Escherichia coli bacteremia in children. A review of 91 cases in 10 years

We reviewed 91 cases of pediatric Escherichia coli bacteremia during a 10-year period. Thirty one patients were afebrile; a significantly greater proportion of these patients were aged less than 1 month, had ampicillin-resistant E coli isolates, or had persistent bacteremia 24 hours after initiating antibiotic therapy. Infection was community acquired in 65 cases; associated urinary tract infection was six times more common in this setting than in nosocomially acquired infections. In 85 cases at least 1 underlying medical condition/focus of infection was identified at the time the positive blood culture was obtained, the most common were immune deficiency states (38 cases), urinary tract infection (29 cases), and lesions of the gastrointestinal tract (27 cases). Polymicrobial bacteremia occurred in five cases. Twelve patients died; significantly associated with death were hypotension requiring pressor therapy, presence of a central venous catheter, and neutropenia.     

Klebsiella pneumoniae bacteremia in children. Fifty-seven cases in 10 years

A review was performed of the 57 cases of Klebsiella pneumoniae bacteremia that occurred in children at our institution during a 10-year period. The rate of K pneumoniae bacteremia relative to all blood cultures in which bacteria were isolated was 1.1%. Children younger than 12 months of age accounted for 38 cases (67%). There were 8 children (14%) who were afebrile at the time bacteremia was documented; other presenting clinical features were generally indistinguishable from those that characterize pediatric bacteremia of more common causes. Fourteen children (25%) were receiving broad-spectrum parenteral antibiotic therapy at the time bacteremia was documented. In 53 patients (93%), an underlying condition predisposing to opportunistic infection was identified, the most common of which were lesions of the gastrointestinal tract (56%), presence of an indwelling central venous catheter (35%), and neutropenia (25%). Klebsiella pneumoniae was a constituent of polymicrobial bacteremia in 15 patients (26%). The overall mortality rate associated with this infection was 20%, with over one half of all deaths occurring in infants who were afebrile at the time bacteremia was documented. Klebsiella pneumoniae bacteremia is a relatively uncommon, serious infection that usually occurs in young children with predisposing underlying conditions, and is associated with a significant mortality rate.     

Polymicrobial bacteremia in pediatric patients

Of 1,352 positive pediatric blood cultures during a 3.6-year period, two or more microorganisms grew from 72 cultures (5.3%), representing 60 patients. Based on predefined operational criteria for clinical interpretation of blood cultures, these cases were retrospectively classified as polymicrobial bacteremia (each organism, ie, a pathogen, 30%), mixed bacteremia/contaminant (20%), or multiple contaminants (50%). Considered individually, gram-positive organisms were isolated more frequently but were more often judged to be contaminants than the less common gram-negative organisms, which were more often thought to be true pathogens. Although one child did have a combined Streptococcus pneumoniae/Hemophilus influenzae bacteremia, these more common pediatric pathogens were underrepresented in those patients with polymicrobial bacteremia, from whom Enterobacteriaceae, streptococci, staphylococci, and anaerobes were more commonly isolated. Hospitalization for a predisposing illness and/or a focus of infection occurred in 88% of the children with confirmed polymicrobial bacteremia.     

