Stratification of Febrile Infants One to Three Months of Age Suspected to have Severe Bacterial Infections According to Complete Blood Count in Mono-Centric Lebanese University Hospital

Background: Fever represents one of the most important reasons for emergency department visits among young infants aged less than 3 months. In 5 to 15 % of cases, fever is caused by a severe bacterial infection. This study aimed to evaluate the precision of using complete blood count differential (CBCD) for identifying febrile infants aged between 1 and 3 months with Severe Bacterial Infections (SBIs). Subjects and Methods: A mono-centric retrospective study was conducted among young febrile infants seen in the Emergency Department (ED) of the Rafic Hariri University Hospital (RHUH) between January 2018 and January 2020. Data were compared using the Chisquare test and one-way analysis of variance (ANOVA) as appropriate and then binary logistic regression was used to identify risk factors of SBI. Results: A total of 200 febrile infants aged between one and three months were included in this study. The prevalence of SBI was 15.5% and the most common bacterial infection was urinary tract infections (UTIs) (65.5% of all SBIs). Pneumonia was the most common diagnosis of the infants in study accounting for 37% of all diagnosis. C reactive protein (CRP) levels, platelets count, and white blood cell (WBC) counts were significantly associated with SBI (P-value < 0.05). Binary regression analysis showed that CRP levels (OR = 1.013) and temperature (OR = 3.78) were risk factors for increased bacteremia and UTIs respectively. Conclusion: This study confirmed that complete blood count differential is not sufficiently accurate test for identifying young infants with SBI. Better diagnostic tools are needed to optimize the identification of young febrile infants with SBIs.