Interpretation of Cerebrospinal Fluid White Blood Cell Counts in Young Infants With a Traumatic Lumbar Puncture.

STUDY OBJECTIVE: We determine the optimal correction factor for cerebrospinal fluid WBC counts in infants with traumatic lumbar punctures. METHODS: We performed a secondary analysis of a retrospective cohort of infants aged 60 days or younger and with a traumatic lumbar puncture (cerebrospinal fluid RBC count ≥10,000 cells/mm3) at 20 participating centers. Cerebrospinal fluid pleocytosis was defined as a cerebrospinal fluid WBC count greater than or equal to 20 cells/mm3 for infants aged 28 days or younger and greater than or equal to 10 cells/mm3 for infants aged 29 to 60 days; bacterial meningitis was defined as growth of pathogenic bacteria from cerebrospinal fluid culture. Using linear regression, we derived a cerebrospinal fluid WBC correction factor and compared the uncorrected with the corrected cerebrospinal fluid WBC count for the detection of bacterial meningitis. RESULTS: Of the eligible 20,319 lumbar punctures, 2,880 (14%) were traumatic, and 33 of these patients (1.1%) had bacterial meningitis. The derived cerebrospinal fluid RBCs:WBCs ratio was 877:1 (95% confidence interval [CI] 805 to 961:1). Compared with the uncorrected cerebrospinal fluid WBC count, the corrected one had lower sensitivity for bacterial meningitis (88% uncorrected versus 67% corrected; difference 21%; 95% CI 10% to 37%) but resulted in fewer infants with cerebrospinal fluid pleocytosis (78% uncorrected versus 33% corrected; difference 45%; 95% CI 43% to 47%). Cerebrospinal fluid WBC count correction resulted in the misclassification of 7 additional infants with bacterial meningitis, who were misclassified as not having cerebrospinal fluid pleocytosis; only 1 of these infants was older than 28 days. CONCLUSION: Correction of the cerebrospinal fluid WBC count substantially reduced the number of infants with cerebrospinal fluid pleocytosis while misclassifying only 1 infant with bacterial meningitis of those aged 29 to 60 days.

Sterile cerebrospinal fluid pleocytosis in young febrile infants with urinary tract infections.

OBJECTIVES: To determine the prevalence of and to identify risk factors for sterile cerebrospinal fluid (CSF) pleocytosis in a large sample of febrile young infants with urinary tract infections (UTIs) and to describe the clinical courses of those patients. DESIGN: Secondary analysis of a multicenter retrospective review. SETTING: Emergency departments of 20 North American hospitals. Patients Infants aged 29 to 60 days with temperatures of 38.0°C or higher and culture-proven UTIs who underwent a nontraumatic lumbar puncture from January 1, 1995, through May 31, 2006. MAIN EXPOSURE: Febrile UTI. OUTCOME MEASURES: Presence of sterile CSF pleocytosis defined as CSF white blood cell count of 10/µL or higher in the absence of bacterial meningitis and clinical course and treatment (ie, presence of adverse events, time to defervescence, duration of parenteral antibiotic treatment, and length of hospitalization). RESULTS: A total of 214 of 1190 infants had sterile CSF pleocytosis (18.0%; 95% confidence interval, 15.9%-20.3%). Only the peripheral white blood cell count was independently associated with sterile CSF pleocytosis, and patients with a peripheral white blood cell count of 15/µL or higher had twice the odds of having sterile CSF pleocytosis (odds ratio, 1.97; 95% confidence interval, 1.32-2.94; P = .001). In the subset of patients at very low risk for adverse events (ie, not clinically ill in the emergency department and without a high-risk medical history), patients with and without sterile CSF pleocytosis had similar clinical courses; however, patients with CSF pleocytosis had longer parenteral antibiotics courses (median length, 4 days [interquartile range, 3-6 days] vs 3 days [interquartile range, 3-5 days]) (P = .04). CONCLUSION: Sterile CSF pleocytosis occurs in 18% of young infants with UTIs. Patients with CSF pleocytosis at very low risk for adverse events may not require longer treatment with antibiotics.

Incidence of sterile cerebrospinal fluid pleocytosis in infants with urinary tract infection.

AIM: To determine the incidence of sterile cerebrospinal fluid (CSF) pleocytosis in infants ≤6 months old with urinary tract infection (UTI). METHODS: Retrospective study of children admitted to a tertiary children's hospital in 2006 and 2007 with UTI who also had a lumbar puncture performed. All urine specimens were tested for anti-microbial activity. RESULTS: Twelve (11.3%) of 106 infants with UTI had concurrent CSF pleocytosis. None of these patients had anti-microbial activity in the urine, showing that they had not received prior antibiotics. None of the 15 neonates (≤28 days old) with UTI and lumbar puncture had CSF pleocytosis. Antibiotics were stopped after a maximum of 10 days. CONCLUSION: Our results are compatible with published reports on the proportion of infants with UTI who have concurrent sterile CSF pleocytosis. We were able to exclude previous antibiotic therapy by measuring urinary anti-microbial activity. Our work supports the hypothesis that CSF pleocytosis in UTI is inflammatory and not because of infection of the central nervous system.