儿科重症监护室铜绿假单胞菌培养阳性患儿临床特征及耐药性分析

目的：总结儿科重症监护室铜绿假单胞菌（pseudomonas aeruginosa, PA）培养阳性患儿的临床特征,为临床早期诊断和合理治疗提供依据。方法：回顾性分析62例PA培养阳性患儿临床资料,包括年龄、受累脏器、发热持续时间、住院时间、转归、机械通气时间、基础疾病、死亡情况、培养结果以及药敏试验结果。结果：62例患儿中,<6月患儿25例（40%）,2岁以下47例（76%）,中位年龄28.8月。27例痰培养或气管插管导管培养1次阳性,3例血培养1次阳性,32例2次以上不同部位（血、痰、气管插管）培养阳性;平均受累脏器2.8个,呼吸系统最常受累,共58人次（94%）;平均发热时间7.3 d;平均住院时间34.2 d。治愈35例（57%）,死亡17例（27%）。51例（82%）应用机械通气,平均通气13.4 d。51例有基础疾病（82%）。17例（27%）死亡,平均年龄17.4个月,CRP平均52.6 mg/L,其中14例白细胞升高或正常,3例白细胞降低。PA对临床常用抗生素的敏感性分别为：头孢哌酮/舒巴坦（72.6%）、美洛培南（70.8%）、亚胺培南（49.1%）、头孢他啶（65.1%）、哌拉西林/他唑巴坦（44.3%）。对头孢唑啉、头孢呋辛及头孢噻肟100%耐药。结论：2岁以下婴幼儿PA感染率较高;呼吸系统最易受累;PA感染患儿多患有基础疾病。PA对常用抗生素敏感性不高。     

Risk of bacteremia in young children with pneumonia treated as outpatients

BACKGROUND: Blood cultures are often obtained as part of the evaluation of children with pneumonia. There are few data regarding the risk of bacteremia with pneumonia in children since introduction of the Haemophilus influenzae type b vaccine. OBJECTIVE: To evaluate the risk of bacteremia in young children with pneumonia who were treated as outpatients. METHODS: A retrospective cohort study of 580 children aged 2 to 24 months who were evaluated by blood culture in a tertiary care children's hospital emergency department between February 1, 1993, and May 31, 1996, and discharged with the diagnosis of pneumonia. RESULTS: The mean patient age was 14.1 months; 339 patients (58.4%) were boys. Thirty-eight patients (6.6%) reported the use of oral antibiotics before initial emergency department evaluation. The prevalence of bacteremia was 1.6% (95% confidence interval, 0.7%-2.9%). Streptococcus pneumoniae was the causative organism in all 9 cases. The serotype was available for 8 of 9 cases. Six (75%) of 8 cases of S pneumoniae bacteremia were caused by serotypes included in the current heptavalent pneumococcal conjugate vaccine, which was not available at the time of this study. The contamination rate was 1.9% (95% confidence interval, 1.0%-3.4%). The mean +/- SD time to blood culture positive for organisms in a continuously monitored system was significantly shorter for pathogens (13.9 +/- 1.3 hours) than for contaminants (21.2 +/- 6.1 hours; P =.01). CONCLUSIONS: Children aged 2 to 24 months with pneumonia who are treated as outpatients are at low risk of bacteremia. Widespread use of the pneumococcal conjugate vaccine may further decrease the incidence of bacteremia in this population.     

Risk of serious bacterial infection in children with fever without a source in the post-Haemophilus influenzae era when antibiotics are reserved for culture-proven bacteremia

OBJECTIVE: To determine the rate of serious bacterial infection in children aged 2 to 36 months with fever without a source in the post-Haemophilus influenzae era, when antibiotic therapy is reserved until blood culture results turn positive. DESIGN AND SETTING: Retrospective review of emergency department, urgent care center, and hospital medical records from an urban children's hospital. PARTICIPANTS: Eligible participants were identified from hospital medical record and microbiology laboratory databases. Immunocompetent individuals aged 2 to 36 months with fever without a source were eligible for enrollment. Exclusion criteria were temperature less than 39.0 degrees C, identifiable focus of infection, current or recent antibiotic use, and hospital admission. INTERVENTIONS AND OUTCOME MEASURES: Enrolled participants were assigned to group 1 (blood culture obtained) or group 2 (no blood culture) and did not receive empiric antibiotic treatment in the emergency department, in the urgent care center, or for home use. Demographic and outcome data were collected on all enrolled patients. RESULTS: During the study, 9241 febrile children were identified; 2641 (29%) met the enrollment criteria. Blood cultures (group 1) were performed on 1202 patients (46%), and 37 (3%) had culture-proven occult bacteremia (95% confidence interval, 2.2%-4.2%). Streptococcus pneumoniae was the most prevalent organism (84%). The mean +/- SD time for reporting a positive blood culture finding was 17.5 +/- 8.5 hours. Two patients (0.08%; 95% confidence interval, 0.009%-0.27%) developed serious bacterial infection, and both recovered completely. CONCLUSION: Reserving antibiotic therapy for culture-proven occult bacteremia was not associated with increased risk of developing serious bacterial infection compared with previously published data.     

