title: Diagnostic value of IL-6, CRP, WBC, and absolute neutrophil count to predict serious bacterial infection in febrile infants.
abstract: Since clinical manifestations of most febrile infants younger than three months old are nonspecific, differentiation of Serious Bacterial Infection (SBI) from self-limiting viral illness is a significant challenge for pediatricians. This study was performed to assess the diagnostic value of white blood cell count (WBC), Absolute Neutrophil Count (ANC), Interleukin -6 (IL-6) and C-reactive protein (CRP) level to predict SBI in febrile infants younger than three months old who were hospitalized. This was a diagnostic test validation study. In this prospective study, 195 febrile infants admitted to 17 Shahrivar Hospital underwent a full sepsis workup including blood, urine, cerebrospinal fluid cultures and chest radiography. WBC count, ANC and CRP and Il-6 level were measured in all patients. Serum IL-6 concentration was measured by Enzyme-linked Immunosorbent Assay test. Then diagnostic, values of these tests for predicting SBI was compared with each other. Of total cases, 112 (57.4%) infants were male. SBI was diagnosed in 29 (14.9%) patients. The most common type of SBI was Urinary Tract Infection (UTI). Serum IL-6 (³20pg/dl) had sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 79/1%, 91.6%,75.4%, 60.3%, respectively and for CRP (³ 10mg/l) values were 81.6%, 89.8%, 78.2%, and 52%,respectively. The predictive values of CRP and IL-6 were higher than WBC and ANC. IL-6 and CRP are more valid and better diagnostic markers for predicting SBI than WBC count and ANC. CRP level seems to be an accessible and cost-effective marker for early diagnosis of SBI. Since by no marker we can totally rule out SBI in febrile infants < three months of age, it is recommended to administer systemic antibiotics until culture results become available.
authors.affiliation: Pediatrics growth disorders research center, 17 Shahrivar Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Marjaneh
authors.initials: M
authors.lastname: Zarkesh
authors.affiliation: Pediatrics growth disorders research center, 17 Shahrivar Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sedaghat
authors.affiliation: Department of Social Medicine, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Abtin
authors.initials: A
authors.lastname: Heidarzadeh
authors.affiliation: Pediatrics growth disorders research center, 17 Shahrivar Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Manizheh
authors.initials: M
authors.lastname: Tabrizi
authors.affiliation: Pediatrics growth disorders research center, 17 Shahrivar Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Kobra
authors.initials: K
authors.lastname: Bolooki-Moghadam
authors.affiliation: Pediatrics growth disorders research center, 17 Shahrivar Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
authors.forename: Soheil
authors.initials: S
authors.lastname: Ghesmati
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001424:Bacterial Infections / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005334:Fever / Q000209:etiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis; D014552:Urinary Tract Infections / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D014777:Virus Diseases / Q000175:diagnosis
chemical_list: D000900:Anti-Bacterial Agents; D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; D002097:C-Reactive Protein
keywords: CRP; Febrile infants; IL-6; Serious bacterial infection