OBJECTIVE To study the clinical feature of nosocomial infection and analyze the correlative reasons,to offer the scientific theory basis for preventing and controlling the nosocomial infection. METHODS A retrospective survey was undertaken in the data of hospitalized cases during 2007. RESULTS Totally 2325 nosocomial infections in 54 505 patients were analyzed in 2007.The infection rate of nosocomial infection was 4.27%;the highest infection rate was in ICU(33.57%);the infection sites were different in distinct departments and the most common infection site was lower respiratory tract(27.19%);among pathogens isolated from nosocomial infection cases,48.05% of them were Gram-negatives,23.25% were virus,14.45% were fungi,and 14.15% were Gram-positives;the infection rate was diverse in different months. CONCLUSIONS Nosocomial infection rate is related to different underlying diseases;there are many effective actions to reduce the nosocomial infection,such as strengthening the nosocomial infection management,using the antibacterial drugs reasonably and preventing communicable diseases prevalence.

Objective To predict the causal relationship between immune cells and osteomyelitis(OM)by using Mendelian randomization.Methods Data sets of 731 immune cells and osteomyelitis were obtained from the UK Biobank and the genome wide association study.The inverse variance weighted method,weighted median method,and MR-Egger method were employed sequentially to verify the causal relationship between the 731 immune cells and osteomyelitis.Cochran's Q test,MR-Egger intercept test,mendelian randomization pleiotropy residual sum and outlier(MR-PRESSO),and leave-one-out analysis were evaluatede the stability and reliability of the results.Results A total of 21 immune cells were found to have a causal relationship with osteomyelitis(P＜0.05).Among them,T regulatory cells,classical dendritic cells and B cells were exhibited more stable causal relationships with osteomyelitis(P＜0.01).Specifically,T regulatory cells(OR=0.925,β=0.078)were identified as protective factors reducing the risk of osteomyelitis,while classical dendritic cells(OR=1.084,β=0.081)and B cells(OR=1.063,β=0.061)were identified as risk factors increasing the risk of osteomyelitis.Conclusion Twenty-one immune cells are genetically associated with the risk of osteomyelitis.