Changing epidemiology of outpatient bacteremia in 3- to 36-month-old children after the introduction of the heptavalent-conjugated pneumococcal vaccine

Risk of Urinary Tract Infection and Bacteremia in Infants Infected With COVID-19

OBJECTIVE

Our objective was to evaluate the risk of urinary tract infection (UTI) and bacteremia in infants 1 year or less of age infected with COVID-19.

METHODS

This was a retrospective study from TriNetX database in the United States. This study was from March 11, 2020, to May 11, 2023, during the COVID-19 pandemic. Patients were included if they were infants, 1 year or less, had a fever, and had a COVID-19 polymerase chain reaction test 1 week before or after presentation to the emergency department (ED) or hospital. We compared outcomes of bacteremia and a UTI in those with COVID-19 and those without COVID-19. Propensity matching was done to account for the confounders of age, gender, race, immune disorders, genitourinary abnormalities, preterm birth, and circumcision.

RESULTS

Infants who were positive for COVID-19 were at a reduced risk of UTI and bacteremia. There was a significant decreased risk of having a UTI if one had COVID-19 (1.0%) versus those without COVID-19 (2.3%) (risk ratio = 0.37, 95% confidence interval = 0.37-0.50, P < 0.001). For bacteremia, there was also a decreased risk if the infant had COVID-19 (0.4%), versus those without COVID-19 (0.5%) (risk ratio = 0.74, 95% confidence interval = 0.56-0.97, P = 0.03).

CONCLUSIONS

Infants with fever found to have COVID-19 had lower risks of UTI and bacteremia.

Predictors of Invasive Bacterial Infection in Febrile Infants Aged 2 to 6 Months in the Emergency Department

Our goal was to identify predictors of invasive bacterial infection (ie, bacteremia and bacterial meningitis) in febrile infants aged 2-6 months. In our multicenter retrospective cohort, older age and lower temperature identified infants at low risk for invasive bacterial infection who could safely avoid routine testing.

Orbital complications of pediatric acute rhinosinusitis in the pneumococcal conjugate vaccine era

OBJECTIVES

To evaluate the impact of the pneumococcal conjugate vaccines (PCVs) introduction on the orbital complications of acute rhino-sinusitis (OC-ARS).

METHODS

A retrospective cohort study of all pediatric patients with OC-ARS during the period 2002-2019. Data included clinical, demographic, laboratory, and microbiology findings. Patients were divided into three groups: before PCV7 introduction (group 1), after PCV7 and before PCV13 (group 2), and after PCV13 (group 3).

RESULTS

Of 265 enrolled patients, 117, 39, and 109 were assigned to groups 1, 2, and 3. During the study period, a significant decrease was recorded in the percentages of patients in Chandler classification severity category 1, with an increase in patients in category 3 (P = 0.011). The yearly incidence of OC-ARS decreased from 12.64 cases per 100,000 population in 2002 to 5.56 per 100,000 in 2008, and 2.99 per 100,000 in 2019 (P < 0.001). Patients aged 0-4 years showed a dramatic decrease from 29 cases per 100,000 population in 2002 to 4.27 per 100,000 in 2019 (P < 0.001). The pathogens retrieved from all cultures performed were Streptococcus pneumoniae (32.5%), non-typeable Haemophilus influenzae (27.5%), Streptococcus Species, (12.5%), and Staphylococcus aureus (20%), with no changes in distribution during the study periods. Surgery was performed in 28 (10.6%) patients.

CONCLUSIONS

A significant decrease was seen in the overall incidence of OC-ARS, mainly attributable to the decrease in patients aged 0-4 years. An increase was recorded in the severity of the disease following PCVs introduction.

Leukopenia, neutropenia, and procalcitonin levels in young febrile infants with invasive bacterial infections

BACKGROUND AND OBJECTIVE

Serum procalcitonin (PCT) is a highly accurate biomarker for stratifying the risk of invasive bacterial infections (IBIs) in febrile infants ≤60 days old. However, PCT is unavailable in some settings. We explored the association of leukopenia and neutropenia with IBIs in non-critically ill febrile infants ≤60 days old, with and without PCT.

METHODS

We conducted a secondary analysis of a prospective observational cohort consisting of 7407 non-critically ill infants ≤60 days old with temperatures ≥38°C. We focused on the risk of IBIs in patients with leukopenia (white blood cell [WBC] count <5000 cells/μL) or neutropenia (absolute neutrophil count [ANC] <1000 cells/μL), categorized to extremes of lower values, and the impact of PCT on these associations. Multiple logistic regression was used to identify independent predictors of IBIs.

RESULTS

Final analysis included 6865 infants with complete data; 45% (3098) had PCT data available. Of the 6865, a total of 111 (1.6%) had bacteremia without bacterial meningitis, 18 (0.3%) had bacterial meningitis without bacteremia, and 19 (0.3%) had both bacteremia and bacterial meningitis. IBI was present in four of 20 (20%) infants with WBC counts ≤2500 cells/μL and four of 311 (1.3%) with ANC <1000 cells/μL. In multivariable logistic regression analysis not including PCT, a WBC count <2500 cells/μL was significantly associated with IBI (OR 13.48, 95% CI 2.92-45.35). However, no patients with leukopenia or neutropenia and PCT ≤0.5 ng/mL had IBIs.

CONCLUSIONS

Leukopenia ≤2500 cells/μL in febrile infants ≤60 days old is associated with IBIs. However, in the presence of normal PCT levels, no patients with leukopenia had IBIs. While this suggests leukopenia ≤2500 cells/μL is a risk factor for IBIs in non-critically ill young febrile infants only when PCT is unavailable or elevated, the overall low frequency of leukopenia in this cohort warrants caution in interpretation, with future validation required.

Epidemiology of bacteremia in a pediatric population - A 10-year study

INTRODUCTION

With the widespread introduction of conjugate meningococcal and pneumococcal vaccines, the prevalence and etiology of invasive bacterial infections have changed. We aimed to review all cases of bacteremia in a level II pediatric department over a ten-year period in the post-pneumococcal conjugate vaccine era.

METHODS

We reviewed all positive blood cultures (BC) obtained in our department between 2007 and 2016. Results were classified as contaminants, potential pathogens or confirmed pathogens, based on species, number of positive BC in the episode and the patients' medical history. Demographic and clinical data were collected for patients with identified pathogens.

RESULTS

A total of 638 positive BC were identified (6.6% of total BC); 120 (1.2%) were considered to represent true bacteremia. The most frequently identified microorganism was Streptococcus pneumoniae (29.2%), with a decrease in the number of cases between 2008 and 2015. Staphylococcus aureus was the second most common organism (19.2%) being 21.7% of these methicillin-resistant. Escherichia coli was the most common isolate in children aged less than three months.

CONCLUSION

We found a rate of true bacteremia in children similar to recent studies. Although Streptococcus pneumoniae remains the most common microorganism, its prevalence may be declining. Monitoring microbiological data in children has implications in practice, particularly in local antibiotic prescription.

Immunization Status and the Management of Febrile Children in the Pediatric Emergency Department: What Are We Doing?

OBJECTIVES

Widespread Haemophilus influenzae and Streptococcus pneumoniae immunization has decreased occult bacteremia and bacterial meningitis rates. Practice has evolved in pediatric emergency departments (PEDs) to favor fewer diagnostic tests for and empiric treatment of invasive bacterial infection. We lack evidence-based guidance on evaluation and treatment of unimmunized (UnI) or underimmunized (UnderI) febrile children. This study aims to determine how parental report of immunization status in febrile PED patients impacts rates of diagnostic testing, interventions, and hospital admissions.

