Predicting serious bacterial infections in infants aged 90 days or less

Background NICE sepsis guidelines advise febrile children aged ≤90 days are at higher risk of serious illness. Therefore, children undergo investigations and receive antibiotic therapy in these cases, despite limited data on actual number of serious bacterial infections (SBI). The Febrile Infants Diagnostic Assessment and Outcomes (FIDO) study, performed on behalf of PERUKI, aimed to evaluate this further.Objectives To determine rates of SBI in children aged ≤90 days with fever ≥ 38°C.To assess clinical features and investigations most significantly associated with SBI.Methods Retrospective analysis of Emergency Department (ED) presentations of febrile infants was conducted across six sites (Belfast, Bristol, Dublin, Glasgow, Leicester and London) between 01.09.2018 and 31.08.2019.The clinical features underwent univariate analysis, and those deemed to be statistically significant (p<0.2) were included in multivariate analysis.Results 535 ED records, out of 543 identified, had complete data and were included. 70 (13.1%) participants were diagnosed with SBI – 6 with bacterial meningitis (1.1%), 7 with bacteraemia (1.3%) and 57 (10.7%) with urinary tract infections.Table 1 shows univariate analysis of individual features. Multivariate analysis of clinical features demonstrated that appearing well was significantly associated with the infant not having a SBI (p=0.008), as was receiving a vaccination in the preceding 24 hours (p<0.0001). No well-appearing infant who received a vaccine within the preceding 24 hours had an SBI.433 (80.9%) participants underwent blood testing, including all 70 of those diagnosed with SBI. The median CRP (p<0.0001) and neutrophil counts (p=0.011) were significantly higher for participants with SBI. There was no significant difference in median white cell count, lymphocyte count or haemoglobin.