Invasive bacterial infections in young afebrile infants with a history of fever

Low adherence to a new guideline for managing febrile infants ≤59 days

Background

Management of young febrile infants is challenging. Therefore, several guidelines have been developed over the last decades. However, knowledge regarding the impact of introducing guidelines for febrile infants is limited. We assessed the impact of and adherence to a novel guideline for managing febrile infants aged ≤59 days.

Methods

This retrospective cross-sectional study was conducted in 2 pediatric emergency departments in Sweden between 2014 and 2021. We compared the management of infants aged ≤59 days with fever without a source (FWS) and the diagnosis of serious bacterial infections (SBIs) before and after implementing the new guideline.

Results

We included 1,326 infants aged ≤59 days with FWS. Among infants aged ≤21 days, urine cultures increased from 49% to 67% (p = 0.001), blood cultures from 43% to 63% (p < 0.001), lumbar punctures from 16% to 33% (p = 0.003), and antibiotics from 38% to 57% (p = 0.002). Only 39 of 142 (28%) infants aged ≤21 days received recommended management. The SBI prevalence was 16.7% (95% CI, 11.0-23.8) and 17.6% (95% CI, 11.7-24.9) before and after the implementation, respectively. Among infants aged ≤59 days, there were 3 infants (0.6%; 95% CI, 0.1-1.7) in the pre-implementation period and 3 infants (0.6%; 95% CI, 0.1-1.7) in the post-implementation period with delayed treated urinary tract infections.

Conclusions

Investigations and antibiotics increased significantly after implementation of the new guideline. However, doing more did not improve the diagnosis of SBIs. Thus, the low adherence to the new guideline may be considered justified. Future research should consider strategies to safely minimize interventions when managing infants with FWS.

Risk-stratification in febrile infants 29 to 60 days old: a cost-effectiveness analysis

Background

Multiple clinical prediction rules have been published to risk-stratify febrile infants ≤60 days of age for serious bacterial infections (SBI), which is present in 8-13% of infants. We evaluate the cost-effectiveness of strategies to identify infants with SBI in the emergency department.

Methods

We developed a Markov decision model to estimate outcomes in well-appearing, febrile term infants, using the following strategies: Boston, Rochester, Philadelphia, Modified Philadelphia, Pediatric Emergency Care Applied Research Network (PECARN), Step-by-Step, Aronson, and clinical suspicion. Infants were categorized as low risk or not low risk using each strategy. Simulated cohorts were followed for 1 year from a healthcare perspective. Our primary model focused on bacteremia, with secondary models for urinary tract infection and bacterial meningitis. One-way, structural, and probabilistic sensitivity analyses were performed. The main outcomes were SBI correctly diagnosed and incremental cost per quality-adjusted life-year (QALY) gained.

Results

In the bacteremia model, the PECARN strategy was the least expensive strategy ($3671, 0.779 QALYs). The Boston strategy was the most cost-effective strategy and cost $9799/QALY gained. All other strategies were less effective and more costly. Despite low initial costs, clinical suspicion was among the most expensive and least effective strategies. Results were sensitive to the specificity of selected strategies. In probabilistic sensitivity analyses, the Boston strategy was most likely to be favored at a willingness-to-pay threshold of $100,000/QALY. In the urinary tract infection model, PECARN was preferred compared to other strategies and the Boston strategy was preferred in the bacterial meningitis model.

Conclusions

The Boston clinical prediction rule offers an economically reasonable strategy compared to alternatives for identification of SBI.

Delays in Time-To-Antibiotics for Young Febrile Infants With Serious Bacterial Infections: A Prospective Single-Center Study

INTRODUCTION

Fear of missed serious bacterial infections (SBIs) results in many febrile young infants receiving antibiotics. We aimed to compare the time to antibiotics between infants with SBIs and those without.

MATERIALS AND METHODS

We recruited febrile infants ≤ 90 days old seen in the emergency department (ED) between December 2017 and April 2021. SBI was defined as (1) urinary tract infection, (2) bacteremia or (3) bacterial meningitis. We compared the total time (median with interquartile range, IQR) from ED arrival to infusion of antibiotics, divided into (i) time from triage to decision for antibiotics and (ii) time from decision for antibiotics to administration of antibiotics.

RESULTS

We analyzed 81 and 266 infants with and without SBIs. Median age of those with and without SBIs were 44 (IQR 19-72) and 29 (IQR 7-56) days, respectively (p = 0.002). All infants with SBIs and 168/266 (63.2%) infants without SBIs received antibiotics. Among 249 infants who received antibiotics, the median total time from ED arrival to infusion of antibiotics was 277.0 (IQR 236.0-385.0) mins for infants with SBIs and 304.5 (IQR 238.5-404.0) mins for those without (p = 0.561). The median time to decision for antibiotics was 156.0 (IQR 115.0-255.0) mins and 144.0 (IQR 105.5-211.0) mins, respectively (p = 0.175). Following decision for antibiotics, infants with SBIs received antibiotics much faster compared to those without [107.0 (IQR 83.0-168.0) vs. 141.0 (94.0-209.5) mins, p = 0.017].