METHODS

This is a retrospective cohort study with chart review of encounters of children aged 3 to 36 months presenting to an academic, tertiary care PED in 2019 using International Classification of Diseases-10 code for fever (R50.9). Inclusion criteria were documented fever of 38°C and higher and well appearance. Encounters were excluded if there was a history of chronic illness or documentation of ill appearance or hemodynamic instability. Encounters were grouped by provider-documented immunization status. Fischer exact test and logistic regression compared rates of diagnostic testing (serum, urine or cerebrospinal fluid laboratory studies, and chest radiographs), interventions (intravenous fluid bolus, intravenous antibiotic or steroid administration, respiratory support, or breathing treatment), and hospital admissions between UnderI, UnI, and fully immunized (FI) groups.

RESULTS

Of the 1813 encounters reviewed, 1093 (60%) included provider-documented immunization status and 788 (43%) met final inclusion criteria: 23 (2.1%) UnI, 44 (5.8%) UnderI, and 721 (92.1%) FI. The UnderI and UnI children experienced significantly higher rates of laboratory evaluation including complete blood count and blood culture, medical intervention, and antibiotic prescriptions while in the PED. No significant differences were observed for rates of chest radiographs, hospital admissions, or 72-hour PED return visits.

CONCLUSIONS

Higher rates of laboratory testing and interventions were observed in UnderI and UnI versus FI febrile patients at a PED, likely demonstrating increased clinical suspicion for invasive bacterial infection in this group despite lacking national guidelines. Given continued vaccine hesitancy, further studies are needed for guiding management of febrile UnI and UnderI children presenting for emergency care.

Resolution of Fever in the Pediatric Emergency Department and Bacteremia

To determine whether a lack of response to antipyretics was associated with bacteremia, we performed a cross-sectional study involving children with an initial temperature ≥38°C presenting to a pediatric emergency department (ED) from 2012 to 2020 who received an antipyretic and had a blood culture obtained. We assessed the association of resolution of fever at specific time points after antipyretic administration with bacteremia adjusting for age, complex chronic condition, blood culture source, type of antipyretic, and height of temperature. Among 6319 febrile children, 242 (3.8%) had bacteremia. The adjusted odds ratio of bacteremia was 1.6 (95% confidence interval: 1.2-2.2) among children who remained febrile at 180 minutes and 1.7 (1.2-2.4) among children who remained febrile at 240 minutes. Among febrile children presenting to a tertiary care ED for whom a blood culture was obtained, the response to an antipyretic varies based on the presence or absence of bacteremia.

Incidence, Characteristics, and Outcomes of Clinically Undetected Bacteremia in Children Discharged Home From the Emergency Department

BACKGROUND

Despite a recent decline in the rates of invasive infections, bacteremia in young children remains a significant challenge. We aimed to describe patient characteristics, microbial etiology, and outcomes of bacteremic, well-appearing children 3-36 months of age who were discharged home from the pediatric emergency department (PED) on their index visit.

METHODS

A retrospective cohort study in the PED of a tertiary children's hospital from 1 June 2015 until 30 June 2021. We included all well appearing, immunocompetent infants 3-36 months old evaluated for fever and discharged home from the PED after a blood culture was drawn. We extracted demographic, clinical and laboratory data from the patient's electronic medical records for the index visit and subsequent encounters.

RESULTS

During the study period, 17,114 children evaluated for fever met the inclusion criteria. Seventy-two patients (0.42%) had positive cultures for known pathogens. Thirty-six (50%) were male and 36 (50%) younger than 1 year. The most common isolates were S. pneumonia 26%. (n = 19), K. Kingae 25%. (n = 18) and Salmonella spp. 13.9% (n = 10). Sixty patients (85.7%) were recalled to the ED or had a scheduled appointment, 10 (14.3%) returned spontaneously and two were followed up by phone. The median time between visits was 28.7 hours (IQR 19.1-41.1). One patient was admitted to intensive care during the course of hospitalization. There were no deaths.

CONCLUSION

The rate of undetected true bacteremia in our study was low and our data suggest that significant clinical deterioration during the first 24 hours is rare.

Serious bacterial infections in young children with fever without source after discharge from emergency department: A National Health Insurance database cohort study

BACKGROUND

Well-appearing febrile young children discharged from the emergency department (ED) after medical assessment are still at risk for serious bacterial infections (SBI). The incidence of SBI and the effectiveness of laboratory tests in the pneumococcal conjugate vaccine era remain unknown.

METHODS

We conducted a study using Taiwan's National Health Insurance claims data from 2004 to 2014. Children aged 2-24 months discharged from the ED with a diagnosis compatible with fever without source (FWS) were enrolled.

RESULTS

The study identified 431,884 children from the ED with FWS. 13.53% of the children had revisits, 8.62% needed hospitalization and 1.57% developed SBI. Younger children had a higher SBI rate, but a lower revisit rate. The revisit rate was 12.22% for children aged 2-6 months, 13.61% for children aged 7-12 months and 13.77% for children aged 13-24 months (p < 0.0001). The SBI rate was 4.44% for children aged 2-6 months, 1.85% for children aged 2-6 months and 0.96% for children aged 13-24 months (p < 0.0001). Children with hemogram tests, compared to those without, had a higher revisit rate (16.30% vs. 13.15%, p < 0.0001), and a higher SBI rate in the children aged 13-24 months (1.30% vs. 0.92%, p < 0.0001); furthermore, children with urinalysis had a significantly higher revisit rate (14.42% vs. 13.24%, p < 0.0001) and higher SBI rate (2.10% vs. 1.40%, p < 0.0001).

CONCLUSION

Children with FWS aged 2-24 months who were discharged from ED after blood test and urinalysis were still at risk for SBI, especially those aged 2-6 months.

Novel Biomarkers Differentiating Viral from Bacterial Infection in Febrile Children: Future Perspectives for Management in Clinical Praxis

Differentiating viral from bacterial infections in febrile children is challenging and often leads to an unnecessary use of antibiotics. There is a great need for more accurate diagnostic tools. New molecular methods have improved the particular diagnostics of viral respiratory tract infections, but defining etiology can still be challenging, as certain viruses are frequently detected in asymptomatic children. For the detection of bacterial infections, time consuming cultures with limited sensitivity are still the gold standard. As a response to infection, the immune system elicits a cascade of events, which aims to eliminate the invading pathogen. Recent studies have focused on these host–pathogen interactions to identify pathogen-specific biomarkers (gene expression profiles), or “pathogen signatures”, as potential future diagnostic tools. Other studies have assessed combinations of traditional bacterial and viral biomarkers (C-reactive protein, interleukins, myxovirus resistance protein A, procalcitonin, tumor necrosis factor-related apoptosis-inducing ligand) to establish etiology. In this review we discuss the performance of such novel diagnostics and their potential role in clinical praxis. In conclusion, there are several promising novel biomarkers in the pipeline, but well-designed randomized controlled trials are needed to evaluate the safety of using these novel biomarkers to guide clinical decisions.

Epidemiology of bacteremia in a pediatric population - A 10-year study

INTRODUCTION

With the widespread introduction of conjugate meningococcal and pneumococcal vaccines, the prevalence and etiology of invasive bacterial infections have changed. We aimed to review all cases of bacteremia in a level II pediatric department over a ten-year period in the post-pneumococcal conjugate vaccine era.

