OBJECTIVE To analyze the epidemiological characteristics of hospital-associated infections(HAIs)in a large scale three-A hospital and assess the occurrence and development trends of HAIs before and after COVID-19 epidemic and during different stages of prevention and control strategies so as to provide scientific bases for HAIs management.METHODS The surveillance data were collected from the patients who were hospitalized in a large scale three-A hospital by nosocomial infection real-time surveillance system from Jan.2018 to Dec.2023.The prevalence trend,infection sites and distribution of pathogens were analyzed.The study period was divided into the pre-epidemic stage and the epidemic stage,the epidemic stage was divided into the strict infection prevention and control phase and the loose infection prevention and control phase.The epidemiological characteristics of HAIs were observed and compared.RESULTS From 2018 to 2023,the prevalence rate of HAIs was decreased from 3.39％to 2.21％,and there was significant difference in the prevalence rate of the infections among the years(x2=105.00,P＜0.001).During the six years,the prevalence rate of HAIs was highest in the internal medicine wards of critical care medicine department(54.91％),and the gram-negative bacteria(56.61％)were dominant among the pathogens.Lower respiratory tract(41.85％),bloodstream(20.93％)and urinary tract(20.50％)ranked the top 3 infection sites;the lower respiratory tract infection ranked the first place before the COVID-19 epidemic and the different stages of epidemic.The overall prevalence rate of HAIs was 3.26％during the epidemic period,remarkably lower than 3.91％before the COVID-19 epidemic(P＜0.001);the overall prevalence rate of HAIs was 2.21％in the loose prevention and control phase of 2023,remarkably lower than 3.78％in the strict prevention and control phase(P＜0.001).CONCLUSIONS The prevalence of HAIs generally shows a downward trend during the six years.The lower respiratory tract is the major infection site,and the gram-negative bacteria are dominant among the pathogens,especially Klebsiella pneumoniae.The prevention and control strategies for the COVID-19 epidemic may facilitate the reduction of incidence of HAIs,and the prevalence rate is remarkably reduced even in the loose prevention and control phase.It is necessary for the hospital to take targeted prevention and control measures based on the departments,carry out rigid surveillance of the major infection sites and patho-gens,and conduct multidisciplinary coordinated prevention and control so as to control the HAIs.

OBJECTIVE To analyze the epidemiological characteristics of hospital-associated infections(HAIs)in a large scale three-A hospital and assess the occurrence and development trends of HAIs before and after COVID-19 epidemic and during different stages of prevention and control strategies so as to provide scientific bases for HAIs management.METHODS The surveillance data were collected from the patients who were hospitalized in a large scale three-A hospital by nosocomial infection real-time surveillance system from Jan.2018 to Dec.2023.The prevalence trend,infection sites and distribution of pathogens were analyzed.The study period was divided into the pre-epidemic stage and the epidemic stage,the epidemic stage was divided into the strict infection prevention and control phase and the loose infection prevention and control phase.The epidemiological characteristics of HAIs were observed and compared.RESULTS From 2018 to 2023,the prevalence rate of HAIs was decreased from 3.39％to 2.21％,and there was significant difference in the prevalence rate of the infections among the years(x2=105.00,P＜0.001).During the six years,the prevalence rate of HAIs was highest in the internal medicine wards of critical care medicine department(54.91％),and the gram-negative bacteria(56.61％)were dominant among the pathogens.Lower respiratory tract(41.85％),bloodstream(20.93％)and urinary tract(20.50％)ranked the top 3 infection sites;the lower respiratory tract infection ranked the first place before the COVID-19 epidemic and the different stages of epidemic.The overall prevalence rate of HAIs was 3.26％during the epidemic period,remarkably lower than 3.91％before the COVID-19 epidemic(P＜0.001);the overall prevalence rate of HAIs was 2.21％in the loose prevention and control phase of 2023,remarkably lower than 3.78％in the strict prevention and control phase(P＜0.001).CONCLUSIONS The prevalence of HAIs generally shows a downward trend during the six years.The lower respiratory tract is the major infection site,and the gram-negative bacteria are dominant among the pathogens,especially Klebsiella pneumoniae.The prevention and control strategies for the COVID-19 epidemic may facilitate the reduction of incidence of HAIs,and the prevalence rate is remarkably reduced even in the loose prevention and control phase.It is necessary for the hospital to take targeted prevention and control measures based on the departments,carry out rigid surveillance of the major infection sites and patho-gens,and conduct multidisciplinary coordinated prevention and control so as to control the HAIs.

Objective To analyse CT and DSA appearances of intrahepatic cholangiocarcinoma,and to improve understanding of intrahepatic cholangiocarcinoma.Methods Plain and enhanced CT scanning were performed in 17 patients with intrahepatic cholangiocarcinoma pathollogically proved,6 patients(6/17) performed dynamic CT scanning,5 performed DSA examinations.Results Pre-contrast CT scanning was a single low density lesions in all patients,post-contrast CT scanning showed slightly inhomogeneous enhancement in 17 patients,3 patients(3/17) showed low density unenhancement area with margin enhancement,2 patients delayed enhancement;Intrahepatic billary delatation was found in 15 patients and was within the lesion in 10 patients(10/15);On DSA,5 patients showed enlaragement increasment and rigidity of supplying arteries and tumour stain.Conclusion CT scanning and DSA were important,investigative methods for intrahepatic cholangiocarcinoma,the billary dilatations with slightly inhomogeneous enhancement lesions is important sign in diagnosising intrahepatic cholangiocarcinoma.