Factors predicting occult bacteremia in young children

A febrile child without a definite localizing sign of infection may be in initial phase of bacteremia which unless treated would result in systemic complication. These instances are referred to as “Occult bacteremia”. The common pathogens isolated in these children areStreptococcus pneumoniae, Hemophilus influenzae andNeisseria meningitidis. A hundred consecutive children in the age group of 3–36 months attending pediatric outpatient department and casualty were clinically evaluated using AIOS (acute illness observation scale) score and were subjected to complete blood counts, smear for malarial parasites, ESR and blood culture. In the 19-month study period, 4 instances of occult bacteremia were identified.Streptococcus pneumoniae was cultured in 3 cases andH. influenzae in one. A febrile and toxic child in the age group of 3–36 months has a high risk of occult bacteremia. High fever of temperature ≥ 102°F, ESR ≥ 15 mm/hour, and total leukocyte count ≥ 15,000 / mm³, in a child with AIOS score of ≥ 10 may be considered for more detailed investigations and early intervention with antimicrobial therapy.     

Low risk of bacteremia in febrile children with recognizable viral syndromes

BACKGROUND: Previous studies of occult bacteremia in febrile children have excluded patients with recognizable viral syndromes (RVS). There is little information in the literature regarding the rate of bacteremia in febrile children with RVS. OBJECTIVE: To determine the rate of bacteremia in children 3 to 36 months of age with fever and RVS. METHODS: We performed a retrospective analysis of all patients 3 to 36 months of age with a temperature > or =39 degrees C seen during a 5 1/2-year period in the Emergency Department of a tertiary care pediatric hospital. From this group those with a discharge diagnosis of croup, varicella, bronchiolitis or stomatitis and no apparent concomitant bacterial infection were considered to have an RVS. The rate of bacteremia was determined for those subjects with RVS who had blood cultures. RESULTS: Of 21,216 patients 3 to 36 months of age with a temperature > or =39 degrees C, 1347 (6%) were diagnosed with an RVS. Blood cultures were obtained in 876 (65%) of RVS patients. Of patients who had blood cultures, true pathogens were found in only 2 of 876 (0.2%) subjects with RVS [95% confidence interval (CI) 0.01, 0.8%]. The rate of bacteremia was 1 of 411 (0.2%) for subjects with bronchiolitis, O of 249 (0%) for subjects with croup, O of 123 (0%) for subjects with stomatitis and 1 of 93 (1.1%) for subjects with varicella. CONCLUSIONS: Highly febrile children 3 to 36 months of age with uncomplicated croup, bronchiolitis, varicella or stomatitis have a very low rate of bacteremia and need not have blood drawn for culture.     

Systemic nontyphoidal Salmonella infection in normal infants in Thailand.

BACKGROUND: The relative paucity of information about systemic nontyphoidal Salmonella (NTS) infection in infants without an underlying disease prompted this study. METHODS: Infants without an underlying disease, who had positive cultures for NTS from their normally sterile sites during 1978 through 1998, were included. Their medical records were reviewed. RESULTS: The study included 75 eligible infants; 68 (91%) had positive blood cultures. The spectrum of disease included transient bacteremia (5), bacteremia without localized infection (37), bone and joint infection (5) and meningitis (28); 53 and 88% of infants were < or =3 and < or =6 months old, respectively. All infants with localized infection were < or =7 months old, and infants with meningitis were 3.35+/-1.87 (mean +/- SD) months old. In bacteremic infants risks for localized infection and meningitis were 30 and 24%, respectively. Abnormal neurologic findings were the only predictor for meningitis. Relapse of meningitis occurred in two infants despite treatment with cefotaxime for 4 and 6 weeks. Severe neurologic deficit occurred in 21% of infants with meningitis. Of 11 infants with meningitis who received early treatment at this tertiary care center, 1 died but none had severe neurologic deficits; whereas of 17 referred cases, 2 died and 6 had severe neurologic abnormalities. No death occurred in infants without meningitis. CONCLUSION: Systemic NTS infection in normal infants has a variable disease spectrum. Infants 0 to 6 months of age are at high risk for localized infection, especially meningitis.     