METHODS

We reviewed all positive blood cultures (BC) obtained in our department between 2007 and 2016. Results were classified as contaminants, potential pathogens or confirmed pathogens, based on species, number of positive BC in the episode and the patients' medical history. Demographic and clinical data were collected for patients with identified pathogens.

RESULTS

A total of 638 positive BC were identified (6.6% of total BC); 120 (1.2%) were considered to represent true bacteremia. The most frequently identified microorganism was Streptococcus pneumoniae (29.2%), with a decrease in the number of cases between 2008 and 2015. Staphylococcus aureus was the second most common organism (19.2%) being 21.7% of these methicillin-resistant. Escherichia coli was the most common isolate in children aged less than three months.

CONCLUSION

We found a rate of true bacteremia in children similar to recent studies. Although Streptococcus pneumoniae remains the most common microorganism, its prevalence may be declining. Monitoring microbiological data in children has implications in practice, particularly in local antibiotic prescription.

True Versus False Bacteremia in Infants and Children Less Than 3 Years of Age

OBJECTIVE

The objective of this study was to examine patient history as well as clinical and laboratory features associated with true bacteremia versus false bacteremia in previously healthy febrile children ages 0 to 36 months in the era of polyvalent conjugate pneumococcal immunization.

METHODS

Using retrospective chart review, we examined history, physical examination, and laboratory characteristics associated with true and false bacteremia. We included subjects under 3 years old, with a positive blood culture obtained in the emergency department or clinic from July 2011 to July 2013, and fever defined as a temperature of greater than or equal to 100.4°F by history or examination. We excluded those with a previously known underlying disease process that could increase the risk for positive blood culture, for example, immunodeficiency, cancer, cystic fibrosis, or significant skin disorders such as severe eczema, as well as patients with any indwelling central line, shunt, or other implanted device, or recent hospitalization for a febrile illness.

RESULTS

Thirty subjects (24%) had true bacteremia, and 97 (76%) had false bacteremia. In the multivariable logistic regression analysis, exposure to sick contacts (odds ratio, 0.1; 95% confidence interval, 0.01-0.6; P = 0.01) and increased hours to positive blood culture (odds ratio, 0.8; 95% confidence interval, 0.8-0.9; P < 0.001) remained significant factors associated with false bacteremia. Age, maximum reported temperature, and reported days of fever were not associated with true bacteremia.

CONCLUSIONS

We found that previously healthy children with true bacteremia are more likely to grow bacteria faster on blood culture and lack exposure to sick contacts than children with false bacteremia.

A multicenter evaluation of viral bloodstream detections in children presenting to the Emergency Department with suspected systemic infection

Background

Fever is a common symptom in children presenting to the Emergency Department (ED). We aimed to describe the epidemiology of systemic viral infections and their predictive values for excluding serious bacterial infections (SBIs), including bacteremia, meningitis and urinary tract infections (UTIs) in children presenting to the ED with suspected systemic infections.

Methods

We enrolled children who presented to the ED with suspected systemic infections who had blood cultures obtained at seven healthcare facilities. Whole blood specimens were analyzed by an experimental multiplexed PCR test for 7 viruses. Demographic and laboratory results were abstracted.

Results

Of the 1114 subjects enrolled, 245 viruses were detected in 224 (20.1%) subjects. Bacteremia, meningitis and UTI frequency in viral bloodstream-positive patients was 1.3, 0 and 10.1% compared to 2.9, 1.3 and 9.7% in viral bloodstream-negative patients respectively. Although viral bloodstream detections had a high negative predictive value for bacteremia or meningitis (NPV = 98.7%), the frequency of UTIs among these subjects remained appreciable (9/89, 10.1%) (NPV = 89.9%). Screening urinalyses were positive for leukocyte esterase in 8/9 (88.9%) of these subjects, improving the ability to distinguish UTI.

Conclusions

Viral bloodstream detections were common in children presenting to the ED with suspected systemic infections. Although overall frequencies of SBIs among subjects with and without viral bloodstream detections did not differ significantly, combining whole blood viral testing with urinalysis provided high NPV for excluding SBI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02699-9.

Association of Bacteremia with Vaccination Status in Children Aged 2 to 36 Months

OBJECTIVE

To determine the association between bacteremia and vaccination status in children aged 2-36 months presenting to a pediatric emergency department.

STUDY DESIGN

Retrospective cohort study of children aged 2-36 months with blood cultures obtained in the pediatric emergency department between January 2013 and December 2017. The exposure of interest was immunization status, defined as number of Haemophilus influenzae type B (Hib) and Streptococcus pneumoniae vaccinations, and the main outcome positive blood culture. Subjects with high-risk medical conditions were excluded.

RESULTS

Of 5534 encounters, 4742 met inclusion criteria. The incidence of bacteremia was 1.5%. The incidence of contaminated blood culture was 5.0%. The relative risk of bacteremia was 0.79 (95% CI 0.39-1.59) for unvaccinated and 1.20 (95% CI 0.52-2.75) for undervaccinated children relative to those who had received age-appropriate vaccines. Five children were found to have S pneumoniae bacteremia and 1 child had Hib bacteremia; all of these subjects had at least 3 sets of vaccinations. No vaccine preventable pathogens were isolated from blood cultures of unvaccinated children. We found no S pneumoniae or Hib in children 2-6 months of age who were not fully vaccinated due to age (95% CI 0-0.13%) and the contamination rate in this group was high compared with children 7-36 months (6.6% vs 3.7%).

CONCLUSIONS

Bacteremia in young children is an uncommon event. Contaminated blood cultures were more common than pathogens. Bacteremia from S pneumoniae or Hib is uncommon and, in this cohort, was independent of vaccine status.

The impact of pneumococcal conjugate vaccine-13 on the incidence of pediatric community-acquired bacteremia

The purpose of this study was to estimate the impact of pneumococcal conjugate vaccine-13 (PCV-13) introduction into the national immunization program in Israel on pneumococcal and non-pneumococcal pediatric community-acquired bacteremia (CAB). This is a retrospective cohort study, including children ≤ 18 years old with CAB, who were hospitalized in Rambam Health Care Campus, a tertiary medical center serving northern Israel, between the years 2004 and 2016. The proportional admission rate of pneumococcal bacteremia among all CAB events and the incidence of CAB and pneumococcal bacteremia per 1000 hospital admissions were compared between the pre- and post-pneumococcal vaccine eras. A total of 275 CAB events were identified. Common isolates were Streptococcus pneumoniae (SPn) (26.9%), Staphylococcus aureus (12.4%), Brucella spp. (11.6%), E. coli (10.9%), and Streptococcus pyogenes (5.8%). The pneumococcal bacteremia rate per 1000 hospital admissions decreased significantly from 1.59 to 0.6 (p < 0.001). The proportional pneumococcal bacteremia rate decreased from 55 (34.4%) to 19 (16.5%) (p 0.001). Penicillin resistance among pneumococcal isolates decreased dramatically from 50.9 to 5.3% (p < 0.001). The rate of bacteremia caused by other pathogens has not been changed significantly at the post-vaccination era (p 0.053). However, an increase in the incidence of S. pyogenes bacteremia from 1.9 to 11.3% (p < 0.001) was noticed. In addition, an outbreak of Brucella bacteremia occurred during the years 2015-2016. This study demonstrates the double positive effect of PVC-13 introduction: a sharp decrease in the proportional rate of pneumococcal bacteremia and in the resistance of SPn to penicillin. Also, there was a moderate decline in the incidence of CAB in exception to bacteremia caused by S. pyogenes. This trend was reversed due to a Brucella outbreak.

