Analysis of bloodstream infections in children with acute myeloid leukemia during induction chemotherapies

Objective: To explore the clinical features of bloodstream infections (BSI) in children with acute myeloid leukemia (AML) during the first induction chemotherapy. Methods: The clinical data, pathogen of BSI, antibiotic susceptibility in vitro, complications and prognosis of 204 newly diagnosed AML children admitted to Blood Diseases Hospital, Chinese Academy of Medical Sciences from August 2009 to December 2015 were analyzed retrospectively. χ2 test was used for the comparison between groups and Logistic regression was used for BSI risk factor analysis. Results: Among 204 patients, 116 were males and 88 were females. The age was 8 (ranged from 1 to 14) years. Among them, 170 patients received MAE chemotherapies (etoposide, mitoxantrone and cytarabine) and 25 received IAE chemotherapies (etoposide, idarubicin and cytarabine). The other 9 patients used granulocyte colony stimulating factor (G-CSF)-priming regimen (aclacinomycin or homoharringtonine, cytarabine and G-CSF) for induction treatments. A total of 28 patients experienced BSI and the incidence rate was 13.7% (28/204), 26 of them developed BSI once and 2 patients developed twice. Gram-positive bacteria were predominant pathogens accounting for 53.3% (16/30) while gram-negative bacteria accounting for 40.0% (12/30) and fungal accounted for 6.7% (2/30). The most common detected pathogens were Coagulase negative Staphylococcus (CoNS, 26.7% (8/30)), followed by Streptococcus spp. (13.3% (4/30)) and Escherichia coli (13.3% (4/30)). Among Gram-negative bacteria (GNB), 3 cases showed carbapenem resistance and 2 cases were Stenotrophomonas maltophilia. BSI-related mortality was 28.6% (8/28). Infections caused by drug-resistant GNB or fungi resulted in 6 fatal cases. The incidence rate of BSI in group with severe neutropenia was higher than in group without it (16.6% (25/151) vs. 5.7% (3/53), χ²=3.933, P=0.047). Multivariable analysis showed severe neutropenia at the onset of fever was independent risk factor of BSI (OR=4.258,95%CI 1.097-16.524,P=0.036). Conclusions: During the first induction chemotherapy courses, Gram-positive bacteria cause most of the BSI. Drug-resistant bacteria related infection often result in fatal outcomes. Severe neutropenia is a significant risk factor.