Clinical Course, Laboratory Findings, and Prognosis of SARS-CoV-2 Infection in Infants up to 90 Days of Age: A Single-Center Experience and a Proposal for a Management Pathway

AIM

To provide a comprehensive description of the clinical features, biochemical characteristics, and outcomes of infants up to 90 days old with COVID-19. Moreover, to assess the severity of the disease and propose an effective management pathway.

METHODS

Retrospective single-center study spanning three years. Patient data includes age, sex, symptoms, comorbidities, blood and urine test results, cultures, admission, length of stay, therapies, intensive care unit admission, and mortality.

RESULTS

A total of 274 patients were enrolled in the study, comprising 55% males. Among them, 60 patients (22%) were under the age of 29 days, while 214 (78%) fell within the 29 to 90 days age range. The overall incidence of SARS-CoV-2 infections was 0.28 per 10,000 Pediatric Emergency Department admissions. Blood inflammatory markers showed no significant abnormalities, and there were no recorded instances of positive blood cultures. Less than 1% of infants showed urinary tract infections with positive urine cultures, and 1.5% of patients had a concurrent RSV infection. Hospitalization rates were 83% for neonates and 67% for infants, with a median length of stay (LOS) of 48 h for both age groups. None of the patients required admission to the Pediatric or Neonatal Intensive Care Unit, and only one required High Flow Nasal Cannula (HFNC). No secondary serious bacterial infections were observed, and all hospitalized patients were discharged without short-term sequelae. No deaths were reported.

DISCUSSION AND CONCLUSIONS

Infants with COVID-19 generally exhibit milder or asymptomatic forms of the disease, making home management a viable option in most cases. Blood tests, indicative of a mild inflammatory response, are recommended primarily for children showing symptoms of illness. Hospitalization precautions for infants without apparent illness or comorbidities are deemed unnecessary. Given the evolving nature of experiences with COVID-19 in infants, maintaining a high level of clinical suspicion remains imperative.

Conundrums in the Management of Febrile Infants under Three Months of Age and Future Research

Febrile infants under three months of age pose a diagnostic challenge to clinicians. Unlike in older children, the rates of invasive bacterial infections (IBIs), such as bacteraemia or meningitis, are high. This greater risk of IBI combined with the practical challenges of assessing young infants results in a cautious approach with many febrile infants receiving parenteral antibiotics "just in case". However, there is a range of validated tailored care guidelines that support targeted investigation and management of febrile infants, with a cohort identified as lower risk suitable for fewer invasive procedures and observation without parenteral antibiotics. This manuscript outlines five common conundrums related to the safe application of tailored-care guidelines for the assessment and management of febrile infants under three months of age. It also explores future research which aims to further refine the management of febrile infants.

Proportion of Successful Lumbar Punctures in Infants Younger Than Three Months

It is important to perform lumbar punctures (LPs) without a single traumatic tap in infants younger than three months owing to the risk of serious complications. The proportion of LPs in which clear cerebrospinal fluid (CSF) was obtained has been previously reported, but some of the procedures involved a traumatic tap. The present study aimed to identify the proportion of LPs in which clear CSF was obtained without a single traumatic tap and the factors associated with successful LPs in infants younger than three months. This retrospective, observational study included children younger than three months who underwent an LP in the pediatric emergency department between April 2018 and March 2021. The primary outcome was the proportion of successful LPs, defined as LPs obtaining clear CSF without a single traumatic tap. Multiple logistic regression analysis was used to identify factors related to successful LPs. Of 126 eligible patients, 121 were included. Among these, 83 (69%) were in the successful group. No factors significantly associated with successful LPs were found. Larger studies based on an accurate definition of successful LPs, such as that provided by this study, are needed to investigate related factors to increase the rate of successful LPs in this age group.

Close Canine Contact: A Case of Infantile Pasteurella Meningitis

This case report presents an interesting and rare cause of meningitis in young infants, Pasteurella multocida. Not only is the organism unusual but the well appearance of the infant made this diagnosis surprising. The 2021 American Academy of Pediatrics (AAP) clinical practice guidelines on well-appearing febrile infants brought a national guideline on the evaluation and management of fever in infants. However, providers should be aware that there is room for shared decision-making and that the guideline will miss a very small percentage of well-appearing infants with invasive bacterial infections.