Occult Bacteremia in Young Children with Very High Fever Without a Source: A Multicenter Study

We carried out a prospective multicenter study including 203 previously healthy well-appearing children who were 3-24 months old with fever without a source ≥40.5°C. Thirty-one (15.3%, 95% confidence interval 11.0-20.9) were diagnosed with serious bacterial infection, including 6 with bacteremia (3%, 95% confidence interval 1.4-6.3). Testing for occult bacteremia in children 3-24 months old with fever without a source should be considered when fever at ≥40.5°C.

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.

High Rate of Febrile Seizures in Japanese Children With Occult Bacteremia

OBJECTIVES

Fever of 39°C or higher and a white blood cell (WBC) count of 15,000/μL or greater are known predictors of occult bacteremia (OB). However, because of a decreasing prevalence of OB, WBC counts have become poor predictors of OB in populations of routinely immunized children. Thus, we aim to evaluate the clinical characteristics of OB in Japanese children and identify potential risk factors for OB.

METHODS

We conducted an observational study of children aged 3 to 36 months old with positive blood cultures for Streptococcus pneumoniae or Haemophilus influenzae at an emergency department in a tertiary care children's hospital between April 2002 and December 2015. Patients with significant underlying diseases, a proven source of infection, or toxic appearance, were excluded.

RESULTS

Positive blood cultures were recorded in 231 patients; of these, 110 were included in the study (S. pneumoniae, n = 102; H. influenzae, n = 8). Median age was 16 (3-34) months. Patients had a high median body temperature of 39.2 (interquartile range, 38.6-39.9) °C and median WBC of 21,120 (interquartile range, 16,408-24,242)/μL. A high rate of febrile seizures (58 patients, 53%) was observed, with complex febrile seizures accounting for 43% of the episodes. Frequency of febrile seizures was positively associated with age (P = 0.001).

CONCLUSIONS

Our study revealed a high rate of children presenting with febrile seizures, especially complex seizures, among children with OB in Japan. A further study is necessary to evaluate the role of febrile seizures as a predictor for OB.

Prevalence of respiratory viruses and antiviral MxA responses in children with febrile urinary tract infection

Blood myxovirus resistance protein A (MxA) has broad antiviral activity, and it is a potential biomarker for symptomatic virus infections. Limited data is available of MxA in coinciding viral and bacterial infections. We investigated blood MxA levels in children hospitalized with a febrile urinary tract infection (UTI) with or without simultaneous respiratory virus infection. We conducted a prospective observational study of 43 children hospitalized with febrile UTI. Nasopharyngeal swab samples were collected at admission and tested for 16 respiratory viruses by nucleic acid detection methods. Respiratory symptoms were recorded, and blood MxA levels were determined. The median age of study children was 4 months (interquartile range, 2–14 months). A respiratory virus was detected in 17 (40%) children with febrile UTI. Of the virus-positive children with febrile UTI, 7 (41%) had simultaneous respiratory symptoms. Blood MxA levels were higher in virus-positive children with respiratory symptoms (median, 778 [interquartile range, 535–2538] μg/L) compared to either virus-negative (155 [94–301] μg/L, P < 0.001) or virus-positive (171 [112–331] μg/L, P = 0.006) children without respiratory symptoms at presentation with febrile UTI. MxA differentiated virus-positive children with respiratory symptoms from virus-negative without symptoms by an area under the receiver operating characteristic curve of 0.96. Respiratory viruses were frequently detected in children with febrile UTI. In UTI with simultaneous respiratory symptoms, host antiviral immune response was demonstrated by elevated blood MxA protein levels. MxA protein could be a robust biomarker of symptomatic viral infection in children with febrile UTI.

The Negative Predictive Ability of Immature Neutrophils for Bacteremia in Children With Community-Acquired Infections

Background: Bacteremia is a serious condition. We aimed to assess the role of immature neutrophils in peripheral blood smears for prediction of bacteremia in children. Methods: In this cross-sectional study conducted in Salvador, Brazil, blood cultures collected from patients aged ≤18 years were identified. White Blood Cell count (WBC) was performed upon admission. Medical charts were reviewed and cases from the community were included. Results: Out of 833 potentially eligible patients, 263 (31.6%) were excluded. Therefore, the study group comprised 570 patients being blood collected for culture upon admission from all of them and WBC performed upon admission from 566. The median age was 2 years (IQR: 9.4 mo-5 y) and 300 (52.6%) were male. Acute respiratory infection was the most frequent diagnosis (n = 388; 68.1%), being 250 (43.9%) lower (LRTI) and 138 (24.2%) upper respiratory tract infections. Blood culture was positive in 9 (1.6%; 95% CI: 0.8-2.9%) cases, out of which 7 (2.8%) had LRTI. Streptococcus pneumoniae (n = 3), Haemophilus (n = 2), Neisseria meningitidis, viridans streptococci, Streptococcus agalactiae, and Acinetobacter baumanii (n = 1 each) were isolated. The total WBC/mm3 did not differ when children with positive or negative blood culture were compared (12,100 [IQR: 6,950-15,250] vs. 11,000 [IQR: 7,900-14,900]; P = 0.9). However, presence of any immature neutrophil was significantly more frequent among patients with bacteremia in comparison with patients without bacteremia (100% [9/9] vs. 40% [223/557]; P < 0.001). The absolute number of immature neutrophils was significantly lower among children without bacteremia (0 [IQR: 0-259] vs. 325 [IQR: 275-1,106]; P < 0.001). Overall, the area under the ROC curve of the number of immature neutrophils in regard to bacteremia was 0.82 (95% CI: 0.76-0.88; P = 0.001). Among 413 patients with absolute number of immature neutrophils <242/mm³, none had bacteremia; among 153 patients with absolute number of immature neutrophils ≥242/mm³, 9 (5.9%) had bacteremia. Absolute number of immature neutrophils ≥242/mm3 showed: sensitivity 100% (95% CI: 71.7-100%), specificity 74.1% (95% CI: 70.4-77.7%), negative predictive value 100% (95% CI: 99.3-100.0%), and positive predictive value 5.9% (95% CI: 2.9-10.5%). When only children with LRTI were analyzed, the results were similar. Conclusion: The absolute number of immature neutrophils in peripheral blood smear is a potential tool to rule out bacteremia among children with community-acquired infections.

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.

High Concentration of C-Reactive Protein Is Associated With Serious Bacterial Infection in Previously Healthy Children Aged 3 to 36 Months With Fever and Extreme Leukocytosis

OBJECTIVES

The aim of the study was to investigate the diagnostic efficacy of C-reactive protein (CRP) in predicting serious bacterial infection (SBI) in febrile children aged 3 to 36 months with extreme leukocytosis (EL), defined as a peripheral white blood cell count of 25,000 to 49,999/mm.

METHODS

The presence of SBI was reviewed in previously healthy children aged 3 to 36 months with a fever of 39°C or higher and EL, who visited a tertiary care hospital emergency department between September 2010 and August 2015. We measured cutoff values of CRP with corresponding likelihood ratios (LRs) and posttest probabilities (PPs).