Follow-up of patients with occult bacteremia in pediatric emergency departments.

Blood cultures are frequently obtained in pediatric emergency departments (EDs) from febrile young children at risk for bacteremia and subsequent development of serious bacterial infections. This study of 105 children with occult bacteremia treated in two large urban pediatric EDs describes the follow-up of these patients and the impact that positive blood culture results have on the detection of serious illness. Seventy-seven percent of patients had a follow-up visit in the ED, 8% had follow-up by telephone alone, and 15% were not contacted. Of the patients who returned to the ED, 49% did so because they were notified of the positive blood culture result. The mean time interval for these patients from registration at the initial visit to report of positive blood culture result was 30.0 hours and, from registration at the initial visit to follow-up visit, was 42.7 hours. Thirty-seven percent of those who returned did so because a follow-up visit was scheduled at the initial encounter, and 13% returned because of persistent illness. Ten children (9.6%), five of whom had been notified of the positive blood culture, returned with serious illnesses. Patients whose diagnosis of serious illness was facilitated by blood culture results had shorter delay in identifying cultures as positive than did patients notified of positive results who did not develop serious illness (16.2 vs 31.6 hours; P < 0.05). The delay in follow-up of children with occult bacteremia limits the usefulness of blood cultures in the early detection of serious illness.(ABSTRACT TRUNCATED AT 250 WORDS)     

Optimizing blood culture practices in pediatric immunocompromised patients: evaluation of media types and blood culture volume

BACKGROUND: The optimal use of blood cultures to determine the etiology of febrile episodes in neutropenic children has not been well-defined. METHODS: Single volume blood cultures using the Pediatric ISOLATOR System (ISO), were compared with variable, weight-based culture volumes using the BACTEC 9240 Culture System (BAC). Additionally the value of routinely inoculating the BACTEC MYCO/F LYTIC culture vial (MFL) as well as the BACTEC AEROBIC/F culture vial (AF) was examined. RESULTS: A total of 2620 cultures had both ISO and BAC inoculated; 182 cultures were positive (7.0% of cultures); 97.8% of positive cultures were detected by the BAC (AF and/or MFL) vs.46.2% detected by the ISO. The advantage of the BAC over the ISO was statistically significant for overall recovery of isolates and bloodstream infections, including most individual organism categories. There were only two instances (one each of histoplasmosis and candidemia) in which a blood stream infection was detected by ISO only. All the isolates judged to be contaminants were recovered by BAC only. AF detected significantly more coagulase-negative Staphylococcus spp. than the MFL. Of the isolates 16%, representing 14% of the bloodstream infections (including Gram-negative infections), were detected by the MFL only. Infections were detected more quickly by BAC than by ISO (P < 0.0001). Among the BAC media types, AF was faster than MFL (P < 0.0001). CONCLUSIONS: Optimal yield of blood cultures in immunocompromised pediatric patients included the use of BAC with a weight-based, graduated volume of culture inoculation and routine use of both AF and MFL.     

Clinical characteristics of children with fever and transient neutropenia who experience serious bacterial infections

