This study investigated the predictive factors for identifying infection-prone febrile infants younger than three months.

We conducted a retrospective study of 167 infants younger than three months with an axillary temperature >38℃ who were hospitalized between 2006 and 2008. If they met any of the following criteria, positive blood culture, CSF WBC ≥11/mm³ or positive CSF culture, urinalysis WBC ≥6/HPF and positive urine culture, WBC ≥6/HPF on microscopic stool examination or positive stool culture, they were considered at high risk for severe infection. Infants with focal infection, respiratory infection or antibiotic administration prior to admission to the hospital were excluded. We evaluated the symptoms, physical examination findings, laboratory data, and the clinical course between the high risk and low risk groups for severe infection.

The high-risk group included 77(46.1%) infants, and the most common diagnosis was urinary tract infection (51.9%). Factors, such as male sex, ESR and CRP were statistically different between the two groups. But, a multilinear regression analysis for severe infection showed that male and ESR factors are significant.

We did not find the distinguishing symptoms and laboratory findings for identifying severe infection-prone febrile infants younger than three months. However, the high-risk group was male and ESR-dominated, and these can possibly be used as predictive factors for severe infection.