Clinical Evaluation of Diagnostic Criteria for Early Prediction of Bacterial Infection in Febrile Neonates

Cho, Jai Il; Lee, Sang Chun; Kim, Hwan Il; Kim, Cheol Am; Kim, Kil Seo

Abstract

PURPOSE: A retrospective study was undertaken to test the hypothesis that febrile neonates, who have bacterial infections, can be accurately predicted early by diagnostic criteria.
METHODS
We conducted a retrospective study of 152 infants, 28 days or less of age, whose rectal temperature was at least 38degrees C. Past history, family history, finding on physical examinations and results of CBC, urinalysis, lumbar puncture, CRP, and cultures of blood, urine and CSF were recorded. The diagnostic criteria for bacterial infection were : presence of identifiable fever focus(skin, soft tissue, bone, joint, eyes, ears), presence of maternal risk factors(malnutrition, fever, infection, premature rupture of membrane) & neonatal risk factors(prematurity, SGA), unhealthy condition at physical examinations, neutrophil index(immature neutrophil count/total neutrophil count ratio)> OR =0.15 and CRP> OR =2.0mg/dL, urinalysis-> OR =5 WBC/high-power field, absence of upper respiratory tract illness in parent and contact people. Febrile neonates who meet any of the diagnostic criteria were considered as high risk for bacterial infection.
RESULTS
The overall incidence of bacterial infections in the 152 febrile neonates was 13.8%(21 neonates) with urinary tract infections in 8 neonates, bacteremia in 8 neonates and meningitis in 5 neonates. Only 1 neonate, who was classified as low risk for bacterial infection, was identified with a bacterial urinary tract infection. The sensitivity, specificity, positive predictive value and negative predictive value of the diagnostic criteria were 95.2, 92.4, 66.7 and 99.2%, respectively.
CONCLUSION
These data show the ability of diagnostic criteria to identify neonates with bacterial infection. Febrile neonates who meet the diagnostic criteria must be treated intensively and those who do not meet the diagnostic criteria can be carefully managed as inpatients or outpatients without administering antimicrobial agents, avoiding iatrogenic complications.