Paediatric emergency departments should manage young febrile and afebrile infants the same if they have a fever before presenting

Aim

Our aim was to evaluate the risk of bacterial meningitis, bacteremia, and urinary tract infection (UTI) in infants ≤60 days who presented to paediatric emergency departments (PEDs) after having fever at home. We also investigated any differences between infants who were afebrile or febrile on presentation.

Methods

This was a multicenter retrospective study of infants ≤60 days presented to four Swedish PEDs during 2014–2020 with reported fever at home. We used relative risks (RR) to compare the prevalence of UTI, bacteremia, and bacterial meningitis between the infants who were afebrile and the infants who were still febrile when they presented to the PED.

Results

The cohort comprised 1926 infants, and 702 (36%) were afebrile on presentation. The prevalence of UTI in the afebrile and febrile infants was 6.1% [95% confidence interval (CI) 4.5–8.2] versus 14.2% (95% CI 12.3–16.2), corresponding to an RR of 0.43 (95% CI 0.31–0.59). In infants ≤28 days, the RR for meningitis was 1.05 (95% CI 0.18–6.23) for afebrile versus febrile infants. Five times more febrile infants underwent a lumbar puncture.

Conclusion

Infants who were afebrile on presentation underwent fewer lumbar punctures, but they had similar rates of bacterial meningitis to febrile infants. Different management approaches are not justified.

Infrared thermometers and infants: The device is hot the baby maybe not

AIM

The risk of serious illness in febrile infants (<60 days old) is high, and so fever often warrants aggressive management. Infrared thermometers are unreliable in young infants despite their ubiquity. We aim to describe the: (i) frequency of infrared thermometer usage; (ii) progression to documented fever in the emergency department (ED) and (iii) rate of serious illness (meningitis, urinary tract infection and bacteremia).

METHODS

In this single-centre retrospective chart review at The Royal Children's Hospital, Melbourne, we audited medical records of infants (<60 days old) presenting to the ED with pre-hospital fever on history over a 12-month period. We described the type of thermometer used at home (tympanic or forehead, 'infrared' vs. axillary or rectal, 'direct') correlated to peak temperature in ED, investigations, treatment and diagnosis. The primary outcome was subsequent fever in ED.

RESULTS

Of 159 infants, two of three had infrared temperature measurement at home. Fifty-one (32.1%) developed fever in ED (direct 28/54, 52% vs. infrared 23/105, 22% RR 2.36 (95% CI 1.52-3.69)). Investigations (75%) and admission (60%) were common. Pre-hospital fever alone was less likely to be associated with serious illness, with fever in ED a much stronger predictor.

CONCLUSIONS

In young infants, infrared thermometer use is common and less likely to predict subsequent fever. Twenty-two percent of infants with fever via infrared measurement had fever in ED. History of fever without confirmation is less likely to signal serious illness. Education to public and health-care providers is required to avoid usage of infrared devices in this population.

Age- and sex-specific prevalence of serious bacterial infections in febrile infants ≤60 days, in Sweden

AIM

The aim of the study was to describe age- and sex-specific prevalence of serious bacterial infections (SBI: urinary tract infection, bacteraemia, meningitis) among febrile infants ≤60 days in Sweden.

METHODS

This is a retrospective study in 4 Pediatric Emergency Departments from 2014 to 2017, in previously healthy, full-term infants ≤60 days with fever without a source.

RESULTS

Of the 1,701 included infants, 214 (12.6%; 95% CI, 11.1-14.3) had an SBI. Urinary tract infection (UTI) was diagnosed in 196 (11.5%; 95% CI, 10.0-13.1) patients. In the ≤28 and 29-60 days age-groups, meningitis prevalence was 0.9% (95% CI, 0.3-2.0) and 0.3% (95% CI, 0.1-0.8), whereas bacteraemia prevalence was 3.2% (95% CI, 1.9-4.9) and 0.6% (95% CI, 0.2-1.3). The SBI prevalence was higher in boys 16.0% (95% CI, 13.8-18.5) than girls 8.0% (95% CI, 6.2-10.2; p<0.001), due to 2-fold higher UTI risk. The prevalence of meningitis in boys was 0.3% (95% CI, 0.1- 0.9) vs. 0.7% (95% CI, 0.2-1.6) in girls and of bacteraemia 1.8% (95% CI, 1.0-2.8) vs. 1.0% (95% CI, 0.4-2.0), respectively.

CONCLUSIONS

The total SBI prevalence was 12.6%, and UTI represented the vast majority. The prevalence of bacteraemia and meningitis was low, particularly in the 29-60 days age group, without significant difference between boys and girls.