CONCLUSION

There was no difference in total time taken to antibiotics between infants with SBIs and without SBIs. Both recognition and administration delays were observed. While all infants with SBIs were adequately treated, more than half of the infants without SBIs received unnecessary antibiotics. This highlights the challenge in managing young febrile infants at initial presentation, and demonstrates the need to examine various aspects of care to improve the overall timeliness to antibiotics.

Limited Utility of SIRS Criteria for Identifying Serious Infections in Febrile Young Infants

(1) Background: Young infants have a high risk of serious infection. The Systematic Inflammatory Response Syndrome (SIRS) criteria can be useful to identify both serious bacterial and viral infections. The aims of this study were to evaluate the diagnostic performance of the SIRS criteria for identifying serious infections in febrile young infants and to identify potential clinical predictors of such infections. (2) Methods: We conducted this prospective cohort study including febrile young infants (aged < 90 days) seen at the emergency department with a body temperature of 38.0 °C or higher. We calculated the diagnostic performance parameters and conducted the logistic regression analysis to identify the predictors of serious infection. (3) Results: Of 311 enrolled patients, 36.7% (n = 114) met the SIRS criteria and 28.6% (n = 89) had a serious infection. The sensitivity, specificity, positive predictive value, and positive likelihood ratio of the SIRS criteria for serious infection was 45.9%, 69.4%, 43.5%, 71.4%, 1.5, and 0.8, respectively. Logistic regression showed that male gender, body temperature ≥ 38.5 °C, heart rate ≥ 178 bpm, and age ≤ 50 days were significant predictors. (4) Conclusions: The performance of the SIRS criteria for predicting serious infections among febrile young infants was poor.

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.

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.

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.

Evaluation of a novel approach to recognising community-acquired paediatric sepsis at ED triage by combining an electronic screening algorithm with clinician assessment

OBJECTIVE

We report the utilisation and impact of a novel triage-based electronic screening tool (eST) combined with clinical assessment to recognise sepsis in paediatric ED.

METHODS

An electronic sepsis screening tool was implemented in the paediatric EDs of two large UK secondary care hospitals between June 2018 and January 2019. Patients eligible for screening were children < 16 years of ages excluding those with minor injuries or who were brought directly to resuscitation. Subsequently, a retrospective evaluation was performed to determine the performance of the tool alone and in combination with clinical assessment after triage, to identify septic patients, using sensitivity, specificity, positive, negative predictive values (PPV and NPV) and likelihood ratios.

RESULTS

19 912 children were triaged during the study period, of whom 90 (0.45%) were classified as having sepsis. 99% of all eligible patients were screened. The eST alerted for 2651 (13.3%) patients. After immediate physician assessment, 151 were treated for sepsis in the ED, of whom 70 had a final diagnosis of sepsis. Eight patients who were not thought to be septic returned with sepsis within 24 hours. The eST showed a sensitivity of 86.7% (95% CI 77.5% to 92.6%), specificity 87.0% (95% CI 86.5% to 87.5%), PPV 2.94% (95% CI 2.35% to 3.68%), NPV 99.9% (95% CI 99.8% to 99.9%) which improved with combined clinical assessment to a sensitivity of 90.0% (95% CI 81.4% to 95.0%), specificity 99.4 (95% CI 99.3% to 99.5%), PPV 42.0 (95% CI 35.0% to 49.3%) and NPV 99.9% (95% CI 99.9% to 99.9%).

CONCLUSION

Utilisation of a novel triage-based eST allowed sepsis screening in over 99% of eligible patients. The screening tool showed good accuracy to recognise sepsis at triage in the ED, which was augmented further by combining it with clinician assessment. The screening tool requires further refinement through multicentre evaluation to avoid missing sepsis cases.

Machine Learning To Predict Serious Bacterial Infections in Young Febrile Infants

BACKGROUND

Recent decision rules for the management of febrile infants support the identification of infants at higher risk of serious bacterial infections (SBIs) without the performance of routine lumbar puncture. We derive and validate a model to identify febrile infants ≤60 days of age at low risk for SBIs using supervised machine learning approaches.

METHODS

We conducted a secondary analysis of a multicenter prospective study performed between December 2008 and May 2013 of febrile infants. Our outcome was SBI, (culture-positive urinary tract infection, bacteremia, and/or bacterial meningitis). We developed and validated 4 supervised learning models: logistic regression, random forest, support vector machine, and a single-hidden layer neural network.

RESULTS

A total of 1470 patients were included (1014 >28 days old). One hundred thirty-eight (9.3%) had SBIs (122 urinary tract infections, 20 bacteremia, and 8 meningitis; 11 with concurrent SBIs). Using 4 features (urinalysis, white blood cell count, absolute neutrophil count, and procalcitonin), we demonstrated with the random forest model the highest specificity (74.9, 95% confidence interval: 71.5%-78.2%) with a sensitivity of 98.6% (95% confidence interval: 92.2%-100.0%) in the validation cohort. One patient with bacteremia was misclassified. Among 1240 patients who received a lumbar puncture, this model could have prevented 849 (68.5%) such procedures.

