Prediction of bacteremia in children with febrile episodes during chemotherapy for acute lymphoblastic leukemia

The purpose was to identify risk factors for bacteremia in febrile episodes occurring during chemotherapy for acute lymphoblastic leukemia (ALL) in children, and to develop a risk score permitting risk-adapted antibiotic therapy. We reviewed a total of 172 febrile episodes occurring during chemotherapy in 31 children and adolescents with ALL. Temperature, hematological parameters, culture findings, and antibiotic therapy were recorded. Bacteremias were classified as transmucosal or CVC-dependent. Blood cultures were positive with mucosal pathogens in 15 cases (9%) and with skin/environmental bacteria in 34 (20%). CVC-dependent infections occurred throughout the treatment phases, while transmucosal primarily during induction therapy. Transmucosal bacteremia was associated with induction therapy, leukocyte count ≤0.5 × 10(9)/L, neutrophil count ≤0.1 × 10(9)/L, monocyte count ≤0.01 × 10(9)/L, and platelet count ≤50 × 10(9)/L. Based on logistic conversion of the odds ratios for the five factors, a weight of 2 was assigned to induction therapy and leukocyte count ≤0.5 × 10(9)/L, and a weight of 1 to the remaining three parameters. The weights were included in a simple additive score ranging from 0 to 7, which defined groups with 4%, 6%, 24%, and 40% risk of transmucosal bacteremia. CVC-dependent bacteremia was not associated with markers of poor bone marrow function. In conclusion, transmucosal bacteremia in children with ALL is related to infiltration or suppression of the bone marrow. A score reflecting the condition of the marrow can define low-risk and high-risk groups and may prove clinically useful.