role of urine Gram stain in young febrile infants with a suspected urinary tract infection: a cohort study

OBJECTIVE

To analyse the performance of the urine Gram stain for predicting a positive urine culture (UC) in young infants with fever without source (FWS) and pyuria.

DESIGN

Observational study; secondary analysis of a prospective registry-based cohort study.

SETTING

Paediatric emergency department; tertiary teaching hospital.

PATIENTS

Infants ≤90 days old with FWS, pyuria and urine Gram stain requested seen between 2010 and 2022.

MAIN OUTCOME MEASURE

Performance of the Gram stain, defined as positive if any bacteria were seen, for predicting urinary tract infection (UTI: UC by urethral catheterisation growing >10 000 CFU/mL of a single bacterial pathogen).

RESULTS

Among 367 febrile infants with pyuria, 281 (76.6%) had a positive Gram stain and 306 (83.3%) had a positive UC (277; 90.5% Escherichia coli).Rates of positive UC in patients with positive and negative Gram stains were 97.2% and 38.4%, respectively (p<0.01), showing a sensitivity of 89.2% (95% CI: 85.2% to 92.2%) and a specificity of 86.9% (95% CI: 76.2% to 93.2%). Sensitivity was lower for diagnosing UTIs caused by bacteria other than E. coli (69.0% vs 91.3% for UTIs caused by E. coli; p<0.01).Two (2.1%) of the 86 infants with negative Gram stains were diagnosed with bacteraemia unrelated to a UTI (Streptococcus pneumoniae and Staphylococcus aureus).

CONCLUSIONS

Around a third of infants with pyuria and a negative Gram stain will eventually be diagnosed with a UTI. These patients have a higher rate of UTIs caused by bacteria other than E. coli. Bacterial infections other than UTIs should also be considered in such cases.

Performance of Febrile Infant Algorithms by Duration of Fever

OBJECTIVES

To analyze the performance of commonly used blood tests in febrile infants ≤90 days of age to identify patients at low risk for invasive bacterial infection (bacterial pathogen in blood or cerebrospinal fluid) by duration of fever.

METHODS

We conducted a secondary analysis of a prospective single-center registry that includes all consecutive infants ≤90 days of age with fever without a source evaluated at 1 pediatric emergency department between 2008 and 2021. We defined 3 groups based on caregiver-reported hours of fever (<2, 2-12, and ≥12) and analyzed the performance of the biomarkers and Pediatric Emergency Care Applied Research Network, American Academy of Pediatrics, and Step-by-Step clinical decision rules.

RESULTS

We included 2411 infants; 76 (3.0%) were diagnosed with an invasive bacterial infection. The median duration of fever was 4 (interquartile range, 2-12) hours, with 633 (26.3%) patients with fever of <2 hours. The area under the curve was significantly lower in patients with <2 hours for absolute neutrophil count (0.562 vs 0.609 and 0.728) and C-reactive protein (0.568 vs 0.760 and 0.812), but not for procalcitonin (0.749 vs 0.780 and 0.773). Among well-appearing infants older than 21 days and negative urine dipstick with <2 hours of fever, procalcitonin ≥0.14 ng/mL showed a better sensitivity (100% with specificity 53.8%) than that of the combination of biomarkers of Step-by-Step (50.0% and 82.2%), and of the American Academy of Pediatrics and Pediatric Emergency Care Applied Research Network rules (83.3% and 58.3%), respectively.

CONCLUSIONS

The performance of blood biomarkers, except for procalcitonin, in febrile young infants is lower in fever of very short duration, decreasing the accuracy of the clinical decision rules.

Clinical Features and a Prediction Nomogram for Prognosis in Children with Escherichia coli Meningitis

BACKGROUND

We aimed to build a prediction nomogram for early prediction of poor prognosis in children with Escherichia coli meningitis and analyzed the course of treatment and discharge criteria.

METHODS

Eighty-seven pediatric patients with E coli meningitis were retrospectively recruited from the Children's Hospital of Chongqing Medical University between June 2012 and November 2021. Univariate analysis and binary logistic analysis were used to evaluate the risk factors, and the prediction model was built.

RESULTS

E coli meningitis is more common in children <3 months old in our study (86.2%). Common complications were subdural effusion (39.1%), followed by hydrocephalus (13.8%) and repeated convulsions (12.6%). The mortality rate and sequelae rate of E coli meningitis in children was ∼10.9% and ∼6.3%, respectively. Univariate analysis showed that 13 clinical indicators were associated with poor prognosis of E coli meningitis in children. In binary logistic analysis, risk factors were seizures (P = .032) and the last cerebrospinal fluid glucose content before discharge (P = .002). A graphical nomogram was designed. The area under the receiver operating characteristic curve was 0.913. The Hosmer-Lemeshow test showed that the model was a good fit (P = .648). Internal validation proved the reliability of the prediction nomogram.

