Abstract: Objective To explore the risk factors and clinical characteristics of agranulocytosis combined with viridans streptococcal bacteremia in children with leukemia. Methods The clinical data of 111 children with agranulocytosis complicated with sepsis were analyzed retrospectively. Results A total of 136 instances of sepsis occurred in 111 children, and 138 strains were detected, of which 25 strains were viridans streptococcus. Among the 25 insatnces (12 boys and 13 girls) of viridans streptococcal sepsis, the median age at the onset of sepsis was 98 ( 66- 138 ) months, the median time from the end of the last chemotherapy was 9 ( 6 - 10 ) d, and the median duration of agranulocytosis was 5 ( 4 - 6 ) d. The median value of neutrophils at the onset of sepsis was 0 . 01 ( 0 - 0 . 01 ) ×109 /L. All the 25 cases had fever, with a heat peak of ( 39 . 3±0 . 7 ) ℃, and the median duration of fever was 1 . 5 ( 1 . 0 - 2 . 8 ) d. Among them, 11 cases had oral infections, 7 cases had upper respiratory tract infections, 3 cases had secondary lung infection, 1 case had gastroenteritis, 1 case had combined toxic encephalopathy, and 5 cases had no other infection symptoms except fever. The 138 strains were divided into three groups: viridans streptococcus group (25 strains), non-viridans streptococcus gram-positive bacteria group (14 strains), and gramnegative bacteria group ( 99 strains). There were statistically differences in age, proportion of acute myeloid leukemia, the peak heat and incidence of oral infection among the three groups (P< 0 . 05 ). The viridans streptococcus group had higher proportion of acute myeloid leukemia and oral infection. Viridans streptococci were 100 % sensitive to vancomycin, linezolid and chloramphenicol, and had a high resistance rate to macrolides and penicillins. Conclusions Viridans streptococci are a common pathogen of agranulocytosis complicated with sepsis. Acute myeloid leukemia and oral infection are high risk factors for viridans streptococci infection. Vancomycin and linezolid can be used as empirical drugs for children with agranulocytosis fever complicated with oral infection.

Key words: viridans streptococci; leukemia; sepsis; agranulocytosis; child