A positive nitrite test was an independent risk factor for invasive bacterial infections in infants under 90 days of age with fever without source

AIM

This study analysed the association between a positive nitrite dipstick test and an invasive bacterial infection (IBI) in infants younger than 90 days of age with fever without source (FWS).

METHODS

We performed a secondary analysis of data from a prospective multicentre study of infants up to 90 days of age with FWS undergoing care in 19 paediatric EDs between October 2011 and September 2013. Invasive bacterial infection was defined as a positive blood or cerebrospinal fluid culture.

RESULTS

The dipstick urinalysis was positive for nitrite or leucocyte esterase in 766 (22.5%) of the 3401 infants we studied, and 270 (35.2%) had a dipstick test that was just positive for nitrite. Overall, 107 were diagnosed with an IBI (3.1%). The IBI prevalence was 2.2% among patients with a normal urine dipstick, 4.4% if they had positive leucocyte esterase test results, 8.3% where the nitrite test was positive and 10.6% when both tests were positive. After multivariate analysis, a positive nitrite test remained an independent risk factor for IBI (odds ratio 2.7, 95% confidence interval 1.4-4.9).

CONCLUSION

In infants under 90 days of age with FWS, a positive nitrite urine dipstick test was an independent risk factor for IBI.

Definite bacterial infection in recently vaccinated febrile infants

AIM

There is insufficient evidence regarding the best approach to evaluating recently vaccinated (RV) infants presenting to the paediatric emergency department with fever. The aim of the present study is to determine the prevalence of bacterial infections in infants presenting with fever within 72 h after vaccination.

METHODS

We retrospectively reviewed the electronic medical record of infants aged between 6 and 12 weeks who presented with a fever ≥38°C to the emergency department from January 2016 to December 2018. Febrile infants who were vaccinated within 72 h prior to their emergency department presentation were matched to those who had not received their vaccines in the previous 72 h. Definite serious bacterial infection was diagnosed based on culture results.

RESULTS

A total of 198 infants (age: 9 ± 1.84 weeks, male: 119 (60.1%)) were enrolled in this study. Overall, 60 of 138 (30.3%) had received their vaccines within the previous 72 h. The prevalence of bacterial infection in RV infants was 5% compared to 15.2% in non-RV infants (P = 0.056). Interestingly, all vaccinated infants who had proven bacterial infection presented to the emergency department with fever within 24 h of vaccination, and all bacterial infections in that group were urinary tract infections.

CONCLUSIONS

The prevalence of bacterial infection among non-RV febrile infants is relatively higher than those RV. However, fever should not be attributed only to the vaccinations, and all febrile RV infants should be carefully evaluated, and at least urine testing should be performed regardless of the time of vaccination.

Automated Versus Manual Band Counts for the Diagnosis of Invasive Bacterial Infections in Infants Who Are Febrile

We conducted a secondary analysis of a prospective study of infants ≤60 days of age who were febrile to assess the diagnostic accuracy of automated vs manual immature neutrophils for invasive bacterial infections. Although manual counts were superior compared with automated counts, bands had suboptimal accuracy overall and had significant variability in test characteristics based on methodology.

Outcomes of Young Infants with Hypothermia Evaluated in the Emergency Department

OBJECTIVE

To assess the prevalence of serious infections and mortality among infants ≤90 days of age presenting to the emergency department with hypothermia.

STUDY DESIGN

We performed a cross-sectional cohort study of infants ≤90 days presenting to any of 40 EDs in the Pediatric Health Information Systems between January 1, 2009, and December 31, 2018. Infants with an International Classification of Diseases, ninth or tenth edition, admission/discharge diagnosis code of hypothermia were included. We determined the prevalence of serious bacterial infection (urinary tract infection, bacteremia, and/or bacterial meningitis), pneumonia, herpes simplex virus (HSV) infection, and emergency department/hospital mortality.

RESULTS

We included 3565 infants (1633 male [50.9%] and 3225 ≤30 days of age [90.5%]). Most (65.0%) presented in the first week of life. There were 389 infants (10.8%) with a complex chronic condition. The prevalence of serious bacterial infection was 8.0% (n = 284), including 2.4% (n = 87) with urinary tract infection, 5.6% (n = 199) with bacteremia, and 0.3% (n = 11) with bacterial meningitis. There were 7 patients (0.2%) with neonatal HSV and 9 (0.3%) with pneumonia; 0.2% (n = 6) died. The presence of a complex chronic condition was associated with the presence of serious bacterial infection (P < .001) and was present in 3 of 6 patients who died. In a sensitivity analysis including patients with any diagnosis code of hypothermia (n = 8122), 14.9% had serious bacterial infection, 0.6% had HSV, and 3.3% had pneumonia; 2.0% died.