CONCLUSIONS

E coli meningitis is more common in children <3 months old in our study. The rate of complications and sequelae are high. The prediction nomogram could be used to assess the risk of poor prognosis in children with E coli meningitis by clinicians.

Rate of invasive bacterial infection in recently vaccinated young infants with fever without source

OBJECTIVE

To compare the rates of invasive bacterial infection (IBI) (bacterial pathogen in blood or cerebrospinal fluid) and urinary tract infection (UTI) in febrile infants between 42 and 90 days of age who had and had not been vaccinated in the previous 48 hours.

DESIGN

Observational study; secondary analysis of a prospective registry-based cohort study.

SETTING

Paediatric emergency department.

PATIENTS

Infants 42-90 days of age with fever without source seen between 2010 and 2021.

MAIN OUTCOME MEASURES

Rates of IBI (bacterial pathogen in blood or cerebrospinal fluid) and UTI (urine culture obtained by an aseptic method yielding growth of ≥10 000 cfu/mL with associated leucocyturia).

RESULTS

We included 1522 infants, including 185 (12.2%) vaccinated in the previous 48 hours. Overall, 19 (1.25%) were diagnosed with an IBI and 282 (18.5%) with a UTI. No recently immunised infants were diagnosed with an IBI (vs 19, 1.4% of those not recently immunised, p=0.2). The UTI rate was higher in infants not recently immunised (20.1% vs 7.0%, p<0.01; OR: 3.3 (1.9-5.9)).

CONCLUSIONS

Although the rate of UTI in recently immunised infants 42-90 days old with fever without a source is lower than in those not recently immunised, recommending screening for UTI seems appropriate. If the lower rate of IBI among recently immunised well-appearing infants is confirmed, the recommendation to systematically perform blood tests in these infants should be reconsidered.

A Nomogram to Predict Bacterial Meningitis-associated Hydrocephalus: A Single-Center Retrospective Study

OBJECTIVE

We aimed to develop a predictive nomogram for the early detection of hydrocephalus in children with bacterial meningitis.

METHODS

This retrospective study was based on data of children with bacterial meningitis admitted to our hospital between January 2016 and December 2020. Risk factors were evaluated using univariate analysis, and the predictive model/nomogram was built using binary logistic analysis. A nomogram calibration plot, Hosmer-Lemeshow test and receiver operating characteristic (ROC) curve evaluated the predictive performance. Ordinary bootstrapping processed the internal validation.

RESULTS

We enrolled 283 patients who matched the inclusion criteria, among whom 41 cases (14.49%) had confirmed bacterial meningitis-associated hydrocephalus (BMAH). The incidence of sequelae in the patients with BMAH was 88.9% (24/27), which was significantly higher than that in the patients without BMAH. Univariate regression analysis revealed that 14 clinical indicators were associated with BMAH. Multivariate analysis identified 4 variables as independent risk factors to establish the predictive model: repeated seizures, loss of consciousness, procalcitonin ≥7.5 ng/dL and mechanical ventilation. And a graphical nomogram was designed. The area under the ROC curve was 0.910. In the Hosmer-Lemeshow test the P value was 0.610. The mean absolute error in the calibration plot was 0.02. Internal validation showed the testing set was in good accordance with the original set when internal validation was performed.

CONCLUSIONS

The predictive model/nomogram of BMAH could be used by clinicians to determine hydrocephalus risk.

Back to School: Academic Functioning and Educational Needs among Youth with Acquired Brain Injury

Youth with a history of traumatic or non-traumatic acquired brain injury are at increased risk for long-lasting cognitive, emotional, behavioral, social, and physical sequelae post-injury. Such sequelae have great potential to negatively impact this population’s academic functioning. Consistently, poorer academic achievement and elevated need for educational supports have been well-documented among youth with a history of acquired brain injury. The current paper reviews the literature on neuropsychological, psychiatric, and academic outcomes of pediatric acquired brain injury. A discussion of special education law as it applies to this patient population, ongoing limitations within the field, and a proposal of solutions are also included.

Utility of the systemic immune-inflammation index to predict serious bacterial infections in infants with fever without a source

INTRODUCTION

This study analyzed the utility of the systemic immune-inflammation index (SII) in predicting serious bacterial infections (SBIs) in infants with fever without a source (FWS).

METHODS

Infants (aged 1-4 months) evaluated in the pediatric emergency department for FWS were divided into two groups: with SBI and without SBI. The efficacy of inflammatory markers in predicting SBI was compared.

