A prospective study of gram-negative bacteremia in children

Background. Hospital- and community-acquired Gram-negative bacteremia is a significant cause of mortality and morbidity in pediatric medical centers. Gram-negative organisms are isolated in >50% of pediatric patients with bacteremia. Objectives. To analyze clinical and epidemiologic variables associated with Gram-negative bacteremia in a tertiary children's medical center. Methods. A 6-year prospective study of children with Gram-negative bacteremia in a tertiary care children's medical center in Israel. Results. Three hundred seventy-four episodes of Gram-negative bacteremia were studied during 6 years. The predominant isolates were Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli, which accounted for 109, 81 and 79 episodes (26, 20 and 19%), respectively. Of all episodes 43% occurred in neonates and infants younger than 2 years and 47% were hospital-acquired. Underlying conditions mainly acute leukemia and lymphoma, were present in 55% of the patients. Urinary tract infection followed by lower respiratory tract infection were the most common identified sources of bacteremia. Central intravenous catheters were associated with 53% of the episodes. The crude mortality was 11.4%. Increased mortality was significantly associated with acute leukemia, neutropenia, hospital-acquired infections and previous corticosteroid therapy (P = 0.03, 0.003, 0.006 and 0.01, respectively). Increased antibiotic resistance of hospital-acquired vs community-acquired isolates was noted; 44 to 77% resistance of nosocomial Klebsiella and Enterobacter sp. to second and third generation cephalosporins and 18% were resistant to amikacin. Conclusions. Klebsiella pneumoniae is currently the most common organism causing Gram-negative bacteremia in children. Because of the relatively high resistance of Gram-negative organisms to second and third generation cephalosporins, we suggest that empiric antibiotic therapy for Gram-negative bacteremia include a combination of an aminoglycoside and an anti-Pseudomonas beta-lactam.