We conducted a retrospective study in a tertiary care hospital in Rionegro, Colombia. Children aged 0–36 months with FWS, who were evaluated in our emergency department (ED) between January 2015 to December 2017, were eligible for inclusion in this study. FWS was defined as a temperature of ≥ 38 8C (less than 10 days of duration to avoid fever of unknown origin with different etiologies to FWS, including noninfectious cause) in the emergency room with no identified infectious source during a physical examination at the hospital (without associated respiratory symptoms including rhinorrhea or nasal congestion, diarrhea process, acute otitis media or other findings on physical examination that allows identifying the source of the fever). All patients with an acquired or congenital immunodeficiency or other major chronic condition (oncologic illness, chronic renal failure, transplant patient, sickles cell disease, presence of a mechanical device such as indwelling catheter, ventricle-peritoneal shunt, auditory prostheses, or an invasive diagnostic or therapeutic procedure in the previous 10 days) were excluded due to the different pathogens implicated in the case of FWS and the different management needed in these cases. Patients with ongoing antibiotic treatment or difficulties communicating due to language problems were also excluded. We considered serious bacterial infection (SBI) those infants finally diagnosed with bacteremia, urinary tract infection, bacterial meningitis, or pneumonia. In our hospital were adapted since 2010 the clinical guideline from the National Institute for Health and Clinical Excellence (NICE) of how to assess and initially manage feverish illness in children aged under 5 years (12). The decision for inpatient versus outpatient management and antibiotic treatment was supported by clinical and laboratory findings at the discretion of the treating physician on a patient-by-patient basis.
The protocol was approved by Review Boards of Clinica Somer and Uniremington University in accordance with the local regulations in clinical research. Informed consent was waived by Review Boards of Clinica Somer and Uniremington University, due to the retrospective nature of this research.
Of each patient, we collected the following data: age, sex, personal history, complete vaccination for Haemophilus influenzae type b (3 doses at 2,4, and 6 months of age) and Streptococcus pneumoniae (2 doses at 4 and 12 months of age), duration of fever, associated symptoms, temperature, previous consultation in the ED, appearance on arrival, physical examination, supplementary tests, isolated microorganism, final diagnosis, and disposition of the patient. In all patients were mandatory to obtain white blood cell counts (WBC), absolute neutrophil count (ANC), serum C-reactive protein (CRP), and Urine dipstick. Urinary tract infection (UTI) was defined as the presence of ≥ 104 colony-forming units per milliliter of a single uropathogen, cultured from a urine specimen obtained by bladder catheterization. Other tests (blood culture, urine culture, chest radiograph, cerebrospinal fluid examination) were obtained at the discretion of the physician in charge.
Clinical and socio-demographic variables information were compared between groups (SBI and non-SBI) with Student’s t-tests or Kruskal–Wallis tests for continuous variables and with Chi2 tests or Fisher’s exact tests for categorical variables. Medians are reported with interquartile ranges (IQRs). All tests were two-tailed, and a value of P ≤0.05 was considered statistically significant. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for each of the possible predictor variables of SBI using logistic regression models, adjusting for potential confounders. We carried out the statistical analysis using STATA 17.0.