RESULTS

The study included 223 infants with a mean age of 76.65 ± 25.42 days; 62 (27.8%) of them were included in the SBI group, and all of them were diagnosed with a urinary tract infection (UTI). The hospitalization rate and length of hospital stay were significantly higher in UTI patients (p < 0.001 for each). The mean SII was 795.76 ± 475.85 in the SBI group and 318.24 ± 300.70 in the non-SBI group, and there was a significant difference between the groups (p < 0.001). In diagnosis of SBI, the area under the curve values were found to be 0.89 [95% confidence interval (CI): 0.85-0.94] for C-reactive protein (CRP), 0.86 (95% CI: 0.81-0.91) for absolute neutrophil count (ANC), 0.84 (95% CI: 0.78-0.89) for the SII, and 0.81 (95% CI: 0.74-0.87) for WBC. In the multivariate logistic regression analysis, high CRP and SII values were found to be predictive factors for UTI without bacteremia (p < 0.001 and p = 0.008, respectively).

CONCLUSION

We found that high CRP and SII values could be predictive for UTI without bacteremia in infants with FWS. The SII may be preferred because it can be easily calculated using the hemogram results, is not accompanied by extra costs, and does not require further blood collection.

COVID-19 Infection in Well-Appearing 30- to 90-Day-Old Infants with Fever without a Source

Fever without a source (FWS) is common clinical status in the young infants. The aim of this study was to evaluate the clinical and laboratory findings of coronavirus disease (COVID-19) infection in well-appearing infants with FWS. Well-appearing febrile infants between 30 and 90 days who were evaluated as FWS in the pediatric emergency department and tested for COVID-19 were divided into two groups: COVID-19 (+) and (-). The clinical and laboratory findings of the patients were compared. The study included 95 febrile infants with FWS, and the mean age was 59.62 ± 16.82 days. The nasopharyngeal COVID-19 polymerase chain reaction test results of 29/95 (30.5%) patients were positive, while 66/95 (69.5%) were negative. The complaints of irritability and nasal congestion were found to be significantly more common in COVID-19-positive patients (p = 0.04 and p = 0.041, respectively). The hospitalization rate (p = 0.009), length of hospital stay (p = 0.026), initiation of antibiotic treatment (p < 0.001) and duration of antibiotic treatment (p = 0.036) were significantly lower in the COVID-19 (+) patients. The C-reactive protein (CRP, p < 0.001), absolute neutrophil count (ANC, p < 0.001), absolute lymphocyte count (ALC, p = 0.015), white blood cell (WBC, p < 0.001) and systemic immune-inflammation index (SII, p < 0.001) were found to be significantly lower in the COVID-19 (+) patient group. There was no significant difference between the groups in terms of neutropenia, lymphopenia or leukopenia. COVID-19 infection may present as an FWS. During the pandemic period, testing for COVID-19 among infants who were evaluated as FWS may reduce unnecessary hospitalizations and antibiotic treatments, and shorten hospital stays and duration of antibiotics.

Blood enterovirus polymerase chain reaction testing in young febrile infants

OBJECTIVE

To analyse the impact of blood enterovirus and human parechovirus PCR (ev-PCR) testing in young infants with fever without a source (FWS).

DESIGN

Observational study, subanalysis of a prospective registry.

SETTING

Paediatric emergency department.

PATIENTS

Infants ≤90 days of age with FWS seen between September 2015 and August 2019 with blood ev-PCR, blood and urine cultures and urine dipstick test performed.

MAIN OUTCOME MEASURES

Prevalence of invasive bacterial infection (IBI: bacterial pathogen in blood or cerebrospinal fluid) in infants with positive or negative ev-PCR test results. Secondarily, we also compared length of stay and antibiotic treatment in hospitalised infants.

RESULTS

Of 703 infants, 174 (24.7%) had a positive blood ev-PCR and none of them were diagnosed with an IBI (vs 2.6% (95% CI 1.3% to 4.0%) of those with a negative result, p=0.02). Prevalence of non-IBI (mainly urinary tract infection) was also lower among infants with a positive blood ev-PCR (2.3% (95% CI 0.1% to 4.5%) vs 17.6% (95% CI 14.3% to 20.8%), p<0.01).Overall, 258 infants were hospitalised (36.6%) and 193 (74.8%) of them received antibiotics. Length of hospital stay and antibiotic treatment were shorter in those with a positive blood ev-PCR (median: 3 days vs 5 days and 1 day vs 5 days, respectively; p<0.01). Differences remained statistically significant among well-appearing infants >21 days old with normal urine dipstick.

CONCLUSION

Blood ev-PCR identifies a group of infants under 90 days of age with FWS at very low risk of IBI. This test may help to guide clinical decision making in young febrile infants.