CONCLUSIONS

Of infants with hypothermia ≤90 days of age, 8.3% had serious bacterial infections or HSV. Compared with literature from febrile infants, hypothermia is associated with a high mortality rate. Complex chronic conditions were particularly associated with poor outcomes. Additional research is required to risk stratify young infants with hypothermia.

Reporting and Categorization of Blood Culture Contaminants in Infants and Young Children: A Scoping Review

BACKGROUND

Blood cultures are obtained routinely for infants and young children for the evaluation for serious bacterial infection. Isolation of organisms that represent possible contaminants poses a management challenge. The prevalence of bacteremia reported in this population is potentially biased by inconsistent contaminant categorization reported in the literature. Our aim was to systematically review the definition and reporting of contaminants within the literature regarding infant bacteremia.

METHODS

A search of studies published between 1986 and mid-September 2016 was conducted using Medline/PubMed. Included studies examined children aged 0 to 36 months for whom blood culture was performed as part of a serious bacterial infection evaluation. Studies that involved children in an intensive care unit, prematurely born children, and immunocompromised children or those with an indwelling catheter/device were excluded. Data extracted included contaminant designation methodology, organisms classified as contaminants and pathogens, and contamination and bacteremia rates.

DISCUSSION

Our search yielded 1335 articles, and 69 of them met our inclusion criteria. The methodology used to define contaminants was described in 37 (54%) study reports, and 16 (23%) reported contamination rates, which ranged from 0.5% to 22.8%. Studies defined contaminants according to organism species (n = 22), according to the patient's clinical management (n = 4), and using multifactorial approaches (n = 11). Many common organisms, particularly Gram-positive cocci, were inconsistently categorized as pathogens or contaminants.

CONCLUSIONS

Reporting and categorization of blood culture contamination are inconsistent within the pediatric bacteremia literature, which limits our ability to estimate the prevalence of bacteremia. Although contaminants are characterized most frequently according to organism, we found inconsistency regarding the classification of certain common organisms. A standardized approach to contaminant reporting is needed.

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.

Application of the Rochester Criteria to Identify Febrile Infants With Bacteremia and Meningitis

OBJECTIVES

The Rochester criteria were developed to identify febrile infants aged 60 days or younger at low-risk of bacterial infection and do not include cerebrospinal fluid (CSF) testing. Prior studies have not specifically assessed criteria performance for bacteremia and bacterial meningitis (invasive bacterial infection). Our objective was to determine the sensitivity of the Rochester criteria for detection of invasive bacterial infection.

METHODS

Retrospective cohort study of febrile infants aged 60 days or younger with invasive bacterial infections evaluated at 8 pediatric emergency departments from July 1, 2012, to June 30, 2014. Potential cases were identified from the Pediatric Health Information System using International Classification of Diseases, Ninth Revision diagnosis codes for bacteremia, meningitis, urinary tract infection, and fever. Medical record review was then performed to confirm presence of an invasive bacterial infection and to evaluate the Rochester criteria: medical history, symptoms or ill appearance, results of urinalysis, complete blood count, CSF testing (if obtained), and blood, urine, and CSF culture. An invasive bacterial infection was defined as growth of pathogenic bacteria from blood or CSF culture.

RESULTS

Among 82 febrile infants aged 60 days or younger with invasive bacterial infection, the sensitivity of the Rochester criteria were 92.7% (95% confidence interval [CI], 84.9%-96.6%) overall, 91.7% (95% CI, 80.5%-96.7%) for neonates 28 days or younger, and 94.1% (95% CI, 80.9%-98.4%) for infants aged 29 to 60 days old. Six infants with bacteremia, including 1 neonate with bacterial meningitis, met low-risk criteria.

CONCLUSIONS

The Rochester criteria identified 92% of infants aged 60 days or younger with invasive bacterial infection. However, 1 neonate 28 days or younger with meningitis was classified as low-risk.