RESULTS

Of 9989 febrile children, 4252 (42.6%) underwent assays for white blood cell and CRP. Of 233 (5.5%) children with EL, 133 (3.1%) were enrolled, of whom 43 (32.3%; 95% confidence interval [CI], 25.0%-40.7%) had SBI, including 33 pyelonephritis, 5 deep abscesses, 3 lobar pneumonia, and 2 soft tissue infections. With the cutoff of 7.8 mg/dL, the sensitivity of CRP in predicting SBI was 81.4% (95% CI, 67.4%-90.3%); the specificity, 80.0% (95% CI, 70.6%-87.0%); the positive predictive value, 66.0% (95% CI, 52.6%-77.3%); the negative predictive value, 90.0% (95% CI, 81.5%-94.9%); the positive LR, 4.1; and the PP, 66.0% (95% CI, 55.6%-75.0%). A CRP concentration of 16.1 mg/dL or higher yielded an LR of 11.2 and a PP of 84.2% (95% CI, 62.1%-94.5%). A CRP concentration of lower than 3.4 mg/dL yielded an LR of 0.05 and a PP of 2.4% (95% CI, 0.3%-14.6%).

CONCLUSIONS

High concentration of CRP is strongly associated with the presence of SBI in febrile children with EL.

Prevalence of Occult Bacteremia in Infants With Very High Fever Without a Source

We carried out a prospective registry-based cohort study at the emergency department of 363 previously healthy well-appearing infants 3-24 months of age with fever without a source ≥40.5°C based on local protocol. Four were diagnosed with occult bacteremia (1.1%; 95% confidence interval: 0-2.2). Recommendations for nontesting for occult bacteremia screening in these children may have to be reconsidered when fever ≥40.5°C. Larger studies are needed to confirm these results.

Dynamics of Severe and Non-severe Invasive Pneumococcal Disease in Young Children in Israel Following PCV7/PCV13 Introduction

BACKGROUND

The introduction of the pneumococcal conjugated vaccines (PCVs) resulted in a substantial reduction of invasive pneumococcal disease (IPD) rates. However, impact on nonsevere IPD (mostly occult bacteremia) has not yet been fully elucidated. We assessed severe and nonsevere IPD (SIPD and NSIPD, respectively) rate dynamics in children < 5 years in Israel before and after PCV7/PCV13 implementation.

METHODS

A prospective, population-based, nationwide surveillance. All IPD episodes recorded from 1999 through 2015 were included. NSIPD was defined as IPD episodes without meningitis, pneumonia or mastoiditis in a child with a favorable outcome (not hospitalized or hospitalized in a nonintensive care unit < 5 days, without mortality). Three subperiods were defined: pre-PCV (1999-2008), PCV7 (2010-2011) and PCV13 (2013-2015). Incidence rate ratios (IRRs) were calculated.

RESULTS

Overall, 4,457 IPD episodes were identified; 3,398 (76.2%) SIPD, 1,022 (22.9%) NSIPD and 37 (0.8%) unknown. In 90% of NSIPD episodes, no focus was identified. In the PCV7 period, NSIPD rates significantly declined by 52%, while SIPD rates declined less prominently by 24%. Following PCV13 introduction, compared with the PCV7 period, NSIPD rates declined nonsignificantly by 17% while SIPD rates declined significantly further by an additional 53%. These trends resulted in overall reductions (comparing PCV13 and pre-PCV periods) of NSIPD and SIPD of 60% (IRR = 0.4; 0.32-0.51) and 64% (IRR = 0.36; 0.32-0.42), respectively.

CONCLUSIONS

Following PCV7/PCV13 introduction, SIPD and NSIPD rates substantially declined, with differences in rate-dynamics, alluding to differences in serotype distribution between the 2 groups. Future surveillance is warranted when considering modification in treatment protocols for suspected occult bacteremia/NSIPD cases.

Trend and outcome of sepsis in children: A nationwide cohort study

AIM

The aim of this study was to investigate the trend of incidence and outcome of paediatric sepsis in a population-based database.

METHODS

Children with sepsis were identified from the 23 million nationwide health insurance claims database of Taiwan. Sepsis was defined by the presence of single ICD-9 code for severe sepsis or septic shock or a combination of ICD-9 codes for infection and organ dysfunction. We analysed the trend of incidence, mortality and source of infection in three age groups: infant (28 days to 1 year), child (1-9 years) and adolescent (10-18 years).

RESULTS

From 2002 to 2012, we identified 38 582 paediatric patients with sepsis, of which 21.3% were infants, 52.8% were children and 25.8% were adolescents. The incidence of sepsis was 336.4 cases per 100 000 population in infants, 3.3 times higher than in children (101.5/100 000 cases) and 7.3 times higher than in adolescents (46.2/100 000 cases). While sepsis incidence decreased from 598.0 to 336.4 cases per 100 000 people in the infant population, it remained relatively unchanged in children and adolescents. For 90-day mortality, there were significant decreases in all three age groups (absolute decrease of 5.0% for infants, 3.7% for children and 14.4% for the adolescents). In the infant population, we observed a decrease in the incidence of lower respiratory tract infections, while the incidence of urinary tract infections remained unchanged.

CONCLUSIONS

The incidence and mortality of sepsis among paediatric patients have decreased substantially between 2002 and 2012, especially among infants. The widespread use of Haemophilus influenzae and pneumococcal vaccines in infants could be a possible explanation.

Occult bacteremia etiology following the introduction of 13-valent pneumococcal conjugate vaccine: a multicenter study in Spain

Little is known about occult bacteremia (OB) in Spain following the introduction of the 13-valent pneumococcal conjugated vaccine (PCV13). Our aim was to describe the microbiologic characteristics and management of OB among children aged 3-36 months in Spain in the era of PCV13. Data were obtained from a multicenter registry of positive blood cultures collected at 22 Spanish emergency departments (ED). Positive blood cultures performed on patients aged 3-36 months from 2011 to 2015 were retrospectively identified. Immunocompetent infants with a final diagnosis of OB were included. Non-well-appearing patients and patients with fever > 72 h were excluded. We analyzed 67 cases (median age 12.5 months [IQR 8.7-19.4]). Thirty-seven (54.4%) had received ≥ 1 dose of PCV. Overall, 47 (70.1%) were initially managed as outpatients (38.3% of them with antibiotic treatment). Phone contact was established with 43 (91.5%) of them after receiving the blood culture result and 11 (23.4%) were hospitalized with parenteral antibiotic. All patients did well. Streptococcus pneumoniae was isolated in 79.1% of the patients (42.2% of the isolated serotypes were included in the PCV13). S. pneumoniae remains the first cause of OB in patients attended in the ED, mainly with non-PCV13 serotypes. Most of the patients with OB were initially managed as outpatients with no adverse outcome.

Epidemiology of Bacteremia in Febrile Infants Aged 60 Days and Younger

STUDY OBJECTIVE

To describe the current epidemiology of bacteremia in febrile infants 60 days of age and younger in the Pediatric Emergency Care Applied Research Network (PECARN).

METHODS

We conducted a planned secondary analysis of a prospective observational study of febrile infants 60 days of age and younger presenting to any of 26 PECARN emergency departments (2008 to 2013) who had blood cultures obtained. We excluded infants with significant comorbidities or critically ill appearance. The primary outcome was prevalence of bacteremia.

RESULTS

Of 7,335 screened infants, 4,778 (65.1%) had blood cultures and were enrolled. Of these patients, 84 had bacteremia (1.8%; 95% confidence interval [CI] 1.4% to 2.2%). The prevalence of bacteremia in infants aged 28 days or younger (47/1,515) was 3.1% (95% CI 2.3% to 4.1%); in infants aged 29 to 60 days (37/3,246), 1.1% (95% CI 0.8% to 1.6%). Prevalence differed by week of age for infants 28 days of age and younger (0 to 7 days: 4/156, 2.6%; 8 to 14 days: 19/356, 5.3%; 15 to 21 days: 15/449, 3.3%; and 22 to 28 days: 9/554, 1.6%). The most common pathogens were Escherichia coli (39.3%; 95% CI 29.5% to 50.0%) and group B streptococcus (23.8%; 95% CI 16.0% to 33.9%). Bacterial meningitis occurred in 19 of 1,515 infants 28 days of age and younger (1.3%; 95% CI 0.8% to 2.0%) and 5 of 3,246 infants aged 29 to 60 days (0.2%; 95% CI 0.1% to 0.4%). Of 84 infants with bacteremia, 36 (42.9%; 95% CI 32.8% to 53.5%) had urinary tract infections (E coli 83%); 11 (13.1%; 95% CI 7.5% to 21.9%) had bacterial meningitis.