Sterile cerebrospinal fluid pleocytosis in young infants with urinary tract infections.

In a multicenter prospective study, 91 of 1025 febrile infants

[Clinical outcome and bacterial characteristics of 99 Escherichia coli meningitis in young infants]. / Méningite à Escherichia coli de l'enfant : analyse descriptive clinique et microbiologique de 99 cas.

OBJECTIVE: To conduct a descriptive analysis of clinical, biological and prognostic aspects of Escherichia coli meningitis in young infants. METHODS: Clinical and biological data on young infants diagnosed with neonatal E. coli meningitis (NECM) between 1988 and 2004 were collected retrospectively and analyzed with respect to the isolates'phenotypic and genotypic characteristics. The molecular analyses focused on the phylogenetic group, the sequence-O-type, and genetic virulence traits. The virulence of lethal strains was tested in a newborn rat meningitis model. RESULTS: The median age of the 99 children analyzed was 10 days (0 to 90 days), and 83 of the patients were newborns. Thirty-three children were premature. Hyper- or hypothermia was the most frequent clinical sign at admission. Intercurrent urinary tract infection was present in 28% of cases, all over 6 days of age. 81% of blood cultures were positive. The CSF cytology was abnormal in 97% of cases. Twelve hours after admission, 34% of infants were transferred to intensive care. One-third of transfontanellar ultrasound scans done on admission were abnormal. CSH sterilization was slow in 15 % of cases, despite appropriate antibiotic therapy. The use of ciprofloxacin was associated with more rapid CSF sterilization (94 % vs 77 %, p=0.03). Six children relapsed. The average follow-up was eight months, and 21 % of children had sequelae. The case lethality rate was 14%. Fatal outcome was associated with signs of septic shock (57% vs 3%, p<10(-4)) and neurological failure (76% vs 19%, p<10(-4)) within the first 24 hours, and with abnormalities on the first ultrasound scan (63% vs 27%, p=0.03). The risk of death was higher among children infected by strains belonging to unusual sequence-O-types (50% vs 18%, p=0.01), which harbored fewer virulence factors (4.8 vs 5.9, p<10(-4)). Only aerobactin was less frequent in lethal strains (71 % vs 94%, p=0.02). Strains belonging to unusual sequence-O-types and that were lethal in the animal model induced a significantly lower level of bacteremia than strains belonging to frequent sequence-O-types (p<0.001). CONCLUSION: E. coli meningitis remains highly lethal in infants. Clinical and molecular analyses showed a link between lethality and infrequent sequence-O-types. The avirulence of these strains in animal models suggests that fatal outcome could be due to host susceptibility more than to strain virulence.

Sterile cerebrospinal fluid pleocytosis in young infants with urinary tract infection.

BACKGROUND: During the first 3 months of life febrile infants are subjected to sepsis workup, which includes evaluation for urinary tract infection (UTI) and meningitis. We investigated the existence of concomitant meningeal inflammation in infants younger than 90 days old affected with UTI. METHODS: We reviewed the medical records of all infants younger than 90 days old, who were hospitalized for UTI from January, 1990, to January, 2001. For the diagnosis of sterile cerebrospinal fluid (CSF) pleocytosis, the child's age, the CSF total white blood cell (WBC) count and the CSF absolute neutrophil count were taken into consideration. CSF pleocytosis was defined as the presence of > or = 35, > or = 21 and > or = 15 WBC/mm3 of CSF during the first, second and third month of life, respectively. The CSF Gram-stained smear, latex agglutination test and bacterial culture were negative. RESULTS: Sterile CSF pleocytosis was found in 15 (12.8%) of 117 infants with UTI who had had a lumbar puncture included in their initial laboratory evaluation. The 15 infants had a median age +/- semiinterquartile range of 40 +/- 25 days (range, 4 to 75 days). In these infants the median CSF WBC count +/- semiinterquartile range was 55 +/- 125/mm3 (range, 21 to 1,270/mm3). CONCLUSIONS: Sterile CSF pleocytosis was found in 12.8% of infants younger than 90 days old with UTI. The pathogenesis of this meningeal inflammation is not fully understood. Although bacterial infection of the subarachnoid space, with low bacterial seeding, cannot be excluded, at least in some cases, it is possible that CSF pleocytosis in some of the infants with UTI is mainly caused by the endotoxin of Gram-negative or other inflammation-inducing molecules of Gram-positive urine pathogens.