OP-040 Diagnostic significance of laboratory investigations in febrile infants under 9 months: bacterial infection assessment and clinical correlation

Aim The aim of the study is to determine the presence of bacterial infection and the diagnostic value of laboratory investigations in patients presenting with fever under 9 months of age. Material and Method Patients admitted to the Pediatric Emergency Department due to fever under 9 months of age whose blood, urine, and cerebrospinal fluid (CSF) cultures were obtained were included. The clinical characteristics, and laboratory results were recorded. Results The median age of the 204 patients included in the study was 64.00 days (27.25–125.50 days) and 59.3% (n = 121) were male. Thirty-five of the patients were in the first 21 days, 62 were between 21–60 days, 42 were 61–90 days and 65 were over 90 days. When symptoms were analyzed, vomiting in 31 (15.2%), impaired consciousness in 31 (15.2%), seizure in 22 (10.8%), respiratory symptoms in 24 (11.8%), and circulatory disorder in 18 patients (8.8%) were present. Respiratory virus panels were examined in 63 (30.8%) patients and 42 (66.6%) were positive. Bacterial cultures showed growth in 18 cultures (seven cerebrospinal fluid cultures, five urine cultures, six blood cultures) of 17 patients. Enterovirus was detected in 14 patients, adenovirus in three patients, and herpes virus in one. Only one of the 17 patients with positive bacterial culture was accompanied by viral infection (influenza). While there was no statistical difference in white blood cell, lymphocyte, and neutrophil counts between proven bacterial and viral infection cases; C-reactive protein and procalcitonin were significantly higher in bacterial infections than in viral infections (p=0.001, p=0.023; respectively). According to AAP criteria, C reactive protein>20 mg/L and procalcitonin>0.5 ng/mL were determinants in apparently well patients. Conclusions In cases of bacterial infections, while clinical features take precedence, the white blood cell count and type do not assist, particularly in well-appearing patients, whereas procalcitonin and C-reactive protein offer significant contributions.