CONCLUSION

The prevalence of bacteremia and meningitis among febrile infants 28 days of age and younger is high and exceeds that observed in infants aged 29 to 60 days. E coli and group B streptococcus are the most common bacterial pathogens.

Variation in Care and Clinical Outcomes in Children Hospitalized With Orbital Cellulitis

OBJECTIVES

To describe variation in the care of children hospitalized with orbital cellulitis and to determine associations with length of stay (LOS), emergency department (ED) revisits, and hospital readmissions.

METHODS

By using the Pediatric Health Information System, we performed a multicenter, retrospective study of children aged 2 months to 18 years with a primary International Classification of Diseases, Ninth Revision, Clinical Modification discharge diagnosis code for orbital cellulitis from 2007 to 2014. We assessed hospital-level variation in the use of diagnostic tests, corticosteroids, and antibiotics individually and in aggregate for association with outcomes (LOS, ED revisits, readmissions) after risk-adjusting for important clinical and demographic factors.

RESULTS

A total of 1828 children met inclusion criteria. Complete blood cell counts (median [interquartile range]: 81.8% [66.7-89.6]), C-reactive protein levels (57.1% [22.2-84.0]), blood cultures (57.9% [48.9-63.6]), and computed tomography imaging (74.7% [66.7-81.0]) were the most frequently performed diagnostic tests, with significant variation observed across hospitals (all P < .001). Corticosteroids were used in 29.2% of children (interquartile range: 18.4-37.5). There was significant variation in antibiotic exposure across hospitals (P < .001). Increased total diagnostic test usage was associated with increased LOS (P = .044), but not with 30-day ED revisits (P = .176) or readmissions (P = .403).

CONCLUSIONS

Children hospitalized with orbital cellulitis experience wide variation in clinical management. Increased hospital-level usage is associated with increased LOS. Our findings highlight a critical need to identify treatment strategies that optimize resource use and outcomes for children hospitalized with orbital cellulitis.

Accuracy of Complete Blood Cell Counts to Identify Febrile Infants 60 Days or Younger With Invasive Bacterial Infections

IMPORTANCE

Clinicians often risk stratify young febrile infants for invasive bacterial infections (IBIs), defined as bacteremia and/or bacterial meningitis, using complete blood cell count parameters.

OBJECTIVE

To estimate the accuracy of individual complete blood cell count parameters to identify febrile infants with IBIs.

DESIGN, SETTING, AND PARTICIPANTS

Planned secondary analysis of a prospective observational cohort study comprising 26 emergency departments in the Pediatric Emergency Care Applied Research Network from 2008 to 2013. We included febrile (≥38°C), previously healthy, full-term infants younger than 60 days for whom blood cultures were obtained. All infants had either cerebrospinal fluid cultures or 7-day follow-up.

MAIN OUTCOMES AND MEASURES

We tested the accuracy of the white blood cell count, absolute neutrophil count, and platelet count at commonly used thresholds for IBIs. We determined optimal thresholds using receiver operating characteristic curves.

RESULTS

Of 4313 enrolled infants, 1340 (31%; 95% CI, 30% to 32%) were aged 0 to 28 days, 2412 were boys (56%), and 2471 were white (57%). Ninety-seven (2.2%; 95% CI, 1.8% to 2.7%) had IBIs. Sensitivities were low for common complete blood cell count parameter thresholds: white blood cell count less than 5000/µL, 10% (95% CI, 4% to 16%) (to convert to 109 per liter, multiply by 0.001); white blood cell count ≥15 000/µL, 27% (95% CI, 18% to 36%); absolute neutrophil count ≥10 000/µL, 18% (95% CI, 10% to 25%) (to convert to  × 109 per liter, multiply by 0.001); and platelets <100  × 103/µL, 7% (95% CI, 2% to 12%) (to convert to × 109 per liter, multiply by 1). Optimal thresholds for white blood cell count (11 600/µL), absolute neutrophil count (4100/µL), and platelet count (362 × 103/µL) were identified in models that had areas under the receiver operating characteristic curves of 0.57 (95% CI, 0.50-0.63), 0.70 (95% CI, 0.64-0.76), and 0.61 (95% CI, 0.55-0.67), respectively.

CONCLUSIONS AND RELEVANCE

No complete blood cell count parameter at commonly used or optimal thresholds identified febrile infants 60 days or younger with IBIs with high accuracy. Better diagnostic tools are needed to risk stratify young febrile infants for IBIs.

Avoidance of voiding cystourethrography in infants younger than 3 months with Escherichia coli urinary tract infection and normal renal ultrasound

BACKGROUND AND OBJECTIVE

Urinary tract infection (UTI) represents the most common bacterial infection in infants, and its prevalence increases with the presence of high-grade vesicoureteral reflux (VUR). However, voiding cystourethrography (VCUG) is invasive, and its indication in infants <3 months is not yet defined. This study aims to investigate, in infants aged 0-3 months, if the presence of Escherichia coli versus non-E. coli bacteria and/or normal or abnormal renal ultrasound (US) could avoid the use of VCUG.

METHOD

One hundred and twenty-two infants with a first febrile UTI were enrolled. High-grade VUR was defined by the presence of VUR grade ≥III. The presence of high-grade VUR was recorded using VCUG, and correlated with the presence of E. coli/non-E. coli UTI and with the presence of normal/abnormal renal US. The Bayes theorem was used to calculate pretest and post-test probability.

RESULTS

The probability of high-grade VUR was 3% in the presence of urinary E. coli infection. Adding a normal renal US finding decreased this probability to 1%. However, in the presence of non-E. coli bacteria, the probability of high-grade VUR was 26%, and adding an abnormal US finding increased further this probability to 55%.

CONCLUSIONS

In infants aged 0-3 months with a first febrile UTI, the presence of E. coli and normal renal US findings allow to safely avoid VCUG. Performing VCUG only in infants with UTI secondary to non-E. coli bacteria and/or abnormal US would save many unnecessary invasive procedures, limit radiation exposure, with a very low risk (<1%) of missing a high-grade VUR.

[Recommendations for the use of rapid diagnosis techniques in respiratory infections in primary care]

Respiratory tract infections rank first as causes of adult and paediatric infectious morbidity in primary care in Spain. These infections are usually self-limiting and are mainly caused by viruses. However, a high percentage of unnecessary antibiotic prescription is reported. Point-of-care tests are biomedical tests, which can be used near the patient, without interference of a laboratory. The use of these tests, many of which have been recently developed, is rapidly increasing in general practice. Notwithstanding, we must mull over whether they always contribute to an effective and high-quality diagnostic process by primary care clinicians. We present a set of criteria that can be used by clinicians and discuss the pros and cons of the instruments available for the management of respiratory tract infections and how to use them appropriately.