Eliminating Lumbar Puncture for Low-Risk Febrile Infants: A Quality Improvement Initiative

BACKGROUND

Bacterial meningitis in low-risk febrile young infants (FYIs) aged >28 days has become increasingly rare. Routine performance of lumbar puncture (LP) in these infants is associated with adverse consequences and may be unnecessary. We modified our clinical practice guideline (CPG) to reduce the number of FYIs 29 to 56 days old who receive LP.

METHODS

This quality improvement project sought to modify a preexisting CPG to diagnose and manage FYIs 0 to 56 days old that eliminated routine performance of LP in children 29 to 56 days old who were considered low-risk for serious bacterial infection. The change was implemented by making adjustments to the online CPG. A statistical process control chart was used to assess the affect of the initiative on our primary outcome of LP rate in this population of FYIs.

RESULTS

Postimplementation of the CPG initiative, 71% of FYIs 29 to 56 days old did not receive LP, compared with 42% preimplementation. This practice change was also associated with fewer hospitalizations, lower median emergency department (ED) length of stay, and fewer 72-hour ED revisits. Over 3 years of sustained practice, 1/713 (0.1%; 95% confidence interval, 0%-0.8%) low-risk FYI returned within 72 hours and was subsequently treated for probable bacterial meningitis, although cerebrospinal fluid culture was negative for bacterial growth.

CONCLUSIONS

A change in CPG reduced the number of LPs performed in febrile infants 29 to 56 days old. This change resulted in fewer LPs, hospitalizations, ED revisits, and a lower ED length of stay for FYIs 29 to 56 days old.

Febrile young infants with abnormal urine dipstick at low risk of invasive bacterial infection

OBJECTIVES

To develop and validate a prediction rule to identify well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick at low risk of invasive bacterial infections (IBIs, bacteraemia or bacterial meningitis).

DESIGN

Ambispective, multicentre study.

SETTING

The derivation set in a single paediatric emergency department (ED) between 2003 and 2017. The validation set in 21 European EDs between December 2017 and November 2019.

PATIENTS

Two sets of well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick (either leucocyte esterase and/or nitrite positive test).

MAIN OUTCOME

Prevalence of IBI in low-risk infants according to the RISeuP score.

RESULTS

We included 662 infants in the derivation set (IBI rate:5.2%). After logistic regression, we developed a score (RISeuP score) including age (≤15 days old), serum procalcitonin (≥0.6 ng/mL) and C reactive protein (≥20 mg/L) as risk factors. The absence of any risk factor had a sensitivity of 96.0% (95% CI 80.5% to 99.3%), a negative predictive value of 99.4% (95% CI 96.4% to 99.9%) and a specificity of 32.9% (95% CI 28.8% to 37.3%) for ruling out an IBI. Applying it in the 449 infants of the validation set (IBI rate 4.9%), sensitivity, negative predictive value and specificity were 100% (95% CI 87.1% to 100%), 100% (95% CI 97.3% to 100%) and 29.7% (95% CI 25.8% to 33.8%), respectively.

CONCLUSION

This prediction rule accurately identified well-appearing febrile infants aged ≤90 days with an abnormal urine dipstick at low risk of IBI. This score can be used to guide initial clinical decision-making in these patients, selecting infants suitable for an outpatient management.

Prevalence of Bacterial Meningitis Among Febrile Infants Aged 29-60 Days With Positive Urinalysis Results: A Systematic Review and Meta-analysis

IMPORTANCE

Fever in the first months of life remains one of the most common pediatric problems. Urinary tract infections are the most frequent serious bacterial infections in this population. All published guidelines and quality initiatives for febrile young infants recommend lumbar puncture (LP) and cerebrospinal fluid (CSF) testing on the basis of a positive urinalysis result to exclude bacterial meningitis as a cause. For well infants older than 28 days with an abnormal urinalysis result, LP remains controversial.

OBJECTIVE

To assess the prevalence of bacterial meningitis among febrile infants 29 to 60 days of age with a positive urinalysis result to evaluate whether LP is routinely required.

DATA SOURCES

MEDLINE and Embase were searched for articles published from January 1, 2000, to July 25, 2018, with deliberate limitation to recent studies. Before analysis, the search was repeated (October 6, 2019) to ensure that new studies were included.

STUDY SELECTION

Studies that reported on healthy, full-term, well-appearing febrile infants 29 to 60 days of age for whom patient-level data could be ascertained for urinalysis results and meningitis status were included.

DATA EXTRACTION AND SYNTHESIS

Data were extracted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and used the Newcastle-Ottawa Scale to assess bias. Pooled prevalences and odds ratios (ORs) were estimated using random-effect models.