Impact of Mobile Device-Based Clinical Decision Support Tool on Guideline Adherence and Mental Workload

OBJECTIVE

To evaluate the individual-level impact of an electronic clinical decision support (ECDS) tool, PedsGuide, on febrile infant clinical decision making and cognitive load.

METHODS

A counterbalanced, prospective, crossover simulation study was performed among attending and trainee physicians. Participants performed simulated febrile infant cases with use of PedsGuide and with standard reference text. Cognitive load was assessed using the NASA-Task Load Index (NASA-TLX), which determines mental, physical, temporal demand, effort, frustration, and performance. Usability was assessed with the System Usability Scale (SUS). Scores on cases and NASA-TLX scores were compared between condition states.

RESULTS

A total of 32 participants completed the study. Scores on febrile infant cases using PedsGuide were greater compared with standard reference text (89% vs 72%, P = .001). NASA-TLX scores were lower (ie, more optimal) with use of PedsGuide versus control (mental 6.34 vs 11.8, P < .001; physical 2.6 vs 6.1, P = .001; temporal demand 4.6 vs 8.0, P = .003; performance 4.5 vs 8.3, P < .001; effort 5.8 vs 10.7, P < .001; frustration 3.9 vs 10, P < .001). The SUS had an overall score of 88 of 100 with rating of acceptable on the acceptability scale.

CONCLUSIONS

Use of PedsGuide led to increased adherence to guidelines and decreased cognitive load in febrile infant management when compared with the use of a standard reference tool. This study employs a rarely used method of assessing ECDS tools using a multifaceted approach (medical decision-making, assessing usability, and cognitive workload,) that may be used to assess other ECDS tools in the future.

Risk of Bacterial Coinfections in Febrile Infants 60 Days Old and Younger with Documented Viral Infections

OBJECTIVE

To determine the risk of serious bacterial infections (SBIs) in young febrile infants with and without viral infections.

STUDY DESIGN

Planned secondary analyses of a prospective observational study of febrile infants 60 days of age or younger evaluated at 1 of 26 emergency departments who did not have clinical sepsis or an identifiable site of bacterial infection. We compared patient demographics, clinical, and laboratory findings, and prevalence of SBIs between virus-positive and virus-negative infants.

RESULTS

Of the 4778 enrolled infants, 2945 (61.6%) had viral testing performed, of whom 1200 (48.1%) were virus positive; 44 of the 1200 had SBIs (3.7%; 95% CI, 2.7%-4.9%). Of the 1745 virus-negative infants, 222 had SBIs (12.7%; 95% CI, 11.2%-14.4%). Rates of specific SBIs in the virus-positive group vs the virus-negative group were: UTIs (33 of 1200 [2.8%; 95% CI, 1.9%-3.8%] vs 186 of 1745 [10.7%; 95% CI, 9.2%-12.2%]) and bacteremia (9 of 1199 [0.8%; 95% CI, 0.3%-1.4%] vs 50 of 1743 [2.9%; 95% CI, 2.1%-3.8%]). The rate of bacterial meningitis tended to be lower in the virus-positive group (0.4%) than in the viral-negative group (0.8%); the difference was not statistically significant. Negative viral status (aOR, 3.2; 95% CI, 2.3-4.6), was significantly associated with SBI in multivariable analysis.

CONCLUSIONS

Febrile infants ≤60 days of age with viral infections are at significantly lower, but non-negligible risk for SBIs, including bacteremia and bacterial meningitis.

Epidemiology and Etiology of Invasive Bacterial Infection in Infants ≤60 Days Old Treated in Emergency Departments

OBJECTIVES

To help guide empiric treatment of infants ≤60 days old with suspected invasive bacterial infection by describing pathogens and their antimicrobial susceptibilities.

STUDY DESIGN

Cross-sectional study of infants ≤60 days old with invasive bacterial infection (bacteremia and/or bacterial meningitis) evaluated in the emergency departments of 11 children's hospitals between July 1, 2011 and June 30, 2016. Each site's microbiology laboratory database or electronic medical record system was queried to identify infants from whom a bacterial pathogen was isolated from either blood or cerebrospinal fluid. Medical records of these infants were reviewed to confirm the presence of a pathogen and to obtain demographic, clinical, and laboratory data.