Serotype distribution of Streptococcus pneumoniae causing invasive disease in children in the post-PCV era: A systematic review and meta-analysis

BACKGROUND

Routine immunisation with pneumococcal conjugate vaccines (PCV7/10/13) has reduced invasive pneumococcal disease (IPD) due to vaccine serotypes significantly. However, an increase in disease due to non-vaccine types, or serotype replacement, has been observed. Serotypes' individual contributions to IPD play a critical role in determining the overall effects of PCVs. This study examines the distribution of pneumococcal serotypes in children to identify leading serotypes associated with IPD post-PCV introduction.

METHODS

A systematic search was performed to identify studies and surveillance reports (published between 2000 and December 2015) of pneumococcal serotypes causing childhood IPD post-PCV introduction. Serotype data were differentiated based on the PCV administered during the study period: PCV7 or higher valent PCVs (PCV10 or PCV13). Meta-analysis was conducted to estimate the proportional contributions of the most frequent serotypes in childhood IPD in each period.

RESULTS

We identified 68 studies reporting serotype data among IPD cases in children. We analysed data from 38 studies (14 countries) where PCV7 was administered and 20 (24 countries) where PCV10 or PCV13 have been introduced. Studies reported early and late periods of PCV7 administration (range: 2001∓13). In these settings, serotype 19A was the most predominant cause of childhood IPD, accounting for 21.8% (95%CI 18.6∓25.6) of cases. In countries that have introduced higher valent PCVs, study periods were largely representative of the transition and early years of PCV10 or PCV13. In these studies, the overall serotype-specific contribution of 19A was lower (14.2% 95%CI 11.1∓18.3). Overall, non-PCV13 serotypes contributed to 42.2% (95%CI 36.1∓49.5%) of childhood IPD cases. However, regional differences were noted (57.8% in North America, 71.9% in Europe, 45.9% in Western Pacific, 28.5% in Latin America, 42.7% in one African country, and 9.2% in one Eastern Mediterranean country). Predominant non-PCV13 serotypes overall were 22F, 12F, 33F, 24F, 15C, 15B, 23B, 10A, and 38 (descending order), but their rank order varied by region.

CONCLUSION

Childhood IPD is associated with a wide number of serotypes. In the early years after introduction of higher valent PCVs, non-PCV13 types caused a considerable proportion of childhood IPD. Serotype data, particularly from resource-limited countries with high burden of IPD, are needed to assess the importance of serotypes in different settings. The geographic diversity of pneumococcal serotypes highlights the importance of continued surveillance to guide vaccine design and recommendations.

Bacteremia in Children 3 to 36 Months Old After Introduction of Conjugated Pneumococcal Vaccines

BACKGROUND AND OBJECTIVES

In June 2010, Kaiser Permanente Northern California replaced all 7-valent pneumococcal conjugate vaccine (PCV7) vaccines with the 13-valent pneumococcal conjugate vaccine (PCV13). Our objectives were to compare the incidence of bacteremia in children 3 to 36 months old by 3 time periods: pre-PCV7, post-PCV7/pre-PCV13, and post-PCV13.

METHODS

We designed a retrospective review of the electronic medical records of all blood cultures collected on children 3 to 36 months old at Kaiser Permanente Northern California from September 1, 1998 to August 31, 2014 in outpatient clinics, in emergency departments, and in the first 24 hours of hospitalization.

RESULTS

During the study period, 57 733 blood cultures were collected in the population of children 3 to 36 months old. Implementation of routine immunization with the pneumococcal conjugate vaccine resulted in a 95.3% reduction of Streptococcus pneumoniae bacteremia, decreasing from 74.5 to 10 to 3.5 per 100 000 children per year by the post-PCV13 period. As pneumococcal rates decreased, Escherichia coli, Salmonella spp, and Staphylococcus aureus caused 77% of bacteremia. Seventy-six percent of all bacteremia in the post-PCV13 period occurred with a source.

CONCLUSIONS

In the United States, routine immunizations have made bacteremia in the previously healthy toddler a rare event. As the incidence of pneumococcal bacteremia has decreased, E coli, Salmonella spp, and S aureus have increased in relative importance. New guidelines are needed to approach the previously healthy febrile toddler in the outpatient setting.

Management and Outcomes of Previously Healthy, Full-Term, Febrile Infants Ages 7 to 90 Days

BACKGROUND

There is considerable variation in the approach to infants presenting to the emergency department and outpatient clinics with fever without a source. We set out to describe the current clinical practice regarding culture acquisition on febrile young infants and review the outcomes of infants with and without cultures obtained.

METHODS

This study analyzed Kaiser Permanente Northern California's electronic medical record to identify all febrile, full term, previously healthy infants born between July 1, 2010, and June 30, 2013, presenting for care between 7 and 90 days of age.

RESULTS

During this 3-year study, 96 156 full-term infants were born at Kaiser Permanente Northern California. A total of 1380 infants presented for care with a fever with an incidence rate of 14.4 (95% confidence interval: 13.6-15.1) per 1000 full term births. Fifty-nine percent of infants 7 to 28 days old had a full evaluation compared with 25% of infants 29 to 60 days old and 5% of infants 61 to 90 days old. Older infants with lower febrile temperatures presenting to an office setting were less likely to have a culture. In the 30 days after fevers, 1% of infants returned with a urinary tract infection. No infants returned with bacteremia or meningitis.

CONCLUSIONS

Fever in a medical setting occurred in 1.4% of infants in this large cohort. Forty-one percent of febrile infants did not have any cultures including 24% less than 28 days. One percent returned in the following month with a urinary tract infection. There was no delayed identification of bacteremia or meningitis.

Epidemiologic and Microbiologic Characteristics of Occult Bacteremia Among Febrile Children in Southern Israel, Before and After Initiation of the Routine Antipneumococcal Immunization (2005-2012)

BACKGROUND

Little is known about the incidence and dynamics of occult bacteremia (OB) among infants/young children following the introduction of pneumococcal conjugate vaccines (PCVs) into the national immunization program in Israel in 2009-2010. The aim of this study was to characterize the epidemiologic and microbiologic picture of OB among febrile infants/children aged 3-36 months in southern Israel, before and after PCVs introduction.

METHODS

Retrospective study enrolling all infants/young children attending the emergency room of a tertiary medical center in southern Israel with fever without source, discharged, and reported with a positive blood culture.

RESULTS

Of 453 true bacteremias, 89 (19.6%) were defined as OB. OB rate was 0.22%; a significant decrease was recorded in OB rates, with the highest rate during 2005 (0.34%) and the lowest during 2011 (0.15%). OB cases decreased in post-PCV (2010-2012) versus prevaccination period (2005-2009) from 66/22,256 cases (0.3%) to 23/13,213 cases (0.17%; p = 0.03). Most frequent single OB pathogens were Streptococcus pneumoniae, Streptococcus viridans spp., and Kingella kingae (39.3%, 10.1%, and 9.0%, respectively); Enterobacteriaceae spp. were isolated in 10 cases (11.2%). No changes were recorded in S. pneumoniae-OB cases; K. kingae-OB decreased significantly (p = 0.047). None of the S. pneumoniae serotypes isolated during 2011-2012 belonged to 13-valent PCV (PCV13). An increase in non PCV13 serotypes was recorded during 2011-2012 (3/3, 100% vs. 7/32, 21.9%, p = 0.01).

CONCLUSION

OB rates decreased significantly following the introduction of PCVs. S. pneumoniae was the most frequent isolated pathogen in OB, but in lower percentages compared with the medical literature. No PCV13 serotypes were detected as a cause of OB during 2011-2012.