A review of consecutive previously healthy children with fever and newly discovered neutropenia without underlying malignancy, evaluated during a three-year period, was performed. A total of 68 episodes occurred in 68 patients; blood culture was performed on each. Of 17 patients who appeared compromised (ill, irritable, toxic) on presentation, five (30%) had either bacteremia or bacterial meningitis. All five patients had clinical evidence of a fulminant disease process on examination. By contrast, all 51 patients who appeared to be well on presentation were culture-negative. Fever and new-onset neutropenia in children is a heterogeneous disorder with several outcomes. Any child with fever and newly discovered neutropenia who appears ill should be presumed to be at high risk for systemic bacterial infection and receive hospitalization for parenteral antibiotic therapy. By contrast, the previously healthy child older than two months of age with fever and new-onset neutropenia who appears to be well, and whose clinical evaluation does not indicate a serious underlying disease process, is at low risk for accompanying systemic bacterial infection; hospitalization with empiric antibiotic therapy pending culture results is not warranted for the majority of such children. Close outpatient monitoring with serial evaluation of the peripheral blood absolute neutrophil count to document bone marrow recovery is recommended for such cases.     

Endophthalmitis following pediatric intraocular surgery for congenital cataracts and congenital glaucoma.

The incidence of endophthalmitis following pediatric anterior segment surgery is currently unknown. The paucity of reports of this entity has led some observers to recommend simultaneous bilateral surgery for congenital cataracts or glaucoma. In this study, we surveyed over 500 pediatric ophthalmologists and glaucoma specialists concerning their knowledge of, or involvement with, endophthalmitis following pediatric intraocular surgery. Seventeen cases of endophthalmitis were documented to occur out of 24,000 reported surgical cases. This results in an incidence estimate of 0.071%, or 7 cases per 10,000, which is similar to that recently reported following adult extracapsular cataract extraction. The presence of infection was diagnosed by the 3rd postoperative day in 82% of cases. An organism was documented by culture in 65% of cases. The organism was gram positive in all cases. Visual outcome was generally poor with 65% having no light perception. The presence of possible concurrent risk factors for postoperative endophthalmitis, including nasolacrimal duct obstruction and upper respiratory infection, was noted in 8 of the 17 cases.     

Detection and quantitation of bacteremia in childhood.

Quantitative blood cultures were sought in 383 children, from whom routine blood cultures were obtained because of fever, by direct plating of 10 and 100 microliter blood onto solidified media. There were 14 positive cultures from 12 patients. These were 7 Hemophilus influenzae type b, 5 Streptococcus penumoniae, and 2 Staphylococcus aureus. The direct-plating technique permitted more rapid identification of positive cultures, and detected three episodes not identified by routine broth culture. Bacterial counts ranged from 20 to greater than 10(4) bacteria/ml blood. In the three cases of H. influenzae type b meningitis, bacteremia exceeded 10(3)/ml. Among nine patients in whom bacteremia was unassociated with meningitis, (bacteremia without evident localized disease 5, pneumonia 2, epiglottitis 1, peritonitis 1), bacteremia was less than 10(3)/ml. This technique may aid detection of bacteremia and help identify those children at highest risk for developing septic complications, such as meningitis.     

Nosocomial infections due to Acinetobacter baumannii in a pediatric intensive care unit in Turkey

The aim of this study is to document the clinical characteristics and outcomes of Acinetobacter baumannii infections in pediatric patients in a pediatric intensive care unit (PICU) in Turkey. The ages ranged from 1 month to 16 years with a mean age of 55.5 months, and the male-to-female ratio was 1:1.5. Ventilator-associated pneumonia (10 patients) was the leading diagnosis, followed by catheter-related blood stream infection (4 patients), and bacteremia and ventilator-associated pneumonia associated with meningitis (1 patient) due to A. baumannii. Mechanical ventilation (93.3%), central venous catheter (73.3%), urinary catheter (93.3%), and broad spectrum antibiotic usage (80%) were the frequently seen risk factors. Neuromuscular (40%) and malignant (26.7%) disorders were the most common underlying diseases. Nosocomial A. baumannii is commonly multidrug-resistant, prolongs the length of stay in the PICU and increases the mortality rates in pediatric critical care.     

Vibrio cholerae sepsis in the neonate

Vibrio cholerae sepsis is infrequent, especially in neonates although sporadic cases have been reported in older patients. We report the case of a neonate who was admitted to the intensive care unit for hypovolemic shock secondary to diarrhea caused by V. cholerae that developed into bacteremia. The predisposing factors were low socioeconomic status, home delivery, delayed presentation at the health center, and active maternal gastrointestinal infection with V. cholerae. The organism identified in blood and feces culture was identified as V. cholerae 0 -1, biotype Thor, serotype Ogawa, which correlated with the clinical presentation.     

