Objective To understand the characteristics of population distribution,risk factors and risk links of occupational exposure among health care workers(HCWs)in a hospital.Methods Occupational exposure among HCWs between January 2011 and June 2014 were monitored,data about occupational categories of HCWs,expo-sure locations,exposure links and exposure modes were analyzed statistically.Results Among 286 occupational ex-posure cases,the female and male HCWs accounted for 22.03% (n=63)and 77.97% (n=223)respectively;the incidence of occupational exposure in 2011 ,2012,2013 and January-June of 2014 was 38.81 %(n=111),26.22% (n=75),23.43% (n=67)and 11 .54% (n=33)respectively;occupational exposure of junior nurses,doctors,nurs-ing attendants,technicians,senior nurses and cleaners was 31 .97%,19.90%,15.79%,7.64%,4.17%,and 2.84% respectively;exposure mainly occurred at the time of sorting waste,withdrawing or changing needles,dis-carding sharps into sharps containers,surgical suturing or instruments passing,and puncturing (including drawing blood),the constituent ratio was 22.38%,19.58%,14.34%,12.94% and 11 .19%,respectively;the main loca-tions where exposure occurred were wards,operating rooms and injection (treatment)rooms,the constituent ratio was 51 .40%,19.58% and 11 .54% respectively.Conclusion Hospital should establish comprehensive occupational exposure monitoring and risk management system,strengthen standard prevention,enhance the training about occu-pational exposure among high-risk population,and monitor and intervene on risk factors and links,so as to reduce the incidence of HCWs’occupational exposure.

Colorectal cancer is a common malignancy of the digestive tract, and the gut microbiota is closely related to the occurrence and development of colorectal cancer. The intestinal florae mainly change the host intestinal immune environment and affect the function of the intes-tinal barrier by releasing toxins and producing metabolites to participate the occurrence and deve-lopment of colon cancer. The intestinal florae can be used as biomarkers for early screening and prognosis prediction for colorectal cancer. In addition, the intestinal florae can affect the efficacy of chemotherapy, radiotherapy and immunotherapy for colorectal cancer. The authors review the research progress of gut microbiota in occurrence and development, screening, prognosis prediction and treatment of colorectal cancer, and discuss the application prospects of gut microbiota in the prevention and treatment of colorectal cancer.

African swine fever(ASF)is a highly contagious and pathogenic disease affecting both domestic and wild pigs,which is caused by African swine fever virus(ASFV).In European epidem-ics,low-virulence strains of ASFV,which do not have hemadsorbing properties,have been identi-fied.Following the identification of highly virulent genotype Ⅱ ASFV strains in China in 2018,subsequently,low-virulence strains of genotype Ⅱ and genotype Ⅰ emerged.Recombination be-tween genotypes Ⅰ and Ⅱ has also led to the occurrence of high-virulence strains.This indicates a complex and diverse genetic evolution of ASFV during the epidemiological transmission,which po-ses significant challenges for vaccine development and disease surveillance.Here,we provide an o-verview of the novel epidemiological characteristics of ASFV,with a focus on genetic variations and pathogenic differences during the outbreaks of ASF.We also explore how ASFV genetic varia-tions impact immune escape and pathogenicity of the virus,and the challenges they pose for vac-cine development,disease diagnosis,and surveillance.The aim of this review is to enhance our un-derstanding of the genetic evolution and mutation mechanisms of ASFV,providing a theoretical basis for the development of vaccines and research on diagnostic technologies.