Patients treated in the ED between January 1, 1993, and December 31, 1996, were considered initially for inclusion in our study population of subjects at risk for occult bacteremia if they were between 3 and 36 months of age and had a triage temperature of 39.0°C or higher recorded in the ED by rectal or tympanic measurement. Subsequently, we excluded children who were (1) admitted to the hospital, transferred to another facility, or died during the visit; (2) discharged with a diagnosis of a specific viral infection (croup, bronchiolitis, varicella, Coxsackievirus, herpangina, or stomatitis); (3) diagnosed with a focal bacterial infection, other than otitis media (pneumonia, abscess, cellulitis, meningitis, sinusitis, osteomyelitis, pyelonephritis, lymphadenitis, cholangitis, mastoiditis, impetigo, scarlet fever, streptococcal pharyngitis, or urinary tract infection); (4) known to have a chronic illness or known immunodeficiency that would alter the approach to febrile illness such as leukemia, agranulocytosis, aplastic anemia, arteritis, renal transplant, congenital heart anomalies, congestive heart failure, cystic fibrosis, human immunodeficiency virus infection, Lyme disease, Kawasaki disease, nephrotic syndrome, and sickle cell anemia. Laboratory tests were performed as part of the ED visit in accordance with the standard protocol in the department for patients meeting risk criteria for occult bacteremia. Children with otitis media were included because previous publications have documented a similar rate of occult bacteremia regardless of the presence of otitis media. The data were analyzed with and without these children to confirm that this was true of our population.