Polymicrobial bacteremia in children. An 11-year experience

The clinical records of all patients with blood cultures positive for a bacterial pathogen were retrospectively examined during an 11-year period to determine the rate of and clinical features associated with polymicrobial bacteremia. During this period, bacteria were isolated in 6302 blood cultures. Of these cultures, 38 instances (0.6%) of polymicrobial bacteremia occurred in 38 patients. In 37 patients (97%), an underlying condition was identified that was considered a predisposing factor for polymicrobial bacteremia--18 patients (42%) had lesions of the gastrointestinal tract, 13 patients (34%) had an indwelling central venous catheter, nine patients (24%) had a malignant neoplasm or were receiving chemotherapy, and nine patients (24%) had neutropenia. A total of 98 pathogenic organisms were isolated; 52 were gram-negative and 46 were gram-positive, and 18 patients (47%) had more than two organisms isolated. Polymicrobial bacteremia was usually clinically indistinguishable from monomicrobial septicemia. Overall mortality was 32%. Polymicrobial bacteremia continues to be a rare, but serious, infectious disease that usually affects children with underlying medical problems and is associated with a high rate of mortality.     

Postoperative mediastinitis in children: epidemiology, microbiology and risk factors for Gram-negative pathogens

BACKGROUND: Mediastinitis, although an infrequent complication of median sternotomy, represents a significant source of morbidity and mortality. OBJECTIVE: To determine the incidence and describe the epidemiology and microbiology of mediastinitis in children after cardiac surgery and to identify risk factors for the development of Gram-negative mediastinitis. STUDY DESIGN: This was a retrospective case-control study nested within the cohort of children, birth to 18 years of age, undergoing median sternotomy between January 1, 1995 and December 31, 2003. RESULTS: Forty-three cases of mediastinitis were identified. The incidence of mediastinitis was 1.4%. Median patient age at time of inciting sternotomy was 32 days (interquartile range, 5 days-9 months). Twenty-three (54%) cases occurred in girls. Median time to onset of infection after surgery was 11 days (range, 4-34 days). Overall Gram-positive organisms were present in 29 (67%) cases, and Gram-negative organisms were present in 13 (30%) cases. The organisms most commonly isolated from mediastinal culture were Staphylococcus aureus (46%), coagulase-negative staphylococci (17%) and Pseudomonas aeruginosa (17%). The rate of concurrent bacteremia was 53% (95% confidence interval, 38-69%). In multivariable analysis, delayed sternal closure was an independent risk factor for the development of Gram-negative mediastinitis (odds ratio, 9.3; 95% confidence interval, 1.5-56.8; P = 0.016). CONCLUSIONS: Although Gram-positive organisms were the most common cause of infection, Gram-negative organisms accounted for one-third of all isolates. More than one-half of patients with mediastinitis had concurrent bacteremia. Delayed sternal closure was an independent risk factor for Gram-negative mediastinitis.     

Occult bacteremia in children with simple febrile seizures

The controversy surrounding the diagnostic workup for simple febrile seizures has centered around the lumbar puncture. This focus has obscured the potential importance of other tests. A retrospective study was performed to determine the frequency of occult bacteremia in simple febrile seizures. In a pediatric emergency department, we identified 115 cases of simple febrile seizures in children treated as outpatients. Blood cultures were performed in 93 (81%) of 115 patients; five (5.4%) were positive. Children were less likely to have blood cultures performed if they were older than 24 months or had a medical history of simple febrile seizures. However, neither age nor history of febrile seizures affected the risk of bacteremia. These data suggest that patients with simple febrile seizures are at approximately the same risk for bacteremia as children with fever alone. Patients with simple febrile seizures should be treated in the same manner as other patients of the same age with regard to the performance of blood cultures.