The evaluation of the presence of serious bacterial infection with laboratory markers in well-appearing children with fever without source

Objectives: Whether to decide for giving antibiotic therapy, it is very important to make a differential diagnosis between serious bacterial infection and viral infection in patients with fever without source. The purpose of this study is to define clinical and laboratory markers which could indicate serious bacterial infection in well-appearing children aged between 3 months-17 years with fever without source. Materials and methods: In this prospective study, we enrolled 118 patients that aged older than 3months (3months-17 years old) which are consulted to pediatric outpatient clinics with fever complaint, well appearing, with normal physical examination and fever without an identifiable cause. All clinical and laboratory data from patients are recorded such as age, gender, temperature level, duration of fever, leukocyte count, neutrophil to lymphocyte ratio, mean platelet volume, erythrocyte sedimentation rate, fibrinogen, C-reactive protein, procalcitonin, urine analysis, chest X-ray, blood and urine cultures. Results: Serious bacterial infection has been detected in 14 patients (11.9 %) amongst 118 patients enrolled. Four patients (28.6 %) diagnosed as occult bacteremia, 6 patients (42.9 %) diagnosed as urinary tract infection and 4 patients (28.6 %) got a diagnosis of pneumonia. In terms of temperature level, duration of fever, leukocyte count, mean platelet volume and fibrinogen level no significant difference has been found. ROC analysis of C-reactive protein value above 0.57 mg/dl calculated as 92.8 % sensitivity and 50.9 % spesificity. When procalcitonin value above 0.58 ng/ml; sensitivity was 92.8 % and specifity was 90.3 %. With the lab-score ≥3; sensitivity was 64.3 % and specifity was 96.2 %. Neutrophil to lymphocyte ratio, C-reactive protein and procalcitonin are detected as independent predictive markers in versatile logistic regression analysis. Conclusion: To determine the presence of serious bacterial infection; neutrophil to lymphocyte ratio, C-reactive protein, procalcitonin and lab-score are effective laboratory methods. Procalcitonin becomes prominent with having the highest sensitivity and specifitiy value as detecting the presence of serious bacterial infection. In order to determine or exclude presence serious bacterial infection in well-appearing children with fever without source; it would be appropriate to use procalcitonin values or evaluation by scoring with procalcitonin, C-reactive protein and complete urine analysis. Key words: Childhood, fever, laboratory markers, serious bacterial infection