关键词: 流感嗜血杆菌, 头孢菌素类, 儿童, 耐药性

Abstract: Objective To investigate the epidemiological characteristics and drug resistance of Haemophilus influenzae (H. influenzae) isolated from children with bloodstream infection, providing scientific basis for precise prevention and control of bloodstream infection. 
Methods The distribution and drug susceptibility concerning 44 strains of H. influenzae isolated from blood samples of hospitalized children aged from 3 months to 7 years were analyzed retrospectively in Hebei Children′s Hospital. Bacterial identification， drug susceptibility analysis and β-lactamase detection were performed using VITEK MS, K-B method and cefnothiophene disk method, respectively. The results of drug sensitivity were interpreted according to the breakpoints of the Clinical and Laboratory Standards Institute (CLSI) in 2020. 
Results Of all patients, 50% (22/44) of the children with bloodstream infection from H. influenzae were infants under the age of 1 years, 95.5% (42/44) cases had clear infection foci, among which 72.7% (32/44) had respiratory tract-related diseases such as pneumonia and bronchitis alone or in combination, and 45.5% (20/44) had meningitis alone or in combination. For 59.1% (26/44) strains of H. influenzae isolated from blood produced β-lactamase, there was the highest resistance rate to cotrimoxazole (75%), followed by ampicillin (61.4%), and the drug resistance rates to chloramphenicol and rifampicin was lower (<10%). All these H. influenzae strains were susceptible to ceftazidime, cefepime, aztreonam, imipenem, meropenem and ciprofloxacin. 
Conclusion Bloodstream infection from H. influenzae in children is more common in infants under the age of one, and pneumonia and meningitis are its common presentations. The third generation cephalosporin can be used as the first choice for empiric therapy.

Key words: haemophilus influenzae, cephalosporins, children, antibiotic resistance