Abstract:Objectives：The investigation of pathogen distribution and drug resistance of nosocomial infection in pediatrics，obstetrics and gynecology is of great significance for the empirical treatment of nosocomial infection in women and children，and also provides a reference for the prevention and control of nosocomial infection. Methods：Patients admitted to the Department of Pediatrics，Obstetrics and Gynecology and diagnosed as nosocomial infection in our hospital from 2019-2022 were selected as research objects. Information on nosocomial infection rate and infection site in these three departments were collected，and bacteria were isolated and identified according to the methods in the National Clinical Examination Operating Procedures.VITEK-2Compact automatic bacterial identification instrument from France Biomeerieux and DL-96 automatic bacterial determination system from Zhuhai were used for bacterial identification and drug susceptibility tests，and the results were judged according to the standards of CLSI. Results：Among the 227，124 pediatric，obstetric and gynecological patients included in the study from 2019 to 2022，770 cases of nosocomial infection occurred，with an incidence rate of 0.34%. Among 770 patients with nosocomial infection，bacteremia and gastrointestinal infection were most common in pediatrics，accounting for 31.87% and 26.02% respectively. Other infections of the male and female genital tract and upper respiratory tract infections were more common in obstetrics，accounting for 15.98% and 14.79% respectively. In gynecology，abdominal（pelvic）cavity tissue and acute pelvic inflammation were more common，accounting for 24.32% and 23.94% respectively. A total of 458 strains of pathogens were isolated and cultured from 770 nosocomial infection patients. Staphylococcus epidermidis（S.epidermidis）and Klebsiella pneumoniae（K.pneumoniae）were the main pathogens in pediatrics，accounting for 23.12% and 20.10% respectively. In obstetrics，Escherichia coli（E.coli）and Enterococcus faecalis（E. faecalis）were dominant，accounting for 23.33% and 20.00% respectively. Escherichia coli（E.coli）was predominant in gynecology，accounting for 53.25%. Pediatric Klebsiella pneumoniae（K.pneumoniae）had no resistance to imipenem and meropenem，obstetric Escherichia coli（E.coli）had no resistance to imipenem and meropenem，gynecological Escherichia coli（E.coli）had 1.11% resistance to imipenem and meropenem，pediatric Staphylococcus epidermidis（S.epidermidis）had no resistance to vancomycin and linezolid，obstetric and gynecological Enterococcus faecalis（E. faecalis）had no resistance to vancomycin and linezolid. Conclusion：The incidence of nosocomial infection in pediatrics，obstetrics and gynecology during 2019-2022 was 0.34%，and the rate of nosocomial infection in pediatrics（1.17%）in our hospital was higher than that in obstetrics（0.12%）and gynecology（0.43%）. The application rate of gynecological antibiotics was significantly higher than that of obstetrics，and non-combined use was the main factor，which resulted in a higher drug resistance rate of pathogens of nosocomial infections in gynecology than in obstetrics. Active monitoring of nosocomial infections in pediatrics，obstetrics and gynecology，and timely analysis and summary of the distribution and drug resistance of nosocomial infections have certain clinical guiding significance for judging nosocomial infections and the therapeutic use of antibiotics.