RESULTS

Of the 442 infants with invasive bacterial infection, 353 (79.9%) had bacteremia without meningitis, 64 (14.5%) had bacterial meningitis with bacteremia, and 25 (5.7%) had bacterial meningitis without bacteremia. The peak number of cases of invasive bacterial infection occurred in the second week of life; 364 (82.4%) infants were febrile. Group B streptococcus was the most common pathogen identified (36.7%), followed by Escherichia coli (30.8%), Staphylococcus aureus (9.7%), and Enterococcus spp (6.6%). Overall, 96.8% of pathogens were susceptible to ampicillin plus a third-generation cephalosporin, 96.0% to ampicillin plus gentamicin, and 89.2% to third-generation cephalosporins alone.

CONCLUSIONS

For most infants ≤60 days old evaluated in a pediatric emergency department for suspected invasive bacterial infection, the combination of ampicillin plus either gentamicin or a third-generation cephalosporin is an appropriate empiric antimicrobial treatment regimen. Of the pathogens isolated from infants with invasive bacterial infection, 11% were resistant to third-generation cephalosporins alone.

Retrospective Evaluation of Infants Aged 1 to 60 Days with Residual Cerebrospinal Fluid (CSF) Tested Using the FilmArray Meningitis/Encephalitis (ME) Panel

In pediatric practice it is common for infants under 2 months of age to undergo evaluation for sepsis when they are ill, often including lumbar puncture to assess for central nervous system (CNS) infection. The FilmArray Meningitis/Encephalitis (ME) panel is a newly approved test for rapid identification of CNS pathogens. Our objective was to study the epidemiology of CNS infection in young infants and the potential impact of rapid multiplex PCR on their care. A performance evaluation of the FilmArray ME panel was conducted from February 2014 to September 2014 at 11 sites. FilmArray ME panel results were compared to reference standards but not shared with providers. In our study, medical records for infants (aged 1 to 60 days) enrolled at three sites were reviewed for clinical, laboratory, and outcome data. A total of 145 infants were reviewed. The median age was 25 days. Most of the infants were hospitalized (134/145 [92%]) and received antibiotics (123/145 [85%]), and almost half (71/145 [49%]) received acyclovir. One infant had a bacterial pathogen, likely false positive, identified by the FilmArray ME panel. Thirty-six infants (25%) had a viral pathogen detected, including 21 enteroviruses. All infants with enteroviral meningitis detected by the FilmArray ME panel and conventional PCR were hospitalized, but 20% were discharged in less than 24 h when conventional PCR results became available. The FilmArray ME panel may play a role in the evaluation of young infants for CNS infection. Results may be used to guide management, possibly resulting in a decreased length of stay and less antimicrobial exposure for infants with low-risk viral infection detected.

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.

Persistent Gaps in Appropriate Use of Empiric Acyclovir in Neonates

The use of empiric acyclovir for suspected neonatal herpes simplex virus (HSV) infection has been debated for years. To identify the gap in the decision to initiate empiric acyclovir, we performed a retrospective chart review and administered a survey to pediatricians to assess current practices regarding evaluation for possible HSV infection. Seventy infants received empiric acyclovir over a 1-year period; of these, 3 infants (4.3%) had positive HSV testing. Fourteen infants were identified as "high-risk" for HSV infection; of these, 13 infants had incomplete testing. Survey results revealed uncertainty in the decision to initiate acyclovir and in the composition of complete diagnostic testing. This study confirmed the clinical uncertainty in the decision to initiate empiric acyclovir. Using this chart review and survey as a baseline, future efforts will focus on a quality improvement project to reduce empiric acyclovir use in low-risk infants and to ensure complete diagnostic evaluation in high-risk infants.

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.

RNA transcriptional biosignature analysis for identifying febrile infants with serious bacterial infections in the emergency department: a feasibility study

OBJECTIVES

To develop the infrastructure and demonstrate the feasibility of conducting microarray-based RNA transcriptional profile analyses for the diagnosis of serious bacterial infections in febrile infants 60 days and younger in a multicenter pediatric emergency research network.

METHODS

We designed a prospective multicenter cohort study with the aim of enrolling more than 4000 febrile infants 60 days and younger. To ensure success of conducting complex genomic studies in emergency department (ED) settings, we established an infrastructure within the Pediatric Emergency Care Applied Research Network, including 21 sites, to evaluate RNA transcriptional profiles in young febrile infants. We developed a comprehensive manual of operations and trained site investigators to obtain and process blood samples for RNA extraction and genomic analyses. We created standard operating procedures for blood sample collection, processing, storage, shipping, and analyses. We planned to prospectively identify, enroll, and collect 1 mL blood samples for genomic analyses from eligible patients to identify logistical issues with study procedures. Finally, we planned to batch blood samples and determined RNA quantity and quality at the central microarray laboratory and organized data analysis with the Pediatric Emergency Care Applied Research Network data coordinating center. Below we report on establishment of the infrastructure and the feasibility success in the first year based on the enrollment of a limited number of patients.

