Background:Acute leukemia is the most common pediatric hematological malignancy.Bloodstream infections (BSIs) are severe complications in these patients during chemotherapy.This study aimed to explore the clinical presentation and etiology of BSI,as well as the common sites of infection,and to provide a basis for the rational regarding antibiotic use.Methods:We performed a retrospective chart review of all pediatric patients who had acute leukemia accompanied by a BSI in our hospital from December 2011 to September 2015.All patients were selected based on clinical presentation and had to have at least one positive blood culture for inclusion.The basic clinical characteristics,blood culture results,and antimicrobial susceptibilities were analyzed.Results:All 231 patients had a fever;of them,12 patients continued to have a fever.Twenty-five patients had nonremitting (NR) leukemia,and 206 patients achieved complete remission (CR).Differences in the duration of fever between the NR and CR groups were significant (9.6 ± 7.9 vs.5.1 ± 3.8 days,P =0.016).One hundred and eighty patients had agranulocytosis.Differences in fever duration between the agranulocytosis and nonagranulocytosis groups were significant (6.2 ± 5.1 vs.4.1 ± 2.6 days,P =0.001).The other sites of infection in these 231 patients were the lung,mouth,digestive tract,and rectum.Blood culture comprised 2635 samples.There were 619 samples,which were positive.Of the 619 positive blood culture samples,59.9％ had Gram-negative bacteria,39.3％ had Gram-positive bacteria,and 0.8％ had fungus.The primary pathogens were Pseudomonas aeruginosa,Enterobactercloacae,Escherichia coli,and Klebsiella pneumoniae.Of these 231 patients,217 patients were cured.The effective treatment ratio was 94％.Conclusions:Gram-negative bacteria were the main pathogenic bacteria in patients with acute leukemia in our center.NR primary illness,agranulocytosis,and drug-resistant pathogenic bacteria were all risk factors for poor prognosis.