Antimicrobial treatment of occult bacteremia: a multicenter cooperative study

This prospective multicenter study was conducted to define more clearly clinical and laboratory criteria that predict a strong probability of occult bacteremia and to evaluate the effect of empiric broad spectrum antimicrobial treatment of these children. Children 3 to 36 months old with fever ≥40°C (104°F) or, ≥39.5°C (103°F) with white blood cells (WBC) ≥15 × 10/liter, and no focus of infection had blood cultures obtained and were randomized to treatment with oral amoxicillin/potassium clavulanate or intramuscular ceftriaxone. Sixty of 519 (11.6%) study patients had positive blood culturesStreptococcus pneumoniae, 51; Haemophilus influenzae b, 6; Neisseria meningitidis, 2; and Group B Streptococcus, 1. Subgroups of high risk were identified as fever ≥39.5°C and WBC ≥15 × 10/liter, 55 of 331 or 16.6% positive with increasing incidence of positive culture with increasing increments of degrees of leukocytosis to WBC ≥30 × 10/liter where 9 of 21 or 42.9% were positive. Subgroups of significantly lower risk were identified as fever ≥39.5°C and WBC