RESULTS

We successfully established the infrastructure at 21 EDs. Over the first 5 months we enrolled 79% (74 of 94) of eligible febrile infants. We were able to obtain and ship 1 mL of blood from 74% (55 of 74) of enrolled participants, with at least 1 sample per participating ED. The 55 samples were shipped and evaluated at the microarray laboratory, and 95% (52 of 55) of blood samples were of adequate quality and contained sufficient RNA for expression analysis.

CONCLUSIONS

It is possible to create a robust infrastructure to conduct genomic studies in young febrile infants in the context of a multicenter pediatric ED research setting. The sufficient quantity and high quality of RNA obtained suggests that whole blood transcriptional profile analysis for the diagnostic evaluation of young febrile infants can be successfully performed in this setting.

Infants 1-90 days old hospitalized with human rhinovirus infection

BACKGROUND

Human rhinovirus (HRV) is a common cause of respiratory illness in children. The impact of HRV infection on 1- to 90-day-old infants is unclear. We hypothesized that HRV infection would be clinically similar to respiratory syncytial virus (RSV) infection in the hospitalized infants.

METHODS

We conducted a retrospective study of hospitalized infants, who were 1-90 days old, with HRV or RSV within the Southern California Kaiser Permanente network over a 1-year period (August 2010 to October 2011).

RESULTS

We identified 245 hospitalized infants who underwent respiratory virus testing. HRV was found in 52 infants (21%) compared to 79 infants (32%) with RSV (P = 0.008). Infants with HRV infection experienced longer hospital stays compared to those with RSV (median length of stay 4 days vs. 3 days, P = 0.009) and had fewer short hospital stays ≤3 days (P = 0.029). There was a trend in infants with HRV infection to be younger (P = 0.071) and have more fevers (P = 0.052).

CONCLUSIONS

Recent advances in diagnostics allow for identification of a broad range of viral pathogens in infants. Compared to RSV, HRV was associated with longer hospital stays. Additional studies and improved, more specific testing, methods are needed to further define the effects of HRV infection in infants 1-90 days old.

Epidemiology of bacteremia in febrile infants in the United States

BACKGROUND

Fever in infants is a common clinical dilemma. The objective of this study was to present data from hospital systems across the northeast, southeast, mid-west, and western United States to identify the pathogens causing bacteremia in febrile infants admitted to general care units.

METHODS

This was a retrospective review of positive blood culture results in febrile infants aged ≤90 days admitted to a general care unit across 6 hospital systems. Data were collected from January 1, 2006 through December 31, 2012 from emergency departments and general inpatient units. Cultures from ICUs, central lines, or infants who had complex comorbidities were excluded, as were repeat cultures positive for the same bacteria. Common contaminants were considered pathogens if they were treated as such.

RESULTS

We identified 181 cases of bacteremia in 177 infants. The most common pathogen was Escherichia coli (42%), followed by group B Streptococcus (23%). Streptococcus pneumoniae was more likely in older infants (P = .01). Non-low-risk bacteremic infants were more likely to have E. coli or group B Streptococcus than low-risk bacteremic infants. We identified no cases of Listeria monocytogenes. Variation between sites was minimal.

CONCLUSIONS

This is the largest and most geographically diverse study to date examining the epidemiology of bacteremia in infants. We suggest E. coli is the most common cause of bacteremia in previously healthy febrile infants admitted to a general inpatient unit. We identified no cases of L monocytogenes and question whether empirical therapy remains necessary for this pathogen.

Cerebrospinal fluid pleocytosis in febrile infants 1-90 days with urinary tract infection

Sterile cerebrospinal fluid pleocytosis occurs in febrile infants with urinary tract infection. Coinfection with enterovirus is a possible cause. We evaluated 57 infants with urinary tract infection and cerebrospinal fluid pleocytosis. All had enterovirus testing by polymerase chain reaction. An explanation for pleocytosis was determined for 24 infants (42%). Enterovirus infection was detected in 4 and is an uncommon cause of cerebrospinal fluid pleocytosis in infants with urinary tract infection.