The Epidemiologic, Microbiologic and Clinical Picture of Bacteremia among Febrile Infants and Young Children Managed as Outpatients at the Emergency Room, before and after Initiation of the Routine Anti-Pneumococcal Immunization

We described the occult bacteremia (OB) and bacteremia with diagnosed focus (BwF) picture among children managed as outpatients at the pediatric emergency room (PER) in southern Israel, before and after the introduction of pneumococcal conjugate vaccines (PCVs) introduction in a retrospective study enrolling all three- to 36-month-old patients with fever >38.0 °C during 2005–2014. Of 511 (0.82% of all febrile patients) true bacteremias, 230 (45%) were managed as outpatients; 96 of 230 (41.7%) had OB and 134 (3.59%) had BwF. OB and BwF rates were 0.22% and 3.02%, respectively. A significant decrease was noted in OB and BwF rates (p = 0.0008 and p = 0.02, respectively). S. pneumoniae (SP, 37.5%), K. kingae (11.4%) and Brucella spp. (8.7%) were the most common OB pathogens and SP (29.8%), S. viridans (13.4%), and Brucella spp. (12.7%) were the most common in BwF patients. PCV13 serotypes were not found among the serotypes isolated post-PCV13 introduction. During 2010–2014 there was an increase in non-PCV13 serotype isolation (p = 0.005). SP was the main pathogen isolated among patients with pneumonia, acute otitis media (AOM) and periorbital cellulitis (62.5%, 33.3% and 60%, respectively). OB and BwF decreased following the introduction of PCVs and SP was the main pathogen in both conditions. Vaccine-SP serotypes were not isolated in OB after PCV13 introduction and non-vaccine serotypes increased significantly.

Etiology and prognostic factors of sepsis among children and adolescents admitted to the intensive care unit

Objective

To determine the etiology and clinical disease progression variables of sepsis associated with the prognosis of patients admitted to a pediatric intensive care unit.

Methods

Prospective and retrospective case series. Data were collected from the medical records of patients diagnosed with sepsis who were admitted to the pediatric intensive care unit of a general hospital from January 2011 to December 2013. Bacteria were identified in blood and fluid cultures. Age, sex, vaccination schedule, comorbidities, prior antibiotic use, clinical data on admission, and complications during disease progression were compared in the survival and death groups at a 5% significance level.

Results

A total of 115 patients, with a mean age of 30.5 months, were included in the study. Bacterial etiology was identified in 40 patients. Altered peripheral perfusion on admission and diagnosis of severe sepsis were associated with complications. A greater number of complications occurred in the group of patients older than 36 months (p = 0.003; odds ratio = 4.94). The presence of complications during hospitalization was associated with death (odds ratio = 27.7). The main etiological agents were Gram-negative bacteria (15/40), Staphylococcus aureus (11/40) and Neisseria meningitidis (5/40).

Conclusion

Gram-negative bacteria and Staphylococcus aureus predominated in the etiology of sepsis among children and adolescents admitted to an intensive care unit. The severity of sepsis and the presence of altered peripheral perfusion on admission were associated with complications. Moreover, the presence of complications was a factor associated with death.

The aetiology of paediatric bloodstream infections changes after pneumococcal vaccination and group B streptococcus prophylaxis

AIM

This study explored the incidence and aetiology of bloodstream infections after patients received the pneumococcal conjugate vaccination and a risk-based intrapartum antibiotic prophylaxis against early onset sepsis caused by group B streptococcus. We also monitored clinically relevant antimicrobial resistance.

METHOD

We studied 3986 positive blood cultures from children up to 17 years of age at a paediatric hospital in Stockholm, Sweden, using data from medical records before and after the initiatives, to reduce early onset sepsis, were introduced in 2007 and 2008.

RESULTS

Bloodstream infections caused by Streptococcus pneumoniae declined by 42% overall (5.6 to 3.2/100 000) and by 62% in previously healthy children under 36 months of age (24.2 to 9.2/100 000). Early onset sepsis caused by group B streptococcus declined by 60% (0.5 to 0.2/1000 live born children). Bacterial meningitis caused by these bacteria decreased by 70%. Staphylococcus aureus and various Gram-negative bacteria became the dominant pathogens, in both previously healthy children and those with underlying disease. Overall, antimicrobial resistance remained low between the two 5-year study periods.

CONCLUSION

Pneumococcal conjugate vaccination and risk-based intrapartum antibiotic prophylaxis against group B streptococcus effectively decreased the incidence of bloodstream infections. Empirical antibiotic therapy should target Staphylococcus aureus in both community and hospital-acquired invasive bacterial infections.

The Value of the "Lab-Score" Method in Identifying Febrile Infants at Risk for Serious Bacterial Infections

Introduction

Most children with fever without source will have a self limited viral infection though a small percent will develop a serious bacterial infection (SBI) like urinary tract infection, pneumonia, bacteraemia, meningitis or sepsis. The challenge facing practitioners is to distinguish between these two groups and currently biomarkers, like C-reactive protein (CRP) and Procalcitonin (PCT), are available for this purpose.The aim of the current study was to identify SBI in infants with fever without an identifiable cause using the recently introduced "Lab-score" combining C-reactive protein, procalcitonin and urine dipstick results.

Methods

This survey is part of an observational study aimed at identifying children with fever without source at risk of SBI. Patients were recruited from the Emergency Department of Tîrgu Mures Emergency Clinical County Hospital, Romania, during 2013. SBI diagnosis was based on urine, blood and cerebrospinal fluid cultures and chest radiographs. For infants, aged 7 days to 12 months, CRP and PCT were determined and the "Lab-score" was calculated. Positive and negative likelihood ratios and post test probabilities were calculated for each parameter and score.

Results

Of the ninety infants included in the study, SBI was diagnosed in nineteen (21.11%). Ten had a urinary tract infection, seven had pneumonia, one had a urinary tract infection and bacteraemia, and one had sepsis. Positive and negative likelihood ratios for CRP (≥40.0 mg/L) and PCT (≥0.5 ng/mL) were 10.27/0.45 and 7.07/0.24 and post-test probabilities 73%/65%. For a "Lab-score" (≥3), positive and negative likelihood ratios were 10.43/0.28, and the posttest probability was 73%.

Conclusions

In our survey the "Lab-score" proved a strong predictor for the identification of febrile infants at risk of SBI, but showed no significant difference compared with CRP and PCT which both proved equally good predictors for SBI.

Occult bacteraemia is uncommon in febrile infants who appear well, and close clinical follow-up is more appropriate than blood tests

AIM

The rate of paediatric occult bacteraemia after the introduction of the 13-valent pneumococcal conjugated vaccine is relatively unknown. We determined the rate, and identified isolated pathogens, in children aged three to 36 months who presented to a paediatric emergency department with fever, but otherwise appeared well. We also analysed the yield of laboratory parameters traditionally considered risk factors for occult bacteraemia.

METHODS

Children aged three to 36 months who were febrile, but otherwise appeared well, were included if they had blood tests in the paediatric emergency department between April 2010 and September 2012.

RESULTS

Of the 591 patients, only six (1.0%) had a true bacterial pathogen and three of those were Streptococcus pneumoniae (0.5%). None of the children with pneumococcal bacteraemia had been immunised. The contaminant rate was 2.7%, and an elevated band count was the best predictor of occult bacteraemia, with positive and negative likelihood ratios of 10 and 0.4, respectively. The yield of the other laboratory parameters was very limited.

CONCLUSION

In the era of the 13-valent pneumococcal conjugated vaccine, occult bacteraemia is an uncommon event in febrile children aged three to 36 who otherwise appear well and close follow-up should replace blood analysis in such cases.