MAIN OUTCOMES AND MEASURES

The primary outcome was the prevalence of culture-proven bacterial meningitis among infants with positive urinalysis results. The secondary outcome was the prevalence of bacterial meningitis, defined by CSF testing or suggestive history at clinical follow-up.

RESULTS

The parent search yielded 3227 records; 48 studies were included (17 distinct data sets of 25 374 infants). The prevalence of culture-proven meningitis was 0.44% (95% CI, 0.25%-0.78%) among 2703 infants with positive urinalysis results compared with 0.50% (95% CI, 0.33%-0.76%) among 10 032 infants with negative urinalysis results (OR, 0.74; 95% CI, 0.39-1.38). The prevalence of bacterial meningitis was 0.25% (95% CI, 0.14%-0.45%) among 4737 infants with meningitis status ascertained by CSF testing or clinical follow-up and 0.28% (95% CI, 0.21%-0.36%) among 20 637 infants with positive and negative urinalysis results (OR, 0.89; 95% CI, 0.48-1.68).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the prevalence of bacterial meningitis in well-appearing febrile infants 29 to 60 days of age with positive urinalysis results ranged from 0.25% to 0.44% and was not higher than that in infants with negative urinalysis results. These results suggest that for these infants, the decision to use LP should not be guided by urinalysis results alone.

The yield of CSF molecular testing in febrile neonates

We retrospectively examined the yield of a cerebrospinal fluid (CSF) multiplex real-time PCR assay of febrile young infants undergoing a full sepsis work-up. Eighty infants were included in the study: Forty-nine (61%) neonates and 31 (39%) 29-90 day-old patients were included in the study. A viral pathogen was detected in 59% (47/80) of the samples, human enterovirus in 53% (42/80) and Human parechovirus in 6% (5/80). The CSF of nearly half of the subjects with CNS infection was without pleocytosis; all CSF cultures were negative. Multiplex PCR CSF testing enhances the diagnosis of pathogen-specific viral CNS infection among febrile young infants.

Accuracy of PECARN rule for predicting serious bacterial infection in infants with fever without a source

OBJECTIVE

To validate the Febrile Infant Working Group of the Pediatric Emergency Care Applied Research Network (PECARN) clinical prediction rule on an independent cohort of infants with fever without a source (FWS).

DESIGN

Secondary analysis of a prospective registry.

SETTING

Paediatric emergency department of a tertiary teaching hospital.

PATIENTS

Infants ≤60 days old with FWS between 2007 and 2018.

MAIN OUTCOME MEASURES

Prevalence of serious bacterial infection (SBI) and invasive bacterial infection (IBI) in low-risk infants according to the PECARN rule.

RESULTS

Among the 1247 infants included, 256 were diagnosed with an SBI (20.5%), including 38 IBIs (3.1%). Overall, 576 infants (46.0%; 95% CI 43.4% to 49.0%) would have been classified as low risk of SBI by the PECARN rule. Of them, 26 had an SBI (4.5%), including 5 with an IBI (2 (0.8%) diagnosed with bacterial meningitis). Sensitivity and specificity of the PECARN rule were 89.8% (95% CI 85.5% to 93.0%) and 55.5% (95% CI 52.4% to 58.6%) for SBI, with an area under the curve of 0.726 (95% CI 0.702 to 0.750). Its sensitivity to identify SBIs was 88.6% (95% CI 82.0% to 92.9%) among infants with a <6-hour history of fever (54.9% of the infants included).

CONCLUSIONS

The PECARN clinical rule for identifying SBI performed less well in our population than in the original study. This clinical rule should be applied cautiously in young infants with a short history of fever.

Epidemiology of Serious Bacterial Infections in Infants Less Than 90 Days in a Military Health System Cohort

BACKGROUND

Management of suspected serious bacterial infections (SBIs) in infants less than 3 months old is challenging. Understanding the epidemiology of SBI is necessary to inform management decisions. Recent publications have challenged the previously accepted distribution of infections by specimen source and pathogen. We sought to describe the burden of SBIs in previously healthy infants less than 90 days old.

METHODS

We conducted a retrospective analysis of the Military Health System database to identify SBI cases among term infants less than 90 days of age from 2005 to 2015. We defined an SBI case as any previously healthy infant with positive cultures for a likely pathogen from blood, urine or cerebrospinal fluid.

RESULTS

Of 467,462 live births between January 2005 and September 2015, 3421 infants had positive cultures. After excluding 1781 episodes with isolates considered nonpathogenic or ICD-9 codes for chronic conditions, the overall incidence of SBI was 3.1 cases/1000 live births. The SBI rate dropped from 5.0 cases/1000 live births in 2005 to 2.0 cases/1000 live births in 2015 (P < 0.001 for trend). The most common pathogen was Escherichia coli (51.3%).

CONCLUSIONS

In this retrospective review of 467,462 live births, the incidence of SBI decreased from 5.0/1000 to 2.0/1000 live births over time. We identified no cases of Listeria monocytogenes. These data can help inform decisions related to treatment and management of infants with suspected bacterial infections.

Performance of blood biomarkers to rule out invasive bacterial infection in febrile infants under 21 days old

OBJECTIVES

To determine the performance of procalcitonin (PCT), C reactive protein (CRP) and absolute neutrophil count (ANC) in identifying invasive bacterial infection (IBI) among well-appearing infants ≤21 days old with fever without source and no leukocyturia. To compare this performance with that in those 22-90 days old.

DESIGN

Substudy of a prospective single-centre registry performed between September 2008 and August 2017.

SETTING

Paediatric emergency department of a tertiary teaching hospital.

PATIENTS

196 infants ≤21 days old and 1331 infants 22-90 days old.

MAIN OUTCOME MEASURES

Sensitivity and negative likelihood ratio of blood tests for ruling out IBI (positive blood or cerebrospinal fluid culture). Abnormal blood test results: PCT ≥0.5 ng/mL, CRP >20 mg/L and ANC >10 000/µL.

RESULTS

Prevalence of IBI in infants ≤21 days old with normal or any abnormal blood test result was 3.6% and 6.8%, respectively (OR 0.52 (95% CI 0.13 to 2.01)), compared with 0.2% and 4.5% in older infants (OR 0.03 (95% CI 0 to 0.17)). Sensitivity and negative likelihood ratio of the blood tests for ruling out IBI in infants ≤21 days were 44.4% (95% CI 18.9% to 73.3%) and 0.79 (95% CI 0.43 to 1.44), respectively (vs 84.6% (95% CI 57.8% to 95.7%)%) and 0.19 (95% CI 0.05 to 0.67) in older infants). The values improved in infants with fever ≥6 hours aged 22-90 days, but not in those ≤21 days.

CONCLUSIONS

PCT, CRP and ANC are not useful for ruling out IBI in febrile infants ≤21 days old. It is still recommended that these patients are admitted and given empirical antibiotic therapy, regardless of their general appearance or blood test results.

Factors Associated with Adverse Outcomes among Febrile Young Infants with Invasive Bacterial Infections

OBJECTIVE

To determine factors associated with adverse outcomes among febrile young infants with invasive bacterial infections (IBIs) (ie, bacteremia and/or bacterial meningitis).

STUDY DESIGN

Multicenter, retrospective cohort study (July 2011-June 2016) of febrile infants ≤60 days of age with pathogenic bacterial growth in blood and/or cerebrospinal fluid. Subjects were identified by query of local microbiology laboratory and/or electronic medical record systems, and clinical data were extracted by medical record review. Mixed-effect logistic regression was employed to determine clinical factors associated with 30-day adverse outcomes, which were defined as death, neurologic sequelae, mechanical ventilation, or vasoactive medication receipt.

RESULTS

Three hundred fifty infants met inclusion criteria; 279 (79.7%) with bacteremia without meningitis and 71 (20.3%) with bacterial meningitis. Forty-two (12.0%) infants had a 30-day adverse outcome: 29 of 71 (40.8%) with bacterial meningitis vs 13 of 279 (4.7%) with bacteremia without meningitis (36.2% difference, 95% CI 25.1%-48.0%; P < .001). On adjusted analysis, bacterial meningitis (aOR 16.3, 95% CI 6.5-41.0; P < .001), prematurity (aOR 7.1, 95% CI 2.6-19.7; P < .001), and ill appearance (aOR 3.8, 95% CI 1.6-9.1; P = .002) were associated with adverse outcomes. Among infants who were born at term, not ill appearing, and had bacteremia without meningitis, only 2 of 184 (1.1%) had adverse outcomes, and there were no deaths.

CONCLUSIONS

Among febrile infants ≤60 days old with IBI, prematurity, ill appearance, and bacterial meningitis (vs bacteremia without meningitis) were associated with adverse outcomes. These factors can inform clinical decision-making for febrile young infants with IBI.

Clinical Features of and Risk Factors for Hydrocephalus in Childhood Bacterial Meningitis

OBJECTIVE

To explore the clinical characteristics of and analyze the risk factors for hydrocephalus in children with bacterial meningitis.

METHODS

Retrospective study of a sample of children with bacterial meningitis seen on the pediatric service of Shengjing Hospital of China Medical University between January 1, 2010, and December 31, 2016.

RESULTS

Overall, 9.36% (25/267) of patients presented with hydrocephalus. Among patients with hydrocephalus, the age at onset of bacterial meningitis was usually <6 months, 15 patients had confirmed bacterial etiology, and 1 patient died. The most significant results of multivariate analysis for hydrocephalus were a rural living situation, altered level of consciousness, previous treatment with antibiotics, initial cerebrospinal fluid protein >2 g/L, C-reactive protein >100 mg/L, and dexamethasone use.

CONCLUSIONS

A severe clinical manifestation and significant laboratory index at admission are the most important predictors of hydrocephalus in children with bacterial meningitis.

Pitfalls in the diagnosis of meningitis in neonates and young infants: the role of lumbar puncture

Meningitis occurs frequently in neonates and can lead to a number of acute, severe complications and long-term disabilities. An early diagnosis of neonatal meningitis is essential to reduce mortality and to improve outcomes. Initial clinical signs of meningitis are often subtle and frequently overlap with those of sepsis, and current haematologic tests do not distinguish sepsis from meningitis. Thus, lumbar puncture (LP) remains the gold standard for the diagnosis of meningitis in infants, and this procedure is recommended in clinical guidelines. Nevertheless, in clinical practice, LP is frequently deferred or omitted due to concerns regarding hypothetical adverse events or limited experience of the performer. Future studies should assess whether a combination of clinical findings and select haematologic tests at disease onset can identify those neonates with the highest risk of meningitis who should undergo LP. Furthermore, clinicians should be convinced that the actual benefits of an early diagnosis of meningitis far outweigh the hypothetical risks associated with LP.

Lumbar Puncture for All Febrile Infants 29-56 Days Old: A Retrospective Cohort Reassessment Study

OBJECTIVES

To determine the incidence of bacterial meningitis (BM) among all febrile infants 29-56 days old undergoing a lumbar puncture (LP) in the emergency department of a tertiary care children's hospital and the number of low-risk febrile infants with BM to reassess the need for routine LP in these infants.

STUDY DESIGN

Retrospective cohort study using a quality improvement registry from July 2007-April 2014. Infants included were 29-56 days old with fever and who had an LP in the emergency department. Low-risk criteria were adapted from the Philadelphia criteria. BM was defined as having a bacterial pathogen isolated from the cerebrospinal fluid. A medical record review of one-third of randomly selected patients in the cohort determined the proportion who met low-risk criteria.

RESULTS

One of 1188 febrile infants (0.08%) had BM; this patient did not meet low-risk criteria. An additional 40 (3.4%) had positive cerebrospinal fluid cultures; all were contaminants. Subanalysis of one-third of the study population revealed that 45.6% met low-risk criteria; the most common reasons for failing low-risk classification included abnormal white blood cell count or urinalysis.

CONCLUSIONS

In a cohort of febrile infants, BM is uncommon and no cases of BM would have been missed had LPs not been performed in those meeting low-risk criteria.

Febrile infant update

PURPOSE OF REVIEW

The approach to febrile young infants remains challenging. This review serves as an update on the care of febrile infants less than 90 days of age with a focus on the changing epidemiology of serious bacterial infection (SBI), refinement of management strategies based on biomarkers, and the development of novel diagnostics.

RECENT FINDINGS

There is high variability in the emergency department management of febrile young infants without significant differences in outcomes. C-reactive protein (CRP) and procalcitonin have emerged as valuable risk-stratification tests to identify high-risk infants. When interpreting automated urinalyses for suspected urinary tract infection (UTI), urine concentration influences the diagnostic value of pyuria. Novel diagnostics including RNA biosignatures and protein signatures show promise in better identifying young febrile infants at risk of serious infection.

SUMMARY

The majority of febrile infants with an SBI will have a UTI but the diagnosis of invasive bacterial infection in infants continues to be challenging. The use of procalcitonin and CRP as biomarkers in prediction algorithms facilitates identification of low-risk infants.

Epidemiology of Cerebrospinal Fluid Cultures and Time to Detection in Term Infants

BACKGROUND

Although meningitis is rare in previously healthy term infants, lumbar puncture is often performed to evaluate for source of illness. This study was performed to determine the time to detection for positive cerebrospinal fluid (CSF) cultures and to provide an update on the current epidemiology of bacterial meningitis in term infants.

METHODS

This study was a multicenter, retrospective review of positive CSF cultures in infants ≤90 days of age. Specimens were drawn in the emergency department or inpatient setting between January 2000 and December 2013. Cultures were deemed true pathogens or contaminant species based on the attending physician's treatment plan. Cultures from premature infants, an operative source, or those with significant medical history were excluded.

RESULTS

A total of 410 positive CSF culture results were included, with 53 (12.9%) true pathogens and 357 (87.1%) contaminant species. The mean ± SD time to detection for true pathogens was 28.6 ± 16.8 hours (95% confidence interval, 24-33.2); for contaminant species, it was 68.1 ± 36.2 hours (95% confidence interval, 64.3-71.9). Forty-three true-positive cases (81.1%) were positive in ≤36 hours. The most common pathogen was group B Streptococcus (51%), followed by Escherichia coli (13%) and Streptococcus pneumoniae (9%).