CONCLUSIONS

We derived and internally validated a supervised learning model for the risk-stratification of febrile infants. Although computationally complex, lacking parameter cutoffs, and in need of external validation, this strategy may allow for reductions in unnecessary procedures, hospitalizations, and antibiotics while maintaining excellent sensitivity.

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.

Variability in Hospital Admission Rates for Neonates With Fever in North Carolina

Background. Despite multiple guidelines recommending admission, there is significant variation among emergency departments (EDs) regarding disposition of neonates presenting with fever. We performed a statewide epidemiologic analysis to identify characteristics that may influence patient disposition in such cases within North Carolina. Methods. This study is a retrospective cohort study of infants 1 to 28 days old with a diagnosis of fever presenting to North Carolina EDs from October 1, 2010, to September 30, 2015, using data from the NC DETECT (North Carolina Disease Event Tracking and Epidemiologic Collection Tool) database. We analyzed various patient epidemiology characteristics and their associations with patients being admitted or discharged from the emergency room setting. Results. Of 2745 unique patient visits for neonatal fever, 1173 (42.7%) were discharged from the ED, while 1572 (57.3%) were either admitted or transferred for presumed admission. Age, sex, region within North Carolina, and the presence of a pediatric service did not significantly influence disposition. An abnormal documented ED temperature was associated with higher likelihood of admission (P < .01). The size of the hospital was also found to be significant when comparing large with small hospitals (P < .01). Government-funded insurance was associated with lower likelihood of admission (P < .01). Conclusions. A high number of neonates diagnosed with fever were discharged home, inconsistent with current recommendations. An association with a government-funded insurance represents a possible health care disparity. Further studies are warranted to further understand these variations in practice.

A Prediction Model to Identify Febrile Infants ≤60 Days at Low Risk of Invasive Bacterial Infection

OBJECTIVES

To derive and internally validate a prediction model for the identification of febrile infants ≤60 days old at low probability of invasive bacterial infection (IBI).

METHODS

We conducted a case-control study of febrile infants ≤60 days old who presented to the emergency departments of 11 hospitals between July 1, 2011 and June 30, 2016. Infants with IBI, defined by growth of a pathogen in blood (bacteremia) and/or cerebrospinal fluid (bacterial meningitis), were matched by hospital and date of visit to 2 control patients without IBI. Ill-appearing infants and those with complex chronic conditions were excluded. Predictors of IBI were identified with multiple logistic regression and internally validated with 10-fold cross-validation, and an IBI score was calculated.

RESULTS

We included 181 infants with IBI (155 [85.6%] with bacteremia without meningitis and 26 [14.4%] with bacterial meningitis) and 362 control patients. Twenty-three infants with IBI (12.7%) and 138 control patients (38.1%) had fever by history only. Four predictors of IBI were identified (area under the curve 0.83 [95% confidence interval (CI): 0.79-0.86]) and incorporated into an IBI score: age <21 days (1 point), highest temperature recorded in the emergency department 38.0-38.4°C (2 points) or ≥38.5°C (4 points), absolute neutrophil count ≥5185 cells per μL (2 points), and abnormal urinalysis results (3 points). The sensitivity and specificity of a score ≥2 were 98.8% (95% CI: 95.7%-99.9%) and 31.3% (95% CI: 26.3%-36.6%), respectively. All 26 infants with meningitis had scores ≥2.

CONCLUSIONS

Infants ≤60 days old with fever by history only, a normal urinalysis result, and an absolute neutrophil count <5185 cells per μL have a low probability of IBI.

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.

Point-of-care testing for procalcitonin in identifying bacterial infections in young infants: a diagnostic accuracy study

Background

The primary objective of this study was to report on the diagnostic accuracy of point-of-care testing (POCT) for procalcitonin (PCT) in identifying invasive bacterial infections in young infants. Invasive bacterial infection was defined as the isolation of a bacterial pathogen in blood or cerebrospinal fluid culture.

Methods

This was a prospective observational diagnostic accuracy study. Young infants less than 90 days of age presenting to the Royal Belfast Hospital for Sick Children with signs of possible bacterial infection were eligible for inclusion. Eligible infants underwent point-of-care testing for procalcitonin in the emergency department. Testing was performed by clinical staff using 0.5 ml of whole blood. Results were available within 20 min.

Results

126 children were included over a 5-month period between September 2017 and January 2018. There were 14 children diagnosed with bacterial infections (11.1%). Of these 4 children were diagnosed with invasive bacterial infections (3.2%). POCT procalcitonin demonstrated an excellent diagnostic accuracy for identifying children with invasive bacterial infection area under the curve (AUC) of 0.97(95% CI, 0.94 to 1.0). At a cut-off value of 1.0 ng/ml is highly accurate at identifying infants at risk of invasive bacterial infection with a sensitivity and specificity of 1.00 and 0.92 respectively.

Conclusions

Point-of-care procalcitonin can be performed quickly in the emergency department and demonstrates an excellent diagnostic accuracy for the identification of young infants with invasive bacterial infections.

Trial registration

NCT03509727 Retrospectively registered on 26th April 2018.