Clinical characteristics and antimicrobial resistance of pneumococcal isolates of pediatric invasive pneumococcal disease in China Kang Cai,1 Yizhong Wang,2 Zhongqin Guo,3 Xiaonan Xu,1 Huajun Li,1 Qingli Zhang1,4 1Department of Pediatrics, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; 2Department of Infectious Diseases, Shanghai Children’s Hospital, Shanghai Jiao Tong University, Shanghai, China; 3School of Public Health and Management, Ningxia Medical University, Yinchuan, China; 4Department of Pediatrics, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Chongming Branch, Shanghai, China Purpose: Streptococcus pneumoniae causes serious infections globally, including invasive pneumococcal disease (IPD). We analyze clinical features of pediatric IPD cases identified in China and antibiotic susceptibility of isolated pneumococcal strains.Methods: Confirmed pediatric IPD patients were prospectively recruited to the study. Symptoms at the time of hospitalization, laboratory tests, antimicrobial susceptibility of pneumococcal isolates, treatments, hospital stay, and residual findings at discharge were analyzed systematically.Results: From January 2008 to December 2017, a total of 123 hospitalized children diagnosed with IPD were enrolled: 68 from pediatric departments of Xinhua Hospital, and 55 from Lanzhou University Second Hospital. Of these pediatric IPD patients, 81 (65.86%) were male, and 98 (79.67%) <5 years old. Most cases (96, 78.05%) were diagnosed during the cold season between September and February. Sepsis was observed in 82 (66.67%) patients, 48 (39.02%) children were diagnosed with meningitis, 41 (33.33%) with pneumonia, 30 (24.39%) with pleurisy, and 4 (3.25%) with osteomyelitis. Underlying diseases were noted in 35 (28.45%) patients and concurrent infections in 45 (36.58%). The overall mortality rate was 2.44%. IPD children who developed sepsis and necrotizing pneumonia showed higher proportions of intensive care-unit admission, intravenous γ-globulin, glucocorticoid use, hemofiltration and ventilator, and longer duration of fever, hospital stay, and antibiotic use than nonsepsis and pneumonia subjects. Antimicrobial resistance of S. pneumoniae showed a highly unsusceptible rate for erythromycin (96.75%), trimethoprim-sulfamethoxazole (79.67%), and tetracycline (77.23%). All isolates were sensitive to vancomycin, linezolid, and levofloxacin.Conclusion: Clinical symptoms were severe in the majority of pediatric IPD patients. More intensive treatments were demanded for IPD children with sepsis and necrotizing pneumonia. High resistance rates for erythromycin, trimethoprim–sulfamethoxazole, and tetracycline were found. Keywords: Streptococcus pneumoniae, children, invasive pneumococcal disease, antimicrobial resistance