CONCLUSIONS

The majority of pathogenic bacteria in CSF exhibit growth within 36 hours. Most growth from CSF cultures in febrile infants is treated as contamination. The epidemiology of meningitis has remained constant, with group B Streptococcus as the predominant pathogen, despite changes noted in the epidemiology of bacteremia in this population.

Outpatient management of selected young febrile infants without antibiotics

OBJECTIVE

To analyse the outpatient management of selected febrile infants younger than 90 days without systematic lumbar puncture and antibiotics.

METHODS

A prospective registry-based cohort study including all the infants ≤90 days with fever without a source (FWS) who were evaluated in a paediatric emergency department (ED) over a 7-year period (September 2007-August 2014). We analysed the outcome of those infants with low-risk criteria for serious bacterial infection (SBI) managed as outpatients without antibiotics and without undergoing a lumbar puncture. Low-risk criteria: Well appearing, older than 21 days of age, no leucocyturia, absolute neutrophil count ≤10 000, serum C reactive protein ≤20 mg/L, procalcitonin <0.5 ng/mL and no clinical deterioration during the stay in the ED (always <24 hours).

RESULTS

1472 infants with FWS attended the ED. Of these, 676 were classified to be at low risk for SBI without performing a lumbar puncture. After staying <24 hours in the short-stay unit of the ED, 586 (86.6%) were managed as outpatients without antibiotics. Two patients were diagnosed with SBI: one occult bacteraemia and one bacterial gastroenteritis. Both were afebrile when evaluated again and did well. No patient returned to the ED due to clinical deterioration. Fifty-one infants (8.7%) returned to the ED mainly due to persistence of fever or irritability. None was diagnosed with definite SBI or non-bacterial meningitis.

CONCLUSIONS

Outpatient management without antibiotics and systematic lumbar puncture is appropriate for selected febrile infants younger than 3 months of age with close follow-up.

Enterovirus neurological disease and bacterial coinfection in very young infants with fever

BACKGROUND

Very little information exists on simultaneous infections by viruses and bacteria in infants with fever without source (FWS).

OBJECTIVES

To investigate the incidence of bacterial coinfection in infants up to 3 months of age with neurological viral infection.

STUDY DESIGN

Prospective study performed in infants below 90 days of age attending the emergency room of two public hospitals in Spain for FWS. Those who had viral screening performed in CSF, together with blood, CSF and urine cultures were included. Herpes virus, EV and HPeV detection in CSF was performed by PCR. Coinfections between viruses in CSF and serious bacterial infections were described.

RESULTS

119 Infants less than 90 days of age were recruited. Forty-five (38%) had viral infection of the central nervous system, and in 8 of them (17.7%) we found a concurrent bacterial infection: 7 urinary tract infections (UTI) and 1 sepsis. In all cases, the virus identified in CSF was EV.

CONCLUSIONS

Bacterial infections were frequent in young infants with viral neurological infections associated to EV. Urinary tract infection was the most common bacterial disease.

Validation of the "Step-by-Step" Approach in the Management of Young Febrile Infants

BACKGROUND

A sequential approach to young febrile infants on the basis of clinical and laboratory parameters, including procalcitonin, was recently described as an accurate tool in identifying patients at risk for invasive bacterial infection (IBI). Our aim was to prospectively validate the Step-by-Step approach and compare it with the Rochester criteria and the Lab-score.

METHODS

Prospective study including infants ≤90 days with fever without source presenting in 11 European pediatric emergency departments between September 2012 and August 2014. The accuracy of the Step-by-Step approach, the Rochester criteria, and the Lab-score in identifying patients at low risk of IBI (isolation of a bacterial pathogen in a blood or cerebrospinal fluid culture) was compared.

RESULTS

Eighty-seven of 2185 infants (4.0%) were diagnosed with an IBI. The prevalence of IBI was significantly higher in infants classified as high risk or intermediate risk according to the Step by Step than in low risk patients. Sensitivity and negative predictive value for ruling out an IBI were 92.0% and 99.3% for the Step by Step, 81.6% and 98.3% for the Rochester criteria, and 59.8% and 98.1% for the Lab-score. Seven infants with an IBI were misclassified by the Step by Step, 16 by Rochester criteria, and 35 by the Lab-score.

CONCLUSIONS

We validated the Step by Step as a valuable tool for the management of infants with fever without source in the emergency department and confirmed its superior accuracy in identifying patients at low risk of IBI, compared with the Rochester